Chitosan-Based Polymeric Nanoparticles as an Efficient Gene Delivery System to Cross Blood Brain Barrier: In Vitro and In Vivo Evaluations.

Significant progress has been made in the field of gene therapy, but effective treatments for brain tumors remain challenging due to their complex nature. Current treatment options have limitations, especially due to their inability to cross the blood-brain barrier (BBB) and precisely target cancer cells. Therefore options that are safer, more effective, and capable of specifically targeting cancer cells are urgently required as alternatives. This current study aimed to develop highly biocompatible natural biopolymeric chitosan nanoparticles (CNPs) as potential gene delivery vehicles that can cross the BBB and serve as gene or drug delivery vehicles for brain disease therapeutics. The efficiency of the CNPs was evaluated via in vitro transfection of Green Fluorescent Protein (GFP)-tagged plasmid in HEK293-293 and brain cancer MG-U87 cell lines, as well as within in vivo mouse models. The CNPs were prepared via a complex coacervation method, resulting in nanoparticles of approximately 260 nm in size. In vitro cytotoxicity analysis revealed that the CNPs had better cell viability (85%) in U87 cells compared to the chemical transfection reagent (CTR) (72%). Moreover, the transfection efficiency of the CNPs was also higher, as indicated by fluorescent emission microscopy (20.56% vs. 17.79%) and fluorescent-activated cell sorting (53% vs. 27%). In vivo assays using Balb/c mice revealed that the CNPs could efficiently cross the BBB, suggesting their potential as efficient gene delivery vehicles for targeted therapies against brain cancers as well as other brain diseases for which the efficient targeting of a therapeutic load to the brain cells has proven to be a real challenge.

Fundamental properties of smart hydrogels for tissue engineering applications: A review.

Tissue engineering is an advanced and potential biomedical approach to treat patients suffering from lost or failed an organ or tissue to repair and regenerate damaged tissues that increase life expectancy. The biopolymers have been used to fabricate smart hydrogels to repair damaged tissue as they imitate the extracellular matrix (ECM) with intricate structural and functional characteristics. These hydrogels offer desired and controllable qualities, such as tunable mechanical stiffness and strength, inherent adaptability and biocompatibility, swellability, and biodegradability, all crucial for tissue engineering. Smart hydrogels provide a superior cellular environment for tissue engineering, enabling the generation of cutting-edge synthetic tissues due to their special qualities, such as stimuli sensitivity and reactivity. Numerous review articles have presented the exceptional potential of hydrogels for various biomedical applications, including drug delivery, regenerative medicine, and tissue engineering. Still, it is essential to write a comprehensive review article on smart hydrogels that successfully addresses the essential challenging issues in tissue engineering. Hence, the recent development on smart hydrogel for state-of-the-art tissue engineering conferred progress, highlighting significant challenges and future perspectives. This review discusses recent advances in smart hydrogels fabricated from biological macromolecules and their use for advanced tissue engineering. It also provides critical insight, emphasizing future research directions and progress in tissue engineering.

Graphene Oxide-Functionalized Bacterial Cellulose-Gelatin Hydrogel with Curcumin Release and Kinetics: In Vitro Biological Evaluation.

Biopolymer-based bioactive hydrogels are excellent wound dressing materials for wound healing applications. They have excellent properties, including hydrophilicity, tunable mechanical and morphological properties, controllable functionality, biodegradability, and desirable biocompatibility. The bioactive hydrogels were fabricated from bacterial cellulose (BC), gelatin, and graphene oxide (GO). The GO-functionalized-BC (GO-f-BC) was synthesized by a hydrothermal method and chemically crosslinked with bacterial cellulose and gelatin using tetraethyl orthosilicate (TEOS) as a crosslinker. The structural, morphological, and wettability properties were studied using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and a universal testing machine (UTM), respectively. The swelling analysis was conducted in different media, and aqueous medium exhibited maximum hydrogel swelling compared to other media. The Franz diffusion method was used to study curcumin (Cur) release (Max = 69.32%, Min = 49.32%), and Cur release kinetics followed the Hixson-Crowell model. Fibroblast (3T3) cell lines were employed to determine the cell viability and proliferation to bioactive hydrogels. Antibacterial activities of bioactive hydrogels were evaluated against infection-causing bacterial strains. Bioactive hydrogels are hemocompatible due to their less than 0.5% hemolysis against fresh human blood. The results show that bioactive hydrogels can be potential wound dressing materials for wound healing applications.

Potential use of iPSCs for disease modeling, drug screening, and cell-based therapy for Alzheimer's disease.

Alzheimer's disease (AD) is a chronic illness marked by increasing cognitive decline and nervous system deterioration. At this time, there is no known medication that will stop the course of Alzheimer's disease; instead, most symptoms are treated. Clinical trial failure rates for new drugs remain high, highlighting the urgent need for improved AD modeling for improving understanding of the underlying pathophysiology of disease and improving drug development. The development of induced pluripotent stem cells (iPSCs) has made it possible to model neurological diseases like AD, giving access to an infinite number of patient-derived cells capable of differentiating neuronal fates. This advance will accelerate Alzheimer's disease research and provide an opportunity to create more accurate patient-specific models of Alzheimer's disease to support pathophysiological research, drug development, and the potential application of stem cell-based therapeutics. This review article provides a complete summary of research done to date on the potential use of iPSCs from AD patients for disease modeling, drug discovery, and cell-based therapeutics. Current technological developments in AD research including 3D modeling, genome editing, gene therapy for AD, and research on familial (FAD) and sporadic (SAD) forms of the disease are discussed. Finally, we outline the issues that need to be elucidated and future directions for iPSC modeling in AD.

Fabrication of amine-functionalized and multi-layered PAN-(TiO2)-gelatin nanofibrous wound dressing: In-vitro evaluation.

The development of advanced multifunctional wound dressings remains a major challenge. Herein, a novel multilayer (ML) electrospun nanofibers (NFs) wound dressing based on diethylenetriamine (DETA) functionalized polyacrylonitrile (PAN), TiO2 nanoparticles (NPs) coating (Ct), and bioderived gelatin (Gel) was developed for potential applications in wound healing. The ML PAN-DETA-Ct-Gel membrane was developed by combining electrospinning, chemical functionalization, synthesis, and electrospray techniques, using a layer-by-layer method. The ML PAN-DETA-Ct-Gel membrane is comprised of an outer layer of PAN-DETA as a barrier to external microorganisms and structural support, an interlayer TiO2 NPs (Ct) as antibacterial function, and a contact layer (Gel) to improve biocompatibility and cell viability. The NFs membranes were characterized by scanning electron microscopy (SEM), surface profilometry, BET analysis, and water contact angle techniques to investigate their morphology, surface roughness, porosity, and wettability. The ML PAN-DETA-Ct-Gel wound dressing exhibited good surface roughness, porosity, and better wettability. Cell morphology, proliferation, and viability were determined using fibroblasts (3T3), and antibacterial assays were performed against six pathogens. The ML PAN-DETA-Ct-Gel NFs membrane showed good cell morphology, proliferation, viability, and antibacterial activity compared with other membranes. This new class of ML NFs membranes offers a multifunctional architecture with adequate biocompatibility, cell viability, and antibacterial activity.

Role of Graphene Oxide in Bacterial Cellulose-Gelatin Hydrogels for Wound Dressing Applications.

Biopolymer-based hydrogels have several advantages, including robust mechanical tunability, high biocompatibility, and excellent optical properties. These hydrogels can be ideal wound dressing materials and advantageous to repair and regenerate skin wounds. In this work, we prepared composite hydrogels by blending gelatin and graphene oxide-functionalized bacterial cellulose (GO-f-BC) with tetraethyl orthosilicate (TEOS). The hydrogels were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscope (AFM), and water contact angle analyses to explore functional groups and their interactions, surface morphology, and wetting behavior, respectively. The swelling, biodegradation, and water retention were tested to respond to the biofluid. Maximum swelling was exhibited by GBG-1 (0.01 mg GO amount) in all media (aqueous = 1902.83%, PBS = 1546.63%, and electrolyte = 1367.32%). All hydrogels were hemocompatible, as their hemolysis was less than 0.5%, and blood coagulation time decreased as the hydrogel concentration and GO amount increased under in vitro standard conditions. These hydrogels exhibited unusual antimicrobial activities against Gram-positive and Gram-negative bacterial strains. The cell viability and proliferation were increased with an increased GO amount, and maximum values were found for GBG-4 (0.04 mg GO amount) against fibroblast (3T3) cell lines. The mature and well-adhered cell morphology of 3T3 cells was found for all hydrogel samples. Based on all findings, these hydrogels would be a potential wound dressing skin material for wound healing applications.

Multifunctional Bioactive Scaffolds from ARX-g-(Zn@rGO)-HAp for Bone Tissue Engineering: In Vitro Antibacterial, Antitumor, and Biocompatibility Evaluations.

Advanced biomaterials are required with enhanced antibacterial and anticancer activities to obtain desirable biocompatibility during and after scaffold implantation in tissue engineering. Here, we report the development of a nanosystem by the hydrothermal method using different zinc (Zn) amounts and reduced graphene oxide (GO). Arabinoxylan, the nanosystem (Zn@rGO), and nanohydroxyapatite polymeric nanocomposites ARX-g-(Zn@rGO)/HAp were prepared by the free radical polymerization method, and porous bioactive scaffolds were fabricated via the freeze-drying technique. The structural, morphological, and elemental analyses of the bioactive scaffolds were conducted using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray analysis. The wetting behavior was studied by a water contact meter and swelling in aqueous and phosphate-buffered saline solutions at 37 °C. The degradation was also studied in the phosphate-buffered saline solution at 37 °C. The increase in Zn content increased the pore size, and hydrophobic behavior shifted to hydrophilic (AGZ-1 = 131.40° at 0 s and 120.60° at 10 s to AGZ-1 = 81.30° at 0 s and 69.20° at 10 s) with the increase in contact time. Maximum swelling was observed in deionized water (AGZ-1 = 52.87%, AGZ-4 = 90.20%), followed by phosphate-buffered saline (PBS; AGZ-1 = 44.80%, AGZ-4 = 67.90%) and electrolyte (AGZ-1 = 32.40%, AGZ-4 = 63.47%), and biodegradation in PBS media increased (AGZ-1 = 36.80%, AGZ-4 = 55.92%). Antimicrobial activities against severe infection-causing pathogens and antitumor activity against U87 cell lines showed exceptional results. Cell viability and cell proliferation studies were conducted against preosteoblast cell lines, and increased cell viability and proliferation were observed from AGZ-1 to AGZ-4. Antimicrobial and anticancer activities were enhanced with the increase of Zn content in the Zn@rGO system. The bioactive scaffolds with different formulations could be potential biomaterials to treat and regenerate defected bone tissue.

Bioactive scaffold (sodium alginate)-g-(nHAp@SiO2@GO) for bone tissue engineering.

Globally, people suffering from bone disorders are steadily increasing and bone tissue engineering is an advanced approach to treating fractured and defected bone tissues. In this study, we have prepared polymeric nanocomposite by free-radical polymerization from sodium alginate, hydroxyapatite, and silica with different GO amounts. The porous scaffolds were fabricated using the freeze drying technique. The structural, morphological, mechanical, and wetting investigation was conducted by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, universal tensile machine, and water contact angle characterization techniques. The swelling, biodegradation, and water retention were also studied. The biological studies were performed (cell viability, cell adherence, proliferation, and mineralization) against osteoblast cell lines. Scaffolds have exhibited different pore morphology SAG-1 (pore size = 414.61 ± 56 µm and porosity = 81.45 ± 2.17 %) and SAG-4 (pore size = 195.97 ± 82 µm and porosity = 53.82 ± 2.45 %). They have different mechanical behavior as SAG-1 has the least compression strength and compression modulus 2.14 ± 2.35 and 16.51 ± 1.27 MPa. However, SAG-4 has maximum compression strength and compression modulus 13.67 ± 2.63 and 96.16 ± 1.97 MPa with wetting behavior 80.70° and 58.70°, respectively. Similarly, SAG-1 exhibited the least and SAG-4 presented maximum apatite mineral formation, cell adherence, cell viability, and cell proliferation against mouse pre-osteoblast cell lines. The increased GO amount provides different multifunctional materials with different characteristics. Hence, the fabricated scaffolds could be potential scaffold materials to treat and regenerate fracture bone tissues in bone tissue engineering.

pH-Responsive PVA/BC-f-GO Dressing Materials for Burn and Chronic Wound Healing with Curcumin Release Kinetics.

Polymeric materials have been essential biomaterials to develop hydrogels as wound dressings for sustained drug delivery and chronic wound healing. The microenvironment for wound healing is created by biocompatibility, bioactivity, and physicochemical behavior. Moreover, a bacterial infection often causes the healing process. The bacterial cellulose (BC) was functionalized using graphene oxide (GO) by hydrothermal method to have bacterial cellulose-functionalized-Graphene oxide (BC-f-GO). A simple blending method was used to crosslink BC-f-GO with polyvinyl alcohol (PVA) by tetraethyl orthosilicate (TEOS) as a crosslinker. The structural, morphological, wetting, and mechanical tests were conducted using Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM), water contact angle, and a Universal testing machine (UTM). The release of Silver-sulphadiazine and drug release kinetics were studied at various pH levels and using different mathematical models (zero-order, first-order, Higuchi, Hixson, Korsmeyer-Peppas, and Baker-Lonsdale). The antibacterial properties were conducted against Gram-positive and Gram-negative severe infection-causing pathogens. These composite hydrogels presented potential anticancer activities against the U87 cell line by an increased GO amount. The result findings show that these composite hydrogels have physical-mechanical and inherent antimicrobial properties and controlled drug release, making them an ideal approach for skin wound healing. As a result, these hydrogels were discovered to be an ideal biomaterial for skin wound healing.

Multifunctional Arabinoxylan-functionalized-Graphene Oxide Based Composite Hydrogel for Skin Tissue Engineering.

Wound healing is an important physiological process involving a series of cellular and molecular developments. A multifunctional hydrogel that prevents infection and promotes wound healing has great significance for wound healing applications in biomedical engineering. We have functionalized arabinoxylan and graphene oxide (GO) using the hydrothermal method, through cross-linking GO-arabinoxylan and polyvinyl alcohol (PVA) with tetraethyl orthosilicate (TEOS) to get multifunctional composite hydrogels. These composite hydrogels were characterized by FTIR, SEM, water contact angle, and mechanical testing to determine structural, morphological, wetting, and mechanical behavior, respectively. Swelling and biodegradation were also conducted in different media. The enhanced antibacterial activities were observed against different bacterial strains (E. coli, S. aureus, and P. aeruginosa); anticancer activities and biocompatibility assays were found effective against U-87 and MC3T3-E1 cell lines due to the synergic effect of hydrogels. In vivo activities were conducted using a mouse full-thickness skin model, and accelerated wound healing was found without any major inflammation within 7 days with improved vascularization. From the results, these composite hydrogels might be potential wound dressing materials for biomedical applications.

Sodium alginate-f-GO composite hydrogels for tissue regeneration and antitumor applications.

Biopolymer-based composite hydrogels have attracted tremendous attention for tissue regeneration and antitumor applications. Since sodium alginate is a biopolymer, they offer excellent therapeutic options with long-term drug release and low side effects. To prepare multifunctional composite hydrogels with anticancer and tissue regeneration capabilities, sodium alginate (SA) and graphene oxide (GO) were covalently linked and crosslinked with tetraethyl orthosilicate (TEOS) by the solvothermal method. The structural and morphological results show that the hydrogels exhibit the desired functionality and porosity. The swelling of hydrogels in an aqueous and PBS medium was investigated. SGT-4 had the highest swelling in both aqueous and PBS media. Swelling and biodegradation of the hydrogel were inversely related. The drug release of SGT-4 was determined in different pH media (pH 6.4, 7.4, and 8.4) and the kinetics of drug release was determined according to the Higuchi model (R2 = 0.93587). Antibacterial activities were evaluated against severe infectious agents. Uppsala (U87) and osteoblast (MC3T3-E1) cell lines were used to determine the anticancer and biocompatibility of the composite hydrogels, respectively. These results suggest that the composite hydrogels could be used as potential biomaterials for tissue regeneration and antitumor applications.

Electroactive polymeric nanocomposite BC-g-(Fe3O4/GO) materials for bone tissue engineering: in vitro evaluations.

Tissue engineering is a cutting-edge approach for using advanced biomaterials to treat defective bone to get desired clinical results. In bone tissue engineering, the scaffolds must have the desired physicochemical and biomechanical natural properties in order to regenerate complicated defective bone. For the first time, polymeric nanocomposite material was developed using cellulose and co-dispersed nanosystem (Fe3O4/GO) by free radical polymerization to fabricate porous polymeric scaffolds via freeze drying. Various characterizations techniques, such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM)/energy dispersive X-ray (EDX), and universal testing machine (UTM) were used to investigate structural, morphological, and mechanical properties. Swelling, biodegradation, and wetting analysis were also performed to evaluate their physicochemical behavior. Intercalation of Fe3O4 nanoparticles into GO-sheets promoted their dispersion into the polymeric matrix. All porous scaffolds possessed a well-interconnected porous structure, while the synergistic effect of Fe3O4/GO reinforces the mechanical strength of porous scaffolds. The compressive strength and Young's modulus were increased by increasing Fe3O4 amount, and maximum mechanical strength was found in HFG-4 and least in HFG-1. However, these porous scaffolds have different swelling and biodegradation behavior due to the variable Fe3O4 intercalations into GO-sheets. Antibacterial activities of porous scaffolds were studied against severe Gram-positive and Gram-negative pathogens and increased Fe3O4 amount in nanosystem increased the antibacterial activities. The cell viability and morphology of pre-osteoblast (MC3T3-E1) cell lines were studied against porous scaffolds and increased cell viability and proliferation were observed from HFG-1 to HFG-4. Hence, the electroactive material could be the potential material for bone tissue engineering.

Development of Biodegradable Bio-Based Composite for Bone Tissue Engineering: Synthesis, Characterization and In Vitro Biocompatible Evaluation.

Several significant advancements in the field of bone regenerative medicine have been made in recent years. However, therapeutic options, such as bone grafts, have several drawbacks. There is a need to develop an adequate bone substitute. As a result, significant bone defects/injuries pose a severe challenge for orthopaedic and reconstructive bone tissue. We synthesized polymeric composite material from arabinoxylan (ARX), ß-glucan (BG), nano-hydroxyapatite (nHAp), graphene oxide (GO), acrylic acid (AAc) through free radical polymerization and porous scaffold fabricated using the freeze-drying technique. These fabricated porous scaffolds were then coated with chitosan solution to enhance their biological activities. The complex structure of BG, nHAp, GO was studied through various characterization and biological assays. The structural, morphological, wetting and mechanical analyses were determined using FT-IR, XRD, XPS, SEM/EXD, water contact angle and UTM. The swelling (aqueous and PBS media) and degradation (PBS media) observed their behavior in contact with body fluid. The biological activities were conducted against mouse pre-osteoblast cell lines. The result found that BGH3 has desirable morphological, structural with optimum swelling, degradation, and mechanical behavior. It was also found to be cytocompatible against MC3T3-E1 cell lines. The obtained results confirmed that the fabricated polymeric scaffolds would be a potential bone substitute to regenerate defective bone with different loading bearing applications for bone tissue engineering.

Antibacterial and Hemocompatible pH-Responsive Hydrogel for Skin Wound Healing Application: In Vitro Drug Release.

The treatment of successive skin wounds necessitates meticulous medical procedures. In the care and treatment of skin wounds, hydrogels produced from natural polymers with controlled drug release play a crucial role. Arabinoxylan is a well-known and widely available biological macromolecule. We produced various formulations of blended composite hydrogels (BCHs) from arabinoxylan (ARX), carrageenan (CG), and reduced graphene oxide (rGO) using and cross-linked them with an optimal amount of tetraethyl orthosilicate (TEOS). The structural, morphological, and mechanical behavior of the BCHs samples were determined using Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM), mechanical testing, and wetting, respectively. The swelling and degradation assays were performed in phosphate-buffered saline (PBS) solution and aqueous media. Maximum swelling was observed at pH 7 and the least swelling in basic pH regions. All composite hydrogels were found to be hemocompatible. In vitro, silver sulfadiazine release profile in PBS solution was analyzed via the Franz diffusion method, and maximum drug release (87.9%) was observed in 48 h. The drug release kinetics was studied against different mathematical models (zero-order, first-order, Higuchi, Hixson-Crowell, Korsmeyer-Peppas, and Baker-Lonsdale models) and compared their regression coefficient (R2) values. It was observed that drug release follows the Baker-Lonsdale model, as it has the highest value (0.989) of R2. Hence, the obtained results indicated that, due to optimized swelling, wetting, and degradation, the blended composite hydrogel BCH-3 could be an essential wound dressing biomaterial for sustained drug release for skin wound care and treatment.

Smart and pH-sensitive rGO/Arabinoxylan/chitosan composite for wound dressing: In-vitro drug delivery, antibacterial activity, and biological activities.

Carbohydrate polymers are biological macromolecules that have sparked a lot of interest in wound healing due to their outstanding antibacterial properties and sustained drug release. Arabinoxylan (ARX), Chitosan (CS), and reduced graphene oxide (rGO) sheets were combined and crosslinked using tetraethyl orthosilicate (TEOS) as a crosslinker to fabricate composite hydrogels and assess their potential in wound dressing for skin wound healing. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), and biological assays were used to evaluate the composite hydrogels. FTIR validated the effective fabrication of the composite hydrogels. The rough morphologies of the composite hydrogels were revealed by SEM and AFM (as evident from the Ra values). ATC-4 was discovered to have the roughest surface. TEM revealed strong homogeneous anchoring of the rGO to the polymer matrix. However, with higher amount of rGO agglomeration was detected. The % swelling at various pHs (1-13) revealed that the hydrogels were pH-sensitive. The controlled release profile for the antibacterial drug (Silver sulfadiazine) evaluated at various pH values (4.5, 6.8, and 7.4) in PBS solution and 37 °C using the Franz diffusion method revealed maximal drug release at pH 7.4 and 37 °C. The antibacterial efficacy of the composite hydrogels against pathogens that cause serious skin diseases varied. The MC3T3-E1 cell adhered, proliferated, and differentiated well on the composite hydrogels. MC3T3-E1 cell also illustrated excellent viability (91%) and proper cylindrical morphologies on the composite hydrogels. Hence, the composite hydrogels based on ARX, CS, and rGO are promising biomaterials for treating and caring for skin wounds.

Development of Antibacterial, Degradable and pH-Responsive Chitosan/Guar Gum/Polyvinyl Alcohol Blended Hydrogels for Wound Dressing.

The present research is based on the fabrication preparation of CS/PVA/GG blended hydrogel with nontoxic tetra orthosilicate (TEOS) for sustained paracetamol release. Different TEOS percentages were used because of their nontoxic behavior to study newly designed hydrogels' crosslinking and physicochemical properties. These hydrogels were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and wetting to determine the functional, surface morphology, hydrophilic, or hydrophobic properties. The swelling analysis in different media, degradation in PBS, and drug release kinetics were conducted to observe their response against corresponding media. The FTIR analysis confirmed the components added and crosslinking between them, and surface morphology confirmed different surface and wetting behavior due to different crosslinking. In various solvents, including water, buffer, and electrolyte solutions, the swelling behaviour of hydrogel was investigated and observed that TEOS amount caused less hydrogel swelling. In acidic pH, hydrogels swell the most, while they swell the least at pH 7 or higher. These hydrogels are pH-sensitive and appropriate for controlled drug release. These hydrogels demonstrated that, as the ionic concentration was increased, swelling decreased due to decreased osmotic pressure in various electrolyte solutions. The antimicrobial analysis revealed that these hydrogels are highly antibacterial against Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram negative (Pseudomonas aeruginosa and Escherichia coli) bacterial strains. The drug release mechanism was 98% in phosphate buffer saline (PBS) media at pH 7.4 in 140 min. To analyze drug release behaviour, the drug release kinetics was assessed against different mathematical models (such as zero and first order, Higuchi, Baker-Lonsdale, Hixson, and Peppas). It was found that hydrogel (CPG2) follows the Peppas model with the highest value of regression (R2 = 0.98509). Hence, from the results, these hydrogels could be a potential biomaterial for wound dressing in biomedical applications.

Chitosan/Poly Vinyl Alcohol/Graphene Oxide Based pH-Responsive Composite Hydrogel Films: Drug Release, Anti-Microbial and Cell Viability Studies.

The composite hydrogels were produced using the solution casting method due to the non-toxic and biocompatible nature of chitosan (CS)/polyvinyl alcohol (PVA). The best composition was chosen and crosslinked with tetraethyl orthosilicate (TEOS), after which different amounts of graphene oxide (GO) were added to develop composite hydrogels. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle was used to analyze the hydrogels. The samples were also evaluated for swelling abilities in various mediums. The drug release profile was studied in phosphate-buffered saline (PBS) at a pH of 7.4. To predict the mechanism of drug release, the data were fitted into kinetic models. Finally, antibacterial activity and cell viability data were obtained. FTIR studies revealed the successful synthesis of CS/PVA hydrogels and GO/CS/PVA in hydrogel composite. SEM showed no phase separation of the polymers, whereas AFM showed a decrease in surface roughness with an increase in GO content. 100 µL of crosslinker was the critical concentration at which the sample displayed excellent swelling and preserved its structure. Both the crosslinked and composite hydrogel showed good swelling. The most acceptable mechanism of drug release is diffusion-controlled, and it obeys Fick's law of diffusion for drug released. The best fitting of the zero-order, Hixson-Crowell and Higuchi models supported our assumption. The GO/CS/PVA hydrogel composite showed better antibacterial and cell viability behaviors. They can be better biomaterials in biomedical applications.

Preparation and Physicochemical Characterization of a Diclofenac Sodium-Dual Layer Polyvinyl Alcohol Patch.

The aim of this study is to prepare a dual layer polyvinyl (PVA) patch using a combination of electrospinning techniques and cryogelation (freeze-thaw process) then subsequently to investigate the effect of freeze-thaw cycles, nanofiber thickness, and diclofenac sodium (DS) loading on the physicochemical and mechanical properties and formulation of dual layer PVA patches composed of electrospun PVA nanofibers and PVA cryogel. After the successful preparation of the dual layer PVA patch, the prepared patch was subjected to investigation to assess the effect of freeze-thaw cycles, nanofiber thickness and percentages of DS loading on the morphology, physiochemical and mechanical properties. Various spectroscopic techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), water contact angle, and tensile tests were used to evaluate the physicochemical and mechanical properties of prepared dual layer PVA patches. The morphological structures of the dual layer PVA patch demonstrated the effectiveness of both techniques. The effect of freeze-thaw cycles, nanofiber thickness, and DS percentage loading on the crystallinity of a dual layer PVA patch was investigated using XRD analysis. The presence of a distinct DS peak in the FTIR spectrum indicates the compatibility of DS in a dual layer PVA patch through in-situ loading. All prepared patches were considered highly hydrophilic because the data obtained was less than 90°. The increasing saturation of DS within the PVA matrix increases the tensile strength of prepared patches, however decreased its elasticity. Evidently, the increasing of electrospun PVA nanofibers thickness, freeze-thaw cycles, and the DS saturation has improved the physicochemical and mechanical properties of the DS medicated dual layer PVA patches, making them a promising biomaterial for transdermal drug delivery applications.

A Comprehensive Review on the Applications of Exosomes and Liposomes in Regenerative Medicine and Tissue Engineering.

Tissue engineering and regenerative medicine are generally concerned with reconstructing cells, tissues, or organs to restore typical biological characteristics. Liposomes are round vesicles with a hydrophilic center and bilayers of amphiphiles which are the most influential family of nanomedicine. Liposomes have extensive research, engineering, and medicine uses, particularly in a drug delivery system, genes, and vaccines for treatments. Exosomes are extracellular vesicles (EVs) that carry various biomolecular cargos such as miRNA, mRNA, DNA, and proteins. As exosomal cargo changes with adjustments in parent cells and position, research of exosomal cargo constituents provides a rare chance for sicknesses prognosis and care. Exosomes have a more substantial degree of bioactivity and immunogenicity than liposomes as they are distinctly chiefly formed by cells, which improves their steadiness in the bloodstream, and enhances their absorption potential and medicinal effectiveness in vitro and in vivo. In this review, the crucial challenges of exosome and liposome science and their functions in disease improvement and therapeutic applications in tissue engineering and regenerative medicine strategies are prominently highlighted.

Synthesis and Characterization of Silver-Coated Polymeric Scaffolds for Bone Tissue Engineering: Antibacterial and In Vitro Evaluation of Cytotoxicity and Biocompatibility.

In bone tissue engineering, multifunctional composite materials are very challenging. Bone tissue engineering is an innovative technique to develop biocompatible scaffolds with suitable orthopedic applications with enhanced antibacterial and mechanical properties. This research introduces a polymeric nanocomposite scaffold based on arabinoxylan-co-acrylic acid, nano-hydroxyapatite (nHAp), nano-aluminum oxide (nAl2O3), and graphene oxide (GO) by free-radical polymerization for the development of porous scaffolds using the freeze-drying technique. These polymeric nanocomposite scaffolds were coated with silver (Ag) nanoparticles to improve antibacterial activities. Together, nHAp, nAl2O3, and GO enhance the multifunctional properties of materials, which regulate their physicochemical and biomechanical properties. Results revealed that the Ag-coated polymeric nanocomposite scaffolds had excellent antibacterial properties and better microstructural properties. Regulated morphological properties and maximal antibacterial inhibition zones were found in the porous scaffolds with the increasing amount of GO. Moreover, the nanosystem and the polymeric matrix have improved the compressive strength (18.89 MPa) and Young's modulus (198.61 MPa) of scaffolds upon increasing the amount of GO. The biological activities of the scaffolds were investigated against the mouse preosteoblast cell lines (MC3T3-E1) and increasing the quantities of GO helps cell adherence and proliferation. Therefore, our findings showed that these silver-coated polymeric nanocomposite scaffolds have the potential for engineering bone tissue.