Wound Dressings Research Articles

Preparation and characterization of structural and antifouling properties of chitosan/polyethylene oxide membranes

It aims to prepare the chitosan (CS) and polyethylene oxide (PEO) hydrogel membranes with different CS/PEO blend ratios (100:0, 95:5, 90:10, 80:20 and 70:30) via solvent casting. The physicochemical properties of these membranes were investigated using various characterization techniques: Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray (EDX), contact angle, and tensile testing. The interaction of PEO and chitosan was investigated by DSC in terms of freezing bound, freezing free, and non-freezing PEO fraction. The cross-sectional surface morphology of membranes displayed a smoother surface with increasing PEO content up to 20 %, beyond which nonhomogeneity on the surface was visible. The antifouling behavior of membranes was investigated by bacterial adherence study, which showed an enhanced antifouling nature of membranes with the increase in the PEO content. The peeling strength of the membranes was measured using a 90° angle peeling test, and it was found that 20 % and more PEO content promotes easy removal from the gelatin slab. In addition to this, live/ dead assay of the CS was performed to visualize the presence of live and dead bacteria on the surface. The CS/PEO blend with 20 % PEO content has properties makes it suitable for use as a protective layer on wound dressings to prevent bacterial growth. It's use in wound dressings has the potential to reduce the pain during the time of dressing removal and improve patient outcomes. The present investigation leads to the development of a CS hydrogel matrix which exhibits very interesting interaction with the PEO moiety along with its innovative feature of antifouling and antimicrobial nature.

Enhancement of Mechanical Properties of Benign Polyvinyl Alcohol/Agar Hydrogel by Crosslinking Tannic Acid and Applying Multiple Freeze/Thaw Cycles.

Hydrogels composed of natural and synthetic polymers have considerable potential for use in diverse areas such as biomedical applications and water purification. This is primarily because of their biocompatibility, biodegradability, and low toxicity. The widespread usage of composite hydrogels is hindered by a lack of simultaneous properties, such as high strength and low swelling rate. Herein, we report the preparation of novel hydrogels composed of polyvinyl alcohol (PVA)-intercalated agar polymer networks physically crosslinked with tannic acid. The hydrogel was subjected to multiple freeze/thaw (F/T) cycles (1, 3, and 5), and it was found to exhibit the highest strength after 5 F/T cycles. After 1 F/T cycle, the tensile strength of the composite hydrogel reached 1.56 MPa with a 1.0 wt% crosslinker, whereas after 5 F/T cycles, it increased to 3.77 MPa with a reduced amount (0.75 wt%) of the crosslinker. In addition, the swelling ability decreased upon increasing the crosslinker content and number of F/T cycles. Furthermore, the hydrogel demonstrated excellent water retention and a strong ability to adhere to different substrates. We have successfully implemented an innovative approach to improve the mechanical properties of PVA-based hydrogels by combining the use of tannic acid as a cross-linking agent and multiple F/T cycles. The developed hydrogels are expected to facilitate new developments in hydrogel technology, thus impacting diverse fields such as biomedical (wound dressing and artificial cartilage).

Baicalin derivative dynamically cross-linked natural polysaccharide hydrogel for diabetic wound healing

Diabetes is a chronic disease affects nearly 10% of the global population, the prolonged metabolic abnormalities and the complex microenvironment in diabetic wounds often leading to impaired healing. To address the typical characteristics of diabetic wounds, such as hyperglycemia, low pH, excessive reactive oxygen species (ROS) production, and chronic inflammation, this study designed a baicalin derivative dynamically cross-linked natural polysaccharide hydrogel (CFPB) and explored its potential to promote diabetic wound healing. The framework of CFPB utilized chitosan and modified with dextran to introduce aldehyde groups via mild grafting, and crosslinked with the modified active substance baicalin to effectively extend the drug delivery time. A series of characterizations demonstrated that CFPB hydrogel possesses excellent mechanical properties, self-healing ability, and responsive release capability. Subsequently, multi-level biological experiments validated the promoting effect of CFPB hydrogel on diabetic wound healing in vitro and in vivo. This study not only offers a potential candidate for the local therapy of diabetic wounds, but also provides new insights for the development of advanced wound dressings.

Physical, antibacterial, blood coagulation, and healing promotion evaluations of chitosan derivative-based composite films

Chitosan is a potentially suitable material for wound dressing, but is undesirably water-insoluble. Although chitosan can be modified to produce water-soluble derivatives, the best chitosan derivative for wound dressings remains unclear. The present study introduced three water-soluble chitosan derivatives, namely, carboxymethyl chitosan, quaternized chitosan (QCS), and carboxymethyl quaternized chitosan, and explored the physical properties, biochemical properties, and wound care effectiveness of films of these derivatives. The QCS-based film exhibited higher absorption ability, mechanical properties, water-vapor permeability, electroconductivity, and antioxidant capacity than the other films. Most importantly, the cationic quaternary ammonium groups facilitated the antibacterial activity (>95 %) and blood coagulant capacity of the QCS-based film. As this film also promoted wound healing, it presented as an ideal candidate for wound dressings.

Effect of the molar mass of chitosan and film casting solvents on the properties of chitosan films loaded with Mentha spicata essential oil for potential application as wound dressing

Chitosan based films endowed with antibacterial features have witnessed remarkable progress as potential wound dressings. The current study aimed at appraising the effects of the molar mass of chitosan (MM) and the film casting acids on the properties of unplasticized chitosan films and plasticized MSO-embedded chitosan films in order to provide best suited film formulation as a potential candidate for wound dressing application. The prepared films were functionally characterized in terms of their qualitative assessment, thickness, density, swelling behavior, water vapor barrier, mechanical and antibacterial properties. Overall, all chitosan films displayed thickness lower than the human dermis even though thicker and denser films were produced with lactic acid. Assessment of the swelling behavior revealed that only high molar mass (HMM) chitosan films may be regarded as absorbent dressings. Moreover, unplasticized HMM lactate (HMM-LA) films furnished lower stiffness and higher percent strain break as compared to acetate films, due to the plasticizing effect of the remaining lactic acid as alluded by the FTIR analysis. Meanwhile, they provided suitable level of moisture and indicated substantial antibacterial activity against S. aureus and E. coli, the most commonly opportunistic bacteria found in infected skin wound. Plasticized chitosan films doped with MSO were significantly thicker and more permeable to water compared to unplasticized films. Furthermore, MSO significantly potentiate the antibacterial effect of chitosan-based films. Therefore, plasticized HMM-LA/MSO chitosan film flashing good swelling behavior, adequate WVTR and WVP, suitable mechanical properties and antibacterial performances substantiated to be a promising antibacterial dressing material for moderately exuding wounds.

Withdrawal: Conductive Hydrogel Dressing With High Mechanical Strength for Joint Wound Healing.

Hydrogel wound dressing can accelerate angiogenesis to achieve rapid wound healing, but traditional hydrogel dressings are difficult to meet the repair of joint sites due to their low mechanical strength. Therefore, we constructed the gel system by designing the chemical-physical interpenetrating network structure to achieve high strength and high toughness of the hydrogel. The high-strength double-network hydrogels were synthesized by simple free radical polymerization and low-temperature physicochemical cross-linking in our experiments. The suspension was obtained by green reduction of graphene oxide with carboxymethyl chitosan, followed by the introduction of acrylamide (AM) to form a covalent cross-linked network, which was immersed in ferric chloride solution to form metal ligand bonds, and finally the chemical-physical dual cross-linked network hydrogel wound dressing was prepared. Here, reduced graphene oxide can enhance electrical conductivity and excellent near-infrared photothermal effect to the hydrogel. The cell viability of this novel wound dressing was above 90.0%, its hemolysis rate was below 2.0%, and the electrical conductivity could reach (6.89 ± 0.07 (mS/cm)). In addition, the stress-strain curve demonstrated that the double cross-linked network hydrogel could reach a stress of more than 0.8MPa at 82.0% strain, and the cyclic compression experiment shows that it can still recover its original shape after five times of repeated compression. This work can provide a reference for the exploitation of high mechanical strength hydrogel wound dressings with good electrical conductivity and near-infrared photothermal effect. This article is protected by copyright. All rights reserved.

Suppression the glucose-induced ferroptosis in endothelial cells by 4OI-loading exosomes hydrogel for the treatment of diabetic foot ulcer

The prevalence of diabetic foot ulcer in individuals with diabetes is approximately 15%, and it is frequently accompanied by vascular dysfunction and infection. The management challenges make it the primary cause for amputation; however, the underlying mechanisms remain poorly understood, thereby impeding the advancement of novel wound dressings and medication. Herein, single-cell sequencing analysis revealed that ferroptosis induced by high glucose levels in vascular endothelial cells (VECs) represents a significant molecular pathological feature in diabetic foot ulcer (DFU) tissue. Furthermore, 4-Octyl itaconate (4OI) exhibited a pronounced protective effect against VECs injury induced by high glucose (HG), and its underlying molecular mechanisms involve the mitigation of HG-induced reactive oxygen species (ROS) injury and ferroptosis in VECs through the regulation Keap1/Nrf2/GPX4. For enhanced application, incubation at 37℃ was used to load 4OI into exosomes, which were subsequently encapsulated within an Alg-DA/GelMA-based hydrogel matrix. Remarkably, the utilization of 4OI-Exo-Gel not only expedited wound healing but also significantly improved the overall quality of healing in DFU. In conclusion, these findings not only demonstrate, for the first time, the remarkable ability of 4OI to enhance diabetic wound healing by mitigating VECs ferroptosis induced by HG, but also provide evidence for the potential clinical translation of a 4OI-loaded exosomes hydrogel in diabetic wound therapy.

Robust, superabsorbent and antibacterial polysaccharide-based hybrid-network hydrogels for wound repair

Hydrogel dressings with multiple functions are ideal options for wound repair. This study developed hydrogel dressings by interpenetrating the physically crosslinked xanthan gum (XG)/carboxylated chitosan (CCS) network and the chemically crosslinked polyacrylamide (PAAm) network via a one-pot method. The XG-CCS/PAAm hydrogels were found to display tunable mechanical properties, due to the formation of strong network structure. The hydrogels exhibited the strongest tensile strength of 0.6 MPa at an XG/CCS ratio of 40/60, while the largest compressive strength of 4.5 MPa is achieved at an XG/CCS ratio of 60/40. Moreover, the hydrogel with an XG/CCS ratio of 60/40 exhibited desirable adhesion strength on porcine skin, which was 3.7 kPa. It also had a swelling ratio, as high as 1200 %. After loading with cephalexin, the XG-CCS/PAAm hydrogels can deliver the antibacterial drugs following a first-order kinetic. As a result, both E. coli and S. aureus can be completely inactivated by the cefalexin-loaded hydrogels after 12 h. Furthermore, the XG-CCS/PAAm hydrogels were found to exhibit excellent biocompatibility as well as effective wound healing ability, as proven by the in vitro and in vivo tests. In this regard, XG-CCS/PAAm hydrogels can act as promising multifunctional wound dressings.

(Invited) Fullerenes for Bio-Applications: The Way of Water

Nano-materials are emerging as important components for a series of bio-applications. In this context, carbon nanostructures such as graphene, carbon nanotubes and fullerenes have unique chemical and physical properties that make them attractive for such applications. Carbon nanomaterials have been used in tissue engineering, biosensing and drug delivery. They have also shown anti-microbial activity. They can be loaded with drugs for controlled local delivery. More importantly, the surface of carbon nanomaterials can be functionalised to enhance their biocompatibility by increasing their water-solubility.In this talk, I will present an update on our work in using fullerenes and their derivatives for developing bio-nanomaterials. I shall focus on the combination of carbon nanostructures and polymeric materials which can result in supramolecular hydrogels with interesting properties. Hydrogels are emerging as important materials in applications such as cellular scaffoldings in regenerative medicine/tissue engineering, tissue replacements, wound dressings, etc.I will present the synthesis of supramolecular hydrogels made from fullerenes of different sizes (C60, C84 and C90–92) that have been hydroxylated and functionalised with hydrophilic oligoethylene glycol chains. To the best of our knowledge, there have been no attempts made at incorporating higher fullerenes and their derivatives into such extended supramolecular structures, before now.I will also show possibilities for extending our approach to endohedral fullerenes such as N@C60. I will show how we can use advanced techniques including AFM to characterise the elasticity of the hydrogels formed. The ability to incorporate endohedral fullerenes in hydrogels may be important in extending the possibility for using these materials as sensors in vitro or even in vivo, exploiting the quantum properties of such molecular systems such as their extended electron and nuclear spin lifetimes.

Hydrogel crosslinking modulates macrophages, fibroblasts, and their communication, during wound healing

Biomaterial wound dressings, such as hydrogels, interact with host cells to regulate tissue repair. This study investigates how crosslinking of gelatin-based hydrogels influences immune and stromal cell behavior and wound healing in female mice. We observe that softer, lightly crosslinked hydrogels promote greater cellular infiltration and result in smaller scars compared to stiffer, heavily crosslinked hydrogels. Using single-cell RNA sequencing, we further show that heavily crosslinked hydrogels increase inflammation and lead to the formation of a distinct macrophage subpopulation exhibiting signs of oxidative activity and cell fusion. Conversely, lightly crosslinked hydrogels are more readily taken up by macrophages and integrated within the tissue. The physical properties differentially affect macrophage and fibroblast interactions, with heavily crosslinked hydrogels promoting pro-fibrotic fibroblast activity that drives macrophage fusion through RANKL signaling. These findings suggest that tuning the physical properties of hydrogels can guide cellular responses and improve healing, offering insights for designing better biomaterials for wound treatment.

ANTIMICROBIAL WOUND DRESSINGS FOR FULL-THICKNESS INFECTED BURN WOUNDS.

Infection of wounds delays healing, increases treatment costs, and leads to major complications. Current methods to manage such infections include antibiotic ointments and antimicrobial wound dressings, both of which have significant drawbacks, including frequent reapplication and contribution to antimicrobial resistance. In this work, we developed wound dressings fabricated with a medical-grade polyurethane coating composed of natural plant secondary metabolites, cinnamaldehyde, and alpha-terpineol. Our wound dressings are easy to change and do not adhere to the wound bed. They kill gram-positive and -negative microbes in infected wounds due to the Food and Drug Administration-approved for human consumption components. The wound dressings were fabricated by dip coating. Antimicrobial efficacy was determined by quantifying the bacteria colonies after a 24 h of immersion. Wound healing and bacterial reduction were assessed in an in vivo full-thickness porcine burn model. Our antimicrobial wound dressings showed a > 5-log reduction (99.999%) of different gram-positive and gram-negative bacteria, while maintaining absorbency. In the in vivo porcine burn model, our wound dressings were superior to bacitracin in decreasing bacterial burden during daily changes, without interfering with wound healing. Additionally, the dressings had a significantly lower adhesion to the wound bed. Our antimicrobial wound dressings reduced the burden of clinically relevant bacteria more than commercial antimicrobial wound dressings. In an in vivo infected burn wound model, our coatings performed as well or better than bacitracin. We anticipate that our wound dressings would be useful for the treatment of various types of acute and chronic wounds.

An Exosome-Laden Hydrogel Wound Dressing That Can Be Point-of-Need Manufactured in Austere and Operational Environments.

Skin wounds often form scar tissue during healing. Early intervention with tissue-engineered materials and cell therapies may promote scar-free healing. Exosomes and extracellular vesicles (EV) secreted by mesenchymal stromal cells (MSC) are believed to have high regenerative capacity. EV bioactivity is preserved after lyophilization and storage to enable use in remote and typically resource-constrained environments. We developed a bioprinted bandage containing reconstituted EVs that can be fabricated at the point-of-need. An alginate/carboxymethyl cellulose (CMC) biomaterial ink was prepared, and printability and mechanical properties were assessed with rheology and compression testing. Three-dimensional printed constructs were evaluated for Young's modulus relative to infill density and crosslinking to yield material with stiffness suitable for use as a wound dressing. We purified EVs from human MSC-conditioned media and characterized them with nanoparticle tracking analysis and mass spectroscopy, which gave a peak size of 118 nm and identification of known EV proteins. Fluorescently labeled EVs were mixed to form bio-ink and bioprinted to characterize EV release. EV bandages were bioprinted on both a commercial laboratory bioprinter and a custom ruggedized 3D printer with bioprinting capabilities, and lyophilized EVs, biomaterial ink, and thermoplastic filament were deployed to an austere Arctic environment and bioprinted. This work demonstrates that EVs can be bioprinted with an alginate/CMC hydrogel and released over time when in contact with a skin-like substitute. The technology is suitable for operational medical applications, notably in resource-limited locations, including large-scale natural disasters, humanitarian crises, and combat zones.

Prussian Blue-Assisted NIR Triggered In-Situ Polymerized Nanocomposite Hydrogel for Wound Repair.

Hydrogels are commonly used as wound dressings to help maintain a moist environment around the wound and isolate contaminants, thus promoting healing. For irregular wounds, the slow healing process and even infection may occur due to the inability of dressings to adhere well to the wound. Prussian blue (PB) is a metal-organic framework (MOF) material with excellent photothermal conversion and superior stability. In this paper, a kind of near-infrared (NIR) light triggered in-situ polymerized antimicrobial hydrogel was prepared. The free radical initiator was encapsulated in the hollow PB by a phase change material (PCM) to maintain stability. The raised temperature triggered by NIR induced the release and decomposition of the initiator. The matrix was formed by the cross-linking of double bonds on modified chitosan. The quaternary amine groups of modified chitosan and the photothermal properties of PB enhanced the antimicrobial properties of the hydrogel. High-quality wound healing was demonstrated in the whole skin defect model. This study provides a new reference for the preparation of in-situ polymerized hydrogel dressings for irregular wounds.

Nanomedicine: An Emerging Tool in Healing Chronic Wounds and its Opportunities

Chronic wounds generally take a lot of time to recover, which becomes a cause of worry for the patient and also makes it difficult to manage them. Chronic wound affects the minds of millions of people worldwide, which results in a high mortality rate. Nanomedicine has emerged as a promising tool in addressing this issue of chronic wounds. Nanomedicine in chronic wound healing holds the potential to revolutionize wound care by offering various personalized treatments and improving patient outcomes. Advanced wound dressings and nanofibresscaffolds promote tissue regeneration, which also accelerates wound closure. Nanomedicine is also able to provoke the various cellular and molecular mechanisms that are involved in the wound microenvironment, showing the anti-inflammatory, antibacterial, and angiogenetic effects. The gene therapy and various inflammation modulations using this emerging tool of nanotechnology show promising results in managing the various chronic wounds. Nanomedicine offers innovative approaches to address these challenges. Nanomedicine also plays a crucial role in tissue engineering, which can also be used for chronic wound treatment. Nanotechnology has enabled the various development of advanced wound dressings and has improved various properties. Nanomedicine also uses antimicrobial nanomaterials, such as silver nanoparticles, to combat the various infections in chronic wounds. The main aim of the review is to provide a concise overview of nanomedicine as a recent tool in healing chronic wounds and also its various opportunities for curing chronic wounds.

In Vitro and In Vivo Evaluation of Electrospun PVA Nanofiber Containing ZnO/Curcumin for Wound Healing Application.

The development of biocompatible wound dressings containing therapeutic agents to accelerate wound healing is an interesting field of study in biomedical sciences. Polyvinyl alcohol (PVA) nanofibers were loaded with zinc oxide nanoparticles (ZnO NPs) and curcumin (Cur) through electrospinning. Thedressings were characterized by SEM and XRD and FTIR. The antioxidant, antibacterial, and cytotoxic activities Cur/ZnO/PVA nanodressing were evaluated using DPPH radical scavenging assay, disc diffusion method, and MTT assay, respectively. Cur/ZnO/PVA nanodressing showed sustained Cur release about 19.7% and 61.1% after 8h and 168h, respectively. Cur/ZnO NPs/PVA mixture had higher antioxidant potential than PVA, ZnO NPs, and Cur. The dressing showed a good antibacterial effect. The in vivo wound healing effect of different types of prepared dressings, includingPVA, Cur/PVA,Cur/ZnO/PVA, and ZnO/PVAnanofibers, was also investigated. PVA dressing containing Cur/ZnO NPs resulted in the highestincrease of wound contraction in rats. The assembly of Cur and ZnO NPs on PVA nanofibers could propose as an effective delivery method toimprovethe wound healing process. The investigated wound dressing could be commercialized and used on a large scale after proper further studies, including clinical trials.

Advancing self‐healing soy protein hydrogel with dynamic Schiff base and metal‐ligand bonds for diabetic chronic wound recovery

AbstractTo address the unique challenges of diabetic wound healing, wound dressings, particularly multifunctional hydrogels have garnered considerable interest. For the first time, a novel environmentally friendly soy protein‐based hydrogel is developed to accelerate the healing of diabetic chronic wounds. Specifically, this hydrogel framework is in direct formation through the dynamic Schiff base between oxidized guar gum and epigallocatechin‐3‐gallate (EGCG)‐modified soy protein isolate. Meantime, the addition of Ag+ enhances the cross‐linking of the hydrogel network by forming metal‐ligand bonds with the catechol groups in EGCG. Interestingly, the stretchability (up to 380%), swelling, and rheology properties of the hydrogel can be controlled by fine‐tuning the density of metal‐ligand bonds, endowing them with a high potential for precise matching. Additionally, various dynamic bonds endow hydrogel with excellent self‐healing ability, adhesiveness, and injectability. This hydrogel also exhibits good antibacterial properties, biocompatibility, and cell migration capabilities. Both in vivo and in vitro experiments demonstrated the outstanding anti‐inflammatory capacity of the hydrogel and its ability to modulate macrophage polarization. Consequently, the hydrogel has proven effective in promoting wound healing in a diabetic full‐thickness wound model through enhanced angiogenesis and collagen deposition. This eco‐friendly plant protein hydrogel offers a sustainable solution for wound care and environmental protection.

Preparation and Physicochemical Properties of Collagen for Wound Dressings

Preparation and Physicochemical Properties of Collagen for Wound Dressings

Release of natural extracts from PVA and PVA-CMC hydrogel wound dressings: a power law swelling/delivery.

PVA hydrogels present many characteristics of the ideal dressing, although without antimicrobial properties. The present work aims to study the physical, mechanical and release characteristics of hydrogel wound dressings loaded with either of two natural herbal products, sage extract and dragon's blood. Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and tensile mechanical testing were used to investigate the structure and properties of the gels. Swelling and degradation tests were conducted according to ISO 10993-9. Release characteristics were studied using UV Spectrophotometry. PVA matrices incorporating sage extract or dragon's blood (DB) present hydrogen bonding between these components. PVA-CMC hydrogels containing sage present similar spectra to PVA-CMC alone, probably indicating low miscibility or interaction between the matrix and sage. The opposite is found for DB, which exhibits more pronounced interference with crystallinity than sage. DB and NaCMC negatively affect Young's modulus and failure strength. All samples appear to reach equilibrium swelling degree (ESD) in 24 h. The addition of DB and sage to PVA increases the gels' swelling capacity, indicating that the substances likely separate PVA chains. The inclusion of CMC contributes to high media uptake. The kinetics profile of media uptake for 4 days is described by a power-law model, which is correlated to the drug delivery mechanism. A PVA-CMC gel incorporating 15% DB, the highest amount tested, shows the most favorable characteristics for flavonoid delivery, as well as flexibility and swelling capacity.

Alginate Cryogels for Rapid Hemostasis and Toluidine Blue-Mediated Photodynamic Inactivation of Bacteria.

The development of new wound dressings with fast hemostatic and bactericidal properties for prehospital care is critical. Antibacterial photodynamic therapy (aPDT) has attracted attention due to its broad-spectrum antibacterial activity and minimal bacterial resistance. However, photosensitizers used in aPDT often face issues such as poor water solubility, short-lived singlet oxygen (1O2), and limited 1O2 diffusion range. In this study, sodium alginate was covalently modified with the photosensitizer toluidine blue O (TBO) and phenylboronic acid (PBA). The modified alginate was then cross-linked with Ca(II) ions and lyophilized to form a cryogel, named SA@Ca(II)@TBO@PBA (SCTP). This cryogel functions as an antibacterial photodynamic wound dressing. The chemical immobilization of TBO and PBA enhanced the cryogel's targeting ability. PBA formed reversible covalent bonds with diol groups on bacterial cell surfaces, allowing the cryogel to capture bacteria effectively and enhance aPDT. The bactericidal efficiency of the cryogel was tested through in vitro antibacterial assays, and its hemostatic properties were confirmed in vivo. The results indicate that this cryogel has excellent hemostatic and antibacterial capabilities, showing great promise as a wound dressing for clinical applications.

Ferulic acid-g-tamarind gum/guar gum based in situ gel-forming powders as wound dressings

The current research endeavour aimed to synthesize ferulic acid grafted tamarind gum/guar gum (FA-g-TG/GG) based powders as wound dressings, which could form in situ gels upon contact with wound exudates. In this context, variable amounts of FA were initially grafted with TG via the Steglich esterification reaction protocol and the resulting conjugates were subsequently amalgamated with GG and lyophilized to produce dry powders (F-1 – –F-3) with average particle size within 5.10–5.54 μm and average angle of repose ∼30°. These powders were structurally characterized with 1H NMR, FTIR, DSC, TGA, XRD and SEM analyses. Pristine TG, FA-g-TG and FA-g-TG/GG powders (F-2) revealed their distinct morphological structures and variable negative zeta potential values (−11.06 mV–25.50 mV). Among various formulation (F-1–F-3), F-2 demonstrated an acceptable powder-to-gel conversion time (within 20 min), suitable water vapour transmission rates (WVTR, 2564.94 ± 32.47 g/m2/day) and excellent water retention abilities and swelling profiles (4559.00 ± 41.57 %) in wound fluid. The powders were cytocompatible and conferred antioxidant activities. The powders also displayed fibroblast cell proliferation, migration and adhesion properties, implying their wound-healing potentials. Thus, the developed in situ gel-forming powders could be employed as promising dressings for wound management.