Inflammation targeted chitosan-based hydrogel for controlled release of diclofenac sodium

miRNA-124 loaded extracellular vesicles encapsulated within hydrogel matrices for combating chemotherapy-induced neurodegeneration

Chemotherapy-induced neurodegeneration represents a significant challenge in cancer survivorship, manifesting in cognitive impairments that severely affect patients' quality of life. Emerging neuroregenerative therapies offer promise in mitigating these adverse effects, with miRNA-124 playing a pivotal role due to its critical functions in neural differentiation, neurogenesis, and neuroprotection. This review article delves into the innovative approach of using miRNA-124-loaded extracellular vesicles (EVs) encapsulated within hydrogel matrices as a targeted strategy for combating chemotherapy-induced neurodegeneration. We explore the biological underpinnings of miR-124 in neuroregeneration, detailing its mechanisms of action and therapeutic potential. The article further examines the roles and advantages of EVs as natural delivery systems for miRNAs and the application of hydrogel matrices in creating a sustained release environment conducive to neural tissue regeneration. By integrating these advanced materials and biological agents, we highlight a synergistic therapeutic strategy that leverages the bioactive properties of miR-124, the targeting capabilities of EVs, and the supportive framework of hydrogels. Preclinical studies and potential pathways to clinical translation are discussed, alongside the challenges, ethical considerations, and future directions in the field. This comprehensive review underscores the transformative potential of miR-124-loaded EVs in hydrogel matrices, offering insights into their development as a novel and integrative approach for addressing the complexities of chemotherapy-induced neurodegeneration.

Potential mitochondrial ROS-mediated damage induced by chitosan nanoparticles bee venom-loaded on cancer cell lines

Recently, numerous studies have confirmed the importance of chitosan nanoparticles (CNP) as a viable drug delivery carrier for increasing the efficacy of anticancer drugs in cancer treatment. It is a macromolecule and natural biopolymer compound, more stable and safer in use than metal nanoparticles. Bee venom (BV), a form of defense venom, has been shown to have anti-tumor, neuroprotective, anti-inflammatory, analgesic, and anti-infectivity properties. Moreover, the regulation of cell death has been linked to reactive oxygen species (ROS)-mediated cell apoptosis, which induces mitochondrial damage and ER stress through oxidative stress events. Therefore, this study aimed to illustrate the ROS-mediated effect on the cancer cells treatment with CNP-loaded BV (CNP-BV) and explained the adverse effects of ROS generation on Mitochondria and ER. We have found that the targeted CNP-BV were high in cytotoxicity against MCF-7 (IC50 437.2 μg/mL) and HepG2 (IC50 109.5 μg/mL) through the induction of massive generation of ROS, which in turn results in activating the mitochondrial cascade and ER stress. These results highlighted the role of ROS generation in inducing apoptosis in cancer cells.

Hydrogel Applications in the Diagnosis and Treatment of Glioblastoma

Glioblastoma multiforme (GBM), a common malignant neurological tumor, has boundaries indistinguishable from those of normal tissue, making complete surgical removal ineffective. The blood-brain barrier (BBB) further impedes the efficacy of radiotherapy and chemotherapy, leading to suboptimal treatment outcomes and a heightened probability of recurrence. Hydrogels offer multiple advantages for GBM diagnosis and treatment, including overcoming the BBB for improved drug delivery, controlled drug release for long-term efficacy, and enhanced relaxation properties of magnetic resonance imaging (MRI) contrast agents. Hydrogels, with their excellent biocompatibility and customizability, can mimic the in vivo microenvironment, support tumor cell culture, enable drug screening, and facilitate the study of tumor invasion and metastasis. This paper reviews the classification of hydrogels and recent research for the diagnosis and treatment of GBM, including their applications as cell culture platforms and drugs including imaging contrast agents carriers. The mechanisms of drug release from hydrogels and methods to monitor the activity of hydrogel-loaded drugs are also discussed. This review is intended to facilitate a more comprehensive understanding of the current state of GBM research. It offers insights into the design of integrated hydrogel-based GBM diagnosis and treatment with the objective of achieving the desired therapeutic effect and improving the prognosis of GBM.

Biocide physically cross-linked hydrogels based on carrageenan and guanidinium polyampholytes for wound healing applications

Over last years, hydrogels based on natural polymers have attracted considerable interest as materials for wound healing. Herein, hydrogel films based on kappa-carrageenan and guanidinium polyampholytes were prepared by the in situ physical cross-linking with potassium chloride and borax, respectively. The polyampholytes were obtained by a free radical copolymerization of 2,2-diallyl-1,1,3,3-tetraethylguanidinium chloride and unsaturated acids. To characterize the composite films, NMR, FTIR, SEM, TGA, XRD, element analysis and tensile test were used. Ampicillin was incorporated into the hydrogels to enhance wound healing potential. The healing-related characteristics, including swelling ratio, drug release and antimicrobial activity, were assessed. The equilibrium swelling ratios were in the range of 3.9-6.5 depending on the polyampholyte composition. According to the in vitro ampicillin release studies, 30-43 % of ampicillin was released from the hydrogels after 5 h at 37 °C and pH 7.4, with drug release being temperature and pH dependent. The ampicillin-loaded films showed a remarkable antimicrobial effect. The inhibition sizes for Escherichia coli and Staphylococcus aureus were 1.10-1.85 and 1.95-2.60 cm, respectively. Although the bi-polymeric hydrogels were thoroughly characterized, with the in vitro study of their biocidal effects carried out in this work, the in vivo drug release assessment needs to be further explored.

Alginate/hyaluronic acid/gelatin ternary blended films as pH-sensitive drug carriers: In vitro ampicillin release and kinetic studies

Researchers continuously focused on the fabrication of innovative drug delivery systems to prevent microbial infections while minimizing systemic side effects. Among these, pH-sensitive antibiotic release systems based on bio-based materials have gained great attention due to their ability to precisely modulate drug kinetics and enhance therapeutic efficacy. Herein, pH-sensitive alginate/hyaluronic acid/gelatin ternary blended films were fabricated for the controlled release of ampicillin. Swelling capacity, hydrolytic degradation profile, pH reversibility and in vitro ampicillin release behavior of produced films were investigated in both simulated gastric (pH 1.2) and intestinal (pH 7.4) environments. The cumulative release amount of ampicillin at pH 1.2 (61.0 ± 1.07 mg drug/g polymer) was greater than that of at pH 7.4 (43.0 ± 1.05 mg drug/g polymer) proved that release behavior of ampicillin for produced films is pH-dependent. Based on the fitted release data, best fit was found as the first-order kinetic model with the highest R2 values of 0.966 and 0.962 for both pH conditions. According to Korsmeyer-Peppas model, drug release mechanism is also controlled by case II-transport. Furthermore, produced films demonstrated excellent cytocompatibility. All results revealed that obtained films could be a promising drug carrier to traditional targeting systems for site-specific, pH-sensitive ampicillin delivery in both gastric and intestine.

A chitosan-α-naphthaldehyde hydrogel film containing pineapple leaf fibers for wound dressing applications

In recent decades, polysaccharide-based hydrogels have gained significant attention due to their natural biocompatibility, biodegradability, and non-toxicity. The potential for using polysaccharides to synthesize hydrogels is due to their ability to support cell proliferation, which is important for practical applications, particularly in the biomedical field. In this study, we have synthesized a chitosan-α-naphthal hydrogel film using a cost-effective one-step synthesis approach. The prepared hydrogel film exhibited high encapsulation efficiency for antibacterial drugs such as ciprofloxacin and lomefloxacin, with the ability to release the antibiotics in a controlled manner over an extended period and prevent long-term bacterial infections. Moreover, the Korsmeyer and Peppas power law, based on Fickian diffusion, was employed to model the entire complex drug release process and predict the drug release behavior. The hydrogel film also shows pH-induced swelling ability due to the presence of an imine bond in the hydrogel network, which is degradable at acidic pH. The incorporated therapeutic agents having antibacterial activity were effective against Gram-negative (Escherichia coli DH5α) and Gram-positive (Staphylococcus aureus subsp. aureus) bacterial strains. A wound dressing material should possess mechanical strength, but the prepared hydrogel film has low mechanical strength. To increase the mechanical strength, we have infused pineapple leaf fibers (PLFs) in the film network, resulting in a mechanical strength of 1.12 ± 0.89 MPa. In addition to its mechanical strength, significant cell viability against human embryonic kidney (HEK-293) cells was observed from in vitro cell culture experiments for this PLF-hydrogel film. As a result, the prepared therapeutic agent-loaded hydrogel film under study meets the requirements to be considered for use as a wound dressing material.

5-Fluorouracil-loaded green chitosan nanoparticles/ guar gum nanocomposite hydrogel in controlled drug delivery

In recent years nanotechnologies have been applied to human health with promising results, especially in the field of drug delivery. Polymeric nanoparticles (NPs) have garnered much importance in controlled drug delivery owing to their size. Chitosan (Cs) is a well-recognized biopolymer and Cs NPs have been widely explored in drug delivery. Nonetheless, reports pertaining to green synthesis of Cs NPs are scarce. Thus, in this study, green synthesis of Cs NPs was accomplished from raw mango peel extract. Spherical Cs NPs with positively charged surface of 33.4 mV was accomplished by this process. Cs NPs, in varied content, were integrated in a guar gum network matrix resulting in a nanocomposite hydrogel. The mechanical and thermal stability of the hydrogel improved upon addition of Cs NPs. The hydrogel exhibited smart swelling, good antioxidant and anti-inflammatory propensities. Cs NPs encapsulating 5-Fluorouracil demonstrated a controlled release drug profile in the colorectum and the kinetics implied the anomalous nature of drug release mechanism. The exposure of the drug-loaded nanocomposite hydrogel displayed improved anticancer effects in HT-29 colon cancer cells. Taken altogether, this study puts forth the greater efficacy of Cs NPs in controlled drug delivery for anticancer therapy.

Thermo-responsive composite nanoparticles based on hydroxybutyl chitosan oligosaccharide: Fabrication, stimulus release and cancer therapy

Designing thermo-responsive nanocarriers based on biopolymers is fascinating and challenging for cancer therapy. In this study, thermo-responsive composite nanoparticles (CNPs) were prepared using hydroxybutyl chitosan oligosaccharide (HBCOS) and sodium caseinate (SC) via electrostatic interactions and covalent crosslinking. The temperature-responsive behaviors of CNPs were induced by the breakage of hydrogen bonds and the shrinkage of chains in nanoparticles. The CNPs exhibited concentration-independent thermo-responsive behavior, non-adsorption aggregation, and non-hemolysis, suggesting excellent stability and thermo-sensitivity. The initial release rate and final amount of DOX released from CNPs at 42 °C were higher than that at 37 °C, showing a thermo-responsive release, which was also more prominent at lower pH. The release of DOX from CNPs followed first order kinetics based on Fickian diffusion. In vitro cytotoxicity assays confirmed the thermo-responsive antitumor activity of DOX-loaded CNPs as the HT-29 cell viability incubated with DOX-loaded CNPs at 42 °C was significantly lower than that at 37 °C. Cellular uptake experiments proved that DOX-loaded CNPs accumulated in the cytoplasm after being endocytosed and promoted DOX release by increasing environment temperature. This study generated stable thermo-sensitive CNPs based on biopolymers, which can be used as potential nanocarriers for the controlled release of anticancer drugs for cancer therapy.

Biomimetic kartogenin containing κ-carrageenan hydrogel for nucleus pulposus regeneration

Intervertebral disc degeneration is a clinical disease that reduces the quality of patient's life. The degeneration usually initiates in the nucleus pulposus (NP), hence the use of hydrogels represents a promising therapeutic approach. However, the viscoelastic nature of hydrogel and its ability to provide biomimetic architecture and biochemical cues influence the regeneration capability. This study focused on tuning the physical nature of a glycosaminoglycan hydrogel (κ-carrageenan) as well as the release kinetics of a chondrogenic factor (kartogenin - KGN) through physical cross-linking. For this, κ-carrageenan was cross linked with 2.5 % and 5 % potassium chloride (KCl) for 15 and 30 min and loaded with KGN molecule at 50 μM and 100 μM. The tight network structure with low water retention and degradation property was seen in hydrogel cross-linked with increased KCl concentration and time. However, optimal degradation along with NP mimicking viscoelastic nature was exhibited by 5 wt% KCl treated hydrogel (H3 hydrogel). All hydrogel groups exhibited burst KGN release at 24 h followed by a sustained release for 5 days. However, hydrogel cross-linked with 5 wt% KCl enhanced chondrogenic differentiation, mainly at lower KGN dose. In summary, this study shows the potential application of biomimetic KGN laden carrageenan hydrogel in NP regeneration.

Designing network structure hydrogels derived from carrageenan- phosphated polymers by covalent and supramolecular interactions for potential biomedical applications

Recently, various efforts have been made to explore the potential of natural polysaccharides derived from sea weeds to promote sustainable development. Herein, carrageenan (CG), a polysaccharide extracted from red sea algae, was utilized to design network structures as hydrogels, aimed at significant applications in drug delivery (DD) systems. Hydrogels were designed by graft copolymerization reaction of poly(bis [2-methacryloyloxy] ethyl phosphate [poly(BMEP)] and poly(acrylic acid) [poly(AAc)] onto CG in the presence of a crosslinking agent. Hydrogels were developed by covalent linkage by graft copolymerization and supramolecular interactions, existing in the copolymers. Copolymers were characterized by Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), 13C-nuclear magnetic resonance (NMR), and X-ray diffraction (XRD) instrumentations. The drug diffusion exhibited a sustained pattern due to polymer-drug interactions. The drug release followed non-Fickian diffusion mechanism and the release profile was most accurately depicted by first order kinetic model. The biocompatible nature of the copolymer was demonstrated from the hemolytic index value signifying minimal adverse interactions with blood component upon exposure. A protein adsorption test was performed using bovine serum albumin (BSA), exhibiting 8.15 ± 0.26 % albumin adsorption. Polymers exhibited mucoadhesive character, evidenced by their requirement of a detachment force measuring 195 ± 4.72 mN for separation from the membrane during interactions with the mucosal surface. The hydrogels exhibited antioxidant properties, evidenced by 2, 2'-Diphenylpicrylhydrazyl (DPPH) assay, revealing copolymer capable of scavenging 58.21 ± 2.26 % of free radical. The hydrogel revealed antimicrobial activity against P. aeruginosa and S. aureus bacteria, a property further enhanced in hydrogels with the drug doxycycline. These findings suggest suitability of these hydrogels for biomedical applications, with a significant emphasis on drug delivery.

Design and evaluation of fluorescent chitosan-starch hydrogel for drug delivery and sensing applications

Composite bio-based hydrogels have been obtaining a significant attention in recent years as one of the most promising drug delivery systems. In the present study, the preparation of composite chitosan-starch hydrogel using maleic acid as a cross-linker was optimized with the help of response surface methodology. The synthesized hydrogel was fluorescent owing to clustering of large number of functional groups. Different analytical techniques, including XRD, FTIR, SEM, XPS, fluorescence and BET were utilized to characterize the prepared hydrogel. XRD analysis confirmed the formation of non-crystalline hydrogel with random arrangement of macromolecular chains. The composite hydrogel exhibited good swelling percentage with pH sensitivity, hemocompatibility and degradability. BET analysis confirmed that the variation in concentration of crosslinker significantly influences the pore volume of the hydrogel. The synthesized composite chitosan-starch hydrogel was utilized as a prospective candidate for controlling drug release. Cefixime as a model drug was loaded onto the synthesized hydrogel utilizing the swelling diffusion method. SEM micrographs showed uniform distribution of drug molecules in the drug loaded hydrogel. In vitro drug release experiments indicated the swelling dependent drug release behaviour of chitosan-starch hydrogel with higher drug release at pH 7.4 (93.08 %) compared to pH 1.2 (67.85 %). The composite chitosan-starch hydrogel was able to prolong and control the drug release up to 12 h. The drug release from the hydrogel followed Korsmeyer-Peppas and Makoid-Banakar model with Fickian diffusion mechanism. Further, the composite hydrogel displayed excitation dependent fluorescence emission with most intense blue emission band at 425 nm with an excitation wavelength of 350 nm. The inclusion of cefixime drug in the hydrogel matrix significantly reduced the fluorescence intensity; the decrease was linearly correlated to the concentration of the drug. Moreover, the fluorescence emission the chitosan-starch hydrogel was found to be dependent upon pH. The synthesized hydrogel is expected to be a potential candidate for controlled drug release as well as for fluorescent sensing applications.

Synthesis of carboxymethyl chitosan-guar gum-poly(vinylpyrrolidone) ternary blended hydrogels with antibacterial/anticancer efficacy and drug delivery applications

Biopolymers have the utmost significance in biomedical applications and blending synthetic polymers has shown favorable characteristics versus individual counterparts. The utilization of the blends can be restricted through the use of toxic chemical agents such as initiators or crosslinkers. In this regard, a chemical agent-free ionizing irradiation is a beneficial alternative for preparing the hydrogels for biomedical applications. In this study, carboxymethyl chitosan (CM-CS), guar gum (GG), and poly(vinylpyrrolidone) (PVP) based ternary blends (TB) were crosslinked using various doses of ionizing irradiation to fabricate hydrogels. The prepared hydrogels were characterized for physicochemical properties, swelling analysis, biological assays, and drug delivery applications. Swelling analysis in distilled water revealed that the hydrogels exhibit excellent swelling characteristics. An in vitro cytocompatibility assay showed that the hydrogels have greater than 90% cell viability for the human epithelial cell line and a decreasing cell viability trend for the human alveolar adenocarcinoma cell line. In addition, the prepared hydrogels possessed excellent antibacterial characteristics against gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli). Finally, the release studies of anti-inflammatory Quercus acutissima (QA) loaded hydrogels exhibited more than 80% release in phosphate-buffered saline (pH = 7.4). These findings suggest that TB hydrogels can be used as suitable carrier media for different release systems and biomedical applications.

Utilizing Silk Sericin as a Biomaterial for Drug Encapsulation in a Hydrogel Matrix with Polycaprolactone: Formulation and Evaluation of Antibacterial Activity

Hydrogels have emerged as a potential tool for enhancing bioavailability and regulating the controlled release of therapeutic agents. Owing to its excellent biocompatibility, silk sericin-based hydrogels have garnered interest in biomedical applications. This study focuses on synthesizing a soft hydrogel by blending silk sericin (SS) and polycaprolactone (PCL) at room temperature. The physicochemical characteristics of the hydrogels have been estimated by different analytical techniques such as UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The rheological studies demonstrate the non-Newtonian behavior of the hydrogels. Further, the porosity analysis indicates a commendable absorption capacity of the hydrogels. The swelling degree of the hydrogels has been checked in both distilled water and buffer solutions of different pHs (2-10). Moreover, the drug release profile of the hydrogels, using diclofenac sodium (DS) as a model drug, has revealed a substantial release of approximately 67% within the first 130 min with a drug encapsulation efficiency of 60.32%. Moreover, both the empty and the drug-loaded hydrogels have shown antibacterial properties against Gram-positive and Gram-negative bacteria, with the drug-loaded hydrogels displaying enhanced effectiveness. Additionally, the prepared hydrogels are biodegradable, demonstrating their future prospects in biomedical applications.

Design and synthesis of drug hydrogels containing carboxymethylcellulose with honeycomb structure and pH-sensitivity as drug delivery systems for adriamycin, metformin, and naproxen

The aim of this research is to prepare and identify functionalized carboxymethylcellulose/mesoporous silica nanohydrogels (CMC/NH2-MCM-41) for obtaining a pH-sensitive system for the controlled release of drugs. The beads of CMC/NH2-MCM-41 nanocomposites were prepared by dispersing NH2-MCM-41 in a CMC polymer matrix and crosslinking with ferric ions (Fe3+). The SEM analysis of samples revealed enhancement in surface porosity of the functionalized nanohydrogel beads compared to the conventional beads. Swelling of the prepared functionalized nanohydrogels was evaluated at various pH values including pH = 7.35-7.45 (simulated body fluid or healthy cells), pH = 6 (simulated intestinal fluid), and pH = 1.5-3.5 (simulated gastric fluid). The swelling of CMC/MCM-41 and CMC/NH2-MCM-41 nanohydrogels at the pH values of simulated body fluid and simulated intestinal fluid is much higher than that of simulated gastric fluid, indicating successful synthesis of pH-sensitive nanohydrogels for drug delivery. The drug loading results showed that drug release in the CMC/NH2-MCM-41 system is much slower than that in the CMC/MCM-41 system. The results of the survival studies for the manufactured systems showed a very good biocompatibility of the designed drug delivery systems for biological applications. By coating the surface of functionalized mesopores with CMC hydrogel, we were able to develop a pH-sensitive intelligent drug delivery system.

Synthesis and Characterization of Cassava Gum Hydrogel Associated with Chlorhexidine and Evaluation of Release and Antimicrobial Activity

Hydrogels from natural sources are attracting increasing interest due to their ability to protect biologically active molecules. Starch extracted from cassava tubers is a promising material for synthesizing these hydrogels. Copolymerization of cassava gum and incorporation of chlorhexidine digluconate (CLX) into the hydrogels is confirmed by changes in the crystallographic profile, as observed through X-ray diffraction, and a shift in the 1000 cm-1 band in the Fourier-transform infrared spectroscopy spectrum. The differential scanning calorimetry reveals changes in the decomposition temperature of the synthesized hydrogels related to CLX volatility. Micrographs illustrate the material's porosity. Release tests indicate a constant linear release over 72 h, while antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans is satisfactory, with 100% effectiveness from 0.5% CLX and the formation of inhibition halos. Toxicity and biocompatibility studies show no cytotoxicity. The continuous release of chlorhexidine is promising for components of biomedical implants and applications as it can ensure antimicrobial action according to specific therapeutic needs.

Theranostic antibacterial hydrogel based on biopolymers cross-linked and doped with phytic acid from rice bran for wound healing

Theranostic antibacterial wound dressing is highly recommended in practical applications. The conventional methods of integrating diagnostic and therapeutic functions have the disadvantages of complicated preparation, mutual interference, inability to effectively broad spectrum antibacterial property, and easy to induce drug-resistant bacteria. Herein, a pH and light-responsive theranostic antibacterial hydrogel is developed by biopolymers polyvinyl alcohol (PVA) and polyaniline (PANI), and cross-linking with phytic acid (PA), which is widely present in rice bran. The biological polymer-based conductive hydrogel enables timely diagnosis and photothermal sterilization in-situ for wound healing. Because PANI is highly sensitive to pH changes in the bacterial microenvironment, the hydrogel can detect bacterial infections at concentrations as low as 103 CFU/mL. Subsequently, PANI absorbs near-infrared light to achieve on-demand exothermic sterilization (under 808 nm irradiation for 20 min, the killing ratios for Staphylococcus aureus and Escherichia coli reached almost 100 %). In addition, the hydrogel can monitor the intensity of joint movement to avoid wound re-tearing sensitively. In vitro cytotoxicity and hemocompatibility experiments and in vivo full-thickness infected wound model indicate that the hydrogel has good biocompatibility, antibacterial ability, and can accelerate the wound healing effectively. This work will promote the development of wearable electronic devices and precision medicine.

Efficient drug delivery potential and antimicrobial activity of biocompatible hydrogels of dextrin/Na-alginate/PVA

Ceftriaxone sodium belongs to the third-generation cephalosporin group and is used intramuscular and intravenous route as a broad-spectrum antibiotic. This research aims to prepare biocompatible hydrogels for targeted delivery of ceftriaxone sodium by parental route. Different proportions of polymers (natural and synthetic) in the presence of cross-linker were synthesized by solvent casting method. Ceftriaxone sodium was loaded in hydrogels in different concentrations and its drug release behavior was evaluated along with swelling and biodegradation analysis. The characterization of hydrogel was done by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) to analyze surface morphology and functional groups involved in the formation of dextrin/Na-alginate/PVA hydrogels loaded with the drug. Thermogravimetric analysis (TGA) was confirmed by thermal stability and degradation pattern of loaded and unloaded hydrogels. The drug-loaded samples presented promising antimicrobial activity against S. aureus and P. multocida and their cytotoxic nature was also studied. Drug release analysis using simulated intestinal fluid (SIF) and phosphate buffer saline(PBS) for the circulatory system shows the consistent release of the drug. The findings unveiled the development of a biocompatible and innovative hydrogel, which has potential advantages for biomedical application, particularly in enhancing the therapeutic efficacy of ceftriaxone sodium drug.

Recent Applications of Chitosan and Its Derivatives in Antibacterial, Anticancer, Wound Healing, and Tissue Engineering Fields

Chitosan, a versatile biopolymer derived from chitin, has garnered significant attention in various biomedical applications due to its unique properties, such as biocompatibility, biodegradability, and mucoadhesiveness. This review provides an overview of the diverse applications of chitosan and its derivatives in the antibacterial, anticancer, wound healing, and tissue engineering fields. In antibacterial applications, chitosan exhibits potent antimicrobial properties by disrupting microbial membranes and DNA, making it a promising natural preservative and agent against bacterial infections. Its role in cancer therapy involves the development of chitosan-based nanocarriers for targeted drug delivery, enhancing therapeutic efficacy while minimising side effects. Chitosan also plays a crucial role in wound healing by promoting cell proliferation, angiogenesis, and regulating inflammatory responses. Additionally, chitosan serves as a multifunctional scaffold in tissue engineering, facilitating the regeneration of diverse tissues such as cartilage, bone, and neural tissue by promoting cell adhesion and proliferation. The extensive range of applications for chitosan in pharmaceutical and biomedical sciences is not only highlighted by the comprehensive scope of this review, but it also establishes it as a fundamental component for forthcoming research in biomedicine.

Synthesis of poly(ionic liquid-OH) mediated deacetylated chitin and its hydrogels: A study on their applications in controlled release of paracetamol and urea

Due to the biodegradable and biocompatible nature of chitin and chitosan, they are extensively used in the synthesis of hydrogels for various applications. In this work, deacetylation of chitin is carried out with alkaline poly(dimethyldiallylammonium-hydroxide) that gave a higher amount of water-soluble chitin (with 84 % of the degree of deacetylation = chitosan0.84) compared to deacetylation using NaOH. The water-soluble chitosan0.84 is used as intercalating chains for the preparation of acrylic acid and vinylimidazole-based hydrogels. The quaternization of imidazole groups is done with 1,ω-dibromoalkanes, which sets off the crosslinking in the above polymer network. A set of three chitosan0.84 intercalated hydrogels, namely Cs-C4-hydrogel, Cs-C5-hydrogel, and Cs-C10-hydrogel are prepared bearing butyl, pentyl, and decyl chains as respective crosslinkers. The swell ratios of these intercalated hydrogels are compared with those of non-intercalated hydrogels (C4-hydrogel, C5-hydrogel, and C10-hydrogel). Chitosan0.84 intercalated Cs-C10-hydrogel has excellent swelling properties (2330 % swelling ratio) among six synthesized hydrogels. SEM analysis reveals that decyl crosslinker-bearing hydrogels are highly porous. The multi-functionality of Cs-C10-hydrogel and C10-hydrogel is explored towards -the controlled release of paracetamol/urea, and methyleneblue dye absorption. These studies disclose that chitosan0.84 intercalated hydrogels are showing superior-swelling behavior, high paracetamol/urea loading capacities and better dye entrapment than their non-intercalated counterparts.

Synthesis and characterization of an innovative sodium alginate/polyvinyl alcohol bioartificial hydrogel for forward-osmosis desalination

Recently, hydrogels have been widely applied as draw agents in forward osmosis (FO) desalination. This work aims to synthesize bioartificial hydrogel from a blend of sodium alginate (SA) and polyvinyl alcohol (PVA) using epichlorohydrin (ECH) as a crosslinker. Then this prepared hydrogel was applied as a draw agent with cellulose triacetate membrane in a batch (FO) cell. The effects of the PVA content in the polymer blend and the crosslinker dose on the hydrogel's swelling capacity were investigated to optimize the hydrogel's composition. Furthermore, the water flux and the reverse solute flux of the optimum SA/PVA hydrogel were evaluated in a batch (FO) unit under the effect of the hydrogel's particle size, feed solution (FS) temperature, FS concentration, and membrane orientation. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and compression strength tests were used to characterize the prepared hydrogel. Results revealed that the equilibrium swelling ratio (%) of 5228 was achieved with a hydrogel that had 25% PVA and a crosslinking ratio of 0.8. FO experiments revealed that the maximum water flux of 0.845 LMH achieved, when distilled water was used as FS, average hydrogel's particle size was 60 µm, and the FS temperature was 40 °C.

Preparation and application of curcumin loaded with citric acid crosslinked chitosan-gelatin hydrogels

While oral administration offers safety benefits, its therapeutic efficacy is hindered by various physiological factors within the body. In this study, a novel approach was explored using a matrix consisting of 2 % chitosan and 2 % gelatin, with citric acid (CA) serving as a green cross-linking agent (ranging from 0.4 % to 1.0 %), and curcumin (Cur) as the model drug to formulate hydrogel carriers. The results showed that a 0.4 % CA concentration, the hydrogel (CGA0.4) reached swelling equilibrium in deionized water within 40 min, exhibiting a maximum swelling index was 539 g/g. The addition of Cur to the CGA hydrogel (CGACur) notably enhanced release efficiency, particularly in simulated intestinal fluid, where Cur release rates exceeded 40 % within 100 min compared to below 8 % in other solutions. Among these hydrogels, CGA0.4Cur exhibited the fastest degradation rate in the combined solution, reaching >90 % degradation after 7 days. Additionally, Cur and CA demonstrated positive effects on the tensile strength, antioxidant activity and antibacterial activity of hydrogels. Compare to the bioaccessibility of CGC (27 %), those of CGACur had increased to over 34 %. These findings offer provide theoretical support for CA-crosslinked chitosan/gelatin gels in delivering hydrophobic bioactive molecules and their application in intestinal drug delivery system.

Preparation, characterization and drug release properties of pH sensitive Zingiber officinale polysaccharide hydrogel beads

The aim of this study was to prepare a drug carrier that could deliver oral insulin to the intestine. A hydrogel beads composed of sodium carboxymethyl cellulose (CMC), Zingiber offtcinale polysaccharide (ZOP) and chitosan (CS) were prepared by ionic gel method as insulin carrier. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and thermogravimetric (TGA) showed that the hydrogel was formed by metal ion coordination between ZOP and CMC and Fe3+, and CS was coated on the surface of the hydrogel ball in the form of non covalent bond. The results showed that the swelling process of hydrogel spheres has significant pH sensitivity. In addition, the hydrogel beads successfully coated insulin, and the drug loading rate (DL) of (ZOP/CMC-Fe3+)@CS could reach 69.43 ± 7.32 mg/g, and the entrapment efficiency (EE) could reach 66.94 ± 7.43 %. In vitro release experiments, the release rate of (CMC/ZOP-Fe3+)@CS in simulated gastric fluid (SGF) for 2 h was <20 %, and the cumulative release rate of insulin after 9 h in simulated intestinal fluid (SIF) reached over 90 %. The results showed that the hydrogel beads prepared in this work could be used as a potential carrier for delivering oral insulin.

Insight into CMC-PVA-fHNTs Nanocomposite Hydrogel as an Advance Carrier for Cefadroxil Monohydrate: Fabrication and Characterization/Angiogenic Potential Analysis

Controlled drug delivery is a key strategy aimed at reducing both the frequency of therapeutic dosages and potential systemic side effects, particularly in the case of high drug concentrations. The nanocomposite hydrogel systems presented in this study were synthesized by combining carboxymethyl cellulose, polyvinyl alcohol, and (3-aminopropyl)triethoxysilane-functionalized halloysite nanotubes (fHNTs). This hydrogel system is a potential candidate for the controlled release of cefadroxil monohydrate. These hydrogels are analyzed by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and rheological measurements. Additionally, swelling properties, porosity, hydrophilicity, drug release, and in vitro and in vivo analyses were also evaluated. The observed trends in swelling and drug release demonstrated that the outcomes are dependent on the presence of fHNTs in the hydrogel matrix. Notably, fHNTs-loaded hydrogels displayed sustained drug release patterns. This innovative approach eliminates the need for traditional encapsulation and presents promising and translatable strategies for achieving more effective drug release.

Development of pH-Responsive, Thermosensitive, Antibacterial, and Anticancer CS/PVA/Graphene Blended Hydrogels for Controlled Drug Delivery

Drug delivery techniques based on polymers have been investigated for their potential to improve drug solubility, reduce systemic side effects, and controlled and targeted administration at infection site. In this study, we developed a co-polymeric hydrogel composed of graphene sheets (GNS), polyvinyl alcohol (PVA), and chitosan (CS) that is loaded with methotrexate (MTX) for in vitro liver cancer treatment. Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) was employed to check the structural properties and surface morphology. Moreover, tests were conducted on the cytotoxicity, hemolytic activity, release kinetics, swelling behaviour and degradation of hydrogels. A controlled release of drug from hydrogel in PBS at pH 7.4 was examined using release kinetics. Maximal drug release in six hours was 97.34%. The prepared hydrogels did not encourage the HepG2 growth and were non-hemolytic. The current study highlights the potential of GNS-based hydrogel loaded with MTX as an encouraging therapy for hepatocellular carcinoma. HepG2 cell viability of MTX-loaded CS-PVA-GNS hydrogel was (IC50 5.87 µg/200 mL) in comparison to free MTX (IC50 5.03 µg/200 mL). These outcomes recommend that hydrogels with GNS ensure improved drug delivery in cancer microenvironment while lessening adverse consequences on healthy cells.

Effect of graphene oxide on sodium alginate hydrogel as a carrier triggering release of ibuprofen

The design and preparation of safe wound dressings with antibacterial and controlled drug release abilities is valuable in medicine. This research focuses on the fabrication of a hydrogel carrier with graphene oxide (GO)-triggered ibuprofen (IBU) release to control inflammation. The hydrogel was prepared by cross-linking the base polymer sodium alginate (SA) and functionalized GO. The morphology of the gel was observed by a scanning electron microscope (SEM), and its structure was analyzed through X-ray diffraction (XRD) and Fourier transform infrared reflection (FTIR) spectroscopy. The effects of GO on swelling capacity, IBU release behavior and antibacterial activity were investigated by using the prepared GO/SA hydrogel as a drug carrier and IBU as a drug model. In vitro studies confirmed that the GO/SA hydrogel had good antimicrobial activity and excellent cytotoxicity. The analysis of cumulative IBU release rates revealed that the addition of GO could promote the release of IBU, and the change in GO content did not have a prominent effect on IBU release. At the same time, the rate of IBU release from the GO/SA hydrogel was affected by near-infrared light. Under a light source, the release rate of IBU increased, and the release amount of IBU showed a clear stepwise increase under light on-off conditions. These results suggest that the GO/SA hydrogel could be a potential antibacterial and anti-inflammatory wound dressing.

Medium composition optimization and characterization of polysaccharides extracted from Ganoderma boninense along with antioxidant activity

Ganoderma is a well-known medicinal macrofungal genus, of which several species have been thoroughly studied from the medicinal perspective, but most species are rarely involved in. In this study, we focus on the polysaccharides extracted from Ganoderma boninense and their antioxidant activity. Ganoderma boninense is a serious pathogen of oil palms that are cultivated commercially in Southeast Asia. Response surface methodology was conducted to optimize the liquid medium composition, and the mycelia biomass reached 7.063 g/L, that is, 1.4-fold compared with the seed medium. The crude and purified polysaccharides extracted from the fermentation broth showed well 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging abilities, and the scavenging abilities of purified polysaccharides reached 94.47 % and 99.88 %, respectively. Six fractions of polysaccharides were extracted and purified from fruiting bodies, mycelia and fermentation broth separately with the elution buffers of distilled water and 0.1 M NaCl solution. Generally, the polysaccharides from fruiting bodies showed stronger protective effect on H2O2-induced HepG2 cell oxidative damage than other fractions. A total of five to seven monosaccharides were identified in the six fractions of polysaccharides. The correlation analysis revealed that the content of fucose was significantly correlated with the antioxidant activity of polysaccharides, while xylose showed negative correlation results. In summary, the polysaccharides from G. boninense have a potential to be used as natural antioxidants.

Commercial hydrogel product for drug delivery based on route of administration

Hydrogels are hydrophilic, three-dimensional, cross-linked polymers that absorb significant amounts of biological fluids or water. Hydrogels possess several favorable properties, including flexibility, stimulus-responsiveness, versatility, and structural composition. They can be categorized according to their sources, synthesis route, response to stimulus, and application. Controlling the cross-link density matrix and the hydrogels' attraction to water while they're swelling makes it easy to change their porous structure, which makes them ideal for drug delivery. Hydrogel in drug delivery can be achieved by various routes involving injectable, oral, buccal, vaginal, ocular, and transdermal administration routes. The hydrogel market is expected to grow from its 2019 valuation of USD 22.1 billion to USD 31.4 billion by 2027. Commercial hydrogels are helpful for various drug delivery applications, such as transdermal patches with controlled release characteristics, stimuli-responsive hydrogels for oral administration, and localized delivery via parenteral means. Here, we are mainly focused on the commercial hydrogel products used for drug delivery based on the described route of administration.

Linear and nonlinear optical parameters of biodegradable chitosan/polyvinyl alcohol/sodium montmorillonite nanocomposite films for potential optoelectronic applications

Innovations in sophisticated optoelectronic devices have increased interest in high-refractive index polymers. Herein, we report innovative nanocomposite films with high linear and nonlinear refractive indices prepared by casting chitosan (Cs) with polyvinyl alcohol (PVA) (50:50 wt%) along with different concentrations (10-50 wt%) of sodium montmorillonite (NaMMT) nanoclay. The refractive indices in addition to other optical parameters of homopolymers and hybrid materials were investigated by UV-Vis. spectroscopy and optical modeling to assess their potential applications in optics. Besides, the structure, morphology, and thermal stability of the prepared films were investigated by a multitude of experimental techniques including X-ray diffraction (XRD), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), and thermogravimetric analysis (TGA/DTG). The ATR-FTIR, XRD, SEM, and AFM measurements confirmed the complete exfoliation of NaMMT nanolayers in the Cs/PVA matrix. The TGA/DTG revealed an increase in the thermal stability of Cs/PVA film with increasing clay content. The UV-Vis. measurements revealed a decrease in the optical energy gap (Eg) and a substantial increase in the linear (nD) and nonlinear (n2) refractive indices as clay content increased. Additionally, the nanohybrids displayed low UV transmission and reflected about 80 % of UV rays, making them excellent candidates for UV protection. For the first time, the dissipation factor (tanδ) in the UV/Vis. region has been calculated and fitted with the Drude-Lorentz model to predict the plasma frequency (ωp), resonance frequency (ω0), and electron lifetime (τ) of pristine polymers and nanocomposites.

A review on versatile applications of biomaterial/polycationic chitosan: An insight into the structure-property relationship

Chitosan is a versatile and generous biopolymer obtained by alkaline deacetylation of naturally occurring chitin, the second most abundant biopolymer after cellulose. The excellent physicochemical properties of polycationic chitosan are attributed to the presence of varied functional groups such as amino, hydroxyl, and acetamido groups enabling researchers to tailor the structure and properties of chitosan by different methods such as crosslinking, grafting, copolymerization, composites, and molecular imprinting techniques. The prepared derivatives have diverse applications in the food industry, water treatment, cosmetics, pharmaceuticals, agriculture, textiles, and biomedical applications. In this review, numerous applications of chitosan and its derivatives in various fields have been discussed in detail with an insight into their structure-property relationship. This review article concludes and explains the chitosan's biocompatibility and efficiency that has been done so far with future usage and applications as well. Moreover, the possible mechanism of chitosan's activity towards several emerging fields such as energy storage, biodegradable packaging, photocatalysis, biorefinery, and environmental bioremediation are also discussed. Overall, this comprehensive review discusses the science and complete information behind chitosan's wonder function to improve our understanding which is much needful as well as will pave the way towards a sustainable future.

Reactive oxygen species-responsive hydrophobic crosslinked chitosan films based on triple-function crosslinkers

Chitosan is widely used in reactive oxygen species (ROS)-responsive films but remains great challenges owing to its weak mechanical strength and strong hydrophilicity. Herein, we synthesized novel hydrophobic crosslinked CS films with ROS-responsive properties and excellent physicochemical properties. A novel crosslinker, 2-((10-carboxydecyl)thio)succinic acid, with long-chain alkanes, three carboxyl groups, and sulfhydryl groups was synthesized and then used to produce thioether-containing crosslinked CS membranes. The results suggested that crosslinking could significantly increase the tensile strength of the film from 15.67 MPa to 24.32 MPa. The compact structure of crosslinked chitosan film improved the hydrophobicity and degradability, reduced the thermal stability and swelling rates, exhibited excellent non- cytotoxicity. The in vitro release studies revealed that crosslinked chitosan films could displayed the highest flux about 1.40 mg/ (cm2 h) and significant NR fluorescence change over 80 %. Collectively, our results demonstrate the applicability of these films as ROS-responsive drug delivery systems.

Application of Chitosan-Based Hydrogel in Promoting Wound Healing: A Review

Chitosan is a linear polyelectrolyte with active hydroxyl and amino groups that can be made into chitosan-based hydrogels by different cross-linking methods. Chitosan-based hydrogels also have a three-dimensional network of hydrogels, which can accommodate a large number of aqueous solvents and biofluids. CS, as an ideal drug-carrying material, can effectively encapsulate and protect drugs and has the advantages of being nontoxic, biocompatible, and biodegradable. These advantages make it an ideal material for the preparation of functional hydrogels that can act as wound dressings for skin injuries. This review reports the role of chitosan-based hydrogels in promoting skin repair in the context of the mechanisms involved in skin injury repair. Chitosan-based hydrogels were found to promote skin repair at different process stages. Various functional chitosan-based hydrogels are also discussed.

Preparation of novel S-allyl cysteine chitosan based nanoparticles for use in ischemic brain treatment

Objective: To enhance the brain bioavailability of S-allyl-l-cysteine (SC) by developing novel S-allyl-l-cysteine chitosan nanoparticles (SC CS NPs) and examining the quantity of SC by developing a novel method of ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) in ischemic rat brain treatment. Methods: The ionotropic gelation method was used to develop S-allyl cysteine-loaded CS NPs. The 4-factor, 5-level central composite design was optimized to determine the effect of independent variables, i.e., particle size, polydispersity index (PDI), zeta potential, EE, and loading capacity, together with their characterization, followed by drug release and intranasal permeation to enhance the brain bioavailability and examination of their neurobehavioral and biochemical parameters with their histopathological examination. Results: SC CS NPs were optimized at the particle size of 93.21 ± 3.31 nm (PDI: 0.317 ± 0.003), zeta potential of 44.4 ± 2.93, and drug loading of 41.23 ± 1.97% with an entrapment efficiency of 82.61 ± 4.93% having sustain and controlled release (79.92 ± 3.86%) with great permeation (>80.0%) of SC. SC showed the retention time of 1.021 min and 162.50/73.05 m/z. SC showed good linearity in the range of 5.0-1300.0 ng mL-1, % inter-and-intraday accuracy of 96.00-99.06% and CV of 4.38-4.38%. We observed significant results, i.e., p < 0.001 for improved (AUC)0-24 and Cmax delivered via i.v. and i.n. dose. We also observed the highly significantly observations of SC CS NPs (i.n.) based on their treatment results for the biochemical, neurobehavioral, and histopathological examination in the developed ischemic MCAO brain rat model. Conclusion: The excellent significant role of mucoadhesive CS NPs of SC was proven based on the enhancement in the brain bioavailability of SC via i.n. delivery in rats and easy targeting of the brain for ischemic brain treatment followed by an improvement in neuroprotection based on a very small dose of SC.

Chitosan-based intelligent polymeric networks for site-specific colon medication delivery: A comprehensive study on controlled release of diloxanide furoate and network formation dynamics

Oral medications are prone to gastric degradation and enzymatic inactivation, diminishing their efficacy. This study investigates a solution by developing intelligent polymeric networks, incorporating chitosan, methacrylic acid, N, N, methylene bisacrylamide, and montmorillonite clay, to enable the controlled release of Diloxanide Furoate (DF), an anti-protozoal drug. Employing a swelling-assisted diffusion technique, drug loading percentages varied from 63.96 % to 76.82 % among different formulations. Increased chitosan and methacrylic acid content enhanced drug loading, while N, N, methylene bisacrylamide and montmorillonite clay demonstrated an inverse relationship affecting diffusion and swelling. Equilibrium swelling studies unveiled formulation-dependent behaviors, with chitosan reducing swelling and methacrylic acid promoting it. Higher N, N, methylene bisacrylamide concentrations decreased swelling, indicating a denser cross-linked structure, while montmorillonite clay reduced hydrophilicity and swelling capacity. Further analyses confirmed successful gel formation, particularly in formulations with higher chitosan, methacrylic acid, and N, N, methylene bisacrylamide content, while montmorillonite clay limited gel fraction due to restricted polymer chain mobility. Techniques such as Fourier transform infrared spectroscopy, Differential scanning calorimetry, and thermal gravimetric analyses supported network development, enhancing thermal stability and cross-linking density. This research underscores the flexibility of polymeric networks for precise drug delivery, offering potential advancements in targeted therapies for various medical conditions.

Evaluation of Opuntia-carrageenan superporous hydrogel (OPM-CRG SPH) as an effective biomaterial for drug release and tissue scaffold

The process of wound healing involves complex interplay of systems biology, dependent on coordination of various cell types, both intra and extracellular mechanisms, proteins, and signaling pathways. To enhance these interactions, drugs must be administered precisely and continuously, effectively regulating the intricate mechanisms involved in the body's response to injury. Controlled drug delivery systems (DDS) play a pivotal role in achieving this objective. A proficient DDS shields the wound from mechanical, oxidative, and enzymatic stress, against bacterial contamination ensuring an adequate oxygen supply while optimizing the localized and sustained delivery of drugs to target tissue. A pH-sensitive SPH was designed by blending two natural polysaccharides, Opuntia mucilage and carrageenan, using microwave irradiation and optimized according to swelling index at pH 1.2, 7.0, and 8.0 and % porosity. Optimized grade was analyzed for surface hydrophilicity-hydrophobicity using OCA. Analytical characterizations were performed using FTIR, TGA, XRD, DSC, reflecting semicrystalline behavior. Mechanical property confirmed adequate strength. In vitro drug release study with ciprofloxacin-HCL as model drug showed 97.8 % release within 10 h, fitting to the Korsmeyer-Peppas model following diffusion and erosion mechanism. In vitro antimicrobial, anti-inflammatory assays, zebrafish toxicity, and animal studies in mice with SPH concluded it as a novel biomaterial.

Quince seed mucilage/β-cyclodextrin/Mmt-Na+-co-poly (methacrylate) based pH-sensitive polymeric carriers for controlled delivery of Capecitabine

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 ranging 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 h. NC hydrogels had higher t1/2 (10.57 h), AUC (121.52 μg.h/ml), and MRT (18.95 h) 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.

Advances in chitosan-based hydrogels for pharmaceutical and biomedical applications: A comprehensive review

The treatment of diseases, such as cancer, is one of the most significant issues correlated with human beings health. Hydrogels (HGs) prepared from biocompatible and biodegradable materials, especially biopolymers, have been effectively employed for the sort of pharmaceutical and biomedical applications, including drug delivery systems, biosensors, and tissue engineering. Chitosan (CS), one of the most abundant bio-polysaccharide derived from chitin, is an efficient biomaterial in the prognosis, diagnosis, and treatment of diseases. CS-based HGs possess some potential advantages, like high values of bioactive encapsulation, efficient drug delivery to a target site, sustained drug release, good biocompatibility and biodegradability, high serum stability, non-immunogenicity, etc., which made them practical and useful for pharmaceutical and biomedical applications. In this review, we summarize recent achievements and advances associated with CS-based HGs for drug delivery, regenerative medicine, disease detection and therapy.

Engineering pH-sensitive erodible chitosan hydrogel composite containing bacteriophage: An interplay between hydrogel and bacteriophage against Staphylococcus aureus

Encapsulation of phages represents a key approach for improving phage stability and controlling phage delivery dosage. The hydrogel made from positively charged quaternized chitosan (QCS) and multivalent crosslinker, aldehyde-modified poly(xylitol sebacate)-co-poly(ethylene glycol) (APP) was introduced for the first time for drug (phage 44AHJD) delivery. The freeze-thawing (FT) treatment enhanced the porous structure and the stress resistance of native hydrogel with increased compression stress (stiffness) from 10 to 20 kPa. The stiffness of the phage-loaded hydrogel (FTP) was suitable for the proper release of phage particles and polymer chains, both working synergistically against bacterial growth. The FTP followed the Korsmeyer-Peppas model's anomalous diffusion of phage particles at different temperatures (30-45 °C) and pH (6.6-8.5) conditions. FTP was sensitive to pH, which released more phage particles at pH-neutral conditions, while the release under acidic and alkaline conditions was more based on gel degradation. The high biocompatibility of FTP hydrogel at its working concentration of 30 mg mL-1 was demonstrated through a hemolysis ratio of <2 %. Sixty percent of the total encapsulated phages and 6 mg mL-1 of hydrogel debris were released after 10 h of hydrogel submerge treatment, which can fight the growing bacteria and the emergence of phage-resistant bacteria.

Enhancing stability of liposomes using high molecular weight chitosan to promote antioxidative stress effects and lipid-lowering activity of encapsulated lutein in vivo and in vitro

Lutein is an antioxidant with multiple beneficial functions. However, its therapeutic potential is hampered by its low water solubility and bioavailability. The goal of this study is to compare the stability of lutein-loaded liposomes (Lu-lip) and low (LC)/high molecular weight (HC) chitosan-coated Lu-lip, along with their antioxidant capacity using H2O2-induced HepG2 cells and their lipid-lowering activity using high-fat diet mice. Both LC and HC reduced the lutein degradation rate by 17.5 % and 26.72 % in a challenging environment at pH 6 and T = 4 °C. Compared to LC, the HC coating improved the size- and zeta-potential-stability of Lu-lip at 5 < pH < 7, with the best performance at pH 6. The HC coating prolonged the lutein release profile, increased the cellular uptake of Lu-lip, and reduced the reactive oxygen species (ROS) levels and the H2O2-induced necrotic cell ratios by increasing the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Animal experiments have shown that oral administration of LC and HC coated Lu-lip can significantly reduce body weight levels, total triglycerides (TG), total cholesterol (TC), and non-high-density lipoprotein (n-HDL-C) in high-fat diet mice while significantly increasing the levels of CAT, SOD and GSH-Px in the liver of mice. LC and HC coated Lu-lip can reduce fat accumulation in the liver and epididymal adipose tissue.

Influence of Poloxamer 188 on Anti-Inflammatory and Analgesic Effects of Diclofenac-Loaded Nanoemulsion: Formulation, Optimization and in Vitro/in Vivo Evaluation

In this study, a polymer-stabilized nanoemulsion (PNE) was developed to improve the inflammatory and analgesic activities of diclofenac (DA). DA-PNEs were prepared from sesame oil and poloxamer 188 (P188), polysorbate 80, and span 80 as emulsifiers and optimized by a systematic multi-objective optimization method. The developed DA-PNEs exhibited thermodynamical stability with low viscosity. The mean diameter, PDI, surface charge, and entrapment efficiency of DA-PNEs were 122.49±3.42 nm, 0.226±0.08, -47.3 ± 3.6 mV, and 93.57±3.4 %, respectively. The cumulative in vitro release profile of DA-PNEs was significantly higher than the neat drug in simulated gastrointestinal fluids. The anti-inflammatory activities of DA-PNEs were evaluated in the λ-carrageenan-induced paw edema model. To investigate the effect of P188 on analgesic and anti-inflammatory activities, a formulation without P188 was also prepared and named DA-NEs. Following oral administration, DA-PNEs showed a significantly higher (p<0.05) effect in reducing pain and inflammation symptoms as compared to free diclofenac and DA-NEs. Moreover, histopathological examination confirmed that DA-PNEs meaningfully reduced the extent of paw edema, comparable to that of DA. Taken together, the findings of the in vitro and in vivo studies suggest that diclofenac-loaded P188-stabilized nanoemulsion can be considered a potential drug delivery system for treating and controlling inflammatory disorders and alleviating pains.

Controllable release of nitric oxide from an injectable alginate hydrogel

Currently, the controlled release of nitric oxide (NO) plays a crucial role in various biomedical applications. However, injectable NO-releasing materials remain an underexplored research field to date. In this study, via the incorporation of S-nitroso-N-acetyl-penicillamine (SNAP) as an NO donor, a family of NO-releasing injectable hydrogels was synthesized through the in situ cross-linking between sodium alginate and calcium ion induced by D-(+)-gluconate δ-lactone as an initiator. Initially, the organic functional groups and the corresponding morphologies of the resulting injectable hydrogels were characterized by IR and SEM spectroscopies, respectively. The NO release times of hydrogels with different SNAP loading amounts could reach up to 36-47 h. Due to the release of NO, the highest antibacterial rates of these injectable hydrogels against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were up to 95 %, respectively. Furthermore, the matrix of these hydrogels demonstrated great water absorption ability, swelling behavior, and degradation performance. Finally, we expect that these NO-releasing injectable hydrogels could have great potential applications various biomedical material fields.

Sodium alginate-carboxymethyl chitosan hydrogels loaded with difenoconazole for pH-responsive release to control wheat crown rot

Increasing concern about environmental pollution has driven the development of controlled release formulations for agrochemicals. Due to the advantages of degradability and responsiveness to environmental stimuli, polysaccharide-based hydrogel is an ideal carrier for agrochemicals controlled release. In this study, a method-easy polysaccharide hydrogel for controlled release of difenoconazole (DZ) was prepared with sodium alginate (SA) and carboxymethyl chitosan (CMCS). Due to its three-dimensional crosslinked mesh structure, the prepared hydrogels (CSDZ) showed an agrochemical load capacity of 9.03 % and an encapsulation efficiency of 68.64 %. The release rate is faster in alkaline solution, followed by neutral solution, and slowest in an acid environment, which is consistent with the swelling behavior. Furthermore, leaching studies showed that CSDZ hydrogels have excellent protective properties for encapsulated agrochemicals. Compared with technical DZ, the results of in vitro and pot antifungal testing showed that CSDZ had a better control effect against wheat crown rot (Fusarium pseudograminearum). Safety assessment studies indicated that CSDZ hydrogels exhibit good biocompatibility on nontargeted organisms (Daphnia magna, zebrafish and Eisenia fetida) and wheat. This study aims to provide a potentially promising approach for the preparation and application of biocompatible polysaccharide-based hydrogels for agrochemical-controlled release in sustainable disease management.

Enhanced Stability of Dopamine Delivery via Hydrogel with Integrated Graphene

The synthesis of graphene-based materials for drug delivery represents an area of active research, and the use of graphene in drug delivery systems is promising due to its unique properties. Thus, in the present work, we discuss the potential of few-layer graphene in a hydrogel system for dopamine release. The hydrogels are frequently used for these systems for their special physico-chemical properties, which can ensure that the drug is effectively released in time. However, the release from such structures is mostly determined by diffusion alone, and to overcome this restriction, the hydrogel can be "improved" with nanoscale fillers like graphene. The release kinetics of the composite obtained were analyzed to better understand how the use of graphene, instead of the more common graphene oxide (GO) and reduced graphene oxide (rGO), affects the characteristics of the system. Thus, the systems developed in this study consist of three main components: biopolymer, graphene, and dopamine. The hydrogels with graphene were prepared by combining two different solutions, one with polyacrylic acid and agarose and one with graphene prepared by the exfoliation method with microwave irradiation. The drug delivery systems were developed by adding dopamine to the obtained hydrogels. After 24 h of release, the presence of dopamine was observed, demonstrating that the system developed can slow down the drug's degradation because of the interactions with the graphene nanoplates and the polymer matrix.

Role and architectural significance of porous chitosan-based scaffolds in bone tissue engineering

In designing and fabricating scaffolds to fill the bone defects and stimulate new bone formation, the biomimetics of the construct is a crucial factor in invoking the bone microenvironment to promote osteogenic differentiation. Regarding structural traits, changes in porous characteristics of the scaffolds, such as pore size, pore morphology, and percentage porosity, may patronize or jeopardize their other physicochemical and biological properties. Chitosan (CS), a biodegradable naturally occurring polymer, has recently drawn considerable attention as a scaffolding material in tissue engineering and regenerative medicine. CS-based microporous scaffolds have been reported to aid osteogenesis under both in vitro and in vivo conditions by supporting cellular attachment and proliferation of osteoblast cells and the formation of mineralized bone matrix. This related notion may be found in numerous earlier research, even though the precise mechanism of action that encourages the development of new bone still needs to be understood completely. This article presents the potential correlations and the significance of the porous properties of the CS-based scaffolds to influence osteogenesis and angiogenesis during bone regeneration. This review also goes over resolving the mechanical limitations of CS by blending it with other polymers and ceramics.

Novel chitosan/γ-alumina/carbon quantum dot hydrogel nanocarrier for targeted drug delivery

Curcumin (CUR) is among the most natural and effective antitumor drugs for cancer treatment. These drugs have low solubility and short half-lives that reduce their effectiveness in drug release systems. Herein, a hydrogel nanocarrier containing chitosan (CS), alumina (γ-Al2O3), and carbon quantum dots (CQDs) was prepared by the water-in-oil-in-water (W/O/W) double nanoemulsion method. DLS revealed a nanocarrier size of 227 nm, with a zeta potential of -37.8 mV, which corroborates its stability. FE-SEM showed its quasi-spherical shape, FT-IR and XRD confirmed the presence of all the components in the nanocomposite and gave information about the intermolecular interactions between them and the crystalline nature of the nanocarrier, respectively. The drug loading (48 %) and entrapment efficiency (86 %) were higher than those reported previously for other CUR nanocarriers. The drug release profile revealed a controlled and stable release, and a pH-sensitive behavior, with faster CUR release in an acid environment. The breast cancer cell line was examined by cytotoxicity and cell apoptosis analyses. The results showed that the slow release over time and the programmed cell death were due to interactions between CUR and the nanocarrier. Considering the results obtained herein, CS/γAl2O3/CQDs/CUR can be considered as a promising new nanosystem for tumor treatment.

Polyvinyl-alcohol, chitosan and graphene-oxide composed conductive hydrogel for electrically controlled fluorescein sodium transdermal release

Accurate and controlled release of drug molecules is crucial for transdermal drug delivery. Electricity, as an adjustable parameter, offers the potential for precise and controllable drug delivery. However, challenges exist in selecting the appropriate drug carrier, electrical parameters, and release model to achieve controlled electronic drug release. To overcome these challenges, this study designed a functional hydrogel using polyvinyl alcohol, chitosan, and graphene oxide as components that can conduct electricity, and constructed a drug transdermal release model using fluorescein sodium salt with proper electrical parameters. The results demonstrated that the hydrogel system exhibited low cytotoxicity, good conductivity, and desirable drug delivery characteristics. The study also integrated the effects of drug release and tissue repair promotion under electrical stimulation. Cell growth was enhanced under low voltage direct current pulses, promoting cell migration and the release of VEGF and FGF. Furthermore, the permeability of fluorescein sodium salt in the hydrogel increased with direct current stimulation. These findings suggest that the carbohydrate polymers hydrogel could serve as a drug carrier for controlled release, and electrical stimulation offers new possibilities for functional drug delivery and transdermal therapy.

Guar gum-based stimuli responsive hydrogels for sustained release of diclofenac sodium

In the current study, hydrogels for the controlled release of diclofenac sodium were synthesized from graphene oxide-reinforced guar gum and poly (N-vinyl-2-pyrrolidone) using the Solution Casting Technique. Varying concentrations of 3-Glycidyloxypropyl trimethoxysilane (GLYMO) were employed for the crosslinking of hydrogels. Further, the characterization of hydrogels was carried out using different techniques such as Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction, thermal analysis and scanning electron microscope. The FTIR investigations reveals particular functionalities and development of hydrogel interfaces. While thermal analysis prophesied that, improvement in forces among hydrogel components is directly proportional to the GLYMO concentration. In-vitro biodegradation test and cell viability assay against HEK-293 cell lines confirmed their biodegradable and biocompatible nature. GPG-32 demonstrated maximum antibacterial activity against P.aeruginosa and E.coli strains. The maximum swelling 2001 % and 1814 % in distilled water were recorded for GPG (control) and GPG-8 respectively that obeyed Fick's law. Hydrogels displayed high swelling responses at pH 6 in buffer and non-buffer solutions. In 2.5 h, 88.7 % diclofenac sodium was released which was determined by UV visible spectrophotometer. In conclusion, guar gum-based non-toxic, biocompatible and biodegradable hydrogels would be a model platform for targeting inflammation and pains. Furthermore, improved mechanical and viscoelastic behavior of hydrogels could also be explored for making drug loaded dressings for wound healing applications.

Exploring the Drug-Loading and Release Ability of FucoPol Hydrogel Membranes

The polysaccharide FucoPol has recently been shown to yield hydrogel membranes (HMs) characterized by good mechanical properties, biocompatibility, and anti-inflammatory activity that render them promising biomaterials for use in the biomedical field. Subsequently to such findings, envisaging their development into novel delivery systems for topical applications, in this study, FucoPol HMs prepared by crosslinking the biopolymer with iron cations were loaded with caffeine or diclofenac sodium as model drugs. Two loading methods, namely diffusion and mixing, were applied to evaluate the FucoPol's HM drug-loading capacity and entrapment efficiency. The diffusion method led to a higher caffeine loading (101.9 ± 19.1 mg/g) in the HM1_DCAF membranes, while the mixing method resulted in a higher diclofenac sodium loading (82.3 ± 5.1 mg/g) in the HM1_DDS membranes. The HM1_DCAF membranes were characterized by increased mechanical and rheological parameters, such as their hardness (130.0 ± 5.3 kPa) and storage modulus (1014.9 ± 109.7 Pa), compared to the HM1_DDS membranes that exhibited lower values (7.3 ± 1.2 kPa and 19.8 ± 3.8 Pa, respectively), probably due to leaching occurring during the drug-loading process. The release profiles revealed a fast release of both APIs from the membranes loaded by diffusion, while a prolonged and sustained release was obtained from the membranes loaded by mixing. Moreover, for all API-loaded membranes, the release mechanism followed Fickian diffusion, with the release rate being essentially governed by the diffusion process. These findings, together with their previously shown biological properties, support the suitability of the developed FucoPol HMs to be used as platforms for the topical delivery of drugs.

Exploration of curcumin-incorporated dual anionic alginate-quince seed gum films for transdermal drug delivery

The idea of combining bioextracted polymers for wound healing applications has emerged in hopes of developing highly flexible and mechanically stable hydrogel films with controlled drug delivery, biocompatibility, and high collagen deposition. In the present research, polysaccharide films composed of Alginate and Quince Seed Gum (QSG) were fabricated by ionic crosslinking, and their potential for curcumin delivery and wound healing were examined. In this regard, microstructure, mechanical properties, thermal stability, physiochemical properties, and biocompatibility of films with three different QSG amounts (25 %, 50 %, and 75 %) were studied. Because of the optimum properties of 25 % QSG films like better transparency (Opacity = 6.1 %), higher flexibility (Elongation = 28.9 %), less water solubility (Water solubility = 66.6 %), proper absorbance (Swelling degree = >600 %), and suitable biocompatibility (Cell viability = >85 %), they were used for drug delivery examination. Curcumin administration through films with and without stearic acid modification was investigated. Stearic Acid (SA) modified samples demonstrated superior compatibility between hydrophobic drug and hydrophilic film. Stearic acid-modified film could prolong the curcumin release up to 48 h and showed increased collagen synthesis and TGF-β expression, making it an excellent candidate for transdermal drug delivery and wound healing applications.

Development of κ-carrageenan-PEG/lecithin bioactive hydrogel membranes for antibacterial adhesion and painless detachment

The issue of wound dressing adherence poses a substantial challenge in the field of wound care, with implications both clinically and economically. Overcoming this challenge requires the development of a hydrogel dressing that enables painless removal without causing any secondary damage. However, addressing this issue still remains a significant challenge that requires attention and further exploration. The present study is focused on the synthesis of hydrogel membranes based on κ-carrageenan (CG), polyethylene glycol (PEG), and soy lecithin (LC), which can provide superior antioxidant and antibacterial attachment properties with a tissue anti adhesion activity for allowing an easy removability without causing secondary damage. The (CG-PEG)/LC mass ratio was varied to fabricate hydrogel membranes via a facile approach of physical blending and solution casting. The physicochemical properties of (CG-PEG)/LC hydrogel membranes were studied by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and mechanical analyses. The membranes showed significantly enhanced mechanical properties with excellent flexibility and had high swelling capacity (˃1000 %), which would provide a moist condition for wound healing. The membranes also exhibited excellent free radical scavenging ability (>60 %). In addition, the (CG-PEG)/LC hydrogel membranes showed reduced peel strength 26.5 N/m as a result of weakening the hydrogel-gelatin interface during an in vitro gelatin peeling test. Moreover, the membrane showed superior antibacterial adhesion activity (>90 %) against both S. aureus and E. coli due to the presence of both PEG and LC. The results also suggested that the hydrogel membranes exhibit NIH3T3 cell antiadhesion property, making them promising material for easy detachment from the healed tissue without causing secondary damage. Thus, this novel combination of (CG-PEG)/LC hydrogel membranes have immense application potential as a biomaterial in the healthcare sector.

Development and characterization of crosslinked k-carrageenan/sericin blend with covalent agents or thermal crosslink for indomethacin extended release

Modified release of multiparticulate pharmaceutical forms is a key therapeutic strategy to reduce side effects and toxicity caused by high and repeated doses of immediate-release oral drugs. This research focused on the encapsulation of indomethacin (IND) in the crosslinked k-Car/Ser polymeric matrix by covalent and thermal methods to evaluate drug delivery modulation and properties of the crosslinked blend. Therefore, the entrapment efficiency (EE %), drug loading (DL %) and physicochemical properties of the particles were investigated. The particles presented a spherical shape and a rough surface with a mean diameter of 1.38-2.15 mm (CCA) and 1.56-1.86 mm (thermal crosslink). FTIR investigation indicated the presence of IDM in the particles and X-ray pattern showed the maintenance of crystallinity of IDM. The in vitro release in acidic medium (pH 1.2) and phosphate buffer saline solution (pH 6.8) was 1.23-6.81 % and 81-100 %, respectively. Considering the results, the formulations remained stable after 6 months. The Weibull equation was adequately fitted for all formulations and a diffusion mechanism, swelling and relaxation of chain were observed. IDM-loaded k-carrageenan/sericin/CMC increases cell viability (> 75 % for neutral red and > 81 % for MTT). Finally, all formulations present gastro-resistance, pH response and altered release and have the potential to be used as drug delivery careers.