An Overview on the Recent Advances in the Treatment of Infected Wounds: Antibacterial Wound Dressings

Collagen-Based Nanoparticles as Drug Delivery System in Wound Healing Applications

Background

Conventional wound dressings often adhere to wounds and can cause secondary injury due to their lack of anti-inflammatory and antibacterial properties. In contrast, collagen-based nanoparticles (NPs) as drug delivery systems exhibit both biocompatibility and biodegradability, presenting a promising avenue for accelerating wound healing processes.

Aims of Study

This review aims to provide a comprehensive overview of the mechanisms involved in wound healing, description of the attributes of ideal wound dressings, understanding of wound healing efficacy of collagen, exploring NPs-mediated drug delivery mechanisms in wound therapy, detailing the synthesis and fabrication techniques of collagen-based NPs, and delineating the applications of various collagen-based NPs infused wound dressings on wound healing.

Methodology

This review synthesizes relevant literature from reputable databases such as Scopus, Science Direct, Google Scholar, and PubMed.

Results

A diverse array of collagen-based NPs, including nanopolymers, metal NPs, nanoemulsions, nanoliposomes, and nanofibers, demonstrate pronounced efficacy in promoting wound closure and tissue regeneration. The incorporation of collagen-based NPs has not only become an agent for the delivery of therapeutics but also actively contributes to the wound healing cascade.

Conclusion

In conclusion, In brief, the use of collagen-based NPs presents a compelling strategy for expediting wound healing processes.

Potential of silver nanoparticles synthesized from Justicia adhatoda metabolites for inhibiting biofilm on urinary catheters

In the present study, we investigated the anti-biofilm effect of urinary catheters fabricated with biogenic nanoparticles synthesized from metabolites of Justicia adhatoda under in vitro conditions against human pathogenic bacteria. Silver nanoparticles were synthesized in the reaction mixture composed of 2 % w/v of 0.1 M of precursor (silver nitrate) and 0.2 g of the metabolites obtained from ethanolic extract of Justicia adhatoda. Characterization of the nanoparticles was done by UV visible spectroscopy, fourier infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X ray diffraction (XRD) to confirm the structural and functional properties. Primary conformation of nanoparticles synthesis by UV visible spectroscopy revealed the notable absorption spectra at 425 nm with a wavelength shift around 450 nm, likely due to surface plasmon resonance excitation. SEM analysis showed spherical, monodisperse, nano scale particles with a size range of 50-60 nm. Crystaline phase of the synthesized nanoparticles was confirmed by x ray diffraction studies which showed the distinct peaks at (2θ) 27.90, 32.20, 46.30, 54.40, and 67.40, corresponding to (111), (200), (220), (222), and (311) planes of nano scale silver. The biocompatibility of these nanoparticles was assessed through zebrafish embryonic toxicity study which showed more than 90 % of embryos were alive and healthy. No marked changes on the blood cells also confirmed best hemocompatibility of the nanoparticles. Synthesized nanoparticles thus obtained were fabricated on the urinary catheter and the fabrication was confirmed by FTIR and SEM analysis. Notable changes in the absorption peaks, uniform coating and embedding of silver nanoparticles studied by FTIR and SEM analysis confirmed the fabrication of silver nanoparticles. The coated catheters demonstrated significant antibacterial activity against pathogenic bacterial strains, including E. coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853. Anti-biofilm studies, conducted using a modified microtiter plate crystal violet assay, revealed effective inhibition of both bacterial adhesion and biofilm development. 85 % of biofilm inhibition was recorded against both the tested strains. The coating method presented in this study shows promise for enhancing infection resistance in commonly used medical devices like urinary catheters, thus addressing device-associated infections.

Nursing bibliometric analysis of wound infections

BACKGROUND

This paper aims to perform a bibliometric analysis of research pertaining to the nursing care of infected wounds. It also aims to examine the current focal points and trends in research development. The paper offers research references that may be useful for practitioners interested in related areas.

METHODS

The Web of Science Core Collection database was queried for publications pertaining to infected wound care. Publication trends and proportions were analyzed using Graphpad Prism v8.0.2. CiteSpace (6.2.4R [64-bit]) and VOSviewer (version 1.6.18) were employed to assess the literature and conduct mapping.

RESULTS

The Web of Science Core Collection database contains 3868 literature related to wound infection care, including 3327 articles and 541 reviews. The literature concerned 117 countries and territories, 4673 institutions, and 20,161 authors. The growth rate of literature was relatively slow before 2015 and markedly accelerated after 2016. Among them, the United States occupies the absolute dominance in research in this field, publishing 37.25% of the papers, and the United States occupies 8 of the top 10 scientific institutions that publish papers. The University of Harvard has published the largest number of papers. Keyword analysis shows a total of 1125 keywords, and through reference literature and time clustering analysis shows that wound healing, sepsis, spine surgery, postoperative infection, nanocrystalline silver, beta lactamase are the current research hotspots.

CONCLUSION

The escalating rate of literary expansion since 2016 suggests that this domain is garnering an increasingly significant amount of interest. Minimizing the risk of patient wound infection is crucial in reducing patients' discomfort and facilitating their prompt recovery. The literature analysis presented in this study serves as a valuable resource for comprehending the current state of the subject and identifying the current areas of focus.

Exploring nanobioceramics in wound healing as effective and economical alternatives

Wound healing is a sophisticated process for which various treatment methods have been developed. Bioceramics with the ability to release inorganic ions in biological environments play a crucial role in cellular metabolism and exhibit bactericidal activity, contributing to numerous physiological processes. Their multifaceted roles in biological systems highlight their significance. The release of different metallic ions from bioceramics enables the repair of both hard and soft tissues. These ions may be effective in cell motility, proliferation, differentiation, adhesion, angiogenesis, and antibiosis. Unlike conventional medications, the bioactivity and antibacterial properties of bioceramics are typically not associated with side effects or bacterial resistance. Bioceramics are commonly recognized for their capcity to facilitate the healing of hard tissues due to their exceptional mechanical properties. In this review, we first explore wound treatment and its prevalent methods, and subsequently, we discuss the application of three primary categories of bioceramics-oxide ceramics, silicate-based ceramics, and calcium-phosphate ceramics-in the context of wound treatment. This review introduces bioceramics as a cost-effective and efficient alternative for wound repair. Our aim is to inspire researchers to incorporate bioceramics with other biomaterials to achieve enhanced, economical, expedited, and safer wound healing.

Multi-mechanism antitumor/antibacterial effects of Cu-EGCG self-assembling nanocomposite in tumor nanotherapy and drug-resistant bacterial wound infections

Chemotherapy and surgery stand as primary cancer treatments, yet the unique traits of the tumor microenvironment hinder their effectiveness. The natural compound epigallocatechin gallate (EGCG) possesses potent anti-tumor and antibacterial traits. However, the tumor's adaptability to chemotherapy due to its acidic pH and elevated glutathione (GSH) levels, coupled with the challenges posed by drug-resistant bacterial infections post-surgery, impede treatment outcomes. To address these challenges, researchers strive to explore innovative treatment strategies, such as multimodal combination therapy. This study successfully synthesized Cu-EGCG, a metal-polyphenol network, and detailly characterized it by using synchrotron radiation and high-resolution mass spectrometry (HRMS). Through chemodynamic therapy (CDT), photothermal therapy (PTT), and photodynamic therapy (PDT), Cu-EGCG showed robust antitumor and antibacterial effects. Cu+ in Cu-EGCG actively participates in a Fenton-like reaction, generating hydroxyl radicals (·OH) upon exposure to hydrogen peroxide (H2O2) and converting to Cu2+. This Cu2+ interacts with GSH, weakening the oxidative stress response of bacteria and tumor cells. Density functional theory (DFT) calculations verified Cu-EGCG's efficient GSH consumption during its reaction with GSH. Additionally, Cu-EGCG exhibited outstanding photothermal conversion when exposed to 808 nm near-infrared (NIR) radiation and produced singlet oxygen (1O2) upon laser irradiation. In both mouse tumor and wound models, Cu-EGCG showcased remarkable antitumor and antibacterial properties.

A 3D bioprinted antibacterial hydrogel dressing of gelatin/sodium alginate loaded with ciprofloxacin hydrochloride

Skin plays a crucial role in human physiological functions, however, it was vulnerable to bacterial infection which delayed wound healing. Nowadays, designing an individual wound dressing with good biocompatibility and sustaining anti-infection capability for healing of chronic wounds are still challenging. In this study, various concentrations of the ciprofloxacin (CIP) were mixed with gelatine (Gel)/sodium alginate (SA) solution to prepare Gel/SA/CIP (GAC) bioinks, following the fabrication of GAC scaffold by an extrusion 3D bioprinting technology. The results showed that the GAC bioinks had good printability and the printed GAC scaffolds double-crosslinked by EDC/NHS and CaCl2 had rich porous structure with appropriate pore size, which were conducive to drug release and cell growth. It demonstrated that the CIP could be rapidly released by 70% in 5 min, which endowed the GAC composite scaffolds with an excellent antibacterial ability. Especially, the antibacterial activities of GAC7.5 against Escherichia coli and Staphylococcus aureus within 24 h were even close to 100%, and the inhibition zones were still maintained 14.78 ± 0.40 mm and 14.78 ± 0.40 mm, respectively, after 24 h. Meanwhile, GAC7.5 also demonstrated impressive biocompatibility which can promote the growth and migration of L929 and accelerate wound healing. Overall, the GAC7.5 3D bioprinting scaffold could be used as a potential skin dressing for susceptible wounds with excellent antibacterial activity and good biocompatibility to meet urgent clinical needs.

Lipid-based nanosystems for wound healing

INTRODUCTION

Wounds, resulting from traumas, surgery, burns or diabetes, are important medical problems due to the complexity of wound healing process regarding healing times and healthcare costs. Nanosystems have emerged as promising candidates in this field thank to their properties and versatile applications in drugs delivery.

AREAS COVERED

Lipid-based nanosystems (LBN) are described for wound treatment, highlighting their different behaviors when interacting with the cutaneous tissue. The role of nanosystems in delivering mostly natural compounds on skin as well as the technological and engineering strategies to increase their efficiency in wound healing effect are reviewed. Finally, in vitro, ex-vivo and in vivo studies are reported.

EXPERT OPINION

LBN have shown promise in addressing the challenges of wound healing as they can improve the stability of drugs used in wound therapy, leading to higher efficacy and fewer adverse effects as compared to traditional formulations. LBNs being involved in the inflammatory and proliferation stages of the wound healing process, enable the modification of wound healing through multiple ways. In addition, the use of new technologies, including 3D bioprinting and photobiomodulation, may lead to potential breakthroughs in wound healing. This would provide clinicians with more potent forms of therapy for wound healing.

Phytochemical Analysis of Centaurea calcitrapa L. Aerial Flowering Parts Serial Solvent Extracts and Its Antibacterial and Antioxidant Activities

To evaluate the phytochemical composition, antibacterial, and antioxidant activity of successive extracts of Centaurea calcitrapa L. (C. calcitrapa) aerial flowering parts, they were assessed in vitro. Using a spectrophotometer, the sample absorbance at 517 nm was used to quantify the scavenging activity. The negative control was DPPH. In the current study, the diffusion using agar wells technique was adapted to measure antimicrobial activity. Phytochemical analysis was performed using the recommended standard procedures. The methanol extract of C. calcitrapa exhibited high levels of total phenolic acids expressed as gallic acid (GA), measured as (97.25 ± 0.73 mg GAE/g) content compared to the chloroform, acetyl acetate, and aqueous extracts (27.42 ± 0.29, 64.25 ± 0.96, and 17.25 ± 0.73 mg GAE/g), respectively. Additionally, the methanol extract had a higher total tannin (27.52 ± 0.53 mg TAE/g) content compared to the chloroform, ethyl acetate, and aqueous extracts (12.02 ± 0.55, 26.01 ± 0.81, and 7.35 ± 0.56 mg TAE/g), respectively, while the aqueous extract contains a lower percentage of flavonoids (141.10 ± 1.31 mg RTE/g) compared to the higher content achieved by the methanol extract (425.93 ± 1.27 mg RTE/g). The hydroxyl groups of the flavonoid and the phenolic compounds found in C. calcitrapa are essentially scavenging free radicals. Radical scavenging activity was highest in the methanol extract (IC50 = 2.82 μg/mL), aqueous extract (IC50 = 8.03 μg/mL), ethyl acetate extract (IC50 = 4.79 μg/mL), and chloroform extract (IC50 = 6.33 μg/mL), as compared to the standard scavenging activity (IC50 = 2.52 μg/mL). The antibacterial properties of C. calcitrapa against Gram-negative bacterial strains Klebsiella pneumoniae, Escherichia coli, Enterobacter aerogenes, and Acinetobacter baumanii, in addition to Gram-positive strains Staphylococcus haemolyticus, Enterococcus faecalis, and Staphylococcus aureus, revealed inhibition zone diameter. The findings of this investigation establish that the aerial flowering parts of C. calcitrapa have substantial antibacterial action against human infections, and the plant can serve as a significant antioxidant that can be employed to prevent and treat severe degenerative diseases brought on by oxidative stress. qPCR showed that C. calcitrapa extracts elevate both SOD1 and SOD2 (cellular oxidation markers) with remarkable folds (1.8-fold for SOD1 and SOD2) with ethyl acetate plant extract against ascorbic acid as a control. This result reflects that C. calcitrapa extracts have remarkable antioxidant activity.

In Vitro Biological Evaluation of an Alginate-Based Hydrogel Loaded with Rifampicin for Wound Care

We report a biocompatible hydrogel dressing based on sodium alginate-grafted poly(N-vinylcaprolactam) prepared by encapsulation of Rifampicin as an antimicrobial drug and stabilizing the matrix through the repeated freeze-thawing method. The hydrogel structure and polymer-drug compatibility were confirmed by FTIR, and a series of hydrogen-bond-based interactions between alginate and Rifampicin were identified. A concentration of 0.69% Rifampicin was found in the polymeric matrix using HPLC analysis and spectrophotometric UV-Vis methods. The hydrogel's morphology was evaluated by scanning electron microscopy, and various sizes and shapes of pores, ranging from almost spherical geometries to irregular ones, with a smooth surface of the pore walls and high interconnectivity in the presence of the drug, were identified. The hydrogels are bioadhesive, and the adhesion strength increased after Rifampicin was encapsulated into the polymeric matrix, which suggests that these compositions are suitable for wound dressings. Antimicrobial activity against S. aureus and MRSA, with an increased effect in the presence of the drug, was also found in the newly prepared hydrogels. In vitro biological evaluation demonstrated the cytocompatibility of the hydrogels and their ability to stimulate cell multiplication and mutual cell communication. The in vitro scratch assay demonstrated the drug-loaded alginate-grafted poly(N-vinylcaprolactam) hydrogel's ability to stimulate cell migration and wound closure. All of these results suggest that the prepared hydrogels can be used as antimicrobial materials for wound healing and care applications.

NIR-responsive electrospun nanofiber dressing promotes diabetic-infected wound healing with programmed combined temperature-coordinated photothermal therapy

BACKGROUND

Diabetic wounds present significant challenges, specifically in terms of bacterial infection and delayed healing. Therefore, it is crucial to address local bacterial issues and promote accelerated wound healing. In this investigation, we utilized electrospinning to fabricate microgel/nanofiber membranes encapsulating MXene-encapsulated microgels and chitosan/gelatin polymers.

RESULTS

The film dressing facilitates programmed photothermal therapy (PPT) and mild photothermal therapy (MPTT) under near-infrared (NIR), showcasing swift and extensive antibacterial and biofilm-disrupting capabilities. The PPT effect achieves prompt sterilization within 5 min at 52 °C and disperses mature biofilm within 10 min. Concurrently, by adjusting the NIR power to induce local mild heating (42 °C), the dressing stimulates fibroblast proliferation and migration, significantly enhancing vascularization. Moreover, in vivo experimentation successfully validates the film dressing, underscoring its immense potential in addressing the intricacies of diabetic wounds.

CONCLUSIONS

The MXene microgel-loaded nanofiber dressing employs temperature-coordinated photothermal therapy, effectively amalgamating the advantageous features of high-temperature sterilization and low-temperature promotion of wound healing. It exhibits rapid, broad-spectrum antibacterial and biofilm-disrupting capabilities, exceptional biocompatibility, and noteworthy effects on promoting cell proliferation and vascularization. These results affirm the efficacy of our nanofiber dressing, highlighting its significant potential in addressing the challenge of diabetic wounds struggling to heal due to infection.

Biochemical Behavior, Influence on Cell DNA Condition, and Microbiological Properties of Wool and Wool-Copper Materials

The paper presents the study concerning the preparation and physio-chemical and biological properties of wool-copper (WO-Cu) materials obtained by the sputter deposition of copper onto the wool fibers. The WO-Cu material was subjected to physio-chemical and biological investigations. The physio-chemical investigations included the elemental analysis of materials (C, N, O, S, and Cu), their microscopic analysis, and surface properties analysis (specific surface area and total pore volume). The biological investigations consisted of the antimicrobial activity tests of the WO-Cu materials against colonies of Gram-positive (Staphylococcus aureus) bacteria, Gram-negative (Escherichia coli) bacteria, and fungal mold species (Chaetomium globosum). Biochemical-hematological tests included the evaluation of the activated partial thromboplastin time and pro-thrombin time. The tested wool-copper demonstrated the ability to interact with the DNA in a time-dependent manner. These interactions led to the DNA's breaking and degradation. The antimicrobial and antifungal activities of the WO-Cu materials suggest a potential application as an antibacterial/antifungal material. Wool-copper materials may be also used as customized materials where the blood coagulation process could be well controlled through the appropriate copper content.

Yolk-shelled silver nanowire@amorphous metal-organic framework for controlled drug delivery and light-promoting infected wound healing

Bacteria-infected wounds healing has been greatly hindered by antibiotic resistance and persistent inflammation. It is crucial to develop multifunctional nanocomposites that possess effective antibacterial properties and can simultaneously accelerate the wound healing process to overcome the above challenges. Herein, we prepared a yolk-shell structured Ag nanowires (NWs)@amorphous hollow ZIF-67 by etching ZIF-67 onto the Ag NWs for infected wound healing for the first time. The etched hollow structure of amorphous ZIF-67 in the nanocomposite makes it a promising platform for loading healing-promoting drugs. We extensively studied the antibacterial and healing-promoting properties of the curcumin (CCM)-loaded nanocomposite (Ag NWs@C-HZ67). Ag NWs, being noble metal materials with plasmonic effects, can absorb a broad range of natural light and convert it to thermal energy. This photothermal conversion further improves the release of antibacterial components and wound healing drugs when exposed to light. During the healing process of an infected wound, Ag and Co ions were released from Ag NWs@C-HZ67 upon direct contact with the wound exudate and under the influence of light irradiation. Simultaneously, the loaded CCM leaked out to repair the infected wound. The minimum inhibitory concentrations of the Ag NWs@C-HZ67 groups against Escherichia coli and Staphylococcus aureus bacteria decreased to 3 and 3 μg ml-1 when exposed to white light. Furthermore, an in vivo assessment of infected wound healing demonstrated that combining Ag NWs@C-HZ67 with light significantly accelerated the wound healing process, achieving 70% healing by the 6th day and almost complete healing by the 8th day. This advanced nanocomposite, consisting of components that possess antibacterial and growth-promoting properties, offers a safe, effective and clinically-translatable solution for accelerating the healing process of infected wounds.

Natural polyphenolic antibacterial bio-adhesives for infected wound healing

Bio-adhesives used clinically, commonly have the ability to fill surgical voids and support wound healing, but which are devoid of antibacterial activity, and thus, could not meet the particular needs of the infected wound site. Herein, a series of natural polyphenolic antibacterial bio-adhesives were prepared via simple mixing and heating of polyphenols and acid anhydrides without any solvent or catalyst. Upon the acid anhydride ring opening and acylation reactions, various natural polyphenolic bio-adhesives could adhere to various substrates (i.e., tissue, wood, glass, rubber, paper, plastic, and metal) based on multi-interactions. Moreover, these bio-adhesives showed excellent antibacterial and anti-infection activity, rapid hemostatic performance and appropriate biodegradability, which could be widely used in promoting bacterial infection wound healing and hot burn infection wound repair. This work could provide a new strategy for strong adhesives using naturally occurring molecules, and provide a method for the preparation of novel multifunctional wound dressings for infected wound healing.

Infection induced inflammation impairs wound healing through IL-1β signaling

Wound healing is impaired by infection; however, how microbe-induced inflammation modulates tissue repair remains unclear. We took advantage of the optical transparency of zebrafish and a genetically tractable microbe, Listeria monocytogenes, to probe the role of infection and inflammation in wound healing. Infection with bacteria engineered to activate the inflammasome, Lm-Pyro, induced persistent inflammation and impaired healing despite low bacterial burden. Inflammatory infections induced il1b expression and blocking IL-1R signaling partially rescued wound healing in the presence of persistent infection. We found a critical window of microbial clearance necessary to limit persistent inflammation and enable efficient wound repair. Taken together, our findings suggest that the dynamics of microbe-induced tissue inflammation impacts repair in complex tissue damage independent of bacterial load, with a critical early window for efficient tissue repair.

Platelet rich fibrin and simvastatin-loaded pectin-based 3D printed-electrospun bilayer scaffold for skin tissue regeneration

Designing multifunctional wound dressings is a prerequisite to prevent infection and stimulate healing. In this study, a bilayer scaffold (BS) with a top layer (TL) comprising 3D printed pectin/polyacrylic acid/platelet rich fibrin hydrogel (Pec/PAA/PRF) and a bottom nanofibrous layer (NL) containing Pec/PAA/simvastatin (SIM) was produced. The biodegradable and biocompatible polymers Pec and PAA were cross-linked to form hydrogels via Ca2+ activation through galacturonate linkage and chelation, respectively. PRF as an autologous growth factor (GF) source and SIM together augmented angiogenesis and neovascularization. Because of 3D printing, the BS possessed a uniform distribution of PRF in TL and an average fiber diameter of 96.71 ± 18.14 nm was obtained in NL. The Young's modulus of BS was recorded as 6.02 ± 0.31 MPa and its elongation at break was measured as 30.16 ± 2.70 %. The wound dressing gradually released growth factors over 7 days of investigation. Furthermore, the BS significantly outperformed other groups in increasing cell viability and in vivo wound closure rate (95.80 ± 3.47 % after 14 days). Wounds covered with BS healed faster with more collagen deposition and re-epithelialization. The results demonstrate that the BS can be a potential remedy for skin tissue regeneration.

Tripeptides Ghk and GhkCu-modified silver nanoparticles for enhanced antibacterial and wound healing activities

Bacterial skin infections represent a major healthcare concern that can delay healing and threaten human health. Silver nanoparticles (AgNPs) have been widely used for antimicrobial purposes; however, their high toxicity limits their applications. Therefore, there is an urgent need to develop simple and efficient therapeutic approaches for treating bacterial infections and promoting wound healing. Here, novel tripeptide (Ghk and GhkCu)-modified AgNPs were developed and subsequently evaluated their antibacterial efficacy against four pathogenic bacterial isolates, cytotoxic properties, and therapeutic effects as a topical treatment for infected wounds. Spherical GhkAgNPs and GhkCuAgNPs with average sizes of 45.92 nm and 56.82 nm exhibited potential antibacterial activity, with a MIC concentration of 8 μg/ml against S. aureus and E. coli. Both AgNPs showed superior bactericidal effects against S. aureus, with complete inhibition after 7 days of treatment. Cytotoxicity assays revealed IC50 (half maximal inhibitory concentrations) values ranging from 6.75 to 6.99 µg/ml in L929 cells. GhkAgNPs displayed accelerated cell migration and facilitated healing up to 92% after 12 h. Furthermore, topical applications of GhkAgNPs and GhkCuAgNPs to S. aureus-infected wounds demonstrated enhanced in vivo wound healing efficacy compared to control groups, as evidenced by increased regenerated epidermal thickness, improved collagen deposition, and downregulation of TNF-α expression. Hence concluded that these novel tripeptides Ghk and GhkCu-modified AgNPs exhibited potent antibacterial effects and significantly promoted wound healing properties.

Using halofuginone-silver thermosensitive nanohydrogels with antibacterial and anti-inflammatory properties for healing wounds infected with Staphylococcus aureus

Contamination by pathogens, such as bacteria, can irritate a wound and prevent its healing, which may affect the physical fitness of the infected person. As such, the development of more novel nano-biomaterials able to cope with the inflammatory reaction to bacterial infection during the wound healing process to accelerate wound healing is required. Herein, a halofuginone‑silver nano thermosensitive hydrogel (HTPM&AgNPs-gel) was prepared via a physical swelling method. HTPM&AgNPs-gel was characterized based on thermogravimetric analysis, differential scanning calorimetry, morphology, injectability, and rheological mechanics that reflected its exemplary nature. Moreover, HTPM&AgNPs-gel was further tested for its ability to facilitate healing of skin fibroblasts and exert antibacterial activity. Finally, HTPM&AgNPs-gel was tested for its capacity to accelerate general wound healing and treat bacterially induced wound damage. HTPM&AgNPs-gel appeared spherical under a transmission electron microscope and showed a grid structure under a scanning electron microscope. Additionally, HTPM&AgNPs-gel demonstrated excellent properties, including injectability, temperature-dependent swelling behavior, low loss at high temperatures, and appropriate rheological properties. Further, HTPM&AgNPs-gel was found to effectively promote healing of skin fibroblasts and inhibit the proliferation of Escherichia coli and Staphylococcus aureus. An evaluation of the wound healing efficacy demonstrated that HTPM&AgNPs-gel had a more pronounced ability to facilitate wound repair and antibacterial effects than HTPM-gel or AgNPs-gel alone, and exhibited ideal biocompatibility. Notably, HTPM&AgNPs-gel also inhibited inflammatory responses in the healing process. HTPM&AgNPs-gel exhibited antibacterial, anti-inflammatory, and scar repair features, which remarkably promoted wound healing. These findings indicated that HTPM&AgNPs-gel holds great clinical potential as a promising and valuable wound healing treatment.

An Injectable, Adhesive, and Self-Healing Hydrogel with Inherently Antibacterial Property for Wound Dressing

Antibacterial hydrogel has emerged as an excellent candidate for wound dressing with the ability to eliminate infection and promote wound healing. Herein, a dynamic hydrogel is developed by Schiff base reaction of mixed charged polypeptides and oxidized dextran (ODex). Specifically, biodegradable polypeptides of 1-(propylthio)acetic acid-3-butylimidazole-modified poly(L-lysine) (PLL-PBIM) and adipate dihydrazide-modified poly(L-glutamic acid) (PLG-ADH) are achieved with tunable substitution and charge. By mixing with ODex, charged polypeptides of PLL-PBIM and PLG-ADH led to an injectable and self-healing hydrogel in seconds. The injectable and self-healing performances of the hydrogels are ascribed to the reversible imine and hydrazone bonds formed between polypeptides and ODex. The positively charged hydrogels exhibited over 95% antibacterial activity against E. coli and S. aureus. An optimized balancing of PLG-ADH and PLL-PBIM significantly reduced the hemolysis rate and cytotoxicity of hydrogels. Therefore, the dynamic hydrogel with excellent biocompatibility and inherently antibacterial ability can have potential application for wound dressing.

Combining Alginate/PVPI-Based Film with Frequency Rhythmic Electrical Modulation System (FREMS) Technology as an Advanced Strategy for Diabetic Wounds

Diabetes is rising as one of the most diffused diseases of the century with the related urgent necessity to face its systemic and local effects on the patients, such as cardiovascular problems, degeneration of limbs, and dysfunction of the wound healing process. The diffusion of leg ulcers has been estimated to be 1.51 for 1000 population, and these non-resolved wounds can produce several social, economic, and mental health issues in diabetic patients. At the same time, these people experience neuropathic pain that causes morbidity and a further decrease in their quality of life. Here, a new study is presented where asodium alginate/Polyvinylpyrrolidone-Iodine complex (PVPI)-based wound dressing is combined with the Frequency Rhythmic Electrical Modulation System (FREMS) technology, an established medical device for the treatment of neuropathic pain and diabetic ulcers. The produced Alginate/PVPI-based films are characterized in terms of morphology, chemistry, wettability, bio-/hemo-compatibility, and clotting capacity. Next, the Alginate/PVPI-based films are used together with FREMS technology in diabetic mice models, and synergism of their action in the wound closure rate and anti-inflammatory properties is found. Hence, how the combination of electrical neurostimulation devices and advanced wound dressings can be a new approach to improve chronic wound treatment is demonstrated.

High-efficiency antibacterial calcium alginate/lysozyme/AgNPs composite sponge for wound healing

Infection poses a significant barrier to effective wound repair, leading to increased inflammatory responses that ultimately result in incomplete and prolonged wound healing. To address this challenge, numerous antibacterial ingredients have been incorporated into dressings to inhibit wound infection. Our previous work demonstrated that lysozyme/silver nanoparticles (LYZ/AgNPs) complexes, prepared using an eco-friendly one-step aqueous method, exhibited excellent antibacterial efficacy with favorable biosafety. To further explore its potential application in advancing wound healing, calcium alginate (CA) with good porosity, water absorption, and water retention capacities was formulated with LYZ/AgNPs to prepare composite sponge (CA/LYZ/AgNPs). As expected, in vivo experiments involving full-thickness skin wound and scald wound healing experiments demonstrated that CA-LYZ-AgNPs composite sponges with excellent biocompatibility exhibited remarkable antibacterial activity against gram-positive bacteria, gram-negative bacteria and fungi, and outperformed the wound healing process efficacy of other commercially available AgNPs-loaded wound dressings. In summary, this work introduces a CA/LYZ/AgNPs sponge featuring exceptional antibacterial efficacy and biocompatibility, thus holding promising potential in wound care applications.

Mupirocin loaded core-shell pluronic-pectin-keratin nanofibers improve human keratinocytes behavior, angiogenic activity and wound healing

In the current study, a core-shell nanofibrous wound dressing based on Pluronic-F127 (F127) containing 2 wt% mupirocin (Mup) core and pectin (Pec)-keratin (Kr) shell was fabricated through coaxial electrospinning technique, and the blended nanofibers were also fabricated from the same materials. The fiber diameter and specific surface area of the blended nanofibers were about 101.56 nm and 20.16 m2/g, while for core-shell nanofibers they were about 97.32 nm and 25.26 m2/g, respectively. The resultant blended and core-shell nanofibers experienced a degradation of 27.65 % and 32.28 % during 7 days, respectively. The drug release profile of core-shell nanofibers revealed a sustained release of Mup over 7 days (87.66 %), while the blended F127-Pec-Kr-Mup nanofibers had a burst release within the first few hours (89.38 % up to 48 h) and a cumulative release of 91.36 % after 7 days. Due to the controlled release of Mup, the core-shell structure significantly improved the human keratinocytes behavior, angiogenic potential and wound healing in a rat model compared to the blended structure. In conclusion, the F127-Mup/Pec-Kr core-shell nanofibrous wound dressing appears to be a promising candidate for the prevention of infection, and can potentially accelerate the recovery and healing of chronic and ischemic wounds.

Real-time in vivo monitoring of the antimicrobial action of combination therapies in the management of infected topical wounds

The increasing prevalence of non-healing infected wounds has become a serious concern in the clinical practice, being associated to population aging and to the rising prevalence of several chronic conditions such as diabetes. Herein, the evaluation of the bactericidal and antibiofilm effects of the natural antiseptic terpenes thymol and farnesol standing alone or in combination with the standard care antiseptic chlorhexidine was carried out both in vitro and in vivo. The in vitro combinatorial treatment of chlorhexidine associated with those terpenes against Staphylococcus aureus in its planktonic and sessile forms demonstrated a superior antibacterial activity than that of chlorhexidine alone. Real-time in vivo monitoring of infection progression and antimicrobial treatment outcomes were evaluated using the bioluminescent S. aureus strain Xen36. In vivo studies on infected wound splinting murine models corroborated the superior bactericidal effects of the combinatorial treatments here proposed. Moreover, the encapsulation of thymol in electrospun Eudragit® S100 (i.e., a synthetic anionic copolymer of methacrylic acid and ethyl acrylate)-based wound dressings was also carried out in order to design efficient antimicrobial wound dressings.

Zn2+ incorporated composite polysaccharide microspheres for sustained growth factor release and wound healing

The development of new wound dressings has always been an issue of great clinical importance and research promise. In this study, we designed a novel double cross-linked polysaccharide hydrogel microspheres based on alginate (ALG) and hyaluronic acid methacrylate (HAMA) from gas-assisted microfluidics for wound healing. The microspheres from gas-assisted microfluidics showed an uniform size and good microsphere morphology. Moreover, this composite polysaccharide hydrogel microspheres were constructed by harnessing the fact that zinc ions (Zn²⁺) can cross-link with ALG as well as histidine-tagged vascular endothelial growth (His-VEGF) to achieve long-term His-VEGF release, thus promoting angiogenesis and wound healing. Meanwhile, Zn²⁺, as an important trace element, can exert antibacterial and anti-inflammatory effects, reshaping the trauma microenvironment. In addition, photo cross-linked HAMA was introduced into the microspheres to further improve its mechanical properties and drug release ability. In summary, this novel Zn²⁺ composite polysaccharide hydrogel microspheres loaded with His-VEGF based on a dual cross-linked strategy exhibited synergistic antimicrobial and angiogenic effects in promoting wound healing.

Copper-based dressing: Efficacy in a wound infection of ex vivo human skin

This study aimed to evaluate the wound healing and antibacterial effects of two experimental copper dressings compared to a commercial silver dressing. Burn wounds were created in the ex vivo human skin biopsies, then were infected by Staphylococcus aureus. Tissues were treated with copper dressings, silver dressing, or a dressing without any antibacterial component. An infected wound tissue without treatment was considered as the control group. Three days after treatments, tissues were analyzed by bacterial count and histology staining, while their media was used to assess the expression of cytokines and chemokines. Histology staining confirmed the presence of second-degree burn wounds and colonization of bacteria in the surface and superficial layer of tissues. The results demonstrated a higher antibacterial effect, improved epithelium formation, and decreased wound area in one of the copper dressings compared to other dressings. Markers associated with infection control increased in both the copper and silver-treated groups. The cytokine profiling analysis revealed increased expression of markers related to angiogenesis and anti-inflammatory responses and decreased pro-inflammatory cytokine responses in the infected wound treated with one of the copper dressings. Our results confirmed the efficacy of the experimental copper dressing in reducing bacteria and promoting wound healing.

Embryonic perfect repair inspired electrospun nanofibers dressing with temperature-sensitive and antibacterial properties for wound healing

Introduction

The development of highly effective wound dressings is crucial for successful clinical applications. Achieving wound closure, preventing infection, and minimizing scarring are key objectives in wound healing. Drawing inspiration from the regenerative mechanisms observed in embryonic tissue repair, we designed a series of wound-contractible dressings with exceptional antibacterial properties.

Methods

This was achieved by encapsulating quaternized silicone (QP12) and poly(N-isopropylacrylamide-co-N-hydroxymethylacrylamide-co-octadecyl acrylate) (PNNS) within electrospun nanofibers of poly(ε-caprolactone) (PCL).

Results and discussion

The resulting nanofibrous dressings demonstrated remarkable thermo-responsive self-contraction and tissue adhesion capabilities, enabling secure adherence to the skin and active wound closure. Notably, these nanofibers exhibited potent antibacterial activity against both Gram-positive and Gram-negative bacteria. Furthermore, they possessed desirable properties such as hydrophilicity, biocompatibility and mechanical properties resembling human skin. A full-thickness skin defect model evaluation revealed that these temperature-sensitive nanofibers expedited wound closure, enhanced wound healing, and suppressed scar formation. This result was evidenced by reduced infiltration of inflammatory cells, well-organized collagen arrangement, and improved vascularization. In summary, we propose that these wound-contractible nanofibers, with their antibacterial and anti-scarring properties, hold great promise as an advanced solution for skin wound repair.

A Gelatin-Based Composite Hydrogel with a "One Stone, Two Birds" Strategy for Photothermal Antibacterial and Vascularization of Infected Wounds

Bacterial infection, prolonged inflammation, and insufficient angiogenesis are the main challenges for effective wound repair. In this work, we developed a stretchable, remodeling, self-healing, and antibacterial multifunctional composite hydrogel for infected wound healing. The hydrogel was prepared using tannic acid (TA) and phenylboronic acid-modified gelatin (Gel-BA) through hydrogen bonding and borate ester bonds and incorporated iron-containing bioactive glasses (Fe-BGs) with uniform spherical morphologies and amorphous structures to achieve GTB composite hydrogels. On one hand, the chelation of Fe³⁺ in Fe-BGs with TA endowed the hydrogel with good photothermal synergistic antibacterial ability; on the other hand, the bioactive Fe³⁺ and Si ions contained in Fe-BGs can recruit cells and synergistically promote blood vessel formation. In vivo animal experiments showed that the GTB hydrogels remarkably accelerated infected full-thickness skin wound healing by improving granulation tissue formation, collagen deposition, and the formation of nerves and blood vessels while decreasing inflammation. This hydrogel with a dual synergistic effect and ″one stone, two birds″ strategy holds immense potential for wound dressing applications.

Engineering ultrasound-activated piezoelectric hydrogels with antibacterial activity to promote wound healing

The development of nanocomposite hydrogel dressings with adhesion and superior mechanical and wound infection inhibition characteristics for wound repair and skin regeneration is urgently needed for clinical applications. In this study, the adhesive piezoelectric antibacterial hydrogels with high expansibility, degradability, and adjustable rheological properties were innovatively prepared by a simple assembly process with carboxymethyl chitosan (CMCS), tannic acid (TA), carbomer (CBM), and piezoelectric FeWO₄ nanorods. As an exogenous mechanical wave, ultrasound can trigger the piezoelectric effect of FeWO₄ and then effectively augment the generation of reactive oxygen species, exhibiting a superior antibacterial efficiency and preventing wound infection. In vitro and in vivo results have demonstrated that piezoelectric hydrogels can accelerate full-thickness skin wound healing in bacteria-infected mice by skin regeneration, inhibiting inflammatory response, increasing collagen deposition, and promoting angiogenesis. Such a discovery provides a representative paradigm for the rational design of piezoelectric hydrogel and effectively serves antibacterial and wound dressing fields.

Autocatalytically hydroxyl-producing composite wound dressing for bacteria-infected wound healing

The creation of wound dressings with low drug resistance and broad-spectrum antibacterial capability is a key topic of scientific interest. To achieve this, a bactericidal wound dressing with the capacity to autocatalytically produce hydroxyl radicals (OH) was developed. The wound dressing was an electrospun PCL/gelatin/glucose composite fiber mesh (PGD) with functional iron-containing metal-organic framework (Fe-MOF) nanozymes. These functional nanozymes (G@Fe) were formed by coupling glucose oxidase (GOx) and Fe-MOF through amide bonds. These nanozymes enabled the conversion of glucose released from the PGD composite mesh into hydroxyl radicals via an autocatalytic cascade reaction to destroy bacteria. The antibacterial efficiency of wound dressings and their stimulation of tissue regeneration were assessed using a MRSA-infected skin wound infection model on the back of SD mice. The G@Fe/PGD wound dressing exhibited improved wound healing capacity and had comparable biosafety to commercial silver-containing dressings, suggesting a potential replacement in the future.

Antibacterial β-Glucan/Zinc Oxide Nanocomposite Films for Wound Healing

Advanced antimicrobial biomaterials for wound healing applications are an active field of research for their potential in addressing severe and infected wounds and overcoming the threat of antimicrobial resistance. Beta-glucans have been used in the preparation of these materials for their bioactive properties, but very little progress has been made so far in producing biomedical devices entirely made of beta-glucans and in their integration with effective antimicrobial agents. In this work, a simple and eco-friendly method is used to produce flexible beta-glucan/nanostructured zinc oxide films, using glucans derived from the yeast Saccharomyces cerevisiae. The properties of the films are characterized through scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, infrared and UV–visible spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and water absorption tests. Finally, the antibacterial properties of the nanostructured zinc oxide and of the composite films are assessed against Staphylococcus epidermidis and Escherichia coli, showing a marked effectiveness against the former. Overall, this study demonstrates how a novel bionanocomposite can be obtained towards the development of advanced wound healing devices.

The Use of Proteins, Lipids, and Carbohydrates in the Management of Wounds

Despite the fact that skin has a stronger potential to regenerate than other tissues, wounds have become a serious healthcare issue. Much effort has been focused on developing efficient therapeutical approaches, especially biological ones. This paper presents a comprehensive review on the wound healing process, the classification of wounds, and the particular characteristics of each phase of the repair process. We also highlight characteristics of the normal process and those involved in impaired wound healing, specifically in the case of infected wounds. The treatments discussed here include proteins, lipids, and carbohydrates. Proteins are important actors mediating interactions between cells and between them and the extracellular matrix, which are essential interactions for the healing process. Different strategies involving biopolymers, blends, nanotools, and immobilizing systems have been studied against infected wounds. Lipids of animal, mineral, and mainly vegetable origin have been used in the development of topical biocompatible formulations, since their healing, antimicrobial, and anti-inflammatory properties are interesting for wound healing. Vegetable oils, polymeric films, lipid nanoparticles, and lipid-based drug delivery systems have been reported as promising approaches in managing skin wounds. Carbohydrate-based formulations as blends, hydrogels, and nanocomposites, have also been reported as promising healing, antimicrobial, and modulatory agents for wound management.

Copper-rich multifunctional Prussian blue nanozymes for infected wound healing

The healing process of infected wounds was limited by bacterial infection, excessive reactive oxygen species (ROS) accumulation, and tissue hypoxia. In order to alleviate the above situations, herein, a copper-rich multifunctional ultra-small Prussian blue nanozymes (HPP@Cu NZs) was constructed for infected wound synergistic treatment. Firstly, hyaluronic acid was modified by branched polyethyleneimine which could form a complex with copper ions, to construct copper-rich Prussian blue nanozymes. Secondly, the HPP@Cu NZs have a uniform ultra-small nano size and excellent photothermal response performance, exhibition of multifunctional enzymatic activity and anti-inflammatory properties. Finally, the slow release of copper ions in the HPP@Cu NZs could effectively promote the formation of new blood vessels, thus giving it multifunctional properties. In vitro and in vivo experiments showed that it not only could effectively inhibit and kill bacteria under 808 nm near-infrared laser but also could remove excessive ROS, regulate oxygen levels, and anti-inflammation. More importantly, the release of copper ions could synergistically promote the healing of infected wounds as well as good biocompatibility. Overall, our studies provide a multifunctional strategy for infected wounds with synergistic treatment based on carrier construction.

Comparison of physical, mechanical and biological effects of leucocyte-PRF and advanced-PRF on polyacrylamide nanofiber wound dressings: In vitro and in vivo evaluations

Platelet-rich fibrin (PRF) is extracted from the blood without biochemical interference and, also, with the ability of a long-term release of growth factors that can stimulate tissue repair and regerenation. Here, leucocyte- and platelet-rich fibrin (L-PRF) and advanced platelet-rich fibrin (A-PRF) were extracted and utilized for the creation of nanofibers containing polyacrylamide (PAAm), PAAm / L-PRF and PAAm / A-PRP through electrospinning processing technique. The effect of the type of PRF on the physical, mechanical and biological properties of the resultant nanofiberous wound dressings are thoroughly evaluated. The results presented in the current study reveals that the fiber diameter is grealtly reduced through the utilization of L-PRF. In addition, mechanical property is also positively affected by L-PRF and the degradation rate is found to be higher compared to A-PRF group. The L929 cells proliferation and adhesion, angiogenesis potential and wound healing ability was significantly higher in PAAm/A-PRF nanofibers compared to pure PAAm and PAAm/L-PRF nanofibers owed to the release of vascular endothelial growth factor (VEGF) and platelet derived growth factor (PDGF). Overall, the utilization of L-PRF or A-PRF can improve the physical, mechanical and biological behavior of nanofiber making them an ideal candidate for wound dressings, with the emphasis on the skin tissue repair and regeneration applications.

Phloroglucinol Derivative Carbomer Hydrogel Accelerates MRSA-Infected Wounds’ Healing

Globally, wound infection is considered to be one of the major healthcare problems, with bacterial infections being the most critical threat, leading to poor and delayed wound healing, and even death. As a superbug, methicillin-resistant Staphylococcus aureus (MRSA) causes a profound hazard to public health safety, prompting us to search for alternative treatment approaches. Herein, the MTT test and Hoechst/propidium iodide (PI) staining demonstrated that PD was slightly less toxic to human fibroblasts including Human keratinocytes (HaCaT) cell line than Silver sulfadiazine (SSD), and Vancomycin (Van). In the MRSA-infected wound model, PD hydrogel (1%, 2.5%) was applied with for 14 days. The wound healing of PD hydrogel groups was superior to the SSD, Van, and control groups. Remarkably, the experimental results showed that PD reduced the number of skin bacteria, reduced inflammation, and upregulated the expression of PCNA (keratinocyte proliferation marker) and CD31 (angiogenesis manufacturer) at the wound site by histology (including hematoxylin–eosin (HE) staining, Masson staining) and immunohistochemistry. Additionally, no toxicity, hemocompatibility or histopathological changes to organs were observed. Altogether, these results suggested the potential of PD hydrogel as a safe, effective, and low toxicity hydrogel for the future clinical treatment of MRSA-infected wounds.