Potential Wound Healing Applications Research Articles

Investigation of the 3D Printability of Covalently Cross-Linked Polypeptide-Based Hydrogels.

The 3D printability of poly(l-lysine-ran-l-alanine) and four-arm poly(ethylene glycol) (P(KA)/4-PEG) hydrogels as 3D biomaterial inks was investigated using two approaches to develop P(KA)/4-PEG into 3D biomaterial inks. Only the “composite microgel” inks were 3D printable. In this approach, P(KA)/4-PEG hydrogels were processed into microparticles and incorporated into a polymer solution to produce a composite microgel paste. Polymer solutions composed of either 4-arm PEG-acrylate (4-PEG-Ac), chitosan (CS), or poly(vinyl alcohol) (PVA) were used as the matrix material for the composite paste. The three respective composite microgel inks displayed good 3D printability in terms of extrudability, layer-stacking ability, solidification mechanism, and 3D print fidelity. The biocompatibility of P(KA)/4-PEG hydrogels was retained in the 3D printed scaffolds, and the biofunctionality of bioinert 4-PEG and PVA hydrogels was enhanced. CS-P(KA)/4-PEG inks demonstrated excellent 3D printability and proved highly successful in printing scaffolds with a narrow strand diameter (∼200 μm) and narrow strand spacing (∼500 μm) while the integrity of the vertical and horizontal pores was maintained. Using different needle IDs and strand spacing, certain physical properties of the hydrogels could be tuned, while the 3D printed porosity was kept constant. This included the surface area to volume ratio, the macropore sizes, and the mechanical properties. The scaffolds demonstrated adequate adhesion and spreading of NIH 3T3 fibroblasts seeded on the scaffold surfaces for 4 days. Consequently, the scaffolds were considered suitable for potential applications in wound healing, as well as other soft tissue engineering applications. Apart from the contribution to new 3D biomaterial inks, this work also presented a new and facile method of processing covalently cross-linked hydrogels into 3D printed scaffolds. This could potentially “unlock” the 3D printability of biofunctional hydrogels, which are generally excluded from 3D printing applications.

Iron manganese silicate incorporated bioactive hydrogels for therapy of skin tumor

There is clinical need to develop a multifunctional composite hydrogel for effectively removing residual tumor tissue and promoting wound healing after surgical resection of skin tumors. Herein, an iron manganese silicate (FeMn(SiO4))-incorporated bioactive hydrogel for photothermal therapy of skin tumor cells has been successfully designed in the present study. The synthesized FeMn(SiO4) (FMS) possessed a hollow sphere structure with rough surface, showing favorable photothermal effect. By incorporating FMS into the sodium alginate (SA) hydrogel, the prepared composite hydrogel (FMS/SA) exhibited the function of eliminating skin tumor cells in vitro by photothermal therapy (PTT). Moreover, attributed to the released bioactive ions (e.g., Fe, Mn and Si ions) from FMS, the FMS/SA composite hydrogel presented desirable biocompatibility, which is expected to benefit for skin wound healing of patients after skin tumor resection. Overall, the FMS/SA composite hydrogel has potential application in skin tumor therapy and wound healing, providing an effective and feasible strategy for the development of a comprehensive therapy for skin tumor after surgery.

Preparation and Evaluation of Chitosan/PVA Based Hydrogel Films Loaded with Honey for Wound Healing Application

In the present study, chitosan/polyvinyl alcohol (PVA)-based honey hydrogel films were developed for potential wound healing application. The hydrogel films were developed by a solvent-casting method and were evaluated in terms of thickness, weight variation, folding endurance, moisture content and moisture uptake. The water vapor transmission rate was found to range between 1650.50 ± 35.86 and 2698.65 ± 76.29 g/m2/day. The tensile strength and elongation at break were found to range between 4.74 ± 0.83 and 38.36 ± 5.39 N, and 30.58 ± 3.64 and 33.51 ± 2.47 mm, respectively, indicating significant mechanical properties of the films. SEM images indicated smooth surface morphology of the films. FTIR, DSC and in silico analysis were performed, which highlighted the docking energies of the protein–ligand complex and binding interactions such as hydrogen bonding, Pi–Pi bonding, and Pi–H bonding between the selected compounds and target proteins; hence, we concluded, with the three best molecules (lumichrome, galagin and chitosan), that there was wound healing potential. In vitro studies pointed toward a sustained release of honey from the films. The antimicrobial performance of the films was investigated against Staphylococcus aureus. Overall, the results signaled the potential application of chitosan/PVA based hydrogel films as wound dressings. Furthermore, in vivo experiments may be required to evaluate the clinical efficacy of honey-loaded chitosan/PVA hydrogel films in wound healing.

Production and characterization of hybrid nanofiber wound dressing containing Centella asiatica coated silver nanoparticles by mutual electrospinning method

The aim of this work is to produce a therapeutic and antimicrobial nanofiber wound dressing material with suitable air permeability, water vapor transmission, water absorption, porosity, thermal and mechanical strength. For this purpose, first of all, Centella asiatica (CA) coated silver nanoparticles (CA-AgNPs) are synthesized with using CA extract as reducing and stabilizing agent. The green synthesized CA-AgNPs are characterized by UV–Vis spectroscopy, transmission electron microscope (TEM), zeta potential and fourier transform infrared (FTIR) spectroscopy measurements. The obtained CA-AgNPs give a single peak in the 420–430 nm range between 200 and 700 nm due to surface plasmon resonance (SPR). The average zeta potential and size of CA-AgNPs is found to be −30.4 mV and 14.8 ± 7.3 nm, respectively. Then, poly caprolactone (PCL) and polyethylene oxide (PEO) nanofibers composition containing CA-AgNPs is synthesized by mutual electrospinning method. Before electrospinning, the PCL solution (12% w/v in chloroform/methanol (70%/30%, v/v)), PEO solution (3.5%, w/v in water) and PEO solutions containing 1%, 5% and 10% (v:v) of CA-AgNPs are prepared. In electrospinning experiments, to synthesis the PCL/PEO nanofibers containing CA-AgNPs, an electrospinning set-up consisting of two high voltage sources, an aluminum rotary roller collector and two syringe pumps (one with a double syringe and the other with a single syringe) is used. To produce the wound dressing materials, PEO solutions containing CA-AgNPs are placed on the double syringe pump and PCL solution is placed on the single syringe pump. The surface and physico-chemical properties of the produced hybrid nanofibers are characterized by field emission scanning electron microscopy (FESEM), energy dispersion spectrometry (EDS), FTIR, X-ray diffractometer (XRD), Brunauer-Emmett-Teller (BET) surface area and porosity analyzer. Also, the thermal and mechanical properties of the obtained materials are investigated. In addition, the air permeability, water uptake capacity, water contact angle, water vapor transmission, in vitro degradation and silver release behavior of the samples are investigated. The results show that mutual dual-spinneret electrospinning technique combines the features of dissimilar components without corruption. Moreover, the in vitro degradation profile and silver release results show that these nanofibers could be used in wound dressing applications in the long term. With antimicrobial studies, PEO/PCL nanofibers containing 5% and 10% CA-AgNPs are found to be effective against Staphylococcus aureus, Escherichia coli and Candida albicans. Also, the cytotoxic properties of nanofibers are investigated by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay and results show the good biocompatibility for L929 fibroblast cells. Results reveal that CA-AgNPs loaded PCL/PEO hybrid nanofibers materials synthesized in this study has a promising potential for wound healing applications.

Multiwalled carbon nanotubes functionalized bacterial cellulose as an efficient healing material for diabetic wounds

The unique pool of features makes bacterial cellulose (BC) a robust platform to tailor its functionalities. Herein, the BC matrix was reinforced with multiwalled carbon nanotubes (MWCNT) to control infection and accelerate the healing process of diabetic wounds. The prepared BC-MWCNT composite film was characterized and antibacterial activity was assessed. Further, the in-vivo wound healing activity was performed and temporal expression of interleukin (IL-1α), tumor necrosis factor (TNF-α), vascular endothelial growth factor (VEGF) and platelets derived growth factor (PDGF) was quantitatively measured by real-time PCR. The characterization results confirmed the reinforcement of the BC matrix with MWCNT. The composite film showed antibacterial activity against all the tested strains. Moreover, the macroscopic analysis of the wound demonstrated faster closure of the diabetic wound in BC-MWCNT group (99% healing) as compared to negative control (77%) in 21 days. Histological studies further supported the results where complete reepithelization of the epidermis and healthy granulation tissue were observed in BC-MWCNT treated group. Molecular studies revealed that BC-MWCNT group showed relatively lesser expression of pro-inflammatory cytokines IL-1α and TNF-α and higher expression of VEGF than control that may have favored the faster healing. This study suggested that the tailorable properties of BC can be exploited to develop composites with potential applications in diabetic wound healing.

Physically cross-linked PVA-quaternized chitosan-Ag NPs composite hydrogel membranes for potential topical wound healing applications: Synthesis, physicochemical properties, and in vitro bioevaluation

Physically cross-linked PVA-quaternized chitosan-Ag NPs composite hydrogel membranes for potential topical wound healing applications: Synthesis, physicochemical properties, and in vitro bioevaluation

Avian Egg: A Multifaceted Biomaterial for Tissue Engineering.

Most components in avian eggs, offering a natural and environmentally friendly source of raw materials, hold great potential in tissue engineering. An avian egg consists of several beneficial elements: the protective eggshell, the eggshell membrane, the egg white (albumen), and the egg yolk (vitellus). The eggshell is mostly composed of calcium carbonate and has intrinsic biological properties that stimulate bone repair. It is a suitable precursor for the synthesis of hydroxyapatite and calcium phosphate, which are particularly relevant for bone tissue engineering. The eggshell membrane is a thin protein-based layer with a fibrous structure and is constituted of several valuable biopolymers, such as collagen and hyaluronic acid, that are also found in the human extracellular matrix. As a result, the eggshell membrane has found several applications in skin tissue repair and regeneration. The egg white is a protein-rich material that is under investigation for the design of functional protein-based hydrogel scaffolds. The egg yolk, mostly composed of lipids but also diverse essential nutrients (e.g., proteins, minerals, vitamins), has potential applications in wound healing and bone tissue engineering. This review summarizes the advantages and status of each egg component in tissue engineering and regenerative medicine, but also covers their current limitations and future perspectives.

Synergistic Effect of Glycyrrhizic Acid and ZnO/Palygorskite on Improving Chitosan-Based Films and Their Potential Application in Wound Healing.

The synergistic effect of chitosan (CS), glycyrrhizic acid (GA) and ZnO/palygorskite (ZnO/PAL) as potential wound dressing was evaluated in the form of films by the solution casting method. The nanocomposite films were well-characterized with ATR-FTIR, XRD and SEM to explore the interactions between CS, GA and ZnO/PAL. Physical, mechanical and antibacterial properties of the nanocomposite films were systematically investigated for their reliability in end-up utilization. Importantly, it was found that the presence of PAL in the films provided enhanced mechanical properties, whereas CS, GA and ZnO supplied a broad-spectrum antibacterial activity, especially for drug-resistant bacteria such as ESBL—E. coli and MRSA. Overall, this research demonstrated that the prepared films can be a promising candidate for wound-care materials.

Surface modification of electrospun wound dressing material by Fe2O3 nanoparticles incorporating Lactobacillus strains for enhanced antimicrobial and antibiofilm activity

Demand for development of advanced antimicrobial and antibiofilm agents is growing due to the prevalence of antibiotic-resistant microbial infections. New antimicrobial surface coatings comprised of the synbiotics (the mixture of probiotics and prebiotics) and biologically synthesized nanoparticles can be an alternative therapy. In this study, two hybrids Lactobacillus plantarum-and Lactobacillus acidophilus-green Fe2O3 nanoparticles (Fe2O3 NPs-LAB) were fabricated for coating the polyvinyl alcohol-prebiotic gum arabic-polycaprolacton nanofibers surface (PVA-GA-PCL), which introduced the Fe2O3 NPs-LAB@PVA-GA-PCL as an emerging class of wound dressing materials. The physicochemical properties of Fe2O3 NPs-LAB hybrids and Fe2O3 NPs-LAB@PVA-GA-PCL were characterized using FE-SEM, EDS, EM, FTIR, XRD and ICP. The results showed spherical Fe2O3 NPs with a mean size diameter of < 100 nm incorporating LAB which revealed great antimicrobial potentials against pathogens Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. These results not only exhibited the biocompatibility of coated nanofibers towards the mouse embryonic fibroblast cell lines, but also showed its antimicrobial and antibiofilm efficacy against the pathogens. The highest growth inhibition of Fe2O3 NPs-LAB@PVA-GA-PCL was obtained against C. albicans. Interestingly, the incorporation of probiotic Lactobacillus and prebiotic GA, as a synbiotic hybrid, revealed synergistic antimicrobial effects, implying their therapeutic potential for wound healing applications.

Injectable and Antioxidative HT/QGA Hydrogel for Potential Application in Wound Healing.

Hydrogels have gained a niche in the market as wound dressings due to their high water content and plasticity. However, traditional hydrogel wound dressings are difficult to fully adapt to irregular-shaped wound areas. Additionally, excessive reactive oxygen species (ROS) accumulated in the damaged area impede the wound healing process. Therefore, hydrogels with injectable and antioxidant properties offer promising qualities for wound healing, but their design and development remain challenges. In this study, HT/QGA (tyramine-grafted hyaluronic acid/gallic acid-grafted quaternized chitosan) hydrogels with injectable and antioxidant properties were prepared and characterized. This hydrogel exhibited excellent injectability, favorable antioxidant activity, and good biocompatibility. Moreover, we evaluated the therapeutic effect of HT/QGA hydrogel in a full-thickness skin injury model. These results suggested that HT/QGA hydrogel may offer a great potential application in wound healing.

Development of chitosan/poly (vinyl alcohol)/graphene oxide loaded with vanadium doped titanium dioxide patch for visible light driven antibacterial activity and accelerated wound healing application

Wound healing is a multi-stage process that is dynamic, interactive, and complicated. However, many nanomaterials are employed to expedite wound healing by demonstrating antibacterial activity or boosting cell proliferation. But only one phase is focused during the wound healing process. As a result, there is a need for optimum wound dressing materials that promotes different wound healing cascades with ideal properties. Herein, Graphene Oxide loaded with vanadium (V) doped titanium dioxide (TiO2) blended with chitosan, and polyvinyl alcohol (CS/PVA/GO/TiO2-V) patch was developed for wound healing. XRD, FTIR and FE-SEM analyses were carried out to study the morphology and structural property of the patch. The fabricated patch has a high surface porosity, excellent moisture vapor transfer rate, appropriate swelling behaviour, and oxygen permeability, which results in an excellent moist environment for wound breathing and effective management of wound exudates. The antibacterial test showed significant antibacterial efficacy against wound infections in the presence of light when compared to dark. In-vitro analysis such as hemocompatibility, cytotoxicity, cell adhesion, and scratch assay show the predicted potential wound healing application with high biocompatibility. These results suggest that CS/PVA/GO/TiO2-V patch provides a microenvironment favourable to cells' growth and differentiation and positively modulates full-thickness wounds' healing.

Fabrication of polyamide 6/honey/boric acid mats by electrohydrodynamic processes for wound healing applications

In this study, polyamide 6, polyamide 6/honey, and polyamide 6/honey/boric acid nanofibrous mats were fabricated by electrospinning and electrospraying technique to be used in wound healing applications. The morphology and diameter of the fiber mats with and without honey and boric acid were examined by scanning electron microscopy. The morphology of fibers showed that all resulting fibers were in the nanometer range with 253–304 nm average fiber diameter. Fourier Transform Infrared spectrum (FT-IR) and thermal gravimetric analysis (TGA) thermograms showed the successful incorporation of honey and boric acid into the fibers. The results demonstrated that increasing the amount of boric acid slightly increased the fiber diameter. Moreover, boric acid incorporation enhanced the hydrophilicity of nanofibers. The wettability and thermal stability of fibers were quite suitable for wound healing applications. Antibacterial tests demonstrated that the polyamide 6/honey fiber was effective against Escherichia coli, while the polyamide 6/honey fibers loaded with boric acid at 5 and 10 wt% concentration were effective against both Escherichia coli and Staphylococcus aureus. However, the fibers had no antibacterial activity against Acinetobacter baumannii and Pseudomonas aeruginosa. The findings showed that polyamide 6/honey and polyamide 6/honey/boric acid nanofibrous scaffolds had desirable characteristics suitable for potential wound healing applications.

Development of Antibacterial and Hemostatic PCL/Zein/ZnO‐Quaternary Ammonium Salts NPs Composite Mats as Wound Dressings

AbstractWound dressings are usually employed to maintain suitable conditions around the injured skin to accelerate wound healing. This paper aims to report functional composite dressings combined with polycaprolactone (PCL) nanofibers, self‐assembly zein coating and modified ZnO nanoparticles (ZnO NPs) for wound management. The synthetic compounds and prepared composite dressings are characterized by Fourier infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy‐dispersive X‐ray spectroscopy. Meanwhile, the water vapor transmission rate, hemostatic performance, antibacterial activity, and cytocompatibility of the composite dressings are systematically tested to evaluate their applicability in wound treatment. The results show that the multilayer dressings can retain moisture and prevent excessive dehydration of wound. In vitro hemostatic test is conducted, and the enhanced blood clotting capacity and the activation of platelets indicate that the desired dressings are able to control hemorrhaging from wound. Meanwhile, the composite dressings with excellent biocidal efficacy against Gram‐positive Staphylococcus aureus (6.01 Log within 30 min) and Gram‐negative Escherichia coli O157:H7 (6.04 Log within 30 min) can effectively prevent wound infection. Furthermore, the dressings show no toxicity which are evidenced in hemolysis and cytocompatibility evaluation, and have potential application for wound healing.

Ciprofloxacin carrier systems based on hectorite/halloysite hybrid hydrogels for potential wound healing applications

The design of multifunctional nanomaterials which can help the healing processes of skin, preventing the bacterial infections, is crucial for the development of suitable therapy for the treatment of chronic lesions. The use of clay minerals in wound healing applications is well documented since the prehistoric period and offers several advantages due to their intrinsic properties.Herein, we report the development of ciprofloxacin carrier systems based on hectorite/halloysite (Ht/Hal) hybrid hydrogels for potential wound healing applications. To achieve this objective firstly the ciprofloxacin molecules were loaded onto Hal by a supramolecular and covalent approach. The so obtained fillers were thoroughly investigated by several techniques and at molecular level by means of quantum mechanics calculations along with empirical interatomic potentials. Afterwards the modified Hal were used as filler for Ht hydrogels. The introduction of modified Hal, in hectorite hydrogel, helps the gel formation with an improvement of the rheological properties. The in vitro kinetic release from both the fillers and from the hybrid hydrogels was studied both at skin's pH (5.4) and under neutral conditions (pH 7.4); in addition, the factors controlling the ciprofloxacin release process were determined and discussed. Finally, the in vitro biocompatibility of the Hal fillers was evaluated by means of cytotoxic assays and laser scanning confocal microscopy on normal human dermal fibroblasts.

Bioinspired short peptide hydrogel for versatile encapsulation and controlled release of growth factor therapeutics

A short bioinspired octapeptide, GV8, can self-assemble under mild conditions into biodegradable supramolecular physical hydrogels with high storage modulus and good biocompatibility. GV8 hydrogels can encapsulate both single or multiple macromolecular protein-based therapeutics in a simple one-pot formulation manner, making it a promising candidate to address challenges faced by existing synthetic polymer or peptide hydrogels with complex gelation and drug-encapsulation processes. Alongside its versatility, the hydrogel exhibits concentration-dependent storage modulus and controlled drug-release action. We demonstrate that GV8 hydrogels loaded with adipose-derived mesenchymal stem cells (ADMSC) secretome remain mechanically robust, and exhibit promising potential for wound healing applications by preserving secretome activity while maintaining a constant supply of ADMSC secretome to promote epithelial cell migration. Overall, our work highlights the potential of GV8 peptide hydrogel as a versatile and safe carrier for encapsulation and delivery of macromolecular therapeutics. Statement of significanceSupramolecular peptide hydrogels are a popular choice for protein-based macromolecular therapeutics delivery; however, despite the development of abundant hydrogel systems, several challenges limit their adaptability and practical applications. GV8 short peptide hydrogel circumvents these drawbacks and demonstrates the ability to function as a versatile growth factor (GF) encapsulant. It can encapsulate precise concentrations of complex adipose-derived mesenchymal stem cells secretome mixtures with a one-pot formulation approach and perform controlled release of GFs with preserved activity without compromising the self-assembly and mechanical properties of the hydrogel's supramolecular network. The significance of GV8 hydrogel lies in its gelation simplicity and versatility to encapsulate and deliver macromolecular therapeutics, thus representing a promising biomaterial for regenerative medicine applications.

Chitosan nanofiber biocomposites for potential wound healing applications: Antioxidant activity with synergic antibacterial effect.

Bacterial wound infection is one of the most common nosocomial infections. The unnecessary employment of antibiotics led to raising the growth of antibiotic‐resistant bacteria. Accordingly, alternative armaments capable of accelerating wound healing along with bactericidal effects are urgently needed. Considering this, we fabricated chitosan (CS)/polyethylene oxide (PEO) nanofibers armed with antibacterial silver and zinc oxide nanoparticles. The nanocomposites exhibited a high antioxidant effect and antibacterial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Besides, based on the results of the cell viability assays, the optimum concentration of ZnONPs and AgNPs in the nanofibrous mats is 0.2% w/v and 0.08% w/v respectively and had no cytotoxicity on fibroblast cells. The scaffold also showed good blood compatibility according to the effects of coagulation time. As well as significant fibroblast migration and proliferation on the wound margin, according to wound‐healing assay. All in all, the developed biocompatible, antioxidant, and antibacterial Ag‐ZnO NPs incorporated CS/PEO nanofibrous mats showed their potential as an effective wound dressing.

Poly (caprolactone)/sodium-alginate-functionalized halloysite clay nanotube nanocomposites: Potent biocompatible materials for wound healing applications

In this study, halloysite nanotubes (HNTs) were subjected to surface functionalization using sodium alginate and incorporated into poly(caprolactone) (PCL) to fabricate nanocomposites for potential wound healing applications. The nanocomposite films were fabricated through the solution casting technique and characterized using various instrumental methods. The films exhibited enhanced thermal and mechanical properties. FE-SEM and AFM analyses confirmed the uniform dispersion of the HNTs and increased roughness of the films, respectively. The swelling properties, in-vitro enzymatic degradation, and anti-inflammatory activity of the films were also analyzed. The MTT assay performed using NIH3T3 cell lines revealed enhanced cell proliferation (126 ± 1.38) of 5 wt% film. Besides, the cell adhesion tests of the films revealed their cytocompatibility. The scratch assay tests conducted for observing the effectiveness of the films for wound closure showed that the 5 wt% film offered a higher rate of fibroblast cell migration (32.24 ± 0.49) than the pristine PCL film. The HRBCMS assay demonstrated the hemocompatibility of these films. The biological test results indicated the delayed enzymatic degradability and haemocompatiblity of nanocomposites with enhanced cell adhesion, cell proliferation, and cell migration capabilities with respect to fibroblast cells. In summary, the synthesized nanocomposite films can be effectively used in wound healing applications after further clinical trials.

A mussel-inspired flexible chitosan-based bio-hydrogel as a tailored medical adhesive

The significant progress in efforts to design hydrogel adhesive mimicking mussels' functions has been witnessed in recent years. However, it is still an arduous challenge to fabricate self-adhesive hydrogel adhesive that tradeoff of exalting features containing scalability, self-healing, degradability, biocompatibility, and antibacterial properties. Herein, we manufactured a multi-functional physical hydrogel adhesive by integrating catechol groups modified chitosan and polyvinyl alcohol (PVA). Intriguingly, the physical gels reinforce durable and repeatable adhesiveness due to the limited auto-oxidation of catechol groups of the 3-(3,4-dihydroxyphenyl) propionic acid modified chitosan (DCS), which can be adhered diametrically on human skin without shedding and residue. Additionally, the dynamic H-bonds between DCS and PVA endows the hydrogel to self-heal under a relatively mild stimulation. The assembly of silver nano armor remarkably enhances the mechanical strength and antibacterial of the hydrogel. Meanwhile, the metal coordination formed between the nano-silver and the hydroxyl groups of catechol and the electrostatic interaction between the silver ions and the hydroxyl groups also contribute to the hydrogel to achieve self-healing. This work provides a neoteric prospect in designing degradable hydrogels with stretchability, self-adhesion, self-healing, antibacterial and biocompatibility for potential applications in tissue adhesion and wound healing.

Injectable nanofiber-polysaccharide self-healing hydrogels for wound healing

Injectable self-healing hydrogels of natural polysaccharides that mimic the extracellular matrix to promote cellular growth are attractive materials for wound healing. Here, a novel hydrogel was fabricated based on carboxymethyl chitosan (CS) and aldehyde functionalized sodium alginate via Schiff base reaction. To enhance the hydrogel's properties, carboxymethyl-functionalized polymethyl methacrylate (PMAA) short nanofibers were obtained through sodium hydroxide-treated polymethyl methacrylate nanofibers, and added to a CS solution. Gelation time was determined for different hydrogels including 0–5 mg/mL PMAA short nanofibers. The nanofiber hydrogels were tested for their injectability and self-healing abilities and were demonstrated to be easily injectable with excellent self-healing abilities. Additionally, in vitro cytocompatibility experiments, good interaction between the cultured cells and hydrogels was seen. Further, the polysaccharide hydrogel containing short PMMA nanofibers significantly facilitated wound healing in rats compared with the polysaccharide hydrogel and control groups. Thus, the developed hydrogel has great potential for wound healing applications.

Evaluation of Composition Effects on the Physicochemical and Biological Properties of Polypeptide-Based Hydrogels for Potential Application in Wound Healing.

In this study, the effect of crosslinking and concentration on the properties of a new library of low-concentration poly(Lys60-ran-Ala40)-based hydrogels for potential application in wound healing was investigated in order to correlate the hydrogel composition with the desired physicochemical and biofunctional properties to expand the assortment of poly-l-lysine (PLL)-based hydrogels suitable for wound healing. Controlled ring-opening polymerization (ROP) and precise hydrogel compositions were used to customize the physicochemical and biofunctional properties of a library of new hydrogels comprising poly(l-lysine-ran-l-alanine) and four-arm poly(ethylene glycol) (P(KA)/4-PEG). The chemical composition and degree of crosslinking via free amine quantification were analyzed for the P(KA)/4-PEG hydrogels. In addition, the rheological properties, pore morphology, swelling behavior and degradation time were characterized. Subsequently, in vitro cell studies for evaluation of the cytotoxicity and cell adhesion were performed. The 4 wt% 1:1 functional molar ratio hydrogel with P(KA) concentrations as low as 0.65 wt% demonstrated low cytotoxicity and desirable cell adhesion towards fibroblasts and thus displayed a desirable combination of properties for wound healing application.