A Review on Chitosan and Cellulose Hydrogels for Wound Dressings

Development of biomaterial composite hydrogel as a passive sampler with potential application in wastewater-based surveillance

Nowadays, the need to track fast-spreading infectious diseases has raised due to the recent COVID-19 disease pandemic. As a response, Wastewater-based Surveillance (WBS) has emerged as an early detection and disease tracking method for large populations that enables a comprehensive overview of public health allowing for a faster response from public health sector to prevent large outbreaks. The process to achieve WBS requires a highly intensive sampling strategy with either expensive equipment or trained personnel to continuously sample. The sampling problem can be addressed by passive sampler development. Chitosan-based hydrogels are recognized for their capability to sample and remove various contaminants from wastewater, including metals, dyes, pharmaceuticals, among others. However, chitosan-based hydrogels unique characteristics, can be exploited to develop passive samplers of genetic material that can be a very valuable tool for WBS. This study aimed to develop a novel chitosan hydrogel formulation with enhanced characteristics suitable for use as a passive sampler of genetic material and its application to detect disease-causing pathogens present in wastewater. The study evaluates the effect of the concentration of different components on the formulation of a Chitosan composite hydrogel (Chitosan, Glutaraldehyde, Microcrystalline cellulose (MCC), and Polyethylene glycol (PEG)) on the hydrogel properties using a Box Hunter & Hunter experimental matrix. Hydrogels' weight, thickness, swelling ratio, microscopic morphology (SEM), FTIR assay, and zeta potential were characterized. The resulting hydrogel formulations were shown to be highly porous, positively charged (Zeta potential up to 35.80 ± 1.44 mV at pH 3) and with high water swelling capacity (up to 703.89 ± 15.00 %). Based on the results, a formulation from experimental design was selected and then evaluated its capacity to adsorb genetic material from a control spiked water with Influenza A virus synthetic vector. The adsorption capacity of the selected formulation was 4157.04 ± 64.74 Gene Copies/mL of Influenza A virus synthetic vector. The developed hydrogel showed potential to be used as passive sampler for pathogen detection in wastewater. However, deeper research can be conducted to improve adsorption, desorption and extraction techniques of genetic material from chitosan-hydrogel matrices.

Evaluation of composition effects on the tissue-adhesive, mechanical and physical properties of physically crosslinked hydrogels based on chitosan and pullulan for wound healing applications

Tissue adhesion of hydrogels plays an important role in wound healing, which can improve the efficiency of wound treatment, stop bleeding, facilitate tissue growth and wound closure. However, most non-covalent crosslinked hydrogels have weak tissue adhesion and rheological properties. Furthermore, it remains a challenge to synthesize a fully physically crosslinked hydrogel with good rheological properties without compromising its tissue adhesion strength. In this paper, a physically crosslinked hydrogel was developed from a mixture of chitosan and pullulan in different polymer volume ratios using aqueous NaOH. Fourier transform infrared spectroscopy, scanning electron microscopy, thermal analysis, rheological and lap shear tests were used to evaluate the influence of polymer volume ratios on the rheological, and tissue adhesive properties of the hydrogels. It was found that the hydrogels possessed high tissue adhesive strength ranging from 18.0 ± 0.90 to 49.0 ± 2.45 kPa and good storage moduli up to 5.157 ± 1.062 kPa. Gentamicin was incorporated into this polymer matrix and the release profile was investigated. The ratio of chitosan and pullulan to obtain hydrogels with optimum viscoelastic and tissue adhesive properties was identified to be CS/PUL 2:1. These results indicated that the synthesized hydrogels can be potential materials for biomedical applications such as medical adhesives and wound dressings.

Recent developments in the design of functional derivatives of edaravone and exploration of their antioxidant activities

Edaravone, a pyrazalone derivative, is an antioxidant and free radical scavenger used to treat oxidative stress-related diseases. It is a proven drug to mitigate conditions prevailing to oxidative stress by inhibiting lipid peroxidation, reducing inflammation, and thereby preventing endothelial cell death. In recent years, considerable interest has been given by researchers in the derivatization of edaravone by adding varieties of substituents of versatile steric and functional properties to improve its antioxidant and pharmacological activity. This review accounts all the important methods developed for the derivatization of edaravone and the impacts of the structural modifications on the antioxidant activity of the motif.

A bacterial cellulose/polyvinyl alcohol/nitro graphene oxide double layer network hydrogel efficiency antibacterial and promotes wound healing

In this study, graphene oxide (GO) was chemically modified utilizing concentrated nitric acid to produce a nitrated graphene oxide derivative (NGO) with enhanced oxidation level, improved dispersibility, and increased antibacterial activity. A double-layer composite hydrogel material (BC/PVA/NGO) with a core-shell structure was fabricated by utilizing bacterial cellulose (BC) and polyvinyl alcohol (PVA) binary composite hydrogel scaffold as the inner network template, and hydrophilic polymer (PVA) loaded with antibacterial material (NGO) as the outer network. The fabrication process involved physical crosslinking based on repeated freezing and thawing. The resulting BC/PVA/NGO hydrogel exhibited a porous structure, favorable mechanical properties, antibacterial efficacy, and biocompatibility. Subsequently, the performance of BC/PVA/NGO hydrogel in promoting wound healing was evaluated using a mouse skin injury model. The findings demonstrated that the BC/PVA/NGO hydrogel treatment group facilitated improved wound healing in the mouse skin injury model compared to the control group and the BC/PVA group. This enhanced wound healing capability was attributed primarily to the excellent antibacterial and tissue repair properties of the BC/PVA/NGO hydrogel.

A comprehensive review on recent progress in chitosan composite gels for biomedical uses

Chitosan (CS) composite gels have emerged as promising materials with diverse applications in biomedicine. This review provides a concise overview of recent advancements and key aspects in the development of CS composite gels. The unique properties of CS, such as biocompatibility, biodegradability, and antimicrobial activity, make it an attractive candidate for gel-based composites. Incorporating various additives, such as nanoparticles, polymers, and bioactive compounds, enhances the mechanical, thermal, and biological and other functional properties of CS gels. This review discusses the fabrication methods employed for CS composite gels, including blending and crosslinking, highlighting their influence on the final properties of the gels. Furthermore, the uses of CS composite gels in tissue engineering, wound healing, drug delivery, and 3D printing highlight their potential to overcome a number of the present issues with drug delivery. The biocompatibility, antimicrobial properties, electroactive, thermosensitive and pH responsive behavior and controlled release capabilities of these gels make them particularly suitable for biomedical applications. In conclusion, CS composite gels represent a versatile class of materials with significant potential for a wide range of applications. Further research and development efforts are necessary to optimize their properties and expand their utility in pharmaceutical and biomedical fields.

Multifunctional antibacterial hydrogels for chronic wound management

Chronic wounds have gradually evolved into a global health challenge, comprising long-term non-healing wounds, local tissue necrosis, and even amputation in severe cases. Accordingly, chronic wounds place a considerable psychological and economic burden on patients and society. Chronic wounds have multifaceted pathogenesis involving excessive inflammation, insufficient angiogenesis, and elevated reactive oxygen species levels, with bacterial infection playing a crucial role. Hydrogels, renowned for their excellent biocompatibility, moisture retention, swelling properties, and oxygen permeability, have emerged as promising wound repair dressings. However, hydrogels with singular functions fall short of addressing the complex requirements associated with chronic wound healing. Hence, current research emphasises the development of multifunctional antibacterial hydrogels. This article reviews chronic wound characteristics and the properties and classification of antibacterial hydrogels, as well as their potential application in chronic wound management.

Assessment of hemostatic ability of biomaterial based on chitosan andEclipta prostrataL. extract

The biomaterials based on chitosan andEclipta prostrataL. extract have been prepared by microemulsion method and solution method (with and without sodium tripolyphosphate (STPP) as a cross-linking agent). The main component inEclipta prostrataL. extract is flavonoid groups. The structure of the chitosan/extract biomaterials was studied by infrared spectroscopy. The chitosan/extract biomaterial using STPP cross-linker appeared an absorption band at 1152 cm-1attributed to the vibrations of C-O-P bonds, which proved that chitosan has crosslinked with STPP. The morphology of the biomaterials was investigated by the dynamic light scattering technique and field emission scanning electron microscopy. The obtained results showed that the particle size of the chitosan/extract biomaterials prepared by microemulsion method and solution method with STPP ranged from 68.06 nm to 1484 nm, with an average particle size of 304.9-1019 nm. The microemulsion method produced biomaterials with much smaller average particle size than the solution method using cross-linkers. The hemostatic ability of the biomaterials was better than that of the control sample based on the time of blood clotting formation and glomerular aggregation ability. The sample with the ratio ofE. prostrataL. extract: chitosan of 1:30 had the lowest hemostasis time (6 min 46 s) and its glomerular aggregation rate after 5 min was 13.05%. This indicated that the biomaterials based on chitosan andE. prostrataL. extract are promising for application in biomedicine as hemostatic materials.

Emerging horizons and prospects of polysaccharide-constructed gels in the realm of wound healing

Polysaccharides, with the abundant availability, biodegradability, and inherent safety, offer a vast array of promising applications. Leveraging the remarkable attributes of polysaccharides, biomimetic and multifunctional hydrogels have emerged as a compelling avenue for efficacious wound dressing. The gels emulate the innate extracellular biomatrix as well as foster cellular proliferation. The distinctive structural compositions and profusion of functional groups within polysaccharides confer excellent physical/chemical traits as well as distinct restorative involvements. Gels crafted from polysaccharide matrixes serve as a robust defense against bacterial threats, effectively shielding wounds from harm. This comprehensive review delves into wound physiology, accentuating the significance of numerous polysaccharide-based gels in the wound healing context. The discourse encompasses an exploration of polysaccharide hydrogels tailored for diverse wound types, along with an examination of various therapeutic agents encapsulated within hydrogels to facilitate wound repair, incorporating recent patent developments. Within the scope of this manuscript, the perspective of these captivating gels for promoting optimal healing of wounds is vividly depicted. Nevertheless, the pursuit of knowledge remains ongoing, as further research is warranted to bioengineer progressive polysaccharide gels imbued with adaptable features. Such endeavors hold the promise of unlocking substantial potential within the realm of wound healing, propelling us toward multifaceted and sophisticated solutions.

Recent research advances on polysaccharide-, peptide-, and protein-based hemostatic materials: A review

Hemorrhage is a potentially life-threatening emergency that can occur at any time or place. Whether traumatic, congenital, surgical, disease-related, or drug-induced, bleeding can lead to severe complications or death. Therefore, the development of efficient hemostatic materials is critical. However, the results and prognosis demonstrated by clinical means of hemostasis do not reach expectations. With the development of technology, novel hemostatic materials have been developed from polysaccharides (chitosan, hyaluronic acid, alginate, cellulose, cyclodextrins, starch, dextran, and carrageenan), peptides (self-assembling peptides), and proteins (silk fibroin, collagen, gelatin, keratin, and thrombin). These new materials exhibit high hemostatic efficacy due to the enhancement or interaction of various hemostatic mechanisms. The main forms include adhesives, sealants, bandages, hemostatic powders, and hemostatic sponges. This article introduces the clotting process and principles of hemostatic methods and reviews the research on polysaccharide-, peptide-, and protein-based hemostatic materials in the last five years. The design ideas and hemostatic principles of polysaccharide-, peptide-, and protein-based hemostatic materials are mainly introduced. Finally, we summarize material designs, advantages, disadvantages, and challenges regarding hemostatic materials.

Recent Advances of Chitosan-Based Hydrogels for Skin-Wound Dressings

The management of wound healing represents a significant clinical challenge due to the complicated processes involved. Chitosan has remarkable properties that effectively prevent certain microorganisms from entering the body and positively influence both red blood cell aggregation and platelet adhesion and aggregation in the bloodstream, resulting in a favorable hemostatic outcome. In recent years, chitosan-based hydrogels have been widely used as wound dressings due to their biodegradability, biocompatibility, safety, non-toxicity, bioadhesiveness, and soft texture resembling the extracellular matrix. This article first summarizes an overview of the main chemical modifications of chitosan for wound dressings and then reviews the desired properties of chitosan-based hydrogel dressings. The applications of chitosan-based hydrogels in wound healing, including burn wounds, surgical wounds, infected wounds, and diabetic wounds are then discussed. Finally, future prospects for chitosan-based hydrogels as wound dressings are discussed. It is anticipated that this review will form a basis for the development of a range of chitosan-based hydrogel dressings for clinical treatment.

Chitosan-Based Biomaterial in Wound Healing: A Review

Wound healing is an evolving and intricate technique that is vital to the restoration of tissue integrity and function. Over the past few decades, chitosan a biopolymer derived from chitin, became known as an emerging biomaterial in the field of healing wounds due to its distinctive characteristics including biocompatibility, biodegradability, affinity to biomolecules, and wound-healing activity. This natural polymer exhibits excellent healing capabilities by accelerating the development of new skin cells, reducing inflammation, and preventing infections. Due to its distinct biochemical characteristics and innate antibacterial activity, chitosan has been extensively researched as an antibacterial wound dressing. Chronic wounds, such as diabetic ulcers and liver disease, are a growing medical problem. Chitosan-based biomaterials are a promising solution in the domain of wound care. The article analyzes the depth of chitosan-based biomaterials and their impact on wound healing and also the methods to enhance the advantages of chitosan by incorporating bioactive compounds. This literature review is aimed to improve the understanding and knowledge about biomaterials and their use in wound healing.

Wound healing potential of silver nanoparticles embedded in optimized bio-inspired hybridized chitosan soft and dry hydrogel

Interactive wound dressings combining healing and antimicrobial potentials, besides ensuring patient compliance with a recognized wound care service gained considerable interest recently. Both hydrogel spray dried microparticles (HMP) and soft hydrogel (G) were prepared. The bio-inspired combinatory platform included natural bio-macromolecules namely: chitosan (CS) and collagen (COL) with wound healing enhancement and connective tissue building capabilities cross linked with the natural genipin (GN) to build a three dimensional structured matrix. The optimized plain hydrogel obtained by a box behnken design (BBD) program (G) scored maximum swelling and porosity. The network was hosted with green synthesized cefotaxime sodium (cef.Na) AgNPs reduced by the anabolic folic acid (FA). Both hydrogels exhibited good antimicrobial activity against gram +ve and -ve bacteria. The wound healing activity, evaluated in injured rats, showed >98 % and complete wound closure after two and three weeks respectively. Oxidative stress minimization was proved by the estimation of biochemical markers malondialdehyde (MDA) and superoxide dismutase (SOD) levels at the wound site.

Stimuli-responsive polysaccharide-based smart hydrogels for diabetic wound healing: Design aspects, preparation methods and regulatory perspectives

Diabetes adversely affects wound-healing responses, leading to the development of chronic infected wounds. Such wound microenvironment is characterized by hyperglycaemia, hyperinflammation, hypoxia, variable pH, upregulation of matrix metalloproteinases, oxidative stress, and bacterial colonization. These pathological conditions pose challenges for the effective wound healing. Therefore, there is a paradigm shift in diabetic wound care management wherein abnormal pathological conditions of the wound microenvironment is used as a trigger for controlling the drug release or to improve properties of wound dressings. Hydrogels composed of natural polysaccharides showed tremendous potential as wound dressings as well as stimuli-responsive materials due to their unique properties such as biocompatibility, biodegradability, hydrophilicity, porosity, stimuli-responsiveness etc. Hence, polysaccharide-based hydrogels have emerged as advanced healthcare materials for diabetic wounds. In this review, we presented important aspects for the design of hydrogel-based wound dressings with an emphasis on biocompatibility, biodegradability, entrapment of therapeutic agents, moisturizing ability, swelling, and mechanical properties. Further, various crosslinking methods that enable desirable properties and stimuli responsiveness to the hydrogels have been mentioned. Subsequently, state-of-the-art developments in mono- and multi- stimuli-responsive hydrogels have been presented along with the case studies. Finally regulatory perspectives, challenges for the clinical translation and future prospects have been discussed.

Multifunctional and theranostic hydrogels for wound healing acceleration: An emphasis on diabetic-related chronic wounds

Hydrogels represent intricate three-dimensional polymeric structures, renowned for their compatibility with living systems and their ability to naturally degrade. These networks stand as promising and viable foundations for a range of biomedical uses. The practical feasibility of employing hydrogels in clinical trials has been well-demonstrated. Among the prevalent biomedical uses of hydrogels, a significant application arises in the context of wound healing. This intricate progression involves distinct phases of inflammation, proliferation, and remodeling, often triggered by trauma, skin injuries, and various diseases. Metabolic conditions like diabetes have the potential to give rise to persistent wounds, leading to delayed healing processes. This current review consolidates a collection of experiments focused on the utilization of hydrogels to expedite the recovery of wounds. Hydrogels have the capacity to improve the inflammatory conditions at the wound site, and they achieve this by diminishing levels of reactive oxygen species (ROS), thereby exhibiting antioxidant effects. Hydrogels have the potential to enhance the growth of fibroblasts and keratinocytes at the wound site. They also possess the capability to inhibit both Gram-positive and Gram-negative bacteria, effectively managing wounds infected by drug-resistant bacteria. Hydrogels can trigger angiogenesis and neovascularization processes, while also promoting the M2 polarization of macrophages, which in turn mitigates inflammation at the wound site. Intelligent and versatile hydrogels, encompassing features such as pH sensitivity, reactivity to reactive oxygen species (ROS), and responsiveness to light and temperature, have proven advantageous in expediting wound healing. Furthermore, hydrogels synthesized using environmentally friendly methods, characterized by high levels of biocompatibility and biodegradability, hold the potential for enhancing the wound healing process. Hydrogels can facilitate the controlled discharge of bioactive substances. More recently, there has been progress in the creation of conductive hydrogels, which, when subjected to electrical stimulation, contribute to the enhancement of wound healing. Diabetes mellitus, a metabolic disorder, leads to a slowdown in the wound healing process, often resulting in the formation of persistent wounds. Hydrogels have the capability to expedite the healing of diabetic wounds, facilitating the transition from the inflammatory phase to the proliferative stage. The current review sheds light on the biological functionalities of hydrogels, encompassing their role in modulating diverse mechanisms and cell types, including inflammation, oxidative stress, macrophages, and bacteriology. Additionally, this review emphasizes the significance of smart hydrogels with responsiveness to external stimuli, as well as conductive hydrogels for promoting wound healing. Lastly, the discussion delves into the advancement of environmentally friendly hydrogels with high biocompatibility, aimed at accelerating the wound healing process.

Nanosilver-Functionalized Hybrid Hydrogels of Carboxymethyl Cellulose/Poly(Vinyl Alcohol) with Antibacterial Activity for Prevention and Therapy of Infections of Diabetic Chronic Wounds

Diabetic foot ulcers (DFUs) are considered one of the most severe chronic complications of diabetes and can lead to amputation in severe cases. In addition, bacterial infections in diabetic chronic wounds aggravate this scenario by threatening human health. Wound dressings made of polymer matrices with embedded metal nanoparticles can inhibit microorganism growth and promote wound healing, although the current clinical treatments for diabetic chronic wounds remain unsatisfactory. In this view, this research reports the synthesis and characterization of innovative hybrid hydrogels made of carboxymethyl cellulose (CMC) and poly(vinyl alcohol) (PVA) chemically crosslinked by citric acid (CA) functionalized with silver nanoparticles (AgNPs) generated in situ using an eco-friendly aqueous process. The results assessed through comprehensive in vitro and in vivo assays demonstrated that these hybrid polymer hydrogels functionalized with AgNPs possess physicochemical properties, cytocompatibility, hemocompatibility, bioadhesion, antibacterial activity, and biocompatibility suitable for wound dressings to support chronic wound healing process as well as preventing and treating bacterial infections. Hence, it can be envisioned that, with further research and development, these polymer-based hybrid nanoplatforms hold great potential as an important tool for creating a new generation of smart dressings for treating chronic diabetic wounds and opportunistic bacterial infections.

Strategies for the Preparation of Chitosan Derivatives for Antimicrobial, Drug Delivery, and Agricultural Applications: A Review

Chitosan has received much attention for its role in designing and developing novel derivatives as well as its applications across a broad spectrum of biological and physiological activities, owing to its desirable characteristics such as being biodegradable, being a biopolymer, and its overall eco-friendliness. The main objective of this review is to explore the recent chemical modifications of chitosan that have been achieved through various synthetic methods. These chitosan derivatives are categorized based on their synthetic pathways or the presence of common functional groups, which include alkylated, acylated, Schiff base, quaternary ammonia, guanidine, and heterocyclic rings. We have also described the recent applications of chitosan and its derivatives, along with nanomaterials, their mechanisms, and prospective challenges, especially in areas such as antimicrobial activities, targeted drug delivery for various diseases, and plant agricultural domains. The accumulation of these recent findings has the potential to offer insight not only into innovative approaches for the preparation of chitosan derivatives but also into their diverse applications. These insights may spark novel ideas for drug development or drug carriers, particularly in the antimicrobial, medicinal, and plant agricultural fields.

Cellulose-Based Metallogels-Part 3: Multifunctional Materials

The incorporation of the metal phase into cellulose hydrogels, resulting in the formation of metallogels, greatly expands their application potential by introducing new functionalities and improving their performance in various fields. The unique antiviral, antibacterial, antifungal, and anticancer properties of metal and metal oxide nanoparticles (Ag, Au, Cu, CuxOy, ZnO, Al2O3, TiO2, etc.), coupled with the biocompatibility of cellulose, allow the development of composite hydrogels with multifunctional therapeutic potential. These materials can serve as efficient carriers for controlled drug delivery, targeting specific cells or pathogens, as well as for the design of artificial tissues or wound and burn dressings. Cellulose-based metallogels can be used in the food packaging industry to provide biodegradable and biocidal materials to extend the shelf life of the goods. Metal and bimetallic nanoparticles (Au, Cu, Ni, AuAg, and AuPt) can catalyze chemical reactions, enabling composite cellulose hydrogels to be used as efficient catalysts in organic synthesis. In addition, metal-loaded hydrogels (with ZnO, TiO2, Ag, and Fe3O4 nanoparticles) can exhibit enhanced adsorption capacities for pollutants, such as dyes, heavy metal ions, and pharmaceuticals, making them valuable materials for water purification and environmental remediation. Magnetic properties imparted to metallogels by iron oxides (Fe2O3 and Fe3O4) simplify the wastewater treatment process, making it more cost-effective and environmentally friendly. The conductivity of metallogels due to Ag, TiO2, ZnO, and Al2O3 is useful for the design of various sensors. The integration of metal nanoparticles also allows the development of responsive materials, where changes in metal properties can be exploited for stimuli-responsive applications, such as controlled release systems. Overall, the introduction of metal phases augments the functionality of cellulose hydrogels, expanding their versatility for diverse applications across a broad spectrum of industries not envisaged during the initial research stages.

Thermosensitive black phosphorus hydrogel loaded with silver sulfadiazine promotes skin wound healing

Wounds can lead to skin and soft tissue damage and their improper management may lead to the growth of pathogenic bacteria at the site of injury. Identifying better ways to promote wound healing is a major unmet need and biomedical materials with the ability to promote wound healing are urgently needed. Here, we report a thermosensitive black phosphorus hydrogel composed of black phosphorus nano-loaded drug silver sulfadiazine (SSD) and chitosan thermosensitive hydrogel for wound healing. The hydrogel has temperature-sensitive properties and enables the continuous release of SSD under near-infrared irradiation to achieve synergistic photothermal and antibacterial treatment. Additionally, it exerts antibacterial effects on Staphylococcus aureus. In a rat skin injury model, it promotes collagen deposition, boosts neovascularization, and suppresses inflammatory markers. In summary, the excellent thermosensitivity, biocompatibility, and wound-healing-promoting qualities of the reported thermosensitive hydrogel make it suitable as an ideal wound dressing in the clinic.

Progress of Hydrogel Dressings with Wound Monitoring and Treatment Functions

Hydrogels are widely used in wound dressings due to their moisturizing properties and biocompatibility. However, traditional hydrogel dressings cannot monitor wounds and provide accurate treatment. Recent advancements focus on hydrogel dressings with integrated monitoring and treatment functions, using sensors or intelligent materials to detect changes in the wound microenvironment. These dressings enable responsive treatment to promote wound healing. They can carry out responsive dynamic treatment in time to effectively promote wound healing. However, there is still a lack of comprehensive reviews of hydrogel wound dressings that incorporate both wound micro-environment monitoring and treatment functions. Therefore, this review categorizes hydrogel dressings according to wound types and examines their current status, progress, challenges, and future trends. It discusses various wound types, including infected wounds, burns, and diabetic and pressure ulcers, and explores the wound healing process. The review presents hydrogel dressings that monitor wound conditions and provide tailored treatment, such as pH-sensitive, temperature-sensitive, glucose-sensitive, pressure-sensitive, and nano-composite hydrogel dressings. Challenges include developing dressings that meet the standards of excellent biocompatibility, improving monitoring accuracy and sensitivity, and overcoming obstacles to production and commercialization. Furthermore, it provides the current status, progress, challenges, and future trends in this field, aiming to give a clear view of its past, present, and future.

The effect of different hemostatic agents following dental extraction in patients under oral antithrombotic therapy: a network meta-analysis

This network meta-analysis was done to thoroughly evaluate the available literature on the use of different hemostatic agents for dental extraction in patients under oral antithrombotic therapy, aiming to identify the agent with the best/worst performance in bleeding control. Considering that such patients have a higher risk of bleeding, choosing the right hemostatic is essential. Twenty-three randomized clinical trials articles were included after completing the literature search. Cyanoacrylate tissue adhesive showed a reduction in the odds of postoperative bleeding events compared with conventional methods (i.e., gauze/cotton pressure, sutures), with a tendency toward a statistical significance (OR 0.03, P = 0.051). Tranexamic acid was the only agent that demonstrated a significantly lower risk of developing postoperative bleeding events (OR 0.27, P = 0.007). Interestingly, chitosan dental dressing and collagen plug had the shortest time to reach hemostasis. However, they ranked last among all hemostatic agents, regarding bleeding events, revealing higher odds than conventional measures. Therefore, it is concluded that the use of cyanoacrylate tissue adhesive and tranexamic acid gives favorable results in reducing postoperative bleeding events following dental extractions. Although chitosan dental dressing and collagen exhibited a faster time to reach hemostasis, they led to a higher occurrence of bleeding events.

Chitosan-Based Hydrogel in the Management of Dermal Infections: A Review

The main objective of this review is to provide a comprehensive overview of the current evidence regarding the use of chitosan-based hydrogels to manage skin infections. Chitosan, a naturally occurring polysaccharide derived from chitin, possesses inherent antimicrobial properties, making it a promising candidate for treating various dermal infections. This review follows a systematic approach to analyze relevant studies that have investigated the effectiveness of chitosan-based hydrogels in the context of dermal infections. By examining the available evidence, this review aims to evaluate these hydrogels' overall efficacy, safety, and potential applications for managing dermal infections. This review's primary focus is to gather and analyze data from different recent studies about chitosan-based hydrogels combating dermal infections; this includes assessing their ability to inhibit the growth of microorganisms and reduce infection-related symptoms. Furthermore, this review also considers the safety profile of chitosan-based hydrogels, examining any potential adverse effects associated with their use. This evaluation is crucial to ensure that these hydrogels can be safely utilized in the management of dermal infections without causing harm to patients. The review aims to provide healthcare professionals and researchers with a comprehensive understanding of the current evidence regarding the use of chitosan-based hydrogels for dermal infection management. The findings from this review can contribute to informed decision-making and the development of potential treatment strategies in this field.

Chitosan-Based Biomaterials for Hemostatic Applications: A Review of Recent Advances

Hemorrhage is a detrimental event present in traumatic injury, surgery, and disorders of bleeding that can become life-threatening if not properly managed. Moreover, uncontrolled bleeding can complicate surgical interventions, altering the outcome of surgical procedures. Therefore, to reduce the risk of complications and decrease the risk of morbidity and mortality associated with hemorrhage, it is necessary to use an effective hemostatic agent that ensures the immediate control of bleeding. In recent years, there have been increasingly rapid advances in developing a novel generation of biomaterials with hemostatic properties. Nowadays, a wide array of topical hemostatic agents is available, including chitosan-based biomaterials that have shown outstanding properties such as antibacterial, antifungal, hemostatic, and analgesic activity in addition to their biocompatibility, biodegradability, and wound-healing effects. This review provides an analysis of chitosan-based hemostatic biomaterials and discusses the progress made in their performance, mechanism of action, efficacy, cost, and safety in recent years.

Delivery of Porphyrins Through Self-Assembling Peptide Hydrogels for Accelerated Healing of Experimental Skin Defects In Vivo

INTRODUCTION

The care and healing of skin defects resulting from different causes has been the object of research to achieve rapid and complete skin regeneration. Hydrogels have been used for their ability to maintain hydration during wound healing, absorb wound exudate, and cover the underlying tissue without adherence while being transparent. In this study, we evaluated the efficacy of a hydrogel (H) with encapsulated porphyrin (H+P) on a rat model of surgically-induced skin defects.

METHODS

Four round 6 mm diameter skin defects were performed under general anesthesia on the dorsal area of 24 three-month-old "Young" and 24 twelve-month-old "Mature" male rats. Each age group was separated into the Control, H, and H+P groups, n=8 each, where no therapy, H, or H+P was respectively applied daily for 20 days. Digital photographs and skin biopsies were taken on the third, seventh, 10th, and 20th postoperative days and evaluated by planimetry, histology, and immunohistochemistry.

RESULTS

Planimetry results demonstrated significantly decreased perimeter, diameter, and area measurements (p<0.005) of group H+P compared to Control and H groups on days 10 and 20 in the young rats, while in the mature rats, the significant differences were evident earlier (perimeter third day p<0.05; diameter and area seventh day p<0.05 and p<0.005, respectively vs. H). Granulation and scar tissue formation were also reduced in the H+P groups although they were not statistically significant.

CONCLUSIONS

The application of H+P on the skin defects benefited the healing process in both young and mature animal groups, as evidenced by the statistically significant findings of planimetry. The beneficial healing process was more pronounced in the mature animals, both in the level of statistical significance as well as regarding time (evident already on the third day of healing), probably due to porphyrin assisting the reduced healing rate, which is observed in organisms of advanced age.

Functionalized bioadhesion-enhanced carboxymethyl cellulose/polyvinyl alcohol hybrid hydrogels for chronic wound dressing applications

Wounds produced by trauma, burns, and chronic diseases cause millions of patients to suffer discomfort, pain, and, in many cases, disability and death, leading to enormous health, social and financial impacts globally. Regrettably, current clinical treatments for chronic wounds remain unsatisfactory. Thus, this study reports for the first time the design, development, and synthesis of chemically biofunctionalized hybrid hydrogels made of carboxymethyl cellulose (CMC) and poly(vinyl alcohol) (PVA) crosslinked by citric acid using an entirely biocompatible and green process. They demonstrated suitable physicochemical properties, cytocompatibility, and hemocompatibility to be applied as a smart wound dressing for skin tissue engineering. These novel hybrids were biofunctionalized with l-arginine and RGD peptide through carbodiimide mediated-amide formation to promote bioadhesion of fibroblast and keratinocyte cells as a potential enhancement for wound healing and skin tissue engineering applications.

Advances in Functional Hydrogel Wound Dressings: A Review

One of the most advanced, promising, and commercially viable research issues in the world of hydrogel dressing is gaining functionality to achieve improved therapeutic impact or even intelligent wound repair. In addition to the merits of ordinary hydrogel dressings, functional hydrogel dressings can adjust their chemical/physical properties to satisfy different wound types, carry out the corresponding reactions to actively create a healing environment conducive to wound repair, and can also control drug release to provide a long-lasting benefit. Although a lot of in-depth research has been conducted over the last few decades, very few studies have been properly summarized. In order to give researchers a basic blueprint for designing functional hydrogel dressings and to motivate them to develop ever-more intelligent wound dressings, we summarized the development of functional hydrogel dressings in recent years, as well as the current situation and future trends, in light of their preparation mechanisms and functional effects.

Research progress on albumin-based hydrogels: Properties, preparation methods, types and its application for antitumor-drug delivery and tissue engineering

Albumin is derived from blood plasma and is the most abundant protein in blood plasma, which has good mechanical properties, biocompatibility and degradability, so albumin is an ideal biomaterial for biomedical applications, and drug-carriers based on albumin can better reduce the cytotoxicity of drug. Currently, there are numerous reviews summarizing the research progress on drug-loaded albumin molecules or nanoparticles. In comparison, the study of albumin-based hydrogels is a relatively small area of research, and few articles have systematically summarized the research progress of albumin-based hydrogels, especially for drug delivery and tissue engineering. Thus, this review summarizes the functional features and preparation methods of albumin-based hydrogels, different types of albumin-based hydrogels and their applications in antitumor drugs, tissue regeneration engineering, etc. Also, potential directions for future research on albumin-based hydrogels are discussed.