Wound Dressing Products: a Translational Investigation from the Bench to the Market

Advancing burn wound treatment: exploring hydrogel as a transdermal drug delivery system

Burn injuries are prevalent and life-threatening forms that contribute significantly to mortality rates due to associated wound infections. The management of burn wounds presents substantial challenges. Hydrogel exhibits tremendous potential as an ideal alternative to traditional wound dressings such as gauze. This is primarily attributed to its three-dimensional (3D) crosslinked polymer network, which possesses a high water content, fostering a moist environment that supports effective burn wound healing. Additionally, hydrogel facilitates the penetration of loaded therapeutic agents throughout the wound surface, combating burn wound pathogens through the hydration effect and thereby enhancing the healing process. However, the presence of eschar formation on burn wounds obstructs the passive diffusion of therapeutics, impairing the efficacy of hydrogel as a wound dressing, particularly in cases of severe burns involving deeper tissue damage. This review focuses on exploring the potential of hydrogel as a carrier for transdermal drug delivery in burn wound treatment. Furthermore, strategies aimed at enhancing the transdermal delivery of therapeutic agents from hydrogel to optimize burn wound healing are also discussed.

Loading of bacterial cellulose dressing with frutalin, a lectin from Artocarpus incisa L

Bacterial cellulose (BC), produced by bacterial fermentation, is a high-purity material. BC can be oxidized (BCOXI), providing aldehyde groups for covalent bonds with drugs. Frutalin (FTL) is a lectin capable of modulating cell proliferation and remodeling, which accelerates wound healing. This study aimed to develop an FTL-incorporated dressing based on BC, and to evaluate its physicochemical properties and biological activity in vitro. An experimental design was employed to maximize FTL loading yield onto the BC and BCOXI, where independent variables were FTL concentration, temperature and immobilization time. BCOXI-FTL 1 (44.96 % ± 1.34) had the highest incorporation yield (IY) at the experimental conditions: 6 h, 5 °C, 20 μg mL-1. The second highest yield was BCOXI-FTL 6 (23.28 % ± 1.43) using 24 h, 5 °C, 100 μg mL-1. Similarly, the same reaction parameters provided higher immobilization yields for native bacterial cellulose: BC-FTL 6 (16.91 % ± 1.05) and BC-FTL 1 (21.71 % ± 1.57). Purified FTL displayed no cytotoxicity to fibroblast cells (<50 μg mL-1 concentration) during 24 h. Furthermore, BCOXI-FTL and BC-FTL were non-cytotoxic during 24 h and stimulated fibroblast migration. BCOXI-FTL demonstrated neutrophil activation in vitro similar to FTL. These promising results indicate that the bacterial cellulose matrices containing FTL at low concentrations, could be used as an innovative biomaterial for developing wound dressings.

Hyaluronate loaded advanced wound dressing in form of in situ forming hydrogel powders: Formulation, characterization, and therapeutic potential

In this paper, a blend composed of alginate-pectin-chitosan loaded with sodium hyaluronate in the form of an in situ forming dressing was successfully developed for wound repair applications. This complex polymeric blend has been efficiently used to encapsulate hyaluronate, forming an adhesive, flexible, and non-occlusive hydrogel able to uptake to 15 times its weight in wound fluid, and being removed without trauma from the wound site. Calorimetric and FT-IR studies confirmed chemical interactions between hyaluronate and polysaccharides blend, primarily related to the formation of a polyelectrolytic complex between hyaluronate and chitosan. In vivo wound healing assays on murine models highlighted the ability of the loaded hydrogels to significantly accelerate wound healing compared to a hyaluronic-loaded ointment. This was evident through complete wound closure in <10 days, accompanied by fully restored epidermal functionality and no indications of the site of excision or treatment. Therefore, all these results suggest that hyaluronate-loaded powders could be a very promising conformable dressing in several wound healing applications where exudate is present.

Accelerating healing of infected wounds with G. glabra extract and curcumin Co-loaded electrospun nanofibrous dressing

This study aimed to construct a nanofibrous wound dressing composed of polyvinyl alcohol (PVA) and chitosan (CS) containing curcumin and Glycyrrhiza glabra root extract to inhibit infection and accelerate wound healing. Loading 10 wt% of G. glabra extract-curcumin (50:50) by electrospinng technique resulted in the formation of nanofibers (NFs) with diameter distribution 303 ± 38 and had a uniform and defect-free morphology. FTIR analysis confirmed the loading of the components without adverse interactions. Also, the results showed extremely high porosity, extraordinary liquid absorption capacity, and complete wettability. In addition, G. glabra extract-curcumin showed significant antioxidant activity and their release profile from NFs was continuous and sustained. Also, the prepared NF could inhibit the growth of both Gram-positive Saureus and Gram-negative E. coli strains. Wound healing evaluation in the infected animal model showed that the NFs caused full wound closure and accelerated skin regeneration. The studies on inhibiting the bacteria growth at the wound site also revealed complete inhibitory effects. Moreover, histopathology studies confirmed the complete regeneration of skin layers, formation of collagen fibers, and angiogenesis. Finally, PVA/CS NFs containing G. glabra extract-curcumin as a multifunctional bioactive wound dressing presented a promising approach for promoting the healing of infected wounds.

Innovative Bio-based Hydrogel Microspheres Micro-Cage for Neutrophil Extracellular Traps Scavenging in Diabetic Wound Healing

Neutrophil extracellular traps (NETs) seriously impede diabetic wound healing. The disruption or scavenging of NETs using deoxyribonuclease (DNase) or cationic nanoparticles has been limited by liberating trapped bacteria, short half-life, or potential cytotoxicity. In this study, a positive correlation between the NETs level in diabetic wound exudation and the severity of wound inflammation in diabetic patients is established. Novel NETs scavenging bio-based hydrogel microspheres 'micro-cage', termed mPDA-PEI@GelMA, is engineered by integrating methylacrylyl gelatin (GelMA) hydrogel microspheres with cationic polyethyleneimine (PEI)-functionalized mesoporous polydopamine (mPDA). This unique 'micro-cage' construct is designed to non-contact scavenge of NETs between nanoparticles and the diabetic wound surface, minimizing biological toxicity and ensuring high biosafety. NETs are introduced into 'micro-cage' along with wound exudation, and cationic mPDA-PEI immobilizes them inside the 'micro-cage' through a strong binding affinity to the cfDNA web structure. The findings demonstrate that mPDA-PEI@GelMA effectively mitigates pro-inflammatory responses associated with diabetic wounds by scavenging NETs both in vivo and in vitro. This work introduces a novel nanoparticle non-contact NETs scavenging strategy to enhance diabetic wound healing processes, with potential benefits in clinical applications.

Advanced Dressings for Chronic Wound Management

Wound healing, particularly for chronic wounds, presents a considerable difficulty due to differences in biochemical and cellular processes that occur in different types of wounds. Recent technological breakthroughs have notably advanced the understanding of diagnostic and therapeutic approaches to wound healing. The evolution in wound care has seen a transition from traditional textile dressings to a variety of advanced alternatives, including self-healing hydrogels, hydrofibers, foams, hydrocolloids, environment responsive dressings, growth factor-based therapy, bioengineered skin substitutes, and stem cell and gene therapy. Technological advancements, such as 3D printing and electronic skin (e-skin) therapy, contribute to the customization of wound healing. Despite these advancements, effectively managing chronic wounds remains challenging. This necessitates the development of treatments that consider performance, risk-benefit balance, and cost-effectiveness. This review discusses innovative strategies for the healing of chronic wounds. Incorporating biomarkers into advanced dressings, coupled with corresponding biosensors and drug delivery formulations, enables the theranostic approach to the treatment of chronic wounds. Furthermore, integrating advanced dressings with power sources and user interfaces like near-field communication, radio frequency identification, and Bluetooth enhances real-time monitoring and on-demand drug delivery. It also provides a thorough evaluation of the advantages, patient compliance, costs, and durability of advanced dressings, emphasizing smart formulations and their preparation methods.

Insights of biopolymeric blended formulations for diabetic wound healing

Diabetic wounds (DWs) pose a significant health burden worldwide, with their management presenting numerous challenges. Biopolymeric formulations have recently gained attention as promising therapeutic approaches for diabetic wound healing. These formulations, composed of biocompatible and biodegradable polymers, offer unique properties such as controlled drug release, enhanced wound closure, and reduced scarring. In this review, we aim to provide a comprehensive overview of the current state of research and future prospects regarding the application of biopolymeric formulations for diabetic wound healing. The review begins by highlighting the underlying pathophysiology of DWs, including impaired angiogenesis, chronic inflammation, and compromised extracellular matrix (ECM) formation. It further explores the key characteristics of biopolymeric materials, such as their biocompatibility, biodegradability, and tunable physicochemical properties, which make them suitable for diabetic wound healing applications. The discussion further delves into the types of biopolymeric formulations utilized in the treatment of DWs. These include hydrogels, nanoparticles (NP), scaffolds, films, and dressings. Furthermore, the review addresses the challenges associated with biopolymeric formulations for diabetic wound healing. In conclusion, biopolymeric formulations present a promising avenue for diabetic wound healing. Their unique properties and versatility allow for tailored approaches to address the specific challenges associated with DWs. However, further research and developments are required to optimize their therapeutic efficacy, stability, manufacturing processes, and regulatory considerations. With continued advancements in biopolymeric formulations, the future holds great promise for improving the management and outcomes of DWs.

Acer tegmentosum extract-mediated silver nanoparticles loaded chitosan/alginic acid scaffolds enhance healing of E. coli-infected wounds

This work developed Acer tegmentosum extract-mediated silver nanoparticles (AgNPs) loaded chitosan (CS)/alginic acid (AL) scaffolds (CS/AL-AgNPs) to enhance the healing of E. coli-infected wounds. The SEM-EDS and XRD results revealed the successful formation of the CS/AL-AgNPs. FTIR analysis evidenced that the anionic group of AL (-COO-) and cationic amine groups of CS (-NH3+) were ionically crosslinked to form scaffold (CS/AL). The CS/AL-AgNPs exhibited significant antimicrobial activity against both Gram-positive (G+) and Gram-negative (G-) bacterial pathogens, while being non-toxic to red blood cells (RBCs), the hen's egg chorioallantoic membrane (HET-CAM), and a non-cancerous cell line (NIH3T3). Treatment with CS/AL-AgNPs significantly accelerated the healing of E. coli-infected wounds by regulating the collagen deposition and blood parameters as evidenced by in vivo experiments. Overall, these findings suggest that CS/AL-AgNPs are promising for the treatment of infected wounds.

Effective antibacterial agents in modern wound dressings: a review

Wound infections are a significant concern in healthcare, leading to long healing times. Traditional approaches for managing wound infections rely heavily on systemic antibiotics, which are associated with the emergence of antibiotic-resistant bacteria. Therefore, the development of alternative antibacterial materials for wound care has gained considerable attention. In today's world, new generations of wound dressing are commonly used to heal wounds. These new dressings keep the wound and the area around it moist to improve wound healing. However, this moist environment can also foster an environment that is favorable for the growth of bacteria. Excessive antibiotic use poses a significant threat to human health and causes bacterial resistance, so new-generation wound dressings must be designed and developed to reduce the risk of infection. Wound dressings using antimicrobial compounds minimize wound bacterial colonization, making them the best way to avoid open wound infection. We aim to provide readers with a comprehensive understanding of the latest advancements in antibacterial materials for wound management.

Wound Dressing Based on Silver Nanoparticle Embedded Wool Keratin Electrospun Nanofibers Deposited on Cotton Fabric: Preparation, Characterization, Antimicrobial Activity, and Cytocompatibility

Wool keratin (WK) protein is attractive for wound dressing and biomedical applications due to its excellent biodegradability, cytocompatibility, and wound-healing properties. In this work, WK-based wound dressings were prepared by depositing WK/poly(vinyl alcohol) (PVA) and silver nanoparticle (Ag NP)-embedded WK/PVA composite nanofibrous membranes on cotton fabrics by electrospinning. Ag NPs were biosynthesized by reduction and stabilization with sodium alginate. The formed Ag NPs were characterized by ultraviolet-visible and Fourier transform infrared (FTIR) spectroscopy, and their size was determined by transmission electron microscopy and image analysis. The formed Ag NPs were spherical and had an average diameter of 9.95 nm. The produced Ag NP-embedded WK/PVA composite nanofiber-deposited cotton fabric surface was characterized by FTIR and dynamic contact angle measurements, and the nanofiber morphologies were characterized by scanning electron microscopy. The average diameter of the nanofibers formed by 0.1% Ag NP-embedded WK/PVA solution was 146.7 nm. The antibacterial activity of the surface of cotton fabrics coated with electrospun composite nanofibers was evaluated against the two most common wound-causing pathogens, Staphylococcus aureus and Pseudomonas aeruginosa. The cotton fabric coated with 0.1% Ag NP-embedded WK/PVA nanofibers showed very good antibacterial activity against both pathogens, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay results showed good cytocompatibility against L-929 mouse fibroblast cells. However, the increase in Ag NP content in the nanofibers to 0.2% negatively affected the cell viability due to the high release rate of Ag ions. The results achieved show that the developed wound dressing has good potential for wound healing applications.

Wound recovery efficacy of retinol based-micellar formulations in an organotypic skin wound model

Impairment of the skin's structural integrity initially results in acute wounds which can become chronic if timely wound closure is not achieved. Chronic wounds (CWs) affect more than 1% of the global population with increasing cases of this condition due to the ageing population. Current wound management relies on debridement, hyperbaric oxygen, antibiotics, and wound dressings, which lack early intervention and specificity. Herein, antibiotics-free retinol-based micellar formulations (RMF) were made and their wound healing efficacy were investigated in vitro. Five different formulations with retinol contents of 0.3% and 1% against a placebo were topically applied to an organotypic full-thickness skin wound model (FT-SWM, MatTek®) with a 3 mm punch wound, and maintained in an incubator for 6 days. The histological analysis of the FT-SWM was conducted at depths of 60 µm and 80 µm. It was found that all the micellar retinol formulations accelerated wound bed contraction, with 0.3% RMF demonstrating the highest efficacy. At the depths of 60 µm and 80 µm, the 0.3% RMF exhibited inner wound diameter contraction of 58% and 77%, respectively, in comparison to the placebo showing 15% and 8%. The RMF significantly accelerated wound healing and can thus be a potential early intervention for speedy wound recovery. It should be pointed out that these results were obtained based on a small sample size and a large sample size will be explored to further validate the results.

Oncological Surgical Wound Care: A Comparison of Theruptor NXT Non-adherent Dressing and the Current Standard of Care

Background Oncological surgeries pose an elevated risk of surgical site infections (SSIs) due to their complexity and various associated treatments, impacting patient outcomes and healthcare costs. This has prompted a focus on advanced wound dressings that provide microbial protection, exudate absorption, and improved product performance, enhancing patient satisfaction. Our study aimed to compare the efficacy and safety of Theruptor NXT with the current standard of care (SOC) practice involving cotton/povidone/micropore dressings in the postoperative wound management of oncological surgeries. Methodology A total of 102 patients who underwent oncological surgeries in the Department of Surgical Oncology, Vydehi Institute of Medical Sciences and Research Centre, Bengaluru, India between May and September 2023 were randomized to Theruptor NXT and SOC dressing groups (51 patients each). The incidence of SSIs, wound pain score, cosmetic appearance of the wound, and adverse events were assessed in the two groups at various intervals, i.e., post-surgery day 2 ± 1, day of discharge, and post-surgery day 30 ± 7. Further, the subject satisfaction and product usage were evaluated on post-surgery day 2 ± 1. Results The baseline characteristics were found to be comparable in both groups, i.e., Theruptor NXT and SOC groups. Further, the SSI rates, scar outcomes, and physiological parameters were also similar between the Theruptor NXT and SOC groups, indicating a similar safety profile of both dressings (p > 0.05). However, the product usage assessment revealed statistically significant differences, favoring Theruptor NXT in terms of superior ease of application, stretchability, exudate management, breathability, and non-adherence properties (p < 0.05). Conclusions Our findings suggest that Theruptor NXT wound dressing is a promising, effective, and user-friendly alternative to SOC wound dressing in diverse clinical settings.

Exploring polysaccharide-based bio-adhesive topical film as a potential platform for wound dressing application: A review

Wound dressings act as a physical barrier between the wound site and the external environment, preventing additional harm; choosing suitable wound dressings is essential for the healing process. Polysaccharide biopolymers have demonstrated encouraging findings and therapeutic prospects in recent decades about wound therapy. Additionally, polysaccharides have bioactive qualities like anti-inflammatory, antibacterial, and antioxidant capabilities that can help the process of healing. Due to their excellent tissue adhesion, swelling, water absorption, bactericidal, and immune-regulating properties, polysaccharide-based bio-adhesive films have recently been investigated as intriguing alternatives in wound management. These films also mimic the structure of the skin and stimulate the regeneration of the skin. This review presented several design standards and functions of suitable bio-adhesive films for the healing of wounds. Additionally, the most recent developments in the use of bio-adhesive films as wound dressings based on polysaccharides, including hyaluronic acid, chondroitin sulfate, dextran, alginate, chitosan, cellulose, konjac glucomannan, gellan gum, xanthan gum, pectin, guar gum, heparin, arabinogalactans, carrageen, and tragacanth gum, are thoroughly discussed. Lastly, to create a road map for the function of polysaccharide-based bio-adhesive films in advanced wound care, their clinical performances and future challenges in making bio-adhesive films by three-dimensional bioprinting are summarized.

Electrospun multi-chamber core-shell nanofibers and their controlled release behaviors: A review

Core-shell structure is a concentric circle structure found in nature. The rapid development of electrospinning technology provides more approaches for the production of core-shell nanofibers. The nanoscale effects and expansive specific surface area of core-shell nanofibers can facilitate the dissolution of drugs. By employing ingenious structural designs and judicious polymer selection, specialized nanofiber drug delivery systems can be prepared to achieve controlled drug release. The synergistic combination of core-shell structure and materials exhibits a strong strategy for enhancing the drug utilization efficiency and customizing the release profile of drugs. Consequently, multi-chamber core-shell nanofibers hold great promise for highly efficient disease treatment. However, little attention concentration is focused on the effect of multi-chamber core-shell nanofibers on controlled release of drugs. In this review, we introduced different fabrication techniques for multi-chamber core-shell nanostructures, including advanced electrospinning technologies and surface functionalization. Subsequently, we reviewed the different controlled drug release behaviors of multi-chamber core-shell nanofibers and their potential needs for disease treatment. The comprehensive elucidation of controlled release behaviors based on electrospun multi-chamber core-shell nanostructures could inspire the exploration of novel controlled delivery systems. Furthermore, once these fibers with customizable drug release profiles move toward industrial mass production, they will potentially promote the development of pharmacy and the treatment of various diseases. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Enhancement of Wound Healing and Angiogenesis Using Mouse Embryo Fibroblasts Loaded in Decellularized Skin Scaffold

Background

Synthetic and natural polymer scaffolds can be used to design wound dressing for repairing the damaged skin tissue. This study investigated acute wound healing process using a decellularized skin scaffold and mouse embryo fibroblast (MEF).

Methods

Mouse skin fragments were decellularized and evaluated by DNA content, toxicity, H&E staining, Raman confocal microscopy, Masson’s trichrome staining, SEM, and biodegradation assays. The fragments were recellularized by the MEFs, and cell attachment and penetration were studied. De- and decellularized scaffolds were used wound dressings in mouse acute wound models as two experimental groups. Using morphological and immunohistochemical assessments, wound healing was evaluated and compared among the experimental and control groups.

Results

DNA content of the decellularized tissue significantly reduced compared to the native control group (7% vs. 100%; p < 0.05). extracellular matrix components, e.g. collagen types I, III, and IV, elastin, and glycosaminoglycan, were well preserved in the decellularized group. The porosity and fiber arrangement in the stroma had a structure similar to normal skin tissue. A significant reduction in healing time was observed in the group treated with a decellularized scaffold. A thicker epidermis layer was observed in the recovered tissue in both experimental groups compared to the control group. Immunostaining showed a positive reaction for CD31 as an endothelial marker in both experimental groups, confirming new vascularization in these groups.

Conclusion

Using MEFs with decellularized skin as a wound dressing increases the rate of wound healing and also the formation of new capillaries. This system could be beneficial for clinical applications in the field of tissue engineering.

Fluid handling by foam wound dressings: From engineering theory to advanced laboratory performance evaluations

This article describes the contemporary bioengineering theory and practice of evaluating the fluid handling performance of foam-based dressings, with focus on the important and clinically relevant engineering structure-function relationships and on advanced laboratory testing methods for pre-clinical quantitative assessments of this common type of wound dressings. The effects of key wound dressing material-related and treatment-related physical factors on the absorbency and overall fluid handling of foam-based dressings are thoroughly and quantitively analysed. Discussions include exudate viscosity and temperature, action of mechanical forces and the dressing microstructure and associated interactions. Based on this comprehensive review, we propose a newly developed testing method, experimental metrics and clinical benchmarks that are clinically relevant and can set the standard for robust fluid handling performance evaluations. The purpose of this evaluative framework is to translate the physical characteristics and performance determinants of a foam dressing into achievable best clinical outcomes. These guiding principles are key to distinguishing desirable properties of a dressing that contribute to optimal performance in clinical settings.

Hydrolyzed Collagen Powder Dressing Improves Wound Inflammation, Perfusion, and Breaking Strength of Repaired Tissue

Objective: Hydrolyzed collagen-based matrices are widely used as wound care dressings. Information on the mechanism of action of such dressings is scanty. The objective of this study was to test the effect of a specific hydrolyzed collagen powder (HCP), which is extensively used for wound care management in the United States. Approach: The effects of HCP on resolution of wound inflammation, perfusion, closure, and breaking strength of the repaired skin were studied in an experimental murine model. Results: In early (day 7) inflammatory phase of wound macrophages, HCP treatment boosted phagocytosis and efferocytosis of wound-site macrophages. In these cells, inducible reactive oxygen species were also higher on day (d) 7. HCP treatment potentiated the expression of anti-inflammatory interleukin (IL)-10 cytokine and proangiogenic vascular endothelial growth factor (VEGF) production. Excisional wounds dressed with HCP showed complete closure on day 21, while the control wounds remained open. HCP treatment also demonstrated improved quality of wound healing as marked by the improved breaking strength of the closed wound tissue/repaired skin. Innovation: These data represent first evidence on the mechanism of action of clinically used HCP. Conclusion: HCP dressing favorably influenced both wound inflammation and vascularization. Improved breaking strength of HCP-treated repaired skin lays the rationale for future studies testing the hypothesis that HCP-treated closed wounds would show fewer recurrences.

pH-Responsive Wound Dressing Based on Biodegradable CuP Nanozymes for Treating Infected and Diabetic Wounds

Nanozymes, emerging nanomaterials for wound healing, exhibit enzyme-like activity to modulate the levels of reactive oxygen species (ROS) at wound sites. Yet, the solo regulation of endogenous ROS by nanozymes often falls short, particularly in chronic refractory wounds with complex and variable pathological microenvironments. In this study, we report the development of a multifunctional wound dressing integrating a conventional alginate (Alg) hydrogel with a newly developed biodegradable copper hydrogen phosphate (CuP) nanozyme, which possesses good near-infrared (NIR) photothermal conversion capabilities, sustained Cu ion release ability, and pH-responsive peroxidase/catalase-mimetic catalytic activity. When examining acute infected wounds characterized by a low pH environment, the engineered Alg/CuP composite hydrogels demonstrated high bacterial eradication efficacy against both planktonic bacteria and biofilms, attributed to the combined action of catalytically generated hydroxyl radicals and the sustained release of Cu ions. In contrast, when applied to chronic diabetic wounds, which typically have a high pH environment, these composite hydrogels exhibit significant angiogenic performance. This is driven by the provision of catalytically generated dissolved oxygen and a beneficial supplement of Cu ions released from the degradable CuP nanozyme. Further, a mild thermal effect induced by NIR irradiation amplifies the catalytic activities and bioactivity of Cu ions, thereby enhancing the healing process of both infected and diabetic wounds. Our study validates that the synergistic integration of photothermal effects, catalytic activity, and released Cu ions can concurrently yield high antibacterial efficiency and tissue regenerative activity, rendering it highly promising for various clinical applications in wound healing.

Supramolecular chitin-based hydrogels with self-adapting and fast-degradation properties for enhancing wound healing

Due to the features of high porosity, high water content, and tunable viscoelasticity, hydrogels have attracted numerous attentions in the promotion of wound closure. However, the lack of abilities to adapt the wounds of complex shapes and prevent postoperative adhesion limits their therapeutic outcomes in wound healing. To address the above challenges, the supramolecular chitin-based (SMCT) hydrogels are created via the host-guest pre-assembly strategy of β-cyclodextrin (βCD) and adamantane (Ad). The reversible host-guest crosslinks endow the SMCT hydrogels with highly dynamic networks, which can better accommodate irregularly shaped wounds compared with the covalent chitin-based hydrogels with similar mechanical properties. In addition, the SMCT hydrogels show rapid in vivo degradability (degradation time ≈ 2 days) due to the enzyme-triggered degradability of chitin, which do not need to be removed from the wounds after service and thus avoid the secondary damage to skin during dressing change. Owing to the hydrophobic cavity of βCD, the SMCT hydrogels can facilitate the load and release of curcumin with anti-inflammatory, antibacterial, and antioxidative activities, thereby significantly improving the wound healing efficiency. This work provides valuable guidance to the design of self-adaptive and fast-degradable hydrogels that hold great potential for enhancing the wound healing in skin and other tissues.

Adhesive, Flexible, and Fast Degradable 3D-Printed Wound Dressings with a Simple Composition

3D printing technology has revolutionized the field of wound dressings, offering tailored solutions with mechanical support to facilitate wound closure. In addition to personalization, the intricate nature of the wound healing process requires wound dressing materials with diverse properties, such as moisturization, flexibility, adhesion, anti-oxidation and degradability. Unfortunately, current materials used in digital light processing (DLP) 3D printing have been inadequate in meeting these crucial criteria. This study introduces a novel DLP resin that is biocompatible and consists of only three commonly employed non-toxic compounds in biomaterials, that is, dopamine, poly(ethylene glycol) diacrylate, and N-vinylpyrrolidone. Simple as it is, this material system fulfills all essential functions for effective wound healing. Unlike most DLP resins that are non-degradable and rigid, this material exhibits tunable and rapid degradation kinetics, allowing for complete hydrolysis within a few hours. Furthermore, the high flexibility enables conformal application of complex dressings in challenging areas such as finger joints. Using a difficult-to-heal wound model, the manifold positive effects on wound healing in vivo, including granulation tissue formation, inflammation regulation, and vascularization are substantiated. The simplicity and versatility of this material make it a promising option for personalized wound care, holding significant potential for future translation.

Collagen-Based Medical Devices for Regenerative Medicine and Tissue Engineering

Assisted reproductive technologies are key to solving the problems of aging and organ defects. Collagen is compatible with living tissues and has many different chemical properties; it has great potential for use in reproductive medicine and the engineering of reproductive tissues. It is a natural substance that has been used a lot in science and medicine. Collagen is a substance that can be obtained from many different animals. It can be made naturally or created using scientific methods. Using pure collagen has some drawbacks regarding its physical and chemical characteristics. Because of this, when collagen is processed in various ways, it can better meet the specific needs as a material for repairing tissues. In simpler terms, collagen can be used to help regenerate bones, cartilage, and skin. It can also be used in cardiovascular repair and other areas. There are different ways to process collagen, such as cross-linking it, making it more structured, adding minerals to it, or using it as a carrier for other substances. All of these methods help advance the field of tissue engineering. This review summarizes and discusses the current progress of collagen-based materials for reproductive medicine.

Antimicrobial Effectiveness Testing of Resorbable Electrospun Fiber Matrix per United States Pharmacopeia (USP) <51>

Contamination of surgical, traumatic, and chronic wounds with microorganisms presents a challenge to successful wound healing. In the present in vitro study, a synthetic electrospun fiber matrix (SEFM) cleared for use in the management of chronic, surgical, and traumatic wounds underwent USP (United States Pharmacopeia) <51> Antimicrobial Effectiveness Testing to determine its in vitro effectiveness against various microorganisms commonly found in non-healing wounds. The SEFM was tested in both sheet (s-SEFM) and micronized form (m-SEFM) against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Aspergillus brasiliensis, Candida albicans, Proteus mirabilis, and Enterococcus faecalis. Testing was performed per the USP <51> standard on days 7, 14, and 28. Both the s-SEFM and m-SEFM met the USP <51> acceptance criteria for all microorganisms. The results obtained for s-SEFM demonstrated >1-log10 reduction against E. coli, S. aureus, P. aeruginosa, P. mirabilis, E. faecalis, and C. albicans at day 7; >3-log10 reduction with no detection of these microbes at days 14 and 28, and no increase from initial inoculum at days 7, 14, and 28 against A. brasiliensis. The results obtained for m-SEFM demonstrated >3-log10 reduction with no detectable microorganisms at day 7. The results observed in this study indicate that the SEFM is effective in vitro at inhibiting bacterial and fungal growth and colonization per USP <51> testing.

Alginate/gum arabic-based biomimetic hydrogel enriched with immobilized nerve growth factor and carnosine improves diabetic wound regeneration

Diabetic foot ulcers (DFUs) often remain untreated because they are difficult to heal, caused by reduced skin sensitivity and impaired blood vessel formation. In this study, we propose a novel approach to manage DFUs using a multifunctional hydrogel made from a combination of alginate and gum arabic. To enhance the healing properties of the hydrogel, we immobilized nerve growth factor (NGF), within specially designed mesoporous silica nanoparticles (MSN). The MSNs were then incorporated into the hydrogel along with carnosine (Car), which further improves the hydrogel's therapeutic properties. The hydrogel containing the immobilized NGF (SiNGF) could control the sustain release of NGF for >21 days, indicating that the target hydrogel (AG-Car/SiNGF) can serve as a suitable reservoir managing diabetic wound regeneration. In addition, Car was able to effectively reduce inflammation and significantly increase angiogenesis compared to the control group. Based on the histological results obtained from diabetic rats, the target hydrogel (AG-Car/SiNGF) reduced inflammation and improved re-epithelialization, angiogenesis, and collagen deposition. Specific staining also confirmed that AG-Car/SiNGF exhibited improved tissue neovascularization, transforming growth factor-beta (TGFβ) expression, and nerve neurofilament. Overall, our research suggests that this newly developed composite system holds promise as a potential treatment for non-healing diabetic wounds.

Emerging drug delivery systems with traditional routes - A roadmap to chronic inflammatory diseases

Inflammation is prevalent and inevitable in daily life but can generally be accommodated by the immune systems. However, incapable self-healing and persistent inflammation can progress to chronic inflammation, leading to prevalent or fatal chronic diseases. This review comprehensively covers the topic of emerging drug delivery systems (DDSs) for the treatment of chronic inflammatory diseases (CIDs). First, we introduce the basic biology of the chronic inflammatory process and provide an overview of the main CIDs of the major organs. Next, up-to-date information on various DDSs and the associated strategies for ensuring targeted delivery and stimuli-responsiveness applied to CIDs are discussed extensively. The implementation of traditional routes of drug administration to maximize their therapeutic effects against CIDs is then summarized. Finally, perspectives on future DDSs against CIDs are presented.

Mechano-Activated Cell Therapy for Accelerated Diabetic Wound Healing

Chronic diabetic wounds are a significant global healthcare challenge. Current strategies, such as biomaterials, cell therapies, and medical devices, however, only target a few pathological features and have limited efficacy. A powerful platform technology combining magneto-responsive hydrogel, cells, and wireless magneto-induced dynamic mechanical stimulation (MDMS) is developed to accelerate diabetic wound healing. The hydrogel encapsulates U.S. Food and Drug Administration (FDA)-approved fibroblasts and keratinocytes to achieve ∼3-fold better wound closure in a diabetic mouse model. MDMS acts as a nongenetic mechano-rheostat to activate fibroblasts, resulting in ∼240% better proliferation, ∼220% more collagen deposition, and improved keratinocyte paracrine profiles via the Ras/MEK/ERK pathway to boost angiogenesis. The magneto-responsive property also enables on-demand insulin release for spatiotemporal glucose regulation through increasing network deformation and interstitial flow. By mining scRNAseq data, a mechanosensitive fibroblast subpopulation is identified that can be mechanically tuned for enhanced proliferation and collagen production, maximizing therapeutic impact. The "all-in-one" system addresses major pathological factors associated with diabetic wounds in a single platform, with potential applications for other challenging wound types.

pH Switchable Nanozyme Platform for Healing Skin Tumor Wound Infected with Drug-Resistant Bacteria

Nanozymes capable of generating reactive oxygen species have recently emerged as promising treatments for wounds infected with drug-resistant bacteria, possessing a reduced possibility of inducing resistance. However, the therapeutic effect is limited by a shortage of endogenous oxy-substrates and undesirable off-target biotoxicity. Herein, a ferrocenyl coordination polymer (FeCP) nanozyme, featuring pH switchable peroxidase (POD)- and catalase (CAT)-like activity is incorporated with indocyanine green (ICG) and calcium peroxide (CaO2 ) to fabricate an H2 O2 /O2 self-supplying system (FeCP/ICG@CaO2 ) for precise treatment of bacterial infections. At the wound site, CaO2 reacts with water to generate H2 O2 and O2 . Acting as a POD mimic under an acidic bacterial microenvironment, FeCP catalyzes H2 O2 into hydroxyl radicals to prevent infection. However, FeCP switches to CAT-like activity in neutral tissue, decomposing H2 O2 into H2 O and O2 to prevent oxidative damage and facilitate wound healing. Additionally, FeCP/ICG@CaO2 shows photothermal therapy capability, as ICG can emit heat under near-infrared laser irradiation. This heat assists FeCP in fully exerting its enzyme-like activity. Thus, this system achieves an antibacterial efficiency of 99.8% in vitro for drug-resistant bacteria, and effectively overcomes the main limitations of nanozyme-based treatment assays, resulting in satisfactory therapeutic effects in repairing normal and special skin tumor wounds infected with drug-resistant bacteria.

A robotic venous leg ulcer system reveals the benefits of negative pressure wound therapy in effective fluid handling

We applied a market-leading, single-use negative pressure wound therapy device to a robotic venous leg ulcer system and compared its fluid handling performance with that of standard of care, superabsorbent and foam dressings and compression therapy. For each tested product, we determined a metrics of retained, residual, evaporated and (potential) leaked fluid shares, for three exudate flow regimes representing different possible clinically relevant scenarios. The single-use negative pressure wound therapy system under investigation emerged as the leading treatment option in the aspects of adequate fluid handling and consistent delivery of therapeutic-level wound-bed pressures. The superabsorbent dressing performed reasonably in fluid handling (resulting in some pooling but no leakage), however, it quickly caused excessive wound-bed pressures due to swelling, after less than a day of simulated use. The foam dressing exhibited the poorest fluid handling performance, that is, pooling in the wound-bed as well as occasional leakage, indicating potential inflammation and peri-wound skin maceration risks under real-world clinical use conditions. These laboratory findings highlight the importance of advanced robotic technology as contemporary means to simulate patient and wound behaviours and inform selection of wound care technologies and products, in ways that are impossible to achieve if relying solely on clinical trials and experience.

pH-responsive scaffolds for tissue regeneration: In vivo performance

A myriad of pH-sensitive scaffolds has been reported in recent decades. Information on their behaviour in vitro under conditions that mimic the pH changes that occur during tissue regeneration is abundant. Differently, the in vivo demonstration of the advantages of pH-responsive systems in comparison with non-responders is more limited. The in vivo scenario is very complex and the intricate relationship between the host response, the overall pathological conditions of the patient, and the risk of colonization by microorganisms is very difficult to imitate in in vitro tests. This review aims to shed light on how the changes in pH between healthy and damaged states and also during the healing process have been exploited so far to develop polymer-based scaffolds that actively contribute in vivo to the healing process avoiding chronification. The main strategies so far tested to prepare pH-responsive scaffolds rely on (i) changes in ionization of natural polymers, ionizable monomers and clays, (ii) reversible cross-linkers, (iii) coatings, and (iv) production of CO2 gas. These strategies are analysed in detail in this review with the description of relevant examples of their performance on specific animal models. The versatility of the techniques used to prepare biocompatible and environment-friendly pH-responsive scaffolds that have been implemented in the last decade may pave the way for a successful translation to the clinic. STATEMENT OF SIGNIFICANCE: We report here on the most recent advances in pH-responsive polymer-based scaffolds that have been demonstrated in vivo to be suitable for wound and bone healing. pH is a critical variable in the tissue regeneration process, and small changes can speed up or completely stop the process. Although there is still a paucity of information on the performance in the complex in vivo environment, recently reported achievements using scaffolds endowed with pH-responsiveness through ionic natural polymers, ionizable monomers and clays, reversible cross-linkers, coatings, or formation of CO2 ensure a promising future towards clinical translation.

Cascade enzymatic preparation of carboxymethyl chitosan-based multifunctional hydrogels for promoting cutaneous wound healing

Designing wound dressings with inherent multifunctional therapeutic effects is desirable for clinical applications. Herein, a series of multifunctional carboxymethyl chitosan (CMCS)-based hydrogels were fabricated by the facile urate oxidase (UOX)-horseradish peroxidase (HRP) cascade enzymatic crosslinking system. For the first time, the cascade enzymatic crosslinking system was not only used for preparing hydrogel wound dressings but also for accelerating wound healing due to the activity retention of the self-compartmental enzymes. A CMCS derivative (HCMCS-mF) synthesized by successively grafting 4-hydroxybenzaldehyde (H) and 5-methylfurfural (mF) on CMCS and a quaternary ammonium crosslinker (QMal) with terminal grafting maleimide (Mal) groups were combined with enzymatic system for the facile preparation of hydrogels. The mild Diels-Alder (DA) crosslinking reaction between mF and Mal groups constructed the first network of hydrogels. The cascade UOX-HRP system mediated the oxidative crosslinking of phenols thus forming the second gel network. Self-entrapped UOX maintained its enzymatic activity and could continuously catalyze the oxidation of uric acid, generating therapeutic allantoin. These porous, degradable, mechanically stable hydrogels with excellent antioxidant performance and enhanced antibacterial capacity could effectively accelerate skin wound repair by simultaneously reducing oxidative stress, relieving inflammation, promoting collagen deposition and upregulating the expression level of CD31.

Experimental and clinical evidence for DACC-coated dressings: an update

OBJECTIVE

To update the evidence in relation to the use of dialkylcarbamoyl chloride (DACC)-coated wound dressings in the prevention, treatment and management of wounds.

METHOD

PubMed and PubMed Central databases were searched to identify articles published since 2020 describing the experimental and clinical evidence for DACC-coated dressings, and their antimicrobial effect, as well as their impact on the prevention and treatment of infected wounds. The identified articles were then narratively reviewed.

RESULTS

The search yielded 113 articles (plus references from ad hoc sources), of which nine met the inclusion criteria. Of the nine included studies, five related to clinical aspects and four were laboratory studies.

CONCLUSION

A number of new studies have provided further evidence for the mode of action of the antimicrobial effect of DACC-coated dressings and its wide spectrum effect (including World Health Organization-prioritised microorganisms). Additional clinical studies have provided evidence of new applications, such as in treating wounds in paediatric patients, and extended the evidence relating to their use in treating surgical site infections. Evidence also shows that DACC-coated wound dressings can aid in the binding of biofilms, and how this technology can align and support antimicrobial stewardship in the prevention of antimicrobial resistance.

Hyaluronate- and Gelatin-based Hydrogels Encapsulating Doxycycline as a Wound Dressing for Burn Injury Therapy

Infection is a critical challenge in burn wound therapy. Wound dressings with antibacterial and multifunctional abilities associated with rapid burn wound healing are urgently needed. Here, we developed a bioadhesive and injectable ECM-mimicking hydrogel dressing with antibacterial capacity for burn injury therapy, which is crosslinked by dynamic boronate ester bonds between modified hyaluronate and gelatin (HG). The antibiotic doxycycline (Doxy) was encapsulated in HG networks for drug delivery around the wound sites. The HG/Doxy hydrogel dressing shows biocompatibility and antibacterial activity against Gram-positive and Gram-negative bacteria. Applying to a rat model of burn wound, the HG/Doxy hydrogel significantly speeds up wound closure by reducing the inflammatory reaction. Furthermore, the HG/Doxy hydrogel accelerates the regeneration of the skin structure by promoting collagen deposition, blood vessel regeneration, and hair follicle formation, eventually shortening the healing periods of burn wounds. These findings demonstrated the clinical potential of the HG/Doxy hydrogels as a promising burn wound dressing.

Therapeutic and pro-healing potential of advanced wound dressings loaded with bioactive agents

Chronic skin wound infections are inextricably linked with high mortality rates. With the rise in the aging population and the threat of diabetes, obesity and lifestyle-based diseases, the risk incurred from invasive wound pathogens has been ever escalating. Thus, more efficacious wound care management is necessary to cope with such morbid illnesses. A plethora of bioactive agents, such as antibiotics, phytochemicals, essential oils, phages among others, has been exploited to develop wound dressings, raising tremendous interest in their prospective use as wound care products. The present review critically focuses on the therapeutic implications of advanced wound dressings that have assisted in the expansion of regenerative medicine and also discusses the practical concerns that have limited their bench-to-market entry.

Hydrophilic Scaffolds Containing Extracts of Stryphnodendron adstringens and Abarema cochliacarpa for Wound Healing: In Vivo Proofs of Concept

The present work aimed to evaluate the healing effect of hydrophilic polymeric resorbable biomembrane scaffolds containing plant extracts obtained from two different species, both popularly known as Stryphnodendron adstringens or Barbatimão. The hydrogel-based scaffolds were characterized and submitted to biological tests using Wistar rats to evaluate their healing capacity. The wound retraction index and the evaluation of the inflammatory process and tissue collagenization were recorded. The extracts showed antioxidant activity with IC50 between 10 and 20 µg/mL (DPPH assay) and 4–6 mmol Trolox/g (FRAP assay). The extract of Stryphnodendron adstringens (SA) presented gallocatechin, epigallocatechin, and O-methylpigalocatechin, while the extract of Abarema cochliacarpa (AC) presented catechin, dimers of procyanidins, di-O-hydroxide, O-deoxyhexosi-hexoside, and epicatechin. The membranes containing SA extract (GELSA) were more rigid, with a more intense color, but less thick, with a more compact structure and few pores. The membranes containing AC extract (GELAC) presented a mechanical profile like the gelatin membrane (GEL), with greater permeability to water vapor. The GELAC and GELSA membranes showed similar thermal degradation profiles. The wounds treated with the membranes containing the extracts obtained high levels of retraction of the wounds with values around 60% and 80% in three and seven days, respectively. These data indicate that the compounds of both species have promising biological activities in the repair process, showing that the extracts accelerated the healing process due to the lower intensity of the inflammatory reaction and the presence of compounds such as catechin and epigallocatechin.