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Multifaceted Roles of Pollen in the Management of Cancer
Abstract
Oral drug delivery of microparticles demonstrates shortcomings like aggregation, decreased loading capacity and batch-to-batch variation, which limits its scale-up. Later, porous structures gained attention because of their large surface-to-volume ratio, high loading capacity and ability to carry biomacromolecules, which undergo degradation in GIT. But there are pitfalls like non-uniform particle size distribution, the impact of porogen properties, and harsh chemicals. To circumvent these drawbacks, natural carriers like pollen are explored in drug delivery, which withstands harsh environments. This property helps to subdue the acid-sensitive drug in GIT. It shows uniform particle size distribution within the species. On the other side, they contain phytoconstituents like flavonoids and polysaccharides, which possess various pharmacological applications. Therefore, pollen has the capability as a carrier system and therapeutic agent. This review focuses on pollen's microstructure, composition and utility in cancer management. The extraction strategies, characterisation techniques and chemical structure of sporopollenin exine capsule, its use in the oral delivery of antineoplastic drugs, and emerging cancer treatments like photothermal therapy, immunotherapy and microrobots have been highlighted. We have mentioned a note on the anticancer activity of pollen extract. Further, we have summarised the regulatory perspective, bottlenecks and way forward associated with pollen.
... The feasibility and efficacy of these microswarms in eliminating bacterial biofilms in clinical biliary stents were demonstrated. It is worth noting that pollen is generally recognized as safe material by the Food and Drug Administration (FDA), making it more easily approved for use in oral and gastrointestinal pharmaceutical preparations [92]. With its favorable biocompatibility, biodegradability, and controlled release behavior, pollen-based magnetic robots offer an innovative approach to effective disease treatment and hold great potential for clinical applications. ...
Magnetic robots possess an innate ability to navigate through hard-to-reach cavities in the human body, making them promising tools for diagnosing and treating diseases minimally invasively. Despite significant advances, the development of robots with desirable locomotion and full biocompatibility under harsh physiological conditions remains challenging, which put forward new requirements for magnetic robots’ design and material synthesis. Compared to robots that are synthesized with inorganic materials, natural organisms like cells, bacteria or other microalgae exhibit ideal properties for in vivo applications, such as biocompatibility, deformability, auto-fluorescence, and self-propulsion, as well as easy for functional therapeutics engineering. In the process, these organisms can provide autonomous propulsion in biological fluids or external magnetic fields, while retaining their functionalities with integrating artificial robots, thus aiding targeted therapeutic delivery. This kind of robotics is named bio-hybrid magnetic robotics, and in this mini-review, recent progress including their design, engineering and potential for therapeutics delivery will be discussed. Additionally, the historical context and prominent examples will be introduced, and the complexities, potential pitfalls, and opportunities associated with bio-hybrid magnetic robotics will be discussed.
... Bees prepare their pollen by mixing their secretions with pollen collected from flowers, resulting in granules containing thousands of pollen grains approximately 1.4 mm-4 mm in size [40]. It is the primary source of nutrients for bees due to its high composition [75,76]. Bee pollen provides many health benefits to humans due to its abundance of proteins, carbohydrates, dietary fiber, and mainly polyunsaturated fatty acids. ...
Over the past eight years, bee products such as wax, honey, propolis, and pollen have generated intense curiosity about their potential food uses; to explore these possibilities, this review examines the nutritional benefits and notable characteristics of each product related to the food industry. While all offer distinct advantages, there are challenges to overcome, including the risk of honey contamination. Indeed, honey has excellent potential as a healthier alternative to sugar, while propolis's remarkable antibacterial and antioxidant properties can be enhanced through microencapsulation. Pollen is a versatile food with multiple applications in various products. In addition, the addition of beeswax to oleogels and its use as a coating demonstrate significant improvements in the quality and preservation of environmentally sustainable foods over time. This study demonstrates that bee products and apitherapy are essential for sustainable future food and innovative medical treatments.
Cancer remains a formidable global challenge necessitating innovative solutions for effective treatment. Tumor relapse and metastasis stay the limitations of current anticancer modalities. The emergence of nanorobots, a product of advanced nanotechnology and microfabrication techniques, has transformed cancer therapy. Drawing inspiration from the science fiction concept of "Fantastic Voyage," nanorobots enable precise interventions at the cellular level. In-built propulsion mechanisms such as endogenous chemical or enzymatic reactions, and employment of exogenous stimuli, like light, ultrasound, and magnetic fields for movement grant them access to unapproachable therapeutic targets. Biomimetic variations of nanorobots, including sperm-based, bacteria-based, and DNA-based designs harness the brilliance of nature for tumor-specific delivery. Their versatility spans chemodynamic, sonodynamic, and phototherapies, alongside groundbreaking immunotherapy. Furthermore, nanorobots excel in the detection of cancer cells and tracking biomarkers, thereby offering promising prospects for enhanced diagnosis and treatment. In this endeavor, we discuss various fabrication methods of nanorobots, their propulsion mechanism, and applications of nanorobots in cancer treatment.
The Trilliaceae family perennial herbaceous plant Trillium govanianum is well known for its diverse geographic spread and essential medicinal qualities. Trillium govanianum Wall. ex D. Don belongs to the genus Trillium (family: Melanthiaceae alt. Trilliaceae) is an endangered medicinal herb of the Himalayan region that has much therapeutic value. It is also known as Himalayan trillium, Nagchhatri, Teenpatra, Matarzela, Triflower, or Birthroot. Trillium govanianum is highly valued for its medicinal properties, especially in regions where it is native. Trillium govanianum has been traditionally used by indigenous individuals for its possible therapeutic properties. The plant's rhizomes, leaves, and flowers have all been used for their medicinal benefits. These parts contain several bioactive compounds such as alkaloids, flavonoids, tannins, and saponins, which exhibit a wide range of pharmacological effects. These effects include anti-inflammatory, antioxidant, analgesic, antidiabetic, and anti-cancer properties. Despite its excellent medicinal properties, the plant is in danger. This review covers the geographical distribution, morphology, and phytochemistry of T. govanianum. Additionally, it highlights the reproductive behavior, agro-technology, and various pharmacological properties of the plant. The review also discusses the reasons for T. govanianum being endangered and strategies for its conservation.
In recent years, the demand for high-quality solar products that combine high efficacy with environmentally friendly characteristics has increased. Among the coral-safe sunscreens, ethylhexyl triazone (Uvinul® T150) is an effective organic UVB filter, photostable and practically insoluble in water, therefore difficult to be formulated in water-based products. Oil-free sunscreens are considered ideal for most skin types, as they are not comedogenic and do not leave the skin feeling greasy. Recent studies reported that pollen grains might represent innovative drug delivery systems for their ability to encapsulate and release active ingredients in a controlled manner. Before being used, the pollen grains must be treated to remove cellular material and biomolecules, which could cause allergic reactions in predisposed subjects; the obtained hollow structures possess uniform diameter and a rigid wall with openings that allow them to be filled with bioactive substances. In the present work, pollen from Lycopodium clavatum has been investigated both as a delivery system for ethylhexyl triazone and as an active ingredient by evaluating its photoprotective capacity. The goal is to obtain environmentally friendly solar aqueous formulations that take advantage of both sunscreen and sporopollenin microcapsules’ UV protection with a relatively low cost, as these pollen grains are widely available.
Naturally occurring micro/nanoparticles provide an incredible array of potential sources when preparing hybrid micro/nanorobots and their intrinsic properties can be exploited as multitasking functionalities of modern robotics as well as ensuring their mass production availability. Herein, magnetic biological bots (BioBots) prepared from defatted sunflower pollen microparticles by ferromagnetic metal layer evaporation on one side of its surface are described. It is demonstrated that the methodology employed introduces magnetic properties to sunflower pollen microparticles‐based BioBots and enable their magnetic actuation. Interestingly, as‐prepared magnetic sunflower pollen‐based BioBots can naturally attract cancer cells due to their opposite charges (positive and negative, respectively). Such attracted cancer cells can then be transported by microrobots. This strong attraction also allows the delivery of drugs intended to kill the cancer cells. Sunflower‐based BioBots can be fabricated in large quantities, and are naturally programmable, making them promising candidates for cancer cell therapy.
Aspirin, also known as acetylsalicylic acid (ASA), is one of the most crucial therapies needed and/or used in a basic health system. Using biocompatible materials to encapsulate ASA would improve its therapeutic efficacy and reduce its side effects via controlled release in physiological environments. Consequently, we explore in this study the feasibility of encapsulation of ASA into the robust Lycopodium clavatum L sporopollenin (LCS) microcapsules. After extracting sporopollenin from their natural micrometer-sized raw spores, the physico-chemical features of the extracted sporopollenin, pure ASA, and sporopollenin loaded with ASA were characterised using various methods, including optical microscopy, Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-vis.) spectroscopy, Thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Additionally, we demonstrate the in vitro release profile of ASA in a triggered gastrointestinal environment utilizing kinetics analysis to investigate the mechanism of release. The LCS microcapsules were found to be excellent encapsulants for the crucial ASA drug and achieved controlled in vitro release, that would enable further investigations to rationally design versatile controlled delivery platforms.
The investigation of the biochemical composition of pollen grains is of the utmost interest for several environmental aspects, such as their allergenic potential and their changes in growth conditions due to climatic factors. In order to fully understand the composition of pollen grains, not only is an in-depth analysis of their molecular components necessary but also spatial information of, e.g., the thickness of the outer shell, should be recorded. However, there is a lack of studies using molecular imaging methods for a spatially resolved biochemical composition on a single-grain level. In this study, Raman spectroscopy was implemented as an analytical tool to investigate birch pollen by imaging single pollen grains and analyzing their spectral profiles. The imaging modality allowed us to reveal the layered structure of pollen grains based on the biochemical information of the recorded Raman spectra. Seven different birch pollen species collected at two different locations in Germany were investigated and compared. Using chemometric algorithms such as hierarchical cluster analysis and multiple-curve resolution, several components of the grain wall, such as sporopollenin, as well as the inner core presenting high starch concentrations, were identified and quantified. Differences in the concentrations of, e.g., sporopollenin, lipids and proteins in the pollen species at the two different collection sites were found, and are discussed in connection with germination and other growth processes.
Honeybee pollen (HBP) chemical composition is highly variable conforming to the floral and geographical origin of the pollen grains. The beneficial effects and functional properties of the HBP are well-known and have been mainly attributed to their high content of antioxidant polyphenols. In this work, twelve HBPs samples from the Southern region of Chile (X Región de Los Lagos) were characterized for the first time according to their botanical origin, phenolic composition, and antioxidant activity. The in vitro gastrointestinal digestion assay was done to simulate the human upper digestive tract. Selected honeybee pollen extracts (HBPEs) were assessed as bioaccessible fractions during an in vitro gastrointestinal digestion. Contents of phenolic compounds, antioxidant capacity, and recovery index of quercetin, myricetin, and cinnamic acid were monitored in different steps of gastrointestinal digestion. Furthermore, the protective effect of in vitro digested HBP towards DNA damage induced by peroxyl radicals was evaluated. The introduced species Brassica rapa L. (Brassicaceae), Lotus pedunculatus Cav. (Fabaceae), and Ulex europaeus L. (Fabaceae) predominated in all the HBPs analyzed, while the native species Buddleja globosa Hope (Scrophulariaceae), Luma apiculata (DC.) Burret (Myrtaceae), Embothrium coccineum J.R. Forst. & G. Forst. (Proteaceae) and Eucryphia cordifolia Cav. (Cunoniaceae) appeared less frequently. The content of polyphenols and antioxidant capacity in HBPEs achieved full bioaccessibility at the end of the intestinal digestion step. However, results obtained by a state-of-the-art technique (i.e. HPLC-DAD) demonstrated relatively low values of bioaccessible quercetin and cinnamic acid after the digestion process. In contrast, myricetin showed a high bioaccessibility in the intestinal digestion steps. The protective effect of in vitro digested HBP towards DNA damage induced by peroxyl radicals showed promising results (up to 91.2% protection). In conclusion, HBPs from the X Region de Los Lagos are rich sources of phenolic antioxidants that protect DNA from strand breakage. Therefore, the potential of HBPEs in preventing gastric and/or intestinal cancer should be further considered.
The design of intelligent delivery systems is becoming popular in the food ingredient sector. The increasing consumer demand for natural ingredients prompted researchers to look for new green solutions and use the goods of nature. Sporopollenin exine capsules (SECs) are obtained from plant pollen by washing out the proteins and genetic material. SECs are empty hollow particles that can be easily filled with hydrophobic and hydrophilic small molecular compounds, but also with proteins, enzymes, and even living probiotic bacteria. The release of compounds from the SECs is regulated by passive diffusion and can be further modulated by coating the SECs with a layer of lipids, proteins, or polysaccharides. SECs can also be functionalized to function as an intelligent delivery system that targets the intestinal mucus or the receptors located on epithelial cell membranes.
Cancer is a major worldwide public health issue, responsible for millions of deaths every year. Cancer cases and deaths are expected to increase rapidly with population growth, age, and lifestyle behaviors that increase cancer risk. Long-term chemotherapy results in acquired drug resistance. Traditional treatment methods have limitations and cannot effectively treat distal metastatic cancers. Application of nanocarriers in multi-chemotherapy must be promoted. With research progress, the shortcomings of traditional nanocarriers have gradually become evident. Carrier-free nanodrugs with desirable bioactivity have attracted considerable attention. In this review, we provide an overview of recent reports on several carrier-free nanodrug delivery systems based on phytochemicals. This review focuses on the advantages of carrier-free nanodrugs, and provides new insights for establishment of ideal cancer treatment nanosystems.
In this study, 5-fluorouracil (5-FU)-loaded pollens of Phoenix dactylifera and their coating with ERS was done and evaluated for the colon-targeted delivery of 5-FU to treat colon cancer. Sporopollenin exine microcapsules (SEMC) from the pollens of Phoenix dactylifera were extracted by the reflux method and 5-FU into SEMC was encapsulated by the vacuum-assisted loading method. 5-FU loaded SEMC was coated with Eudragit® RS-100 (ERS) by the organic solvent-evaporation technique under vacuum to avoid the discharge of 5-FU in the stomach and small intestine. Morphological and physicochemical characterization of drug-loaded SEMC (coated/uncoated) was performed by scanning electron microscopy (SEM), FTIR, XRD, and DSC. The encapsulation and drug loading were determined by the direct method, and an in vitro release study was performed in simulated gastric and intestinal fluids (SGF/SIF). The colon-specific delivery of 5-FU from the SEMC was assessed in terms of pharmacokinetics and gastrointestinal tract distribution after oral administration in rats. The successful encapsulation and loading of 5-FU into SEMC by a vacuum-assisted loading technique and its coating with ERS by a solvent-evaporation technique were achieved. SEM images of uncoated SEMC have shown porous structures, and coating with ERS reserved their morphology with a smooth surface and discrete microstructures and the 5% w/v ERS acetone solution. ERS-coated SEMC sustained the release of 5-FU until 24 h in SIF, while it was up to 12 h only from uncoated SEMC. The maximum plasma concentration (Cmax) of 5-FU from uncoated SEMC was 102.82 μg/mL after 1 h, indicating a rapid release of 5-FU in the upper gastrointestinal tract. This concentration decreased quickly with a half-life of 4 h, AUC0-t was 264.1 μg/mL.h, and MRT0-inf was 5.2 h. The Cmax of 5-FU from ERS-coated SEMC was 19.47 μg/mL at 16 h. The Cmax of 5-FU in small intestines was 406.2 μg/g at 1 h from uncoated SEMC and 1271.5 μg/g at 12 h from coated SEMC. Conclusively, a 249.9-fold higher relative bioavailability of 5-FU was achieved with the ERS-coated SEMC in colon tissues than that from uncoated SEMC.
Introduction: Cancer can be defined as an illness of reformed gene expression. There are numerous agents affecting gene expression and altering cellular activities. Nanotechnology has offered the possibility of modulating tumor suppressor genes’ expression, improving kinetics of gene-targeted therapeutics, and simplifying drug delivery to tumors and across bio-complexes.Methods: Gene expressions of caspase3, 8 and 9, Bax and Bcl2 were assessed after RNA extraction and cDNA synthesis by real-time polymerase chain reaction (PCR) in an ovarian cancerous cell line (A2780). Real-time PCR was employed to determine the change fold of apoptotic genes in the cells exposed to the biosynthesized CeO2-NPs (cerium oxide nanoparticles) at the dose of 0, 7, 9, and 11 μg/mL after 24 hours of incubation. Results: Our findings displayed a significant increase in the antioxidant genes’ expression in the A2870 cells. The results exhibited that the biosynthesized CeO2-NPs could enhance the Bax/Bcl2 ratio in a dose-dependent way. Also, the expression of caspase3, 8, and 9 up-regulated significantly under the dose of 11 μg/mL.Conclusion: Considering the effects of the bio-fabricated CeO2-NPs on the expression of apoptotic genes in ovarian cancerous cell lines, these nanoparticles (NPs) may be employed in pharmacology to develop new anti-cancer medications.
Mechanisms that favour rare species are key to the maintenance of diverse communities1,2,3. One of the most critical tasks for conservation of flowering plant biodiversity is to understand how plant–pollinator interactions contribute to the maintenance of rare species4,5,6,7. Here we show that niche partitioning in pollinator use and asymmetric facilitation confer fitness advantage of rarer species in a biodiversity hotspot using phylogenetic structural equation modelling that integrates plant–pollinator and interspecific pollen transfer networks with floral functional traits. Co-flowering species filtered pollinators via floral traits, and rarer species showed greater pollinator specialization leading to higher pollination-mediated male and female fitness than more abundant species. When plants shared pollinator resources, asymmetric facilitation via pollen transport dynamics benefitted the rarer species at the cost of more abundant species, serving as an alternative diversity-promoting mechanism. Our results emphasize the importance of community-wide plant–pollinator interactions that affect reproduction for biodiversity maintenance.
We developed a dual microencapsulation platform for the type 2 diabetes drug metformin (MTF), which is aimed to increase its bioavailability. We report the use of Lycopodium clavatum sporopollenin (LCS), derived from their natural spores, and raw Phoenix dactylifera L. (date palm) pollens (DPP) for MTF microencapsulation. MTF was loaded into LCS and DPP via a vacuum and a novel method of hydration-induced swelling. The loading capacity (LC) and encapsulation efficiency (EE) percentages for MTF-loaded LCS and MTF-loaded DPP microcapsules were 14.9% ± 0.7, 29.8 ± 0.8, and 15.2% ± 0.7, 30.3 ± 1.0, respectively. The release of MTF from MTF-loaded LCS microcapsules was additionally controlled by re-encapsulating the loaded microcapsules into calcium alginate (ALG) microbeads via ionotropic gelation, where the release of MTF was found to be significantly slower and pH-dependent. The pharmacokinetic parameters, obtained from the in vivo study, revealed that the relative bioavailability of the MTF-loaded LCS-ALG beads was 1.215 times higher compared to pure MTF, following oral administration of a single dose equivalent to 25 mg/kg body weight MTF to streptozotocin (STZ)-induced diabetic male Sprague-Dawley rats. Significant hypoglycemic effect was obtained for STZ-induced diabetic rats orally treated with MTF-loaded LCS-ALG beads compared to control diabetic rats. Over a period of 29 days, the STZ-induced diabetic rats treated with MTF-loaded LCS-ALG beads showed a decrease in the aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglycerides, cholesterol, and low-density lipoprotein-cholesterol (LDL-C) levels, as well as an increase in glutathione peroxidase (GPx) and a recovery in the oxidative stress biomarker, lipid peroxidation (LPx). In addition, histopathological studies of liver, pancreas, kidney, and testes suggested that MTF-loaded LCS-ALG beads improved the degenerative changes in organs of diabetic rats. The LCS-ALG platform for dual encapsulation of MTF achieved sustained MTF delivery and enhancement of bioavailability, as well as the improved biochemical and histopathological characteristics in in vivo studies, opening many other intriguing applications in sustained drug delivery
Purpose
Apatinib (Apa) is a novel anti-vascular endothelial growth factor with the potential to treat diabetic retinopathy (DR); a serious condition leading to visual impairment and blindness. DR treatment relies on invasive techniques associated with various complications. Investigating topical routes for Apa delivery to the posterior eye segment is thus promising but also challenging due to ocular barriers. Hence, the study objective was to develop Apa-loaded bovine serum albumin nanoparticles (Apa-BSA-NPs) coated with hyaluronic acid (HA); a natural polymer possessing unique mucoadhesive and viscoelastic features with the capacity to actively target CD44 positive retinal cells, for topical administration in DR.
Methods
Apa-BSA-NPs were prepared by desolvation using glutaraldehyde for cross-linking. HA-coated BSA-NPs were also prepared and HA: NPs ratio optimized. Nanoparticles were characterized for colloidal properties, entrapment efficiency (EE%), in vitro drug release and mucoadhesive potential. In vitro cytotoxicity on rabbit corneal epithelial cells (RCE) was assessed using MTT assay, while efficacy was evaluated in vivo in a diabetic rat model by histopathological examination of the retina by light and transmission electron microscopy. Retinal accumulation of fluorescently labeled BSA-NP and HA-BSA-NP was assessed using confocal microscope scanning.
Results
Apa-HA-BSA-NPs prepared under optimal conditions showed size, PdI and zeta potential: 222.2±3.56 nm, 0.221±0.02 and −37.3±1.8 mV, respectively. High EE% (69±1%), biphasic sustained release profile with an initial burst effect and mucoadhesion was attained. No evidence of cytotoxicity was observed on RCE cells. In vivo histopathological studies on DR rat model revealed alleviated retinal micro- and ultrastructural changes in the topical HA-Apa-BSA-NP treated eyes with normal basement membrane and retinal thickness comparable to normal control and intravitreally injected nanoparticles. Improved retinal accumulation for HA-BSA-NP was also observed by confocal microscopy.
Conclusion
Findings present HA-Apa-BSA-NPs as a platform for enhanced topical therapy of DR overcoming the devastating ocular complications of the intravitreal route.
The microstructures of quenched and tempered steels have been traditionally explored by transmission electron microscopy (TEM) rather than scanning electron microscopy (SEM) since TEM offers the high resolution necessary to image the structural details that control the mechanical properties. However, scanning electron microscopes, apart from providing larger area coverage, are commonly available and cheaper to purchase and operate compared to TEM and have evolved considerably in terms of resolution. This work presents detailed comparison of the microstructure characterization of quenched and tempered high-strength steels with TEM and SEM electron channeling contrast techniques. For both techniques, similar conclusions were made in terms of large-scale distribution of martensite lath and plates and nanoscale observation of nanotwins and dislocation structures. These observations were completed with electron backscatter diffraction to assess the martensite size distribution and the retained austenite area fraction. Precipitation was characterized using secondary imaging in the SEM, and a deep learning method was used for image segmentation. In this way, carbide size, shape, and distribution were quantitatively measured down to a few nanometers and compared well with the TEM-based measurements. These encouraging results are intended to help the material science community develop characterization techniques at lower cost and higher statistical significance.
Purpose of Review
Medicinal products for allergen immunotherapy (AIT) of food allergies have gained enormous momentum in recent years. With this new class of products entering marketing authorization procedures, compliance to regulatory requirements becomes a critical element. Here, an overview is provided on specific requirements and aspects concerning the quality control and manufacturing of these products.
Recent Findings
Recent developments in the field of AIT for food allergies are divers, including products for oral, epicutaneous, and subcutaneous application, most notably targeting egg, milk, and peanut allergy. As the source materials for food AIT product are typically produced for food consumption and not for medicinal purposes, unique challenges arise in the manufacturing processes and controls of these medicinal products. Individual approaches are needed to assure acceptable quality, including control of relevant quantitative and qualitative characteristics. Major characteristics for quality verification include determination of protein content, total allergenic activity, and major allergen content. The applied manufacturing processes need to be established such that relevant process parameters are kept within justified limits and consistency of produced batches is assured.
Summary
Allergen products for food AIT present specific challenges with respect to quality aspects that differentiate them from other commonly available AIT products. While established regulation is available and provides clear guidance for most aspects, other issues require consideration of new and individual settings relevant here. Consequently, as experience grows, respective amendments to currently available guidance may be needed.
The aim of this study was to synthesize chitosan nanoparticles loaded with rapeseed extract (RPE-CN) and to evaluate its therapeutic effects. The RPE-CNwas synthesized (Ion gelation), characterized (DLS, FTIR, atomic and electron microscopy) and their toxicity was evaluated by MTT method.Anti-inflammatory and pro-apoptotic effects were evaluated by qPCR method. Its antioxidant power was measured by ABTS, DPPH and FRAP methods and CAM method was used to evaluate its anti-angiogenic effects.Treatment with RPE-CN(Ps: 93.81 nm, PDI: 0.3, and ζ p: +35mv) reduced MCF7 cell viability and increased expression of genes associated with apoptosis (Caspase-3 and Caspase-9), inflammation (IL10) and antioxidant (SOD).RPE-CN exhibited notable inhibition in ABTS, DPPH, and Fe3+-TPTZ free radicals. Finally, angiogenesis in CAM tissue was suppressed by the down-regulation of VEGFR gene expression. According to the results, RPE-CN can be introduced as a potential chemo-preventive agent in the treatment of cancer.
Pollen is a male flower gametophyte located in the anthers of stamens in angiosperms and a considerable source of compounds with health protective potential. In the present work, phytochemical screening was carried out as well as analysis of the antioxidant and antibacterial properties of pollen extracts from Micromeria fruticosa, Achillea fragrantissima, and Phoenix dactylifera growing wild in Palestine. Phytochemical screening examined the total flavonol, flavone and phenolic content. The DPPH (1,2-Diphenyl-1-Picrylhydrazyl) and FRAP (ferric reducing antioxidant power) methods were used to assess antioxidant propriety, and disc diffusion, minimum inhibitory and bactericidal concentration tests were used to test the pollen extract’s antibacterial activity against multidrug-resistant (MDR) clinical isolates. The highest level of total phenolic was found in the extract of Micromeria fruticosa (56.78 ± 0.49 mg GAE (Gallic Acid Equivalent)/g). The flavone and flavonol content of samples ranged from 2.48 ± 0.05 to 8.03 ± 0.01 mg QE (Quercetin Equivalent)/g. Micromeria fruticosa pollen with IC50 values of 0.047 and 0.039 mg/mL in the DPPH and FRAP assays, respectively, showed the greatest radical scavenging action. In addition, this pollen showed a mild antibacterial action against the microorganisms studied, with MICs varying from 0.625 to 10 mg/mL and inhibition diameters ranging from 13.66 ± 1.5 to 16.33 ± 1.5 mm.
Lycopodium is a genus of the family Pteridophytes, which is widely distributed in temperate and tropical climates and tropical mountains. Plants of genus Lycopodium are ancient medicinal plants which have been used in different traditional medicinal system to treat many diseases, mainly focus on central nervous system and inflammation-related diseases. Rigorous pharmacological and clinical studies conducted in recent decades have demonstrated their special efficacy in the treatment of Alzheimer's disease (AD). Furthermore, secondary metabolites and extracts from these plants have been proven to possess neuroprotective, anti-tumor, anti-inflammatory, anti-microbial, and antiviral effects, which supports most of traditional medicinal uses of Lycopodium plants. To date, a total of 508 secondary metabolites have been reported from the 46 species belonging to genus Lycopodium. Among those metabolites, Lycopodium alkaloids and serratene triterpenoids represent two major classes of bioactive ingredients. Notably, huperzine A, a Lycopodium alkaloid originally isolated from L. serratum, was licensed in China as a drug for the treatment of AD and in the United States as a dietary supplement. Besides, serratane-type triterpenoids may be potential candidates for the development of anticancer drugs. This review covers the literatures available from 1947 to 2020 and mainly discusses knowledge on ethnopharmacology, secondary metabolites, pharmacological activities, clinical trials, toxicology, and quality control of Lycopodium species. In addition, the present review also draws attention to the gaps that still exist in the scientific studies on Lycopodium plants, which would accelerate the contemporary development of this traditional medicinal plant.
Graphic abstract
Currently, bee-gathered pollen (bee pollen) is commonly used worldwide as a dietary supplement and is recognized for its curative properties. Floral pollen is also important but is less recognized due to a lack of investigation. This study aims to determine the morphological characteristics and nutritional and phytochemical properties of floral maize pollen. Fresh pollen grains harvested from a farm of maize plants are yellow in colour and spheroid in shape. They change to amber and indented prismatic solid shapes when dehydrated. The main composition of floral maize pollen is carbohydrates (44.30±3.73%), followed by moisture (23.38±5.73%), crude proteins (17.16±3.13%), crude fibres (9.56±0.92%), and ash (4.98±0.11%), while the lowest content is observed for crude fats (0.62±0.06%). The predominant mineral is potassium (768.50±11.40 mg 100 g ⁻¹ ), followed by sodium (695.10±9.70 mg 100 g ⁻¹ ), calcium (147.20±12.60 mg 100 g ⁻¹ ), and magnesium (97.30±2.9 mg 100 g ⁻¹ ). The microelements (with average values) consist of iron (49.50±3.30 mg 100 g ⁻¹ ) and zinc (30.00±3.70 mg 100 g ⁻¹ ). Excellent phytochemical properties add value to floral maize pollen. Maize pollen contains a high total phenolic content (TPC) and total flavonoid content (TFC) of 783.02 mg GAE 100 g ⁻¹ and 1706.83 mg QE 100 g ⁻¹ , respectively, and possesses strong antioxidant activity of 10.54 mg mL ⁻¹ . Maize floral pollen and derived products can serve as future food resources for human consumption and as a source of functional and bioactive compounds in nutraceutical and pharmaceutical industries.
This article provides an update on the global cancer burden using the GLOBOCAN 2020 estimates of cancer incidence and mortality produced by the International Agency for Research on Cancer. Worldwide, an estimated 19.3 million new cancer cases (18.1 million excluding nonmelanoma skin cancer) and almost 10.0 million cancer deaths (9.9 million excluding nonmelanoma skin cancer) occurred in 2020. Female breast cancer has surpassed lung cancer as the most commonly diagnosed cancer, with an estimated 2.3 million new cases (11.7%), followed by lung (11.4%), colorectal (10.0 %), prostate (7.3%), and stomach (5.6%) cancers. Lung cancer remained the leading cause of cancer death, with an estimated 1.8 million deaths (18%), followed by colorectal (9.4%), liver (8.3%), stomach (7.7%), and female breast (6.9%) cancers. Overall incidence was from 2‐fold to 3‐fold higher in transitioned versus transitioning countries for both sexes, whereas mortality varied <2‐fold for men and little for women. Death rates for female breast and cervical cancers, however, were considerably higher in transitioning versus transitioned countries (15.0 vs 12.8 per 100,000 and 12.4 vs 5.2 per 100,000, respectively). The global cancer burden is expected to be 28.4 million cases in 2040, a 47% rise from 2020, with a larger increase in transitioning (64% to 95%) versus transitioned (32% to 56%) countries due to demographic changes, although this may be further exacerbated by increasing risk factors associated with globalization and a growing economy. Efforts to build a sustainable infrastructure for the dissemination of cancer prevention measures and provision of cancer care in transitioning countries is critical for global cancer control.
Despite several decades of research into encapsulation of bacteria, most of the proposed technologies are in the form of immobilized cultures. In this work, sporopollenin exine capsules (SECs) opened, using silica particles which act as pressing micro‐probes, and loaded with Lactobacillus casei (L. casei) cells, are described for the first time. The proposed encapsulation provided ≈30× higher encapsulation yield (30.87%), compared to direct compression of SECs (0.99%). Encapsulated L. casei cells show 1.21‐ and 2.25‐folds higher viability compared to free cells, in in vitro simulated fasted and fed media representing the human gastrointestinal (GI) tract, respectively. Encapsulated L. casei can proliferate inside the SECs, generating enough pressure to cause the SECs to burst and release the viable and metabolically active cells. The noticeable difference with the application of the SECs as a means of encapsulation is that the SECs may act as a bioreactor and provide time for the encapsulated cells to multiply thousands of times before being released, following the SEC's burst. The unique advantages of SECs alongside the proposed encapsulation method, demonstrates the potential application of SECs as delivery system of probiotics to the distal part of the human GI tract.
Electrochemistry, although an ancient field of knowledge, has become of paramount importance in the synthesis of materials at the nanoscale, with great interest not only for fundamental research but also for practical applications. One of the promising fields in which electrochemistry meets nanoscience and nanotechnology is micro/nanoscale motors. Micro/nano motors, which are devices able to perform complex tasks at the nanoscale, are commonly multifunctional nanostructures of different materials-metals, polymers, oxides-and shapes-spheres, wires, helices-with the ability to be propelled in fluids. Here, we first introduce the topic of micro/nanomotors and make a concise review of the field up to day. We have analyzed the field from different points of view (e.g. materials science and nanotechnology, physics, chemistry, engineering, biology or environmental science) to have a broader view of how the different disciplines have contributed to such exciting and impactful topic. After that, we focus our attention on describing what electrochemical technology is and how it can be successfully used to fabricate and characterize micro/nanostructures composed of different materials and showing complex shapes. Finally, we will review the micro and nanomotors fabricated using electrochemical techniques with applications in biomedicine and environmental remediation, the two main applications investigated so far in this field. Thus, different strategies have thus been shown capable of producing core-shell nanomaterials combining the properties of different materials, multisegmented nanostructures made of, for example, alternating metal and polymer segments to confer them with flexibility or helicoidal systems to favor propulsion. Moreover, further functionalization and interaction with other materials to form hybrid and more complex objects is also shown.
Sporopollenin-mediated control drug delivery has been studied extensively owing to its desirable physicochemical and biological properties. Herein, sporopollenin was successfully extracted from C. libani and P. nigra pollens followed by loading of a commonly known anticancer drug Oxaliplatin. Drug loading and physicochemical features were confirmed by using light microscopy, FT-IR, SEM and TGA. For the first-time, real-time cell analyzer system xCELLigence was employed to record the Oxaliplatin loaded sporopollenin-mediated cell death (CaCo-2 and Vero cells) in real time. Both the release assays confirmed the slow release of oxaliplatin from sporopollenin for around 40–45 h. The expression of MYC and FOXO-3 genes has been significantly increased in CaCo2 cell and decreased non-cancerous Vero cell confirming the fact that sporopollenin-mediated control release of oxaliplatin is promoting apoptosis cell death preventing the spread of negative effects on nearby healthy cells. All the results suggested that C. libani and P. nigra can be suitable candidates for the slow delivery of drugs.
Pancreatic cancer is the most lethal malignancy of the gastrointestinal tract. Due to its propensity for early local and distant spread, affected patients possess extremely poor prognosis. Currently applied treatments are not effective enough to eradicate all cancer cells, and minimize their migration. Besides, these treatments are associated with adverse effects on normal cells and organs. These therapies are not able to increase the overall survival rate of patients; hence, finding novel adjuvants or alternatives is so essential. Up to now, medicinal herbs were utilized for therapeutic goals. Herbal-based medicine, as traditional biotherapeutics, were employed for cancer treatment. Of them, apigenin, as a bioactive flavonoid that possesses numerous biological properties (e.g., anti-inflammatory and anti-oxidant effects), has shown substantial anticancer activity. It seems that apigenin is capable of suppressing the proliferation of cancer cells via the induction of cell cycle arrest and apoptosis. Besides, apigenin inhibits metastasis via down-regulation of matrix metalloproteinases and the Akt signaling pathway. In pancreatic cancer cells, apigenin sensitizes cells in chemotherapy, and affects molecular pathways such as the hypoxia inducible factor (HIF), vascular endothelial growth factor (VEGF), and glucose transporter-1 (GLUT-1). Herein, the biotherapeutic activity of apigenin and its mechanisms toward cancer cells are presented in the current review to shed some light on anti-tumor activity of apigenin in different cancers, with an emphasis on pancreatic cancer.
Sporopollenin-mediated controlled drug delivery has been studied extensively owing to its physicochemical and biological charachteristics. In the present study, sporopollenin was successfully extracted from pollen grains of C. libani and P. nigra followed by the loading of a commonly known anticancer drug Oxaliplatin. Both the drug loading and physicochemical features were confirmed by using light microscopy, FT-IR, SEM and TGA. For the first time, real-time cell analyzer system, xCELLigence, was employed to record the Oxaliplatin-loaded and sporopollenin-mediated cell death (CaCo-2 and Vero cells) in real time. Both the assays confirmed the slow release of Oxaliplatin from sporopollenin for around 40-45 h. The expression of MYC and FOXO-3 genes significantly increased in CaCo2 cell and decreased non-cancerous Vero cell confirming that sporopollenin-mediated controlled release of Oxaliplatin was promoting apoptosis cell death preventing the spread of its negative effects to nearby healthy cells. All the results suggested that C. libani and P. nigra could be suitable candidates for slow delivery of drugs.
The outer wall of pollen and spores, namely the exine, is composed of sporopollenin which is highly resistant to chemical reagents and enzymes. Here, we demonstrate that phenylpropanoid pathway derivatives are essential components of sporopollenin in seed plants. Spectral analyses show that the autofluorescence of Lilium and Arabidopsis sporopollenin is similar to that of lignin. Thioacidolysis and NMR analyses of pollen from Lilium and Cryptomeria show that the sporopollenin of seed plants contains phenylpropanoid derivatives, including p-hydroxybenzoate (p-BA), p-coumarate (p-CA), ferulate (FA) and lignin guaiacyl (G) units. Signals from the phenylpropanoid pathway genes fused to VENUS fluorescent proteins demonstrate that the phenylpropanoid pathway is expressed in the tapetum in Arabidopsis, which is consistent with the fact that the sporopollenin precursor originates from the tapetum. Further germination and comet assays show that this pathway plays an important role in pollen protection against UV radiation. In the pteridophyte plants species Ophioglossum and Lycopodium, phenylpropanoid derivatives including p-BA and p-CA were also detected, but G units were not. Together, our results indicate that phenylpropanoid derivatives are essential for sporopollenin synthesis in vascular plants. In addition, sporopollenin autofluorescence spectra of bryophytes such as Physcomitrella and Haplocladium exhibit distinct characteristics compared with those of vascular plants, indicating diversity of sporopollenin among land plants.
Cancer has become a significant public health problem with high disease burden and mortality. At present, radiotherapy and chemotherapy are the main means of treating cancer, but they have shown serious safety problems. The severity of this problem has caused further attention and research on effective and safe cancer treatment methods. Polysaccharides are natural products with anti-cancer activity that are widely present in a lot of plants, and many studies have found that inducing apoptosis of cancer cells is one of their important mechanisms. Therefore, this article reviews the various ways in which plant polysaccharides promote apoptosis of cancer cells. The major apoptotic pathways involved include the mitochondrial pathway, the death receptor pathway, and their upstream signal transduction such as MAPK pathway, PI3K/AKT pathway, and NF-κB pathway. Moreover, the paper has also been focused on the absorption and toxicity of plant polysaccharides with reference to extant literature, making the research more scientific and comprehensive. It is hoped that this review could provide some directions for the future development of plant polysaccharides as anticancer drugs in pharmacological experiments and clinical researches.
Pollen studies are important for the assessment of present and past environment, including biodiversity, sexual reproduction of plants and plant-pollinator interactions, monitoring of aeroallergens, and impact of climate and pollution on wild communities and cultivated crops. Although information on chemical composition of pollen is of importance in all of those research areas, pollen chemistry has been rarely measured due to complex and time-consuming analyses. Vibrational spectroscopies, coupled with multivariate data analysis, have shown great potential for rapid chemical characterization, identification and classification of pollen. This study, comprising 219 species from all principal taxa of seed plants, has demonstrated that high-quality Raman spectra of pollen can be obtained by Fourier transform (FT) Raman spectroscopy. In combination with Fourier transform infrared spectroscopy (FTIR), FT-Raman spectroscopy is obtaining comprehensive information on pollen chemistry. Presence of all the main biochemical constituents of pollen, such as proteins, lipids, carbohydrates, carotenoids and sporopollenins, have been identified and detected in the spectra, and the study shows approaches to measure relative and absolute content of these constituents. The results show that FT-Raman spectroscopy has clear advantage over standard dispersive Raman measurements, in particular for measurement of pollen samples with high pigment content. FT-Raman spectra are strongly biased toward chemical composition of pollen wall constituents, namely sporopollenins and pigments. This makes Raman spectra complementary to FTIR spectra, which over-represent chemical constituents of the grain interior, such as lipids and carbohydrates. The results show a large variability in pollen chemistry for families, genera and even congeneric species, revealing wide range of reproductive strategies, from storage of nutrients to variation in carotenoids and phenylpropanoids. The information on pollen’s chemical patterns for major plant taxa should be of outstanding value for various studies in plant biology and ecology, including aerobiology, palaeoecology, forensics, community ecology, plant-pollinator interactions, and climate effects on plants.
Pollen’s practically-indestructible shell structure has long inspired the biomimetic design of organic materials. However, there is limited understanding of how the mechanical, chemical, and adhesion properties of pollen are biologically controlled and whether strategies can be devised to manipulate pollen beyond natural performance limits. Here, we report a facile approach to transform pollen grains into soft microgel by remodeling pollen shells. Marked alterations to the pollen substructures led to environmental stimuli responsiveness, which reveal how the interplay of substructure-specific material properties dictates microgel swelling behavior. Our investigation of pollen grains from across the plant kingdom further showed that microgel formation occurs with tested pollen species from eudicot plants. Collectively, our experimental and computational results offer fundamental insights into how tuning pollen structure can cause dramatic alterations to material properties, and inspire future investigation into understanding how the material science of pollen might influence plant reproductive success. Pollen is an abundant material; but, currently has limited applications. Here, the authors turn pollen grains into soft microgel by de-esterification of pectin molecules and explore the mechanical and structural changes of the pollen grains using physical and modelling approaches.
The production of large quantities of micromachines and microrobots is limited by fabrication methods and the use of synthetic templates. Pollen is one of the most stable structures in the world, capable of surviving harsh treatment and for millions of years. Pollen grains are available in large variety of shapes and sizes. The use of a wide variety of naturally abundant, nontoxic pollen grains for the efficient fabrication of platinum‐pollen (Pt‐pollen) hybrid microrobots capable of fast propulsion for environmental and biomedical applications is demonstrated. Nine different pollen grains are selected and modified (dandelion, pine, lotus, sunflower, poppy, camellia, lycopodium, cattail, and galla) to demonstrate the robustness of different types of pollen grains for potential applications in environmental remediation. The efficient mobility rendered by the fabricated microrobots enhances their performance in the removal of heavy metals in aqueous medium. Furthermore, they can be used as doxorubicin carriers. Nine different naturally abundant and nontoxic pollen grains (dandelion, pine, lotus, sunflower, poppy, camellia, lycopodium, cattail, and galla) are selected and modified for the fabrication of microrobots. These microrobots are capable of fast propulsion and have enhanced environmental‐remediation performance. These microrobots can also be used as doxorubicin carriers.
The present paper describes the preparation of magnetic hollow biocomposites (MgBC) from Lycopodium clavatum (LC) pollens by using microwave chemistry and investigates their catalytic activities on the model reaction of Rhodamine B (RhB), which is a representative environmental organic pollutant, in the presence sodium borohydride. The fabricated MgBC displayed unique microstructure with a narrow size distribution of 28±0.45 μm and surface, which was decorated with reticulate web‐like micro ridges surrounded by pores and Fe3O4 nanoparticles (a spherical form with an average size of about 8.54±2.74 nm). The produced MgBCs exhibited high efficiency and excellent catalytic reduction performance for RhB (100 % removed within 230 sec), which could be ascribed to unique structure and high surface area of the Fe3O4 doped bio‐composite. Furthermore, the MgBCs recycled five times using an external magnet without a major loss of catalytic efficiency. Therefore, MgBC can be used as effective and suitable recycled catalysts for practical applications.
Flavonoids are polyphenolic compounds subdivided into 6 groups: isoflavonoids, flavanones, flavanols, flavonols, flavones and anthocyanidins found in a variety of plants. Fruits, vegetables, plant-derived beverages such as green tea, wine and cocoa-based products are the main dietary sources of flavonoids. Flavonoids have been shown to possess a wide variety of anticancer effects: they modulate reactive oxygen species (ROS)-scavenging enzyme activities, participate in arresting the cell cycle, induce apoptosis, autophagy, and suppress cancer cell proliferation and invasiveness. Flavonoids have dual action regarding ROS homeostasis—they act as antioxidants under normal conditions and are potent pro-oxidants in cancer cells triggering the apoptotic pathways and downregulating pro-inflammatory signaling pathways. This article reviews the biochemical properties and bioavailability of flavonoids, their anticancer activity and its mechanisms of action.
Among the various dosage forms, oral medicine has extensive benefits including ease of administration and patients' compliance, over injectable, suppositories, ocular and nasal. Despite of extensive demand and emerging advantages, over 50% of therapeutic molecules are not available in oral form due to their physicochemical properties. More importantly, most of the biologics, proteins, peptide, and large molecular drugs are mostly available in injectable form. Conventional oral drug delivery system has limitation such as degradation and lack of stability within stomach due to presence of highly acidic gastric fluid, hinders their therapeutic efficacy and demand more frequent and higher dosing. Hence, formulation for controlled, sustained, and targeted drug delivery, need to be designed with feasibility to target the specific region of gastrointestinal (GI) tract such as stomach, small intestine, intestine lymphatic, and colon is challenging. Among various oral delivery approaches, mucoadhesive vehicles are promising and has potential for improving oral drug retention and controlled absorption to treat local diseases within the GI tract, as well systemic diseases. This review provides the overview about the challenges and opportunities to design mucoadhesive formulation for oral delivery of therapeutics in a way to target the specific region of the GI tract. Finally, we have concluded with future perspective and potential of mucoadhesive formulations for oral local and systemic delivery.
Traditional Chinese herbal medicine (TCHM) is the naturally available pharmaceutical with millennia of evolution from ancient China, capable of a superior therapeutic index and minimized unwanted effects on the human body. This work presents a therapeutic microrobotic platform based on pollen typhae (PT), a typical type of TCHM, fabricated by coating porous PT microspheres with Fe3O4 nanoparticles (PT robots) via electrostatic adsorption. The PT robots exhibit effective and controllable motion in various biological media upon external magnetic control and, meanwhile, preserve the inherent hemostasis property of PT. The blood clotting capacity of PT robots is attributed to their stimulation of the endogenous blood coagulation pathway and platelets with increased counts, which could be further improved by their effective magnetic propulsion. The remote magnetic control also allows the manipulation of PT robots in mice stomach, inducing enhanced binding and prolonged retention of PT robots in stomach mucosa. Moreover, PT robots upon magnetic control show an enhanced hemostatic effect in treating the mice bearing acute gastric bleeding compared with other passive groups. This work offers a facile and feasible route to integrate TCHM with manmade micromachines possessing the innate curative features of TCHM. Such a design expanded the versatility of microrobots and can be generalized to vast types of TCHM for broader biomedical applications.
Naringenin is an important phytochemical which belongs to the flavanone group of polyphenols, and is found mainly in citrus fruits like grapefruits and others such as tomatoes and cherries plus medicinal plants derived food. Available evidence demonstrates that naringenin, as herbal medicine, has important pharmacological properties, including anti-inflammatory, antioxidant, neuroprotective, hepatoprotective, and anti-cancer activities. Collected data from in vitro and in vivo studies shows the inactivation of carcinogens after treatment with pure naringenin, naringenin-loaded nanoparticles, and also naringenin in combination with anticancer agents in various malignancies, such as colon cancer, lung neoplasms, breast cancer, leukemia and lymphoma, pancreatic cancer, prostate tumors, oral squamous cell carcinoma, liver cancer, brain tumors, skin cancer, cervical and ovarian cancer, bladder neoplasms, gastric cancer, and osteosarcoma. Naringenin inhibits cancer progression through multiple mechanisms, like apoptosis induction, cell cycle arrest, angiogenesis hindrance, and modification of various signaling pathways including Wnt/ß-catenin, PI3K/Akt, NF-ĸB, and TGF-β pathways. In this review, we demonstrate that naringenin is a natural product with potential for the treatment of different types of cancer, whether it is used alone, in combination with other agents, or in the form of the naringenin-loaded nanocarrier, after proper technological encapsulation.
This study highlights the protective role developed by encapsulation of Diclofenac Sodium (DIC) into natural Lycopodium Clavatum spores (LCS) to reduce gastric ulcerations associated with DIC administration in stomach of rats. Microencapsulation of DIC into empty LCS extracted from their natural, raw spore species was explored for the first time. LCS were characterized before and after drug loading using light microscopy, SEM, FTIR, TGA and particle size analyses. Different microencapsulation techniques (passive diffusion, vacuum-assisted and a combined passive-vacuum), varying loading duration and drug amounts were evaluated. Gastro-ulcerogenic activity of DIC loaded LCS against plain DIC was evaluated in rats. FTIR and TGA confirmed successful DIC encapsulation within the internal cavities of LCS. SEM, light micrographs and particle size analysis showed that drug loaded spores retained well defined microstructures similar to raw spores, with uniform size distributions of 20–25 μm. Encapsulation efficiency of DIC loaded LCS by vacuum-assisted loading was the highest (50%) compared to other loading techniques. A biphasic release pattern was achieved for drug loaded spores, with an initial fast release up till 2 h followed by a sustain release for 24 h, in phosphate buffer (pH 6.8), while ≥80% of plain DIC was released within 1 h. DIC loaded LCS showed substantial stomach protective action from related gastric ulcerations associated with DIC. Hence, a simple, reproducible approach utilizing Lycopodium Clavatum spores as natural encapsulant for oral delivery was established, with uniform micro-size distribution.
Adoptive T cell immunotherapy is a powerful strategy for clinical cancer treatment. As a critical step to generate clinical-grade T cell products for therapeutic applications, novel approaches for T cell activation and expansion attract increasing attention. Here, we develop hydrogel-integrated natural pollens as artificial antigen-presenting scaffolds for ex vivo T cell expansion. Black phosphorus is presented in the scaffolds that allow for NIR-triggered release of cytokines and antibodies for T cell activation. Besides, the distinctive spike structure and high surface area of pollens contribute to T cell cluster formation and enhance their local proliferation. After ex vivo expansion, the activated T cells exhibit robust antitumor activity. Therefore, these features demonstrate that the novel pollen-based antigen-presenting scaffolds are promising for therapeutic T cell preparation.
Background
: Herbal Nano Medicines (HNMs) are nano-sized medicine containing herbal drugs as extracts, enriched fractions or biomarker constituents. HNMs have certain advantages because of their increased bioavailability and reduced toxicities. There are very few literature reports that address the common challenges of herbal nanoformulations, such as selecting the type/class of nanoformulation for an extract or a phytochemical, selection and optimisation of preparation method and physicochemical parameters. Although researchers have shown more interest in this field in the last decade, there is still an urgent need for systematic analysis of HNMs.
Purpose
: This review aims to provide the recent advancement in various herbal nanomedicines like polymeric herbal nanoparticles, solid lipid nanoparticles, phytosomes, nano-micelles, self-nano emulsifying drug delivery system, nanofibers, liposomes, dendrimers, ethosomes, nanoemulsion, nanosuspension, and carbon nanotube; their evaluation parameters, challenges, and opportunities. Additionally, regulatory aspects and future perspectives of herbal nanomedicines are also being covered to some extent.
Methods
: The scientific data provided in this review article are retrieved by a thorough analysis of numerous research and review articles, textbooks, and patents searched using the electronic search tools like Sci-Finder, ScienceDirect, PubMed, Elsevier, Google Scholar, ACS, Medline Plus and Web of Science.
Results
: In this review, the authors suggested the suitability of nanoformulation for a particular type of extracts or enriched fraction of phytoconstituents based on their solubility and permeability profile (similar to the BCS class of drugs). This review focuses on different strategies for optimising preparation methods for various HNMs to ensure reproducibility in context with all the physicochemical parameters like particle size, surface area, zeta potential, polydispersity index, entrapment efficiency, drug loading, and drug release, along with the consistent therapeutic index.
Conclusion
: A combination of herbal medicine with nanotechnology can be an essential tool for the advancement of herbal medicine research with enhanced bioavailability and fewer toxicities. Despite the challenges related to traditional medicine's safe and effective use, there is huge scope for nanotechnology-based herbal medicines. Overall, it is well stabilized that herbal nanomedicines are safer, have higher bioavailability, and have enhanced therapeutic value than conventional herbal and synthetic drugs.
Pollen is an excellent natural substance that plays an essential role in the reproduction of plants. In this review, we explain the structure, compositions, and characteristics of pollens. We consider pollen as a multifunctional tool that can be used in therapeutic/diagnostic systems. This microcapsule can be used in the forms of the hollow microcapsule, microgel, and composite, and also can be a tool for the synthesis of micro/nanostructures in various medical applications and used for the production of genetically modified plants that affect human health. In addition, we investigate the capability of this multifunctional tool in the immune system targeting that acts as an immunomodulator. In all applications and capabilities, we explain the potential of using nanostructures as parts of these systems and as auxiliary tools for promoting the applications of pollen. It is expected that soon, with the help of pollen-based therapeutic/diagnostic systems with the ability to immune system targeting, we will achieve effective and targeted therapeutic systems for the treatment of inflammatory and autoimmune diseases. In this paper, we suggest some ideas that may be a new step for future researches.
In angiosperms, mature pollen is wrapped by a pollen wall, which is important for maintaining pollen structure and function. Pollen walls provide protection from various environmental stresses and preserve pollen germination and pollen tube growth. The pollen wall structure has been described since pollen ultrastructure investigations began in the 1960s. Pollen walls, which are the most intricate cell walls in plants, are composed of two layers: the exine layer and intine layer. Pollen wall formation is a complex process that occurs via a series of biological events that involve a large number of genes. In recent years, many reports have described the molecular mechanisms of pollen exine development. The formation process includes the development of the callose wall, the wavy morphology of primexine, the biosynthesis and transport of sporopollenin in the tapetum, and the deposition of the pollen coat. The formation mechanism of the intine layer is different from that of the exine layer. However, few studies have focused on the regulatory mechanisms of intine development. The primary component of the intine layer is pectin, which plays an essential role in the polar growth of pollen tubes. Demethylesterified pectin is mainly distributed in the shank region of the pollen tube, which can maintain the hardness of the pollen tube wall. Methylesterified pectin is mainly located in the top region, which is beneficial for improving the plasticity of the pollen tube top. In this review, we summarize the developmental process of the anther, pollen and pollen wall in Arabidopsis; furthermore, we describe the research progress on the pollen wall formation pattern and its molecular mechanisms in detail.
There are multiple obstacles for the storage and digestion of orally administered bioactive macromolecules. This study developed a low-cost and sustained-release delivery system (sporopollenin exine capsules with zein/tannic acid modification) of proteins with excellent storage stability, and at the same time provided insights into the sustained-release mechanism through exploring the interaction between zein and tannic acid (TA). β-Galactosidase (β-Gal) was utilized as a model protein and loaded into sporopollenin exine capsules (SECs), which were then coated with the zein/TA system. Under the optimized zein/TA conditions, the zein/TA system showed better performance than the zein alone system in the sustained release of β-Gal, with the residual activity of about 70.26% after 24 h of simulated digestion. Evaluation of the storage stability demonstrated a β-Gal residual activity of nearly 90% for 28 days at 25 °C. Additionally, FTIR analysis demonstrated that the stability of the zein/TA system depends on both hydrogen bonding and certain covalent bonding through the Schiff-base reaction, and the sustained release is regulated by the bonding strength.
Pollen grains of 92 Bougainvillea genotypes were examined using a light microscope (LM) and scanning electron microscope (SEM) to identify taxonomic characteristics and the relationship between pollen morphology and germination capacity. The shapes of fresh pollen grains of Bougainvillea genotypes are spheroidal to prolate-spheroidal or suboblate after infolding. The sexine of Bougainvillea pollen grains consists of columellae and a reticulate cristatum, with or without microechini. The distribution pattern of the tectum microechini is uniform on the pollen grains within each genotype, yet it is variable among the different genotypes. Pollen with a smooth reticulate cristatum was observed in the genotypes of B. peruviana, while pollen with muri covering the cristatum were found in the genotypes of B. glabra and B. spectabilis. The pollen grains of each Bougainvillea germplasm have a wide range of diameters. The mean diameter of the pollen grains of the diploid genotypes ranged from 22.2 to 32.1 μm, while that of the polyploid genotypes ranged from 26.7 to 40.4 μm. The germinated pollen grains were observed in the diploid and tetraploid genotypes, the pollen germination rate of which was commonly less than 20 %. The size of germinated pollen grains was significantly larger than that of the silent ones, which indicated that the nonuniform distribution of grain size is a key reason for the low germination capacity of Bougainvillea pollen.
Palmitic acid-modified bovine serum albumin (PAB) was synthetized and found to own remarkable scavenger receptor-A (SR-A) targeting ability in vitro and in vivo, through which activated macrophages took up PAB nanoparticles (PAB NPs) 9.10 times more than bovine serum albumin nanoparticles (BSA NPs) and PAB NPs could delivery anti-inflammatory drugs celastrol (CLT) to inflamed tissues more effectively than BSA NPs. Compared with chondroitin sulfate modified BSA NPs targeting activated macrophages via CD44, PAB NPs show a more prominent targeting effect whether in vivo or in vitro. And PAB also demonstrated excellent biosafety compared to maleylated BSA, a known SR-A ligand that was lethal in our study. Furthermore, in adjuvant-induced arthritis rats, CLT-PAB NPs significantly improved disease pathology at a lower CLT dose with high safety, compared with CLT-BSA NPs. In addition, compared with the existing ligands with SR-A targeting due to strong electronegativity, the enhanced electronegativity and introduced PA are both important for the SR-A targeting effect of PAB. Therefore, PAB provides a novel direction for the treatment of rheumatoid arthritis and design of new ligands of SR-A.
Protein-gold nanoparticle (AuNP) bioconjugates have many potential applications in nanomedicine. A thorough understanding of the interaction between the protein and AuNP is critical to engineering these functional bioconjugates with desirable properties. In this work, we investigate the role of free thiols presented by the protein on the stability of the protein-AuNP conjugate. Human serum albumin (HSA) was modified with 2-iminothiolane (Traut’s reagent) to introduce additional thiols onto the protein surface, and three variants of HSA were synthesized to present 1, 5, and 20 free thiols by controlling the molar excess of the chemical modifier. Protein exchange studies on AuNPs were conducted using these HSA species and an IgG antibody which exhibited 10 free thiols. Antibody-AuNP conjugates were synthesized, purified, and dispersed in solutions containing each of the HSA species. No protein exchange was detected with the HSA or modified HSA containing 5 thiols; however, 85% of the antibody was displaced on the AuNP surface by the extensively thiolated HSA presenting 20 free thiols. Furthermore, the impact of the protein adsorption sequence was probed in which each of the HSA species were pre-adsorbed onto the AuNP and dispersed in a solution of antibody. The antibody fully displaced the HSA with a single thiol from the AuNP within 3 h, required 24 h to completely displace the modified HSA containing 5 thiols, and was unable to displace the modified HSA containing 20 thiols. These results indicate that the number of Au-S interactions governs the binding interaction between the protein and AuNP. This work provides further insight into the protein-AuNP binding mechanism and identifies important design principles for engineered proteins to optimize bioconjugates.
In recent years the use of natural antioxidants in foodstuffs and personal care products has become increasingly important for consumers and therefore manufacturers. In this work, sporopollenin exine capsules (SpECs), extracted from spores of the common club moss Lycopodium clavatum L, have been shown to protect an ω-3 oil from oxidation caused by natural light or accelerated oxidation with UV irradiation. The mechanism of action has been shown to be principally by free radical quenching as opposed to light shielding, supported by evidence of similarity in levels of protection when the ratio of SpECs to oil was 0.2 % w/v compared with 50 % w/w. The antioxidant effect is not materially altered by the extraction process from the raw material and is clearly an inherent property of the sporopollenin contained in the spores of L. clavatum due to the accessible phenolic groups on the surface on the SpECs. These results provide promising evidence that SpECs could be useful as a bio-sourced antioxidant for protecting ω-3 oils and related oxidation-prone molecules.
Metallic nanoparticulates (MNPs) are metal particulate of nanodimensions (such as gold NPs, silver NPs, and iron oxide NPs) that have been attracting the scientist over a century in various fields and now widely exploited for drug delivery and diagnostic applications. These nanostructured materials can be synthesized, and their surface modified/functionalized with different functional groups allow them to conjugate with moieties like therapeutics, diagnostics, and ligands. The various physicochemical properties, advantages, disadvantages, as well as characteristics of the metal nanoparticles, are comprehensively discussed, and insight into the site-specific drug targeting strategies for the management of chronic disorders. This chapter provides the detailed information on the synthesis of MNPs by various methods and characterization, with main emphasis on gene and drug delivery perspectives along with toxicity apprehensions. Present chapter also deals with the interactions of tailored MNPs and biological cells, factors affecting the cellular uptake and the intracellular destiny of MNPs, and also degradation of MNPs and its impact on nanotoxicity based on various literatures.
Palynology (Gr.palynos, dust) is the study of spores and pollen grains. Spores and pollen grains have a number of morphological and ultrastructural features. These palyno-logical features have provided a wealth of characters that have been important in inferring phylogenetic relationships of plants. In addition, the features of spores and pollen grains can often be used to identify a particular plant taxon. For this reason, palynological studies are used extensively to examine the fossil record, a field called paleo-palynology. The identity, density, and frequency of pollen grains at a particular stratigraphic level can give information as to the plant species present at that time and place. Paleo-palynolgical studies are thus used to determine plant community structure and to gauge, by extrapolation over time, shifts in climate.
The sporopollenin exine capsules (SECs) have recently attracted the attention of biological applications. The stability of SECs in human fluids is important issue to develop the controllable methods for the drug delivery system. Here, we analyzed the human plasma-triggered degradation of three species of SECs, i.e., camellia (Camellia sinensis L.), cattail (Typha angustifolia L.), and dandelion (Taraxacum officinale L.), regarding the physical and chemical aspects. The field emission scanning electron microscopy (FESEM) images showed no significant changes in the surface morphology of the SECs as increasing incubation time in human plasma, but we observed the increase of the rupture ratio by dynamic image particle analysis (DIPA). Also, Fourier-transform infrared spectroscopy (FTIR) combined with principal component analysis (PCA) addressed the chemical degradation in a species-specific manner. Specifically, the OH groups of camellia SECs, COC groups of cattail SECs, and CO groups of dandelion SECs showed significant changes.