Antibacterial Wound Dressings Research Articles

Nanocomposite sponge based on sodium alginate, polyvinyl alcohol, carbon dots, and woolly hedge nettle antibacterial extract for wound healing

Skin ulcers associated with significant bleeding and bacterial infections can be life-threatening and pose significant challenges in clinical settings. To solve this problem, there is an increasing need for biomaterials that have hemostatic and antibacterial properties. Such biomaterials are highly desirable as they could help to promote wound healing and prevent infections, thus improving patient therapeutic outcomes. Inspired by this content, a new type of nanocomposite sponge based on sodium alginate (SA) and polyvinyl alcohol (PVA) was created with the combination of carbon dots (CDs) and woolly hedge nettle extract (HNE) as an antibacterial and hemostatic wound dressing. The prepared samples were characterized by different techniques. The properties of CDs were determined by FT-IR and XRD. SEM confirmed the creation of porous and interconnected structures. The developed nanocomposite sponge showed suitable physicochemical properties such as hydrophilicity, water vapor transmission rate, water absorption, and mechanical properties. Also, the cytotoxicity and hemolysis percentage of these sponges were within the permissible range. In addition, the antibacterial activity of the sponges increased by adding HNE. Finally, In vivo studies showed that these sponge nanocomposites can have a potential healing function for wound dressing applications.

Antibacterial Polyhydroxyurethane-Gelatin Wound Dressings with In Situ-Generated Silver Nanoparticles or Hyperthermia Induced by Near-Infrared Light Absorption

Antibacterial Polyhydroxyurethane-Gelatin Wound Dressings with In Situ-Generated Silver Nanoparticles or Hyperthermia Induced by Near-Infrared Light Absorption

Development of cross‐linked polyvinyl alcohol/sodium caseinate/silver nanoparticle electrospun mats for antibacterial wound dressing

AbstractIn this study, nanofibers were produced by the electrospinning method by adding 1%, 3%, 5%, and 7% silver nanoparticles (Ag NPs) into the polyvinyl alcohol/sodium caseinate (60/40, w/w) mixture. Electrospun materials were cross‐linked by immersion in a glutaraldehyde bath. Thus, antibacterial wound dressings that could be used on exuding wounds were developed. According to the scanning electron microscopy images of nanofibers, the cross‐linking process by immersion method did not cause negative effects such as breakage or adhesion on the surface of fibers. The cross‐linking of nanofibers was demonstrated by the presence of acetal linkages by Fourier‐transform infrared spectroscopy analysis. The cross‐linking process significantly improved the thermal properties of the nanofibers. The lowest crystallinity calculated in the differential scanning calorimeter was observed in the 3% Ag NP‐added nanofiber with a value of 1.83%. It exhibited the lowest total soluble matter content with a value of 11.98% owing to its high cross‐linking density. In addition, the 3% Ag NP‐added nanofiber, which had the highest toughness and ductility, displayed the highest tensile stress with 3.5 MPa and the highest tensile strain with 7.53%. Moreover, it showed 78.11% cell viability on the L929 fibroblast cell line at the end of the 24th hour. It was indicated that although the electrospun mats maintained 100% antibacterial effectiveness, they could not be used as a wound dressing for 48 h. It was reported that only 3% Ag NP‐added nanofiber could be used as a 100% effective antibacterial wound dressing for both Escherichia coli and Staphylococcus aureus provided that it was renewed every 24 h. Consequently, it was notified that cross‐linking by the immersion method can be used in biomedical applications.Highlights The antibacterial effects of Ag NP‐doped PVA/NaCAS electrospun mats were significant. The cross‐linking process did not induce toxic effects some of the nanofibers. High cross‐linking density was observed in the nanofibers. The swelling property of nanofibers is a good feature required in an ideal wound dressing.

Silver Nanoparticles Biosynthesis Using White Nest-Swiftlet Extract: A Sustainable Pathway for Nanomedicine Applications

Demand of antibacterial-based metal nanoparticles biomaterials against broad ranges of pathogenic microorganisms show unique functionality in a wide range of applications. Silver nanoparticles (AgNPs) play a major role especially in nanomedicine field; thus, there are urge to find more economic and eco-friendly synthesis method without harming the consumers and/or patients. In this study, an aqueous of white nest-swiftlet (Aerodramus fuciphagus) extract was used as bio-reductant and stabilizing agent to synthesis the AgNPs. The changes colour from colourless to reddish brown within 15 minutes under heat condition, 50 mM AgNO3 concentration and 3, 4, and 5 % (w/v) edible bird nest (EBN) dose indicated the successful of AgNPs biosynthesis by using visual indication. Further characterization of AgNPs was carried out by UV-visible spectroscopy through presence of plasmon resonance band between 410 nm to 430 nm. Infrared spectroscopy technique was used to analyse the involvement of biomolecules in EBN reduced the AgNPs. Their morphology and particle size analysed by field emission scanning electron microscopy (FESEM) showed nearly spherical in size with average diameter of 35 nm. Energy dispersive X-ray (EDX) attached with FESEM evaluate the composition of silver in the solutions. The content of silver increasing with the concentration of EBN extract. On the basis of results and facts, the green approach on AgNPs synthesis through EBN can be proposed as ecologically and economically feasible approach to become antibacterial wound dressing.

A Cysteine-Maleimide-Based Design for Hemostatic, Antibacterial, and Biodegradable Wound Dressing.

The field of clinical surgery frequently encounters challenges related to atypical wound tissue healing, resulting in the development of persistent chronic wounds or aesthetically displeasing scar tissue. The use of wound dressings crafted from mussel adhesive proteins and hyaluronic acid has demonstrated the potential in mitigating these undesirable outcomes. However, the synergistic effects of these two biomaterials remain underexplored. In this study, we have engineered a versatile, degradable, and biocompatible dressing that comprises recombinant 3,4-dihydroxyphenylalanine (DOPA)-modified mussel adhesive proteins and maleimide-functionalized hyaluronic acid. We have successfully fabricated this biocompatible dressing and conducted comprehensive experimental assessments to confirm its hemostatic, antibacterial, and biocompatible characteristics. Importantly, this dressing exclusively incorporates biologically derived materials characterized by low toxicity and minimal immunogenicity, thus holding immense promise for clinical applications in the field of wound healing.

Engineering of a decellularized bovine skin coated with antibiotics-loaded electrospun fibers with synergistic antibacterial activity for the treatment of infectious wounds.

An ideal antibacterial wound dressing with strong antibacterial behavior versus highly drug-resistant bacteria and great wound-healing capacity is still being developed. There is a clinical requirement to progress the current clinical cares that fail to fully restore the skin structure due to post-wound infections. Here, we aim to introduce a novel two-layer wound dressing using decellularized bovine skin (DBS) tissue and antibacterial nanofibers to design a bioactive scaffold with bio-mimicking the native extracellular matrix of both dermis and epidermis. For this purpose, polyvinyl alcohol (PVA)/chitosan (CS) solution was loaded with antibiotics (colistin and meropenem) and electrospun on the surface of the DBS scaffold to fabricate a two-layer antibacterial wound dressing (DBS-PVA/CS/Abs). In detail, the characterization of the fabricated scaffold was conducted using biomechanical, biological, and antibacterial assays. Based on the results, the fabricated scaffold revealed a homogenous three-dimensional microstructure with a connected pore network, a high porosity and swelling ratio, and favorable mechanical properties. In addition, according to the cell culture result, our fabricated two-layer scaffold surface had a good interaction with fibroblast cells and provided an excellent substrate for cell proliferation and attachment. The antibacterial assay revealed a strong antibacterial activity of DBS-PVA/CS/Abs against both standard strain and multidrug-resistant clinical isolates of Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli. Our bilayer antibacterial wound dressing is strongly suggested as an admirable wound dressing for the management of infectious skin injuries and now promises to advance with preclinical and clinical research.

Electrospun Antimicrobial Drug Delivery Systems and Hydrogels Used for Wound Dressings.

Wounds and chronic wounds can be caused by bacterial infections and lead to discomfort in patients. To solve this problem, scientists are working to create modern wound dressings with antibacterial additives, mainly because traditional materials cannot meet the general requirements for complex wounds and cannot promote wound healing. This demand is met by material engineering, through which we can create electrospun wound dressings. Electrospun wound dressings, as well as those based on hydrogels with incorporated antibacterial compounds, can meet these requirements. This manuscript reviews recent materials used as wound dressings, discussing their formation, application, and functionalization. The focus is on presenting dressings based on electrospun materials and hydrogels. In contrast, recent advancements in wound care have highlighted the potential of thermoresponsive hydrogels as dynamic and antibacterial wound dressings. These hydrogels contain adaptable polymers that offer targeted drug delivery and show promise in managing various wound types while addressing bacterial infections. In this way, the article is intended to serve as a compendium of knowledge for researchers, medical practitioners, and biomaterials engineers, providing up-to-date information on the state of the art, possibilities of innovative solutions, and potential challenges in the area of materials used in dressings.

Fabrication of bioinspired keratin/sodium alginate based biopolymeric mat loaded with herbal drug and green synthesized zinc oxide nanoparticles as a dual drug antimicrobial wound dressing

Dual drug antibacterial wound dressings with biological materials possess crucial wound healing characteristics including biocompatibility, non-toxicity, degradability, mechanical strength and antibacterial properties. The study focusses on fabricating keratin (K)‑sodium alginate (A) based wound dressings by loading green synthesized zinc oxide nanoparticles (ZnO NPs) using C. roseus (leaf extract) and M. recutita (Chamomile flower part) herbal drug (CH) as a bioactive dual antibacterial wound dressing for the first time. The optimized ZnO NPs and CH exhibits strong physiochemical and electrostatic interactions (FT-IR, XRD and SEM) on the fabricated K-A-CH-ZnO biopolymeric mats. Moreover, the tiny porous network of the biopolymeric mat enhances thermal stability, hydrophilicity, mechanical strength and explores the water vapor transmission (2538.07 g/m2/day) and oxygen permeability (7.38 ± 0.31 g/m2) to maintain moist environment and cell-material interactions. During enzymatic degradation studies, ZnO NPs and CH of biopolymeric mat not only retains structural integrity but also increases the characteristic of swelling with sustained drug release (57 %) in 144 h which accelerates wound healing process. Also, K-A-CH-ZnO mat exhibited excellent antibacterial effects against B. subtilis and E. coli. Furthermore, NIH 3T3 fibroblast cell behavior using MTT assay and in vivo evaluations of biopolymeric mat depicted enhanced biocompatibility with increased collagen deposition at the wound site as a prominent dual drug medicated antimicrobial wound dressing.

Electrospun nylon 6/hyaluronic acid/chitosan bioactive nanofibrous composite as a potential antibacterial wound dressing.

Hyaluronic acid (HA) and chitosan (CS), as natural biomaterials, display excellent biocompatibility and stimulate the growth and proliferation of fibroblasts. Furthermore, nylon 6 (N6) is a low-cost polymer with good compatibility with human tissues and high mechanical stability. In this study, HA and CS were applied to modify N6 nanofibrous mat (N6/HA/CS) for potential wound dressing. N6/HA/CS nanofibrous composite mats were developed using a simple one-step electrospinning technique at different CS concentrations of 1, 2, and 3 wt%. The results demonstrated that incorporating HA and CS into N6 resulted in increased hydrophilicity, as well as favorable physical and mechanical properties. In addition, the minimum inhibitory concentration and (MIC) optical density techniques were used to determine the antibacterial properties of N6/HA/CS nanofibrous composite mats, and the results demonstrated that the composites could markedly inhibit the growth of Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli. Because of its superior mechanical properties, substantial antimicrobial effects, and hydrophilic surface, N6/HA/CS at 2 wt% of CS (N6/HA/CS2) was chosen as the most suitable nanofibrous mat. The swelling, porosity, gel content, and in vitro degradation studies imply that N6/HA/CS2 nanofibrous composite mat has proper moisture retention and biodegradability. Furthermore, the N6/HA/CS2 nanofibrous composite mat was discovered to be nontoxic to L929 fibroblast cells and to even improve cell proliferation. Based on the findings, this research offers a simple and rapid method for creating material that could be utilized as prospective wound dressings in clinical environments.

One-step fabrication of an injectable antibacterial collagen hydrogel with in situ synthesized silver nanoparticles for accelerated diabetic wound healing

Developing antibacterial collagen-based wound dressings that target multidrug-resistant bacteria holds promise for healing diabetic wounds prone to infection, yet traditional approaches pose persistent challenges of cytotoxicity and uneconomical steps. To address these issues, we develop a biocompatible, eco-friendly, one-step cross-linking and reduction strategy, fabricating injectable antibacterial collagen hydrogels containing in situ-generated silver nanoparticles for diabetic wound care. By exposing the collagen-silver ion (Ag+) mixture to visible light, collagen-silver nanoparticle (Col I/AgNPs) hydrogels were one step created, eliminating the need for additional cross-linkers and toxic reducing agents. The synergistic interaction between collagen and silver ions was the first time investigated, revealing a pivotal redox reaction with a dual role that simultaneously initiated collagen cross-linking and reduced Ag+ to AgNPs. The resulting biocompatible Col I/AgNPs hydrogel was found to have multifunctional properties, exhibiting excellent injectability, enhanced biological activity, and outstanding broad-spectrum antimicrobial ability. Furthermore, animal experiments utilizing a diabetic full-thickness wound model demonstrated their excellent in vivo healing efficacies, capable of establishing efficient antibacterial barriers and serving as bioactive regenerative scaffolds. Our study proposes an innovative one-step approach to create injectable antibacterial collagen-silver nanoparticle hydrogels, highlighting their potential as advanced dressings for diabetic wound treatment and other biomedical applications.

Augmented wound healing potential of photosensitive GelMA hydrogel incorporating antimicrobial peptides and MXene nanoparticles.

Introduction: Wound healing is a delicate and complex process influenced by many factors. The treatment of skin wounds commonly involves the use of wound dressings, which remain a routine approach. An ideal dressing can provide protection and a suitable environment for wound surfaces by maintaining moisture and exhibiting good biocompatibility, mechanical strength, and antibacterial properties to promote healing and prevent infection. Methods: We encapsulated tick-derived antibacterial polypeptides (Os) as a model drug within a methylacrylyl gelatin (GelMA) hydrogel containing MXene nanoparticles. The prepared composite hydrogels were evaluated for their wound dressing potential by analyzing surface morphology, mechanical properties, swelling behavior, degradation properties, antibacterial activity, and cytocompatibility. Results: The results demonstrated excellent mechanical strength, swelling performance, degradation behavior, and antibacterial activity of the prepared composite hydrogels, effectively promoting cell growth, adhesion, and expression of antibacterial peptide activity. A full-thickness rat wound model then observed the wound healing process and surface interactions between the composite hydrogels and wounds. The composite hydrogel significantly accelerated wound closure, reduced inflammation, and sped epithelial formation and maturation. Discussion: Incorporating antibacterial peptides into GelMA provides a feasible strategy for developing excellent antibacterial wound dressings capable of tissue repair. In conclusion, this study presents a GelMA-based approach for designing antibacterial dressings with strong tissue regenerative ability.

Antibacterial and antioxidant wound dressings with pH responsive release properties accelerate chronic wound healing

Accelerating chronic wound healing is of great clinical significance. In this study, a bilayer pad (PCL-TH/PVA-Alg@CUR) with tetracycline hydrochloride (TH) loaded polycaprolactone (PCL) nanofiber as the outer layer (PCL-TH), and poly (vinyl alcohol) (PVA) hydrogel loaded with sodium alginate microspheres (Alg) encapsulating of curcumin (CUR) as the inner layer (PVA-Alg@CUR) was prepared to accelerate the chronic wound healing. The prepared bilayer pad shows a porous structure and can release CUR specifically according to the pH of chronic wounds. Moreover, it has good water vapor transmittance and water absorption ability, and its mechanical properties can meet the daily expansion and contraction of the skin. The antimicrobial and antioxidant properties of the bilayer pads were verified by the inhibition zone, co-culture method and in vitro free radical scavenging experiments. In addition, in vivo experiments have shown that the bilayer pad can inhibit the bacteria at the wound site and accelerate the healing of the chronic diabetic wound infected by bacteria. This study indicates the prepared antibacterial and antioxidant bilayer dressing with pH responsive release property have potential clinical applications.

Ciprofloxacin-loaded electrospun nanofibres for antibacterial wound dressings

A wound is an injury that damages the normal structure and function of the skin and the underlying tissue. Disruption of the wound healing process causes chronic wounds, which are usually associated with microbial infections. In this work, ciprofloxacin was loaded into electrospun nanofibres to generate antibacterial wound dressings. Electrospun nanofibres are suitable for wound dressings due to their adaptability to the wound contour, high porosity for gas exchange, and a high surface area for absorbing wound exudate. Ciprofloxacin was successfully incorporated in polyvinyl alcohol (PVA) and PVA/alginate-blended electrospun nanofibres, with mean diameters ranging from 258 to 460 nm. The materials were characterized using differential scanning calorimetry (DSC) and X-ray diffraction (XRD) to examine the thermal properties and physical form of the drug and polymers. Fourier transform infrared spectroscopy (FTIR) was used to characterise intermolecular interactions within the materials. DSC thermograms showed all the fibres have a PVA enthalpy relaxation peak at 47 °C and a PVA melting endotherm at 229 °C. The XRD patterns indicated decreased crystallinity of PVA after electrospinning. No crystalline drug could be detected in the fibres by either XRD or DSC. FTIR spectra showed the formation of hydrogen bonds between PVA and alginate in the fibres. All the electrospun nanofibres have high water uptake capacity (190%–381%). The ciprofloxacin-loaded electrospun nanofibres also have high drug encapsulation efficiency, above 90%. The drug release profiles demonstrated controlled-release of the drug, following the Korsmeyer-Peppas model. The antibacterial efficacy of the nanofibres was evaluated by isothermal microcalorimetric assays, with the ciprofloxacin-loaded nanofibres found to exhibit equivalent antibacterial efficacy against Staphylococcus aureus and Pseudomonas aeruginosa to pure ciprofloxacin. Hence, the fibres fabricated in this work have the potential to be used as advanced systems to prevent infection during wound healing.

A new starch based wound dressing modified by graphene oxide/silver nanowire nanoparticles

Considering the special effect of wound treatment in the field of medicine, antibacterial wound dressings preparation is one of the main challenges in successful wound healing. In this research, a starch (St)/polyvinyl alcohol (PVA) nanofiberous mat modified with graphene oxide (GO)-silver nanowire (AgNW) hybrid was fabricated. Initially, silver nanowires were synthesized by the polyol method, then GO-AgNW nanoparticle was prepared as a biocompatible and antibacterial biofilm. Reducing the diameter of nanofibers due to the addition of starch and GO-AgNW nanoparticles leads to fibroblast proliferation, increased collagen secretion, reduced inflammation and wound closure. Nanofibrous mats showed significant antibacterial activity against Staphylococcus aureus and Escherichia coli microorganisms. The largest zone of bacterial inhibition was obtained for Starch/PVA nanofibers containing 8% GO-AgNWs hybrid (27.11 and 24.62 mm). The use of GO-AgNW nanoparticles without drugs is an important point due to the strong antibacterial property of silver nanowire. The measured contact angle of nanofibrous mats was in the range of 57.8° as a desirable level of hydrophilicity for wound dressings. The degree of swelling obtained about 491.12%, and the water vapor transmission rate of 2549 ± 36 (g/m2.day) as a proof for accelerating wound healing. Finally, the results indicated that St/PVA/GO-AgNWs composite electrospun fibers could be a suitable candidate for the treatment of infectious wounds, surgical wounds, minor burns, etc.

Optimization of Citrus aurantifolia peel extract encapsulation in alginate-gelatin hydrogel microbeads for antibacterial wound dressing applications

The extract of Citrus aurantifolia peel has been encapsulated into alginate-gelatin-based microbeads using an external ionotropic gelation method to apply antibacterial wound dressings. Such variables, like the alginate-gelatin ratio, extract quantity, and CaCl2 cross-linkers, were optimized to produce a good yield, well-distributed size, and encapsulation efficiency. Antibacterial efficacy was tested against both S. aureus and E. coli. Optimal microbead characteristics were obtained at alginate:gelatin concentration ratio of 1.75 %:0.25 % (w/v), with 15 mg of extract and a 2 % CaCl2 cross-linker. These conditions resulted in the microbeads with 82.94 ± 1.056 % yield, particle sizes between 1.080–1.244 µm, and encapsulation efficiency of 79.127 ± 0.186 %. The microbeads exhibited an almost spherical morphology with a slightly rough surface. The extract release mechanism out of the microbeads was governed by both diffusion and erosion of the shells following the Korsmeyer-Peppas kinetic model (k = 1.014 ± 0.007/min). Upon immobilizing the microbeads on gauze, an add-on percentage of 73.98 % was observed. Moreover, the gauze-immobilized microbeads inhibited S. aureus and E. coli growth with inhibition zones of 11±1.48 and 12.56±4.89 mm, respectively. In conclusion, the antibacterial alginate-gelatin-based microbeads have demonstrated optimal characteristics and exhibited effective inhibition against S. aureus and E. coli, showcasing their potential as antibacterial wound dressings.

Emulsion template fabricated gelatin-based scaffold functionalized by dialdehyde starch complex with antibacterial antioxidant properties for accelerated wound healing

Gelatin and starch are considered as promising sustainable materials for their abundant production and good biodegradability. Efforts have been made to explore their medical application. Herein, scaffolds based on gelatin and starch with a preferred microstructure and antibacterial antioxidant property were fabricated by the emulsion template method. The dialdehyde starch was firstly combined with silver nanoparticles and curcumin to carry out the efficient hybrid antibacterial agent. Then, the gelatin microsphere of appropriate size was prepared by emulsification and gathered by the above agent to obtain gelatin-based scaffolds. The prepared scaffolds showed porous microstructures with high porosity of over 74 % and the preferred pore sizes of ∼65 μm, which is conducive to skin regeneration. Moreover, the scaffolds possessed a good swelling ability of over 640 %, good degradability of over 18 days, excellent blood compatibility, and cell compatibility. The promising antibacterial and antioxidant properties came from the hybrid antibacterial agent were affirmed. As expected, the gelatin-based scaffolds fabricated by the emulsion template method with a preferred microstructure can facilitate more adhered fibroblasts. In summary, gelatin-based scaffolds functionalized by starch-based complex expanded the application of abundant sustainable materials in the biomedical field, especially as antibacterial antioxidant wound dressings.

Antifouling Zwitterionic Nanofibrous Wound Dressing for Long-Lasting Antibacterial Photodynamic Therapy.

Nanofibrous mats as a wound dressing have received great attention in recent year. The development of biocompatible dressings with antibiofouling capability and long-lasting antibacterial properties is important but challenging. Antibacterial photodynamic therapy (aPDT) effectively eliminates pathogens via a photodynamic process that can circumvent the emergence of antibiotic-resistant pathogens. In this study, we integrated the zwitterionic materials (2-methacryloyloxyethyl phosphorylcholine (MPC) moiety) and aPDT photosensitizer, methylene blue (MB), to fabricate a long-lasting antibacterial nanofibrous mat using electrospinning technology. The prepared nanofibers possessed an appropriate water absorption and retention ability, superior cytocompatibility, and antibiofouling ability against both proteins and L929 cell adhesion. MB-loaded nanofibrous mats have exhibited superior aPDT against Gram-positive Staphylococcus aureus compared to Gram-negative Escherichia coli under moderate irradiation (100 W m-2) due to the presence of an extra outer membrane of Gram-negative bacteria serving as a protective barrier. In vitro release study demonstrated that the nanofibrous mat had a long-lasting drug release profile, which can efficiently suppress bacterial growth via aPDT. The antibacterial ability of the MB-loaded nanofibrous mat was commensurate or slightly inferior to antibiotics such as tetracycline and kanamycin, suggesting that it has the potential to be used as an antibiotic alternative. Overall, this zwitterionic nanofibrous mat with long-lasting aPDT function and nonadherent properties has potential as a promising antibacterial wound dressing.

Physical dynamic double-network hydrogels as dressings to facilitate tissue repair.

Double-network hydrogels can be tuned to have high mechanical strength, stability, elasticity and bioresponsive properties, which can be combined to create self-healing, adhesive and antibacterial wound dressings. Compared with single-network hydrogel, double-network hydrogel shows stronger mechanical properties and better stability. In comparison with chemical bonds, the cross-linking in double networks makes them more flexible than single-network hydrogels and capable of self-healing following mechanical damage. Here, we present the stepwise synthesis of physical double-network hydrogels where hydrogen bonds and coordination reactions provide self-healing, pH-responsive, tissue-adhesive, antioxidant, photothermal and antibacterial properties, and can be removed on demand. We then explain how to carry out physical, chemical and biological characterizations of the hydrogels for use as wound dressings, yet the double-network hydrogels could also be used in different applications such as tissue engineering scaffolds, cell/drug delivery systems, hemostatic agents or in flexible wearable devices for monitoring physiological and pathological parameters. We also outline how to use the double-network hydrogels in vivo as wound dressings or hemostatic agents. The synthesis of the ureido-pyrimidinone-modified gelatin, catechol-modified polymers and the hydrogels requires 84 h, 48 h and 1 h, respectively, whereas the in vivo assays require 3.5 weeks. The procedure is suitable for users with expertise in biomedical polymer materials.

Accessible approach of fabricating pH‐responsive nanofibrous membranes with photothermal effect as antibacterial wound dressings

AbstractThe synergistic antibacterial effect of photothermal and drug treatments is a promising therapeutic method for treating the persistent bacterial infection of chronic wounds. In this study, we used electrospinning to fabricate functionalized poly(ε‐caprolactone) (PCL) nanofiber membranes as antibacterial wound dressings after incorporating tannic acid (TA) and ferric ion (Fe3+). The abilities of pH‐responsive controlled release TA and the photothermal effect of the membrane were obtained by introducing the TA/Fe3+ complexes. Additionally, the membrane had a defined nanofibrous network structure, excellent mechanical properties, hydrophilicity, and water uptake ability. While the controlled release of TA endowed the membrane with high antibacterial properties at different pH values, the antibacterial ratio was further enhanced by approximately 10% under the photothermal synergistic effect. These results indicate that the PCL/TA/Fe3+ nanofiber membranes could be regarded as an ideal candidate for treating bacterial infection of chronic wounds.

Electroactive Hydrogels with Photothermal/Photodynamic Effects for Effective Wound Healing Assisted by Polydopamine-Modified Graphene Oxide.

Antibacterial hydrogel wound dressings have attracted considerable attention in recent years. However, bacterial infections can occur at any point during the wound-healing process. There is a demand for hydrogels that possess on-demand antibacterial and excellent wound repair properties. Herein, we report a near-infrared (NIR)-light-responsive indocyanine green (ICG)-loaded polydopamine (PDA)-mediated graphene oxide (PGO) and amorphous calcium phosphate (CaP)-incorporated poly(vinyl alcohol) (PVA) hydrogel using a mussel-inspired approach. PGO was reduced by PDA, which endowed the hydrogel with electroactivity and provided abundant sites for loading ICG. Amorphous CaP was formed in situ in the PVA hydrogel to enhance its mechanical properties and biocompatibility. Taking advantage of the high photothermal and photodynamic efficiency of ICG-PGO, the ICG-PGO-CaP-PVA hydrogel exhibited fascinating on-demand antibacterial activity through NIR light irradiation. Moreover, the thermally induced gel-sol conversion of PVA accelerated the release of Ca ions and allowed the hydrogel to adapt to irregular wounds. Meanwhile, PGO endows the hydrogel with conductivity and cell affinity, which facilitate endogenous electrical signal transfer to control cell behavior. In vitro and in vivo studies demonstrated that the ICG-PGO-CaP-PVA hydrogel exhibited a strong tissue repair activity under NIR light irradiation. This mussel-inspired strategy offers a novel way to design hydrogel dressings for wound healing.