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The purpose of the present investigation was to prepare pH-sensitive hydrogels from photo-crosslinked poly(ethylene glycol) diacrylate (PEG-DA). Rutile titanium dioxide (TiO2) was employed to modify the PEG-DA hydrogels. The rutile titanium dioxide (TiO2) nanoparticles were prepared by direct oxidation of titanium in the presence of polyethylene gl...
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... Nanokristalin metal ve alaşımlarının üretiminde kullanılan ilk yöntem olan gaz yoğunlaştırma tekniği aşağıdan yukarıya yaklaşımıyla çalışmaktadır. Kimyasal buhar kaplama, kimyasal buhar yoğunlaştırma, elektroeğirme, sol jel ve sprey piroliz yöntemleri de bu yaklaşımın en çok bilinen diğer uygulamalarıdır [8][9][10][11][12]. Nanoakışkanlar, nanopartiküllerin baz akışkan içinde dağıtılmasıyla hazırlanır. ...
Ülkemizde ve dünyada teknolojinin gelişmesi ile enerji ihtiyacı her geçen gün artmaktadır. Bu sebeple, ısı enerjisinin verimli kullanılması çok önemlidir. Az miktarlarda nanomalzeme kullanılarak oluşturulan nanoakışkan sistemler üstün termofiziksel özellikleri nedeni ile ısı transferini ve enerji verimliliğini artırmaktadırlar. Bu sebeple nanoakışkanların üretilmesi ve termofiziksel özelliklerinin incelenmesi önem arz etmektedir. Bu çalışmada, yüksek sıcaklıkta oksidasyon yöntemi ile Polietilen glikol (PEG) ve Alginat katkı maddeleri varlığında titanium dioksit (TiO2) nanopartiküllerinin sentezlenmesi ve sentezlenen nano titanyum dioksitlerden farklı konsantrasyonlarda su bazlı nanoakışkan elde edilmesi amaçlanmıştır. Ayrıca, yüzey aktif madde türünün ve konsantrasyonunun nanoakışkanın stabilizasyonuna etkisini incelemek amacı ile farklı konsantrasyonlarda sodyum dodesil sülfat (SDS) ve arap zamkı kullanılmıştır. Sentezlenen TiO2 partiküllerinin karakterizasyonu için XRD, SEM, FTIR ve BET ölçümlerinden yararlanılmıştır. Nanoakışkanların önemli termofiziksel özelliklerinden stabilizasyonu ve yoğunluğu da bu çalışma kapsamında ölçülmüştür. Gerçekleştirilen deneysel çalışmalar sonucunda, Alginat katkı maddesi ile üretilen TiO2 nanopartiküllerinin, nanoakışkanın stabilizasyonunda PEG katkı maddesi ile üretilene göre daha başarılı olduğu görülmüştür.
... Where, M ∞ is designated as the maximum insulin fraction that can be released in maximum time and rate constant is signified by "K" [38]. ...
... From FA1-FA3 hydrogel formulations (Fig. 2a), the maximum q value at pH 7.4 was decreased from 30 to 20.77 with an increase in cross-linker MBA contents. As the value of cross-link density increased, resultant dense nexus restricted entrance of swelling media, hence causing less swelling [38]. A p-value <0.01 showed a significant impact of MBA on the hydrogel swelling ratio. ...
... The findings demonstrate that Donepezil HCl is released in a regulated manner. [87] Poly(ethylene gly-col) diacrylate (PEG-DA). ...
... Eq. 14 M t /M ∞ represents the Capecitabine release quantity at time t, k is the rate constant, and exponent n highlights the mode of CBE release [52]. ...
In current work, quince seed mucilage and β-Cyclodextrin based pH regulated hydrogels were developed using aqueous free radical polymerization to sustain Capecitabine release patterns and to overcome its drawbacks, such as high dose frequency, short half-life, and low bioavailability. Developed networks were subjected to thermal analysis, Fourier transforms infrared spectroscopy, powder x-ray diffraction, elemental analysis, scanning electron microscopy, equilibrium swelling, and in-vitro release investigations to assess the network system's stability, complexation, morphology, and pH responsiveness. Thermally stable pH-responsive cross-linked networks were formed. Nanocomposite hydrogels were prepared by incorporating Capecitabine-containing clay into the swollen hydrogels. All the formulations exhibited equilibrium swelling raging from 67.98% to 92.98% at pH 7.4. Optimum Capecitabine loading (88.17%) was noted in the case of hydrogels, while it was 74.27% in nanocomposite hydrogels. Excellent gel content (65.88%-93.56%) was noticed among developed formulations. Elemental analysis ensured the successful incorporation of Capecitabine. Nanocomposite hydrogels released 80.02% longer than hydrogels after 30 hours. NC hydrogels had higher t1/2 (10.57 hours), AUC (121.52 μg.h/ml), and MRT (18.95 hours) than hydrogels in oral pharmacokinetics. These findings imply that the pH-responsive carrier system may improve Capecitabine efficacy and reduce dosing frequency in cancer therapy. Toxicity profiling proved the system's safety, non-toxicity, and biocompatibility.
... Here, M ∞ is the maximum amount of drug release at the maximum time interval, while K is the rate constant [34]. ...
... This is due to increased crosslinking density with increasing MBA contents in hydrogel networks because of more crosslink points created by MBA. That resulted in lesser expansion of hydrogel networks and, hence, decreased swelling [34]. Similarly, in BA4-BA6 hydrogel formulations (Figure 2b), the increase in swelling ratio (29.38-55.55) ...
Oral delivery of insulin has always been a challenging task due to harsh gut environment involving variable pH and peptidase actions. Currently, no Food and Drug Administration (FDA) approved oral insulin formulation is commercially available, only intravenous (IV) or subcutaneous (SC) routes. Therefore, it is really cumbersome for diabetic patients to go through invasive approaches for insulin delivery on daily basis. In the present study, a novel pH-responsive hydrogel nanocomposite (NC) system was developed and optimized for safe oral delivery of insulin. Black seed polysaccharide extract-based hydrogel (BA hydrogel) was formulated by free radical polymerization and loaded with insulin. Blank BA hydrogel was also incorporated with insulin-loaded montmorillonite nanoclay (Ins-Mmt) to form an Ins-Mmt-BA hydrogel NC and compared with the insulin-loaded hydrogel. Swelling, sol-gel analysis and in vitro release studies proved that Ins-Mmt-BA6 hydrogel NC has the best formulation, with 96.17% maximum insulin released in 24 h. Kinetic modeling applied on insulin release data showed the Korsemeyer-Peppas model (R 2 = 0.9637) as the best fit model with a super case II transport mechanism for insulin transport (n > 0.89). Energy Dispersive X-ray (EDX) Spectroscopy, Fourier Transformed Infrared (FTIR) spectroscopy and Powdered X-ray diffraction (PXRD) analysis results also confirmed successful development of a hydrogel NC with no significant denaturation of insulin. Toxicity results confirmed the safety profile and biocompatibility of the developed NC. In vivo studies showed a maximum decrease in blood glucose levels of 52.61% and percentage relative bioavailability (% RBA) of 26.3% for an Ins-Mmt-BA hydrogel NC as compared to BA hydrogels and insulin administered through the SC route.
... PEG hydrogels are also used for 3D cultures with stem cells to evaluate their efficacy in hiPSCs differentiation and the behavior of mMSCs at similar stiffness of myocardial infarction microenvironments in vivo [171,172]. In addition, PEG, by itself or combined with polycaprolactone, has good potential to encapsulate diverse bioactive molecules for lowering complicating factors derived from hydrogels [173,174]. Another increasing application of PEG hydrogels is to encapsulate the bioactive factors to promote cellular functions for 3D cultured cells. Research of de Sousa Araújo E et al. describes synthesis of the in situ chondroitin-sulfate-crosslinked PEG hydrogels through the Diels-Alder click reaction. ...
Hydrogels are crosslinked polymer chains with three-dimensional (3D) network structures, which can absorb relatively large amounts of fluid. Because of the high water content, soft structure, and porosity of hydrogels, they closely resemble living tissues. Research in recent years shows that hydrogels have been applied in various fields, such as agriculture, biomaterials, the food industry, drug delivery, tissue engineering, and regenerative medicine. Along with the underlying technology improvements of hydrogel development, hydrogels can be expected to be applied in more fields. Although not all hydrogels have good biodegradability and biocompatibility, such as synthetic hydrogels (polyvinyl alcohol, polyacrylamide, polyethylene glycol hydrogels, etc.), their biodegradability and biocompatibility can be adjusted by modification of their functional group or incorporation of natural polymers. Hence, scientists are still interested in the biomedical applications of hydrogels due to their creative adjustability for different uses. In this review, we first introduce the basic information of hydrogels, such as structure, classification, and synthesis. Then, we further describe the recent applications of hydrogels in 3D cell cultures, drug delivery, wound dressing, and tissue engineering.
... This behavior, known as the polyelectrolyte effect, stems from the ionization of carboxylic groups [3,4]. Ionization or deprotonation produces negative charges throughout the network, resulting in the confirmation of extended chains and globules to coil transition [5][6][7]. ...
Different combinations of polymers, aspartic acid (ASP), alginic acid (AL), and monomer acrylic acid (AA) were crosslinked in the presence of an initiator ammonium peroxodisulfate (APS) and cross-linker ethylene glycol dimethacrylate (EGDMA) to develop aspartic acid/alginic acid-co-poly(acrylic acid) (ASP/ALPAA) (semi-interpenetrating polymer network (SIPN)) hydrogels by the free radical polymerization technique for the controlled delivery of ibuprofen (IBP). Various studies such as dynamic swelling studies, drug loading, in vitro drug release and sol−gel analysis were carried out for the hydrogels. Higher swelling was observed at higher pH 7.4 as compared to lower pH 1.2, due to the presence of carboxylic groups of polymers and the monomer. Hence, pH-dependent swelling was exhibited by the developed hydrogels which led to a pH-dependent drug release and vice versa. The structural properties of the hydrogels were assessed by FTIR, PXRD, TGA, DSC, and SEM which confirmed the fabrication and stability of the developed structure. FTIR analysis revealed the reaction of both polymers with the monomer during the polymerization process and confirmed the overlapping of the monomer on the backbone of the both polymers. The disappearance of high intense crystalline peaks and the encapsulation of the drug by the hydrogel network was confirmed by PXRD. TGA and DSC showed that the developed hydrogels were thermally more stable than their basic ingredients. Similarly, the surface morphology of the hydrogels was analyzed by SEM and showed a smooth surface with few pores. Conclusively, ASP/ALPAA hydrogels have the potential to deliver IBP for a long period of time in a controlled way.
... In the current study, we investigated the synthesis and utility of PEG-DA and PEG-DA/HEMA hydrogels filled with low concentrations of nanoparticle TiO 2 for the controlled Donepezil HCl. Previous work has shown that addiction of metals, metal oxide nanoparticles such as titanium dioxide into hydrogels develops the antimicrobial properties of hydrogels and mechanical characteristics [28][29]. The swelling degree and release capacities of the hydrogel systems and the influence of the pH medium and type of photoinitator on the release properties were also examined. ...
... Titanium powder was ordered from Alfa Aesar. The complete experimental procedure of TiO 2 synthesis was reported previously in detail [29]. Donepezil HCl was a kind gift by Abdi İbrahim Company. ...
... Thus, synthetic hydrogels need modification with suitable biological components to promote signals of cellular function. On the other hand, synthetic hydrogels such as PEG represent a very good candidate for the encapsulation of various bioactive factors, drugs, and chemicals to avoid complicating systemic factors derived from hydrogels for a more controlled comparison of encapsulated materials [34]. Recently, it has been reported that the combination of arginine-glycine-aspartic acid (RGD) groups or alginate-PEG hydrogel improved the spread and proliferation of fibroblasts and enhanced the osteogenic differentiation of mesenchymal stem cells (MSCs) for 3D cell culture [35]. ...
The process of evaluating the efficacy and toxicity of drugs is important in the production of new drugs to treat diseases. Testing in humans is the most accurate method, but there are technical and ethical limitations. To overcome these limitations, various models have been developed in which responses to various external stimuli can be observed to help guide future trials. In particular, three-dimensional (3D) cell culture has a great advantage in simulating the physical and biological functions of tissues in the human body. This article reviews the biomaterials currently used to improve cellular functions in 3D culture and the contributions of 3D culture to cancer research, stem cell culture and drug and toxicity screening.
In this comprehensive investigation, a novel pH-responsive hydrogel system comprising mimosa seed mucilage (MSM), β-cyclodextrin (β-CD), and methacrylic acid (MAA) was developed via free radical polymerization technique to promote controlled drug delivery. The hydrogel synthesis involved strategic variations in polymer, monomer, and crosslinker content in fine-tuning its drug-release properties. The resultant hydrogel exhibited remarkable pH sensitivity, selectively liberating the model drug (Capecitabine=CAP) under basic conditions while significantly reducing release in an acidic environment. Morphological, thermal, and structural analyses proved that CAP has a porous texture, high stability, and an amorphous nature. In vitro drug release experiments showcased a sustained and controlled release profile. Optimum release (85.33%) results were recorded over 24 hours at pH 7.4 in the case of MMB9. Pharmacokinetic evaluation in healthy male rabbits confirmed bioavailability enhancement and sustained release capabilities. Furthermore, rigorous toxicity evaluations and histopathological analyses ensured the safety and biocompatibility of the hydrogel. This pH-triggered drug delivery system can be a promising carrier system for drugs involving frequent administrations.
