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1 Synthesis of PEI polymers, (a) b-PEI synthesis by ring opening polymerization of aziridine, and (b) l-PEI synthesis by acid-catalyzed hydrolysis of poly(2-ethyl-2-oxazolin).
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Polyethyleneimine (PEI) is a cationic polymer used as a gold standard in non-viral gene delivery. The extraordinary cationic charge and buffering capacity of the PEI has been beneficial for complexation with nucleic acids (DNA/RNA) and endosomal/lysosomal release via the so-called “proton-sponge” effect. However, there have been serious concerns re...
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Highly efficient and selective chemical reactions are desired. For small molecule chemistry, the reaction rate can be varied by changing the concentration, temperature, and solvent used. In contrast for large biomolecules, the reaction rate is difficult to modify by adjusting these variables because stringent biocompatible reaction conditions are r...
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... Hence, modification of PEI-based vector played an important role by improving transfection efficiency and reducing toxicity. [29][30][31] For example, Weiping Wang et al. studied about simultaneous delivery of miR21a and Adriamycin by hyaluronic acid-PEI coated gold nanoparticles, demonstrating a synergistic effect of miR21a and Adriamycin against drug resistance in HepG2 cell line. In addition, they showed that miR21a not only had a significant role in tumor growth inhibition but also increased the sensitivity of cancer cells against Adriamycin. ...
Over‐expression of miR21 plays an important role in several cancers by promoting cancer cell proliferation, migration, invasion, and metastasis. Here, we attempted to prepare a beta cyclodextrin‐polyethyleneimine‐graphene quantum dot (βCD‐PEI‐GQD) nanocarrier for cellular delivery of miR21a. For this purpose, tosylated‐βCD and GQD were conjugated to branched PEI. The product was characterized by FTIR, ¹H‐NMR, and fluorescence spectroscopy. The morphology, particle size distribution, and ζ‐potential of miR21a were examined by TEM and DLS following overnight incubation with βCD‐PEI‐GQD in aqueous media. The miR21 silencing was measured by stem‐loop RT‐PCR in HepG2 human hepatoma cell line. Cellular uptake and cell toxicity assays were determined by fluorescence microscopy and Trypan blue staining method, respectively. The formation of miR21a/CD‐PEI‐GQD Nanoplex with a decreased average size of 114 nm and a ζ‐potential (+36.1 mV) lower than CD‐PEI‐GQD nanocarrier by adding miR21a was confirmed at optimum C/P ratio =8.7. RT‐PCR revealed that miR21a/βCD‐PEI‐GQD Nanoplex significantly downregulated miR21 expression levels effectively. Overall, miR21a delivery using CD‐PEI‐GQD is presented as a novel trackable nanocarrier for cancer therapy.
... It has been proved that PEI is an effective doping agent for various organic and inorganic semiconducting materials, such as fullerene derivative (PCBM) (Dong et al., 2016), poly(benzimidazobenzophenanthroline) (BBL) (Yang et al., 2021), naphthalene diimide derivative (P(NDI2OD-T2)) (Long et al., 2017), polythiophene derivatives (PDBTAZ, PPzDPDP-BT, PDBPyBT, and PDQT) (Sun et al., 2015), carbon nanotubes (Rdest and Janas, 2021), graphite oxide (Tadjenant et al., 2020), and MoS 2 (Hong et al., 2017). In addition, the cationic polyelectrolyte also helps to improve the stability of reduced products via physical encapsulation and strong electrostatic attraction (Remant Bahadur and Uludağ, 2016). However, there is as yet no report on the doping of PEI on unsubstituted PDI or on the effect of PEI in suppressing the aggregation and stabilization of PDI radical anions. ...
N-doping of perylene diimides (PDIs) to create stable radical anions is significant for harvesting photothermal energy due to their intensive absorption in the near-infrared (NIR) region and non-fluorescence. In this work, a facile and straightforward method has been developed to control the doping of perylene diimide to create radical anions using organic polymer polyethyleneimine (PEI) as a dopant. It was demonstrated that PEI is an effective polymer-reducing agent for the n-doping of PDI toward the controllable generation of radical anions. In addition to the doping process, PEI could suppress the self-assembly aggregation and improve the stability of PDI radical anions. Tunable NIR photothermal conversion efficiency (maximum 47.9%) was also obtained from the radical-anion-rich PDI-PEI composites. This research provides a new strategy to tune the doping level of unsubstituted semiconductor molecules for varying yields of radical anions, suppressing aggregation, improving stability, and obtaining the highest radical anion-based performance.
... Polymeric-and lipidoic-based non-viral siRNA delivery systems rely on the complexation of the negatively-charged oligonucleotide sequence with a positively-charged counter-ion for efficient encapsulation, and can also enhance endosomal escape of siRNA [34,35]. Polyethyleneimine (PEI) and its derivatives are widely used as a counter-ion in polymeric NPs formulations, and in commercial transfection reagents [36][37][38]. However, PEI is toxic to various cells, and may cause severe toxicity in vivo [39][40][41][42][43]. Extensive studies are performed to generate safe and effective proprietary counter-ions [33,[44][45][46][47][48][49][50][51][52][53], and positivelycharged peptides have gained considerable interest as alternative counter-ions [54]. ...
Pancreatic ductal adenocarcinoma (PDAC) is among the leading causes of cancer-related death, and it is highly resistant to therapy owing to its unique extracellular matrix. VAV1 protein, overexpressed in several cancer diseases including pancreatic cancer (PC), increases tumor proliferation and enhances metastases formation, which are associated with decreased survival. We hypothesized that an additive anti-tumor effect could be obtained by co-encapsulating in PLGA nanoparticles (NPs), the negatively charged siRNA against VAV1 (siVAV1) with the positively charged anti-tumor LL37 peptide, as a counter-ion. Several types of NPs were formulated and were characterized for their physicochemical properties, cellular internalization, and bioactivity in vitro. NPs' biodistribution, toxicity, and bioactivity were examined in a mice PDAC model. An optimal siVAV1 formulation (siVAV1-LL37 NPs) was characterized with desirable physicochemical properties in terms of nano-size, low polydispersity index (PDI), neutral surface charge, high siVAV1 encapsulation efficiency, spherical shape, and long-term shelf-life stability. Cell assays demonstrated rapid engulfment by PC cells, a specific and significant dose-dependent proliferation inhibition, as well as knockdown of VAV1 mRNA levels and migration inhibition in VAV1+ cells. Treatment with siVAV1-LL37 NPs in the mice PDAC model revealed marked accumulation of NPs in the liver and in the tumor, resulting in an increased survival rate following suppression of tumor growth and metastases, mediated via the knockdown of both VAV1 mRNA and protein levels. This proof-of-concept study validates our hypothesis of an additive effect in the treatment of PC facilitated by co-encapsulating siVAV1 in NPs with LL37 serving a dual role as a counter ion as well as an anti-tumor agent.
... PEI-modified NPs bind with and condense DNA to form spherical structures, which were fused with the endosome and elicited the "proton sponge effect" to escape endosomal degradation [210]. Several studies have emphasized on the application of this polymer in gene therapy [211][212][213]. In 2015, PEI was utilized for delivering Cas9 and gRNA for the first time, leading to the knockout of the Ptch1 gene in the cerebellum of newborn mice [214]. ...
Inherited Retinal Diseases (IRDs) are considered one of the leading causes of blindness worldwide. However, the majority of them still lack a safe and effective treatment due to their complexity and genetic heterogeneity. Recently, gene therapy is gaining importance as an efficient strategy to address IRDs which were previously considered incurable. The development of the clustered regularly-interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) system has strongly empowered the field of gene therapy. However, successful gene modifications rely on the efficient delivery of CRISPR-Cas9 components into the complex three-dimensional (3D) architecture of the human retinal tissue. Intriguing findings in the field of nanoparticles (NPs) meet all the criteria required for CRISPR-Cas9 delivery and have made a great contribution toward its therapeutic applications. In addition, exploiting induced pluripotent stem cell (iPSC) technology and in vitro 3D retinal organoids paved the way for prospective clinical trials of the CRISPR-Cas9 system in treating IRDs. This review highlights important advances in NP-based gene therapy, the CRISPR-Cas9 system, and iPSC-derived retinal organoids with a focus on IRDs. Collectively, these studies establish a multidisciplinary approach by integrating nanomedicine and stem cell technologies and demonstrate the utility of retina organoids in developing effective therapies for IRDs.
... Otherwise, PEI is a positively charged synthetic polymer widely used in the delivery of different genetic materials, which, beside the protection following administration, is also capable of selectively delivering and releasing the loaded bioactives inside the cytoplasm, improving the therapeutic activity of the system [47]. Containing a particular arrangement of amino groups along the backbone chain, PEI has an extraordinary cationic charge density (at reduced pH values) and buffering capacity, which are postulated to be underlying factors in its complexation abilities with nucleic acids (DNA/RNA) and endosomal/lysosomal release via the "proton-sponge" effect [48,49]. The formulation of PEI-based vectors for gene therapy drug delivery, along with their ability to promote gene transfection in vitro and in vivo, was pioneered by Boussif and co-workers in 1995 [50]. ...
Gene-based therapy represents the latest advancement in medical biotechnology. The principle behind this innovative approach is to introduce genetic material into specific cells and tissues to stimulate or inhibit key signaling pathways. Although enormous progress has been achieved in the field of gene-based therapy, challenges connected to some physiological impediments (e.g., low stability or the inability to pass the cell membrane and to transport to the desired intracellular compartments) still obstruct the exploitation of its full potential in clinical practices. The integration of gene delivery technologies with electrospun fibrous architectures represents a potent strategy that may tackle the problems of stability and local gene delivery, being capable to promote a controlled and proficient release and expression of therapeutic genes in the targeted cells, improving the therapeutic outcomes. This review aims to outline the impact of electrospun-fibrous-architecture-mediated gene therapy drug delivery, and it emphatically discusses the latest advancements in their formulation and the therapeutic outcomes of these systems in different fields of regenerative medicine, along with the main challenges faced towards the translation of promising academic results into tangible products with clinical application.
... Polyelectrolytes have great potential in nanomedicine, 5,18 however their clinical development has lagged behind lipid nanoparticles (LNPs) due to the additional challenges relating to their dispersity, clearance, and degradation. 19,20 Amongst polymeric delivery systems for nucleic acids, polyethyleneimine (PEI) 21,22 and poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) 23 are some of the most widely studied systems, with PEI representing the 'gold standard' for polymer transfection. These polymeric materials bind to DNA through electrostatic interactions between the basic amine groups within their structure (which become cationic under physiological conditions) and the negatively charged phosphate backbone of the nucleic acid, forming complexes known as 'polyplexes' that are up to several hundred nm in size. ...
We describe the development of a modular, functionalizable platform for biocompatible core-shell block copolymer nanofibers of controlled length (22 nm-1.3 μm) and low dispersity produced via living crystallization-driven self-assembly (CDSA). The nanofibers possessed a crystalline poly(fluorenetrimethylenecarbonate) (PFTMC) core and a basic poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) corona. We demonstrate that the coronal chain terminus can be easily modified to incorporate imaging agents such as BODIPY dyes, and targeting groups such as folic acid (FA). Segmented and random block comicelle nanofibers with spatially defined or mixed coronal terminal groups provided further opportunities for tailoring nanofiber surface chemistry. The PDMAEMA corona was shown to be both pH- and thermo-responsive. Nanospheres were also produced by suppressing crystallization of the PFTMC core during self-assembly and these facilitated studies into the effects of particle morphology. In vitro studies on the enzymatic degradation of PFTMC16-b-PDMAEMA131 nanofibers and nanospheres using lipase revealed that short nanofibers degraded over three times slower than nanospheres. The cytotoxicity of PFTMC16-b-PDMAEMA131 nanofibers and nanospheres was compared to PDMAEMA homopolymer and branched polyethyleneimine using WI-38 and HeLa cells and appeared to be primarily influenced by surface chemistry, with particle morphology a secondary factor. These results lay the groundwork for the future development of precision polymer nanofibers that may find use in several applications, from the delivery of nucleic acids into cells, to uses as lubricants or as surface coatings. In particular, this system may enable fundamental studies on the effects of particle morphology on nucleic acid delivery.
... In addition to chemotherapeutic drugs, antitumor gene drugs (including DNA and RNA), can also be encapsulated into such supramolecular hydrogel. As gene drugs are negatively charged, cationic polymers or polycations such as polyethyleneimine (PEI) [105], poly (L-lysine) (PLL) [106], polyamidoamine (PAMAM) den- drimers [107], and poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) [108] form particulate complexes with DNA or RNA producing polyplexes. To fabricate CD-based supramolecular hydrogel, above mentioned cationic polymers or polycations usually are modified with PEG. ...
Cyclodextrin (CD) is one of the most versatile substances produced by nature and can form supramolecular hydrogels with polymers or small molecules based on non-covalent interactions such as host–guest interaction and hydrogen bonding. CD-based host–guest supramolecular hydrogels have a widespread application in the field of local drug delivery due to their unique properties, such as excellent biocompatibility, shear-thinning nature, and stimuli responsiveness. In this review, we briefly introduce the formation of supramolecular hydrogels with different types of CD (α, β, and γ-CD) and in vitro physicochemical characteristics of these hydrogels. We also describe CD-based host–guest supramolecular hydrogels application in local drug delivery, ranging from intra-tumoral/peritumoral, subcutaneous, intra-articular, bone defect site, intramyocardial and ocular administration to transdermal and intra-renal administration. In addition, this review discusses the challenges and future directions about the clinical translation of CD-based host–guest supramolecular hydrogels.
... There were attempts to target and deliver therapeutic genes to reverse pathogenic chondrocytes back to normal using non-viral or viral vectors as carriers [4]. The disadvantages of the non-viral vectors include toxicity and instability [5], while the viral vectors have been widely employed as promising tools for gene therapy. Several gene therapies in clinical trials in humans were mediated by viral vectors, including lentivirus, adenovirus, and adeno-associated virus (AAV) [6]. ...
Osteoarthritis (OA) is a degenerative joint disease characterized by progressive deterioration and loss of articular cartilage. There is currently no treatment to reverse the onset of OA. Thus, we developed a targeted delivery strategy to transfer genes into primary human chondrocytes as a proof-of-concept study. We displayed a chondrocyte-affinity peptide (CAP) on the pIII minor coat protein of the M13 filamentous bacteriophage (phage)-based particle carrying a mammalian transgene cassette under cytomegalovirus CMV promoter and inverted terminal repeats (ITRs) cis elements of adeno-associated virus serotype 2 (AAV-2). Primary human articular chondrocytes (HACs) were used as an in vitro model, and the selectivity and binding properties of the CAP ligand in relation to the pathogenic conditions of HACs were characterized. We found that the CAP ligand is highly selective toward pathogenic HACs. Furthermore, the stability, cytotoxicity, and gene delivery efficacy of the CAP-displaying phage (CAP.Phage) were evaluated. We found that the phage particle is stable under a wide range of temperatures and pH values, while showing no cytotoxicity to HACs. Importantly, the CAP.Phage particle, carrying a secreted luciferase (Lucia) reporter gene, efficiently and selectively delivered transgene expression to HACs. In summary, it was found that the CAP ligand preferably binds to pathogenic chondrocytes, and the CAP.Phage particle successfully targets and delivers transgene to HACs.
... However, additional improvements are necessary to produce viable carriers for clinical applications. 1,2 Poly(ethyleneimine) (PEI), one of the most commonly used polycations, is considered as the "gold standard" in nonviral gene delivery due to the high density of protonable amine groups, which provides PEI with remarkable transfection capabilities 3 and sensitivity to the pH, a desired characteristic for the fabrication of smart carriers. 4 PEI can be synthesized in two main structures, namely, the linear form (IPEI), which only contains secondary amines, and the branched form (bPEI), which contains primary, secondary, and tertiary amino groups. ...
Poly(ethyleneimine) (PEI) is one of the most widely used cationic polymers for gene delivery. The high molecular weight polymer, which is commercially available, is highly efficient but also very cytotoxic. The reduction in charge density by using nonlinear architectures based on low molecular weight (LMW) PEI is a promising approach to produce safer DNA-vectors. Herein, a group of cationic graft copolymers with different composition containing a hydrophobic biocompatible backbone and LMW linear PEI (lPEI) grafts obtained by ring opening polymerization and click chemistry was studied. The self-assembly and DNA complexation behavior of these materials was analyzed by the gel retardation assay, zeta potential measurements, and dynamic light scattering. The copolymers formed positively charged particles in water with average sizes between 270 and 377 nm. After they were added to DNA in serum-free medium, these particles acquired negative/near-neutral charges and increased in size depending on the N/P ratio. All copolymers showed reduced cytotoxicity compared to the 25 kDa lPEI used as reference, but the transfection efficiency was reduced. This result suggested that the cationic segments were too small to fully condense the DNA and promote cellular uptake, even with the use of several grafts and the introduction of hydrophobic domains. The trends found in this research showed that a higher degree of hydrophobicity and a higher grafting density can enhance the interaction between the copolymers and DNA. These trends could direct further structural modifications in the search for effective and safe vectors based on this polycation.
... For the successful delivery of siRNA into K562 cells, we used lipidmodified 1.2 kDa PEI polymers as they exhibit inherent buffering capacity that helps in endosomal release of the nucleic acid via "protonsponge " effect [50] . Multiple lipid-modified PEIs and corresponding disulfide (-ss-modified) linked counterparts were screened for this purpose. ...
Uncontrolled proliferation of the myeloid cells due to BCR-ABL fusion has been successfully treated with tyrosine kinase inhibitors (TKIs), which improved the survival rate of Chronic Myeloid Leukemia (CML) patients. However, due to interactions of CML cells with bone marrow microenvironment, sub-populations of CML cells could become resistant to TKI treatment. Since integrins are major cell surface molecules involved in such interactions, the potential of silencing integrin-β1 on CML cell line K562 cells was explored using short interfering RNA (siRNA) delivered through lipid-modified polyethyleneimine (PEI) polymers. Reduction of integrin-β1 in K562 cells decreased cell adhesion towards human bone marrow stromal cells and to fibronectin, a major extracellular matrix protein for which integrin-β1 is a primary receptor. Interaction of K562 cells with fibronectin decreased the sensitivity of the cells to BCR-ABL siRNA treatment, but a combinational treatment with integrin-β1 and BCR-ABL siRNAs significantly reduced colony forming ability of the cells. Moreover, integrin-β1 silencing enhanced the detachment of K562 cells from hBMSC samples (2 out of 4 samples), which could make them more susceptible to TKIs. Therefore, the polymeric-siRNA delivery targeting integrin-β1 could be beneficial to reduce interactions with bone marrow microenvironment, aiding in the response of CML cells to therapeutic treatment.
