Wound Dressings Update

Barley β-glucan bioactive films: Promising eco-friendly materials for wound healing

Mixtures containing β-glucans were extracted from barley, under both mild and high alkaline conditions, to prepare biodegradable films (MA and HA, respectively), as natural dressings with intrinsic therapeutic properties. An in-depth characterization was performed to evaluate the impact of mild and high alkaline conditions on chemical, physicochemical, and biological features for potential use in wound treatments. Both MA and HA films exhibited a good ability to absorb water and simulate wound fluid, which helps maintain optimal tissue hydration. Moreover, their oxygen permeability (147.6 and 16.4 cm3 × μm/m2 × 24 h × Pa × 107, respectively) appeared adequate for the intended application. Biocompatibility tests showed that the films do not harm human dermal fibroblasts. Impressively, they promote cell attachment and growth, with MA having a stronger effect due to its higher β-glucan content. Furthermore, MA films can modulate macrophage behaviour in an inflamed microenvironment, reducing oxidative stress and pro-inflammatory cytokines, while simultaneously increasing levels of anti-inflammatory cytokines. In a scratch test, HA films allowed for faster fibroblast migration within the first 16 h compared to MA. Overall, this study demonstrates that developing β-glucan based films from barley, through a sustainable and cost-effective process, holds great promise for skin applications. These films exhibit significant potential to promote wound healing and modulate inflammation.

Innovative approaches to wound healing: insights into interactive dressings and future directions

The objective of this review is to provide an up-to-date and all-encompassing account of the recent advancements in the domain of interactive wound dressings. Considering the gap between the achieved and desired clinical outcomes with currently available or under-study wound healing therapies, newer more specific options based on the wound type and healing phase are reviewed. Starting from the comprehensive description of the wound healing process, a detailed classification of wound dressings is presented. Subsequently, we present an elaborate and significant discussion describing interactive (unconventional) wound dressings. Latter includes biopolymer-based, bioactive-containing and biosensor-based smart dressings, which are discussed in separate sections together with their applications and limitations. Moreover, recent (2-5 years) clinical trials, patents on unconventional dressings, marketed products, and other information on advanced wound care designs and techniques are discussed. Subsequently, the future research direction is highlighted, describing peptides, proteins, and human amniotic membranes as potential wound dressings. Finally, we conclude that this field needs further development and offers scope for integrating information on the healing process with newer technologies.

In Situ Formation of Hydrogel Wound Dressing Based on Carboxymethyl Chitin/Tannic Acid for Promoting Skin Wound Healing

Triggering the healing process of drug-resistant bacteria-infected wounds has attracted great attention due to global morbidity that may induce gangrene, amputation, and even death. Here, a chitin derivative, carboxymethyl chitosan (CMC), tannic acid (TA), and Cu2+ were used for hydrogel engineering. Using sodium bicarbonate as the neutralizer and reductant, hydrogen bonds between CMC and TA and in situ Cu(OH)2 generation via ion coordination force between Cu2+ and TA facilitated the synthesis of CMC/TA/Cu hydrogel. Cu2+ and TA release, cytotoxicity, in vitro cell migration, angiogenesis, and antidrug-resistant bacteria were measured. Besides, wound closure was evaluated in vivo using the methicillin-resistant Staphylococcus aureus (MRSA)-infected excisional dermal wound mouse model. Negligible toxicity was observed both in vitro and in vivo. Dermal cell migration and angiogenesis were significantly enhanced. In vivo, the CMC/TA/Cu hydrogel induced effective re-epithelialization, collagen deposition, inflammatory alleviation, and MRSA inhibition during wound repair in mice. All these results confirmed that the CMC/TA/Cu hydrogel is a promising novel dressing for chronic wound healing in clinic.

Porosity controlled soya protein isolate-polyethylene oxide multifunctional dual membranes as smart wound dressings

Multifunctional membranes S7P0.7, S7P3.0, and dual membranes composed of soya protein isolate (SPI) and polyethylene oxide (PEO) were produced for wound dressing applications. The internal structure of the membranes was confirmed by scanning electron microscopy (SEM) to be homogeneous and coarser with a porous-like network. S7P3.0 showed the tensile strength of 0.78 ± 0.04 MPa. In the absence of antibiotics, the dual membrane (combination of S7P0.7 and S7P3.0) exhibited potential antibacterial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria. Hemolysis quantitative data presented in the image demonstrates that all samples exhibited hemolysis levels below 5 %. Dual membrane showed 77.93 ± 9.5 % blood uptake which reflects its absorption capacity. The combination of S7P0.7 and S7P3.0 influenced the dual membrane's antibacterial, biocompatibility, and good hemolytic potentials. The dual membranes' promising histology features after implantation suggest they could be used as wound dressings.

Effectiveness of wound contact layers in enabling undisturbed wound management: a case series

OBJECTIVE

Wound contact layers (WCLs) are intended to protect and support wounds during the healing process. An open, non comparative, case series clinical evaluation was undertaken to assess the impact of these dressings on establishing an undisturbed wound environment that supports effective wound management, and to allow the establishment of limits of duration of the wear time for the experimental WCLs.

METHOD

The primary objectives of this clinical evaluation were to assess the ability of the WCLs to prevent tissue disturbance to the wound and surrounding skin and for the clinicians to have confidence to extend the wear time of the WCL dressings. For them to have confidence in leaving the dressings in place for extended periods, the assessment of the wound and periwound skin condition and an assessment of patient comfort was performed: assessment of wound and periwound condition in relation to tissue adherence of the dressing to the wound resulting in tissue damage/bleeding (to wound and/or periwound skin) and cellular infiltration into the WCL; assessment of patient wearing comfort and satisfaction; assessment of WCL wear time, relating to times between dressing changes as judged by the clinician.

RESULTS

Based upon five parameters used to assess the extent to which the WCLs Atrauman, Atrauman Silicone and Atrauman Ag (HARTMANN, Germany) disturbed the underlying tissues-bleeding, wound tissue damage, periwound skin damage, tissue ingrowth and dressing adherence-the majority (>95%) of assessments indicated low or no disturbance of tissue. Over the 14 days of study assessment, the mean (±standard deviation) wear time was 7.3±1.2 days for the Atrauman group, 9.9±2.8 days for the Atrauman Silicone group, and 5.8±1.0 days for the Atrauman Ag group. All dressings were well tolerated by patients and rated highly in terms of in-use dressing performance.

CONCLUSION

The results indicate that Atrauman WCLs are suitable for the management of a variety of wounds as they promote an undisturbed wound environment, including extended wear time.

Fundamental advances in hydrogels for the development of the next generation of smart delivery systems as biopharmaceuticals

Recent advances in developing and applying therapeutic peptides for anticancer, antimicrobial and immunomodulatory remedies have opened a new era in therapeutics. This development has resulted in the engineering of new biologics as part of a concerted effort by the pharmaceutical industry. Many alternative routes of administration and delivery vehicles, targeting better patient compliance and optimal therapeutic bioavailability, have emerged. However, the design of drug delivery systems to protect a range of unstable macromolecules, including peptides and proteins, from high temperatures, acidic environments, and enzymatic degradation remains a priority. Herein, we give chronological insights in the development of controlled-release drug delivery systems that occurred in the last 70 years or so. Subsequently, we summarise the key physicochemical characteristics of hydrogels contributing to the development of protective delivery systems concerning drug-targeted delivery in the chronospatial domain for biopharmaceuticals. Furthermore, we shed some light on promising hydrogels that can be utilised for systemic bioactive administration.

Carboxymethyl Chitosan/Tannic Acid Hydrogel with Antibacterial, Hemostasis, and Antioxidant Properties Promoting Skin Wound Repair

Local causes of slow wound healing include infection and wound hemorrhage. Using sodium bicarbonate as a neutralizer, a variety of carboxymethyl chitosan-tannic acid (CMC-TA) composite hydrogels solidify through hydrogen bonding in this study. The best-performing hydrogel was synthesized by altering the concentration of TA and exhibited remarkable mechanical properties and biocompatibility. Following in vitro characterization tests, the CMC-TA hydrogel exhibited remarkable antibacterial and antioxidant properties, as well as quick hemostasis capabilities. In the in vivo wound healing study, the results showed that the CMC-TA hydrogel could relieve inflammation and promote the recovery of skin incision, re-epithelialization, and collagen deposition. Overall, this multifunctional hydrogel could be an ideal wound dressing for the clinical therapy of full-thickness wounds.

Green tea catechin-grafted silk fibroin hydrogels with reactive oxygen species scavenging activity for wound healing applications

BACKGROUND

Overproduction of reactive oxygen species (ROS) is known to delay wound healing by causing oxidative tissue damage and inflammation. The green tea catechin, (-)-Epigallocatechin-3-O-gallate (EGCG), has drawn a great deal of interest due to its strong ROS scavenging and anti-inflammatory activities. In this study, we developed EGCG-grafted silk fibroin hydrogels as a potential wound dressing material.

METHODS

The introduction of EGCG to water-soluble silk fibroin (SF-WS) was accomplished by the nucleophilic addition reaction between lysine residues in silk proteins and EGCG quinone at mild basic pH. The resulting SF-EGCG conjugate was co-crosslinked with tyramine-substituted SF (SF-T) via horseradish peroxidase (HRP)/H2O2 mediated enzymatic reaction to form SF-T/SF-EGCG hydrogels with series of composition ratios.

RESULTS

Interestingly, SF-T70/SF-EGCG30 hydrogels exhibited rapid in situ gelation (< 30 s), similar storage modulus to human skin (≈ 1000 Pa) and superior wound healing performance over SF-T hydrogels and a commercial DuoDERM® gel dressings in a rat model of full thickness skin defect.

CONCLUSION

This study will provide useful insights into a rational design of ROS scavenging biomaterials for wound healing applications.

Recent Progress in Development of Dressings Used for Diabetic Wounds with Special Emphasis on Scaffolds

Diabetic wound (DW) is a secondary application of uncontrolled diabetes and affects about 42.2% of diabetics. If the disease is left untreated/uncontrolled, then it may further lead to amputation of organs. In recent years, huge research has been done in the area of wound dressing to have a better maintenance of DW. These include gauze, films, foams or, hydrocolloid-based dressings as well as polysaccharide- and polymer-based dressings. In recent years, scaffolds have played major role as biomaterial for wound dressing due to its tissue regeneration properties as well as fluid absorption capacity. These are three-dimensional polymeric structures formed from polymers that help in tissue rejuvenation. These offer a large surface area to volume ratio to allow cell adhesion and exudate absorbing capacity and antibacterial properties. They also offer a better retention as well as sustained release of drugs that are directly impregnated to the scaffolds or the ones that are loaded in nanocarriers that are impregnated onto scaffolds. The present review comprehensively describes the pathogenesis of DW, various dressings that are used so far for DW, the limitation of currently used wound dressings, role of scaffolds in topical delivery of drugs, materials used for scaffold fabrication, and application of various polymer-based scaffolds for treating DW.

Polymeric biomaterials for wound healing applications: a comprehensive review

Chronic wounds have been a global health threat over the past few decades, requiring urgent medical and research attention. The factors delaying the wound-healing process include obesity, stress, microbial infection, aging, edema, inadequate nutrition, poor oxygenation, diabetes, and implant complications. Biomaterials are being developed and fabricated to accelerate the healing of chronic wounds, including hydrogels, nanofibrous, composite, foam, spongy, bilayered, and trilayered scaffolds. Some recent advances in biomaterials development for healing both chronic and acute wounds are extensively compiled here. In addition, various properties of biomaterials for wound-healing applications and how they affect their performance are reviewed. Based on the recent literature, trilayered constructs appear to be a convincing candidate for the healing of chronic wounds and complete skin regeneration because they mimic the full thickness of skin: epidermis, dermis, and the hypodermis. This type of scaffold provides a dense superficial layer, a bioactive middle layer, and a porous lower layer to aid the wound-healing process. The hydrophilicity of scaffolds aids cell attachment, cell proliferation, and protein adhesion. Other scaffold characteristics such as porosity, biodegradability, mechanical properties, and gas permeability help with cell accommodation, proliferation, migration, differentiation, and the release of bioactive factors.

ELECTROSPUN SODIUM ALGINATE/POLY(ETHYLENE OXIDE) NANOFIBERS FOR WOUND HEALING APPLICATIONS: CHALLENGES AND FUTURE DIRECTIONS

Alginate is an interesting natural biopolymer to be considered for biomedical applications due to its advantages and good biological properties. These biological properties make electrospun alginate nanofibers suitable for various uses in the biomedical field, such as wound healing dressings, drug delivery systems, or both. Unfortunately, the fabrication of alginate nanofibers by electrospinning is very challenging because of the high viscosity of the solution, high surface tension and rigidity in water due to hydrogen bonding, and also their diaxial linkages. This review presents an overview of the factors affecting the electrospinning process of sodium alginate/poly(ethylene oxide) (SA/PEO), the application of SA/PEO in drug delivery systems for wound healing applications, and the degradation and swelling properties of SA/PEO. The challenges and future directions of SA/PEO in the medical field are also discussed.

Composite Membrane Dressings System with Metallic Nanoparticles as an Antibacterial Factor in Wound Healing

Wound management is the burning problem of modern medicine, significantly burdening developed countries’ healthcare systems. In recent years, it has become clear that the achievements of nanotechnology have introduced a new quality in wound healing. The application of nanomaterials in wound dressing significantly improves their properties and promotes the healing of injuries. Therefore, this review paper presents the subjectively selected nanomaterials used in wound dressings, including the metallic nanoparticles (NPs), and refers to the aspects of their application as antimicrobial factors. The literature review was supplemented with the results of our team’s research on the elements of multifunctional new-generation dressings containing nanoparticles. The wound healing multiple molecular pathways, mediating cell types, and affecting agents are discussed herein. Moreover, the categorization of wound dressings is presented. Additionally, some materials and membrane constructs applied in wound dressings are described. Finally, bacterial participation in wound healing and the mechanism of the antibacterial function of nanoparticles are considered. Membranes involving NPs as the bacteriostatic factors for improving wound healing of skin and bones, including our experimental findings, are discussed in the paper. In addition, some studies of our team concerning the selected bacterial strains’ interaction with material involving different metallic NPs, such as AuNPs, AgNPs, Fe₃O₄NPs, and CuNPs, are presented. Furthermore, nanoparticles’ influence on selected eukaryotic cells is mentioned. The ideal, universal wound dressing still has not been obtained; thus, a new generation of products have been developed, represented by the nanocomposite materials with antibacterial, anti-inflammatory properties that can influence the wound-healing process.

Enhancing wound healing dressing development through interdisciplinary collaboration

The process of wound healing includes four phases: Hemostasis, inflammation, proliferation, and remodeling. Many wound dressings and technologies have been developed to enhance the body's ability to close wounds and restore the function of damaged tissues. Several advancements in wound healing technology have resulted from innovative experiments by individual scientists or physicians working independently. The interplay between the medical and scientific research fields is vital to translating new discoveries in the lab to treatments at the bedside. Tracing the history of wound dressing development reveals that there is an opportunity for deeper collaboration between multiple disciplines to accelerate the advancement of novel wound healing technologies. In this review, we explore the different types of wound dressings and biomaterials used to treat wounds, and we investigate the role of multidisciplinary collaboration in the development of various wound management technologies to illustrate the benefit of direct collaboration between physicians and scientists.

Manejo de heridas traumáticas de difícil cicatrización con colgajos microvasculares

OBJECTIVE

Present different flap alternatives when performing microvascular free-flap reconstruction in acute hard-to-heal wounds.

METHOD

A retrospective review of patients whose acute hard-to-heal wounds were treated with microvascular free-flap reconstruction. Data on demographics, wound aetiology, diagnostic, previous treatment, free-flap type, free-flap size, complications and follow up were analysed.

RESULTS

A total of 20 patients received microvascular free-flap reconstruction. The median age was 39.5 years. Twenty free-flap reconstructions were performed. These included: 3 cross-leg free flap, 1 cross-leg vascular cable bridge flap, 2 fibula osteocutaneous flap, 6 anterolateral thigh (ALT) flap, 3 thoracodorsal artery perforator (TDAP) flap, 3 fasciomyocutaneous flap, and 2 femoral artery fasciocutaneous flap. A patient required microvascular anastomosis due to hematoma; the rest did not present complications during their postoperative. Previous treatment included negative pressure wound therapy (12 patients) and surgical debridement with silver hydrogel dressings (8 patients).

CONCLUSION

Hard-to-heal wounds can be unresponsive to traditional wound healing practices or local flaps. They often require free-flap reconstruction, using tissues similar to those compromised. Microvascular techniques can be an effective alternative.

Manejo de heridas traumáticas de difícil cicatrización con colgajos microvasculares

OBJECTIVE

Present different flap alternatives when performing microvascular free-flap reconstruction in acute hard-to-heal wounds.

METHOD

A retrospective review of patients whose acute hard-to-heal wounds were treated with microvascular free-flap reconstruction. Data on demographics, wound aetiology, diagnostic, previous treatment, free-flap type, free-flap size, complications and follow up were analysed.

RESULTS

A total of 20 patients received microvascular free-flap reconstruction. The median age was 39.5 years. Twenty free-flap reconstructions were performed. These included: 3 cross-leg free flap, 1 cross-leg vascular cable bridge flap, 2 fibula osteocutaneous flap, 6 anterolateral thigh (ALT) flap, 3 thoracodorsal artery perforator (TDAP) flap, 3 fasciomyocutaneous flap, and 2 femoral artery fasciocutaneous flap. A patient required microvascular anastomosis due to hematoma; the rest did not present complications during their postoperative. Previous treatment included negative pressure wound therapy (12 patients) and surgical debridement with silver hydrogel dressings (8 patients).

CONCLUSION

Hard-to-heal wounds can be unresponsive to traditional wound healing practices or local flaps. They often require free-flap reconstruction, using tissues similar to those compromised. Microvascular techniques can be an effective alternative.

Evaluation of biochemical parameters in Rubus tereticaulis treated rats and its implications in wound healing

We evaluated the effects of Rubus tereticaulis in healing process by determining the total carbonyl content, collagen synthesis, and total protein level on rat wounded tissues. Wounds were performed in the back of 54 Wistar rats, using a biopsy punch instrument with 0.6 mm in diameter. Rats were randomly divided into three groups: (i) un-treatment wounds group served as "controls", (ii) Madecassol® used as "positive control" group, and (iii) the application of topical cream of R. tereticaulis served as "treatment" group of wound healing. The animals were killed at the end of experiment under anesthesia with ketamine, and tissue samples were collected for the evaluation at three times intervals (3rd, 7th, and 14th day). The wounded areas were analyzed for total carbonyl content, collagen, and total protein levels by HPLC, ELISA, and spectrophotometric methods, respectively. Total carbonyl content in the treatment group was significantly lower in comparison with control group on 3rd day (2.839 ± 0.438 vs. 3.216 ± 0.216 nmol carbonyl/mol protein; p < 0.5) and 14th days (4.222 ± 0.128 vs. 4.784 ± 0.077 nmol carbonyl/mol protein; p < 0.05), respectively. New collagen formation on the wound sites after the initial injury was noted in the treated and positive control groups (5.310 ± 0.331 vs. 5.164 ± 0.377 mg collagen/g wet tissue) at the 3rd day than control group (2.180 ± 0.718 mg collagen/g wet tissue, p < 0.01), and in treated and positive control groups at 7th day (9.654 ± 0.201, 9.053 ± 1.062 mg collagen/g wet tissue, p < 0.01); and in treated and positive control groups at 14th day (8.469 ± 0.236, 5.631 ± 0.531 mg collagen/g wet tissue, respectively; p < 0.05) in comparison with the control group. Total protein level of samples did not change significantly between the groups. Thus, application of R. tereticaulis ameliorated the wound healing process in rats as it facilitated collagen formation through healing of the wound. Evaluating total carbonyl content by HPLC could be useful as an advance procedure for quantification of healing.

Effects of Electrospun Fibrous Membranes of PolyCaprolactone and Chitosan/Poly(Ethylene Oxide) on Mouse Acute Skin Lesions

Polycaprolactone (PCL) is a synthetic polymer with good mechanical properties that are useful to produce biomaterials of clinical application. It can be successfully combined with chitosan, which enhances the biomaterial properties through the modulation of molecular and cellular mechanisms. The objective of this study was to evaluate the effects of the use of electrospun fibrous membranes consisting of polycaprolactone (PCL) or polycaprolactone coated with chitosan and poly(ethylene oxide) (PCL+CHI/PEO) on mouse skin lesions. Sixty four Black-57 mice were divided into PCL and PCL+CHI/PEO groups. A 1 cm2 lesion was made on the animals' backs, and the membranes were sutured in place. The tissues were extracted on the 3rd, 7th, and 14th days after the lesion. The tissues were analyzed by histology with Hematoxylin and Eosin (H&E) and Sirius Red stains, morphometry, immunohistochemistry, and Western blot. On the 3rd, 6th, and 9th days after the lesion, the PCL+CHI/PEO group showed a higher wound-healing rate (WHR). On the 3 day, the PCL+CHI/PEO group showed a greater amount of inflammatory infiltrate, greater expression of proliferating cell nuclear antigen (PCNA), and smooth muscle actin (α-SMA) (p < 0.05) compared to the PCL group. On the 7th day after the lesion, the PCL+CHI/PEO group showed a greater amount of inflammatory infiltrate, expression of Tumor Necrosis Factor (TNF-α) and PCNA (p < 0.05). In addition, it showed a greater immunolabeling of Monocyte Chemoattractant Protein-1 (MCP-1) and deposition of collagen fibers compared to the PCL group. The PCL+CHI/PEO membrane modulated the increase in the inflammatory infiltrate, the expression of MCP-1, PCNA, and α-SMA in lesions of mice.

Nanomaterials for Wound Dressings: An Up-to-Date Overview

As wound healing continues to be a challenge for the medical field, wound management has become an essential factor for healthcare systems. Nanotechnology is a domain that could provide different new approaches concerning regenerative medicine. It is worth mentioning the importance of nanoparticles, which, when embedded in biomaterials, can induce specific properties that make them of interest in applications as materials for wound dressings. In the last years, nano research has taken steps to develop molecular engineering strategies for different self-assembling biocompatible nanoparticles. It is well-known that nanomaterials can improve burn treatment and also the delayed wound healing process. In this review, the first-line of bioactive nanomaterials-based dressing categories frequently applied in clinical practice, including semi-permeable films, semipermeable foam dressings, hydrogel dressings, hydrocolloid dressings, alginate dressings, non-adherent contact layer dressings, and multilayer dressings will be discussed. Additionally, this review will highlight the lack of high-quality evidence and the necessity for future advanced trials because current wound healing therapies generally fail to provide an excellent clinical outcome, either structurally or functionally. The use of nanomaterials in wound management represents a unique tool that can be specifically designed to closely reflect the underlying physiological processes in tissue repair.

First-Line Interactive Wound Dressing Update: A Comprehensive Review of the Evidence

Wound management is a significant and growing issue worldwide. Knowledge of dressing products and clinical expertise in dressing selection are two major components in holistic wound management to ensure evidence-based wound care. With expanding global market of dressing products, there is need to update clinician knowledge of dressing properties in wound care. Optimal wound management depends on accurate patient assessment, wound diagnosis, clinicians’ knowledge of the wound healing process and properties of wound dressings. We conducted a comprehensive review of the physical properties of wound dressing products, including the advantages and disadvantages, indications and contraindications and effectiveness of first-line interactive/bioactive dressing groups commonly used in clinical practice. These include semipermeable films, foams, hydroactives, alginates, hydrofibers, hydrocolloids, and hydrogels. In making decisions regarding dressing product selection, clinicians need to ensure a holistic assessment of patient and wound etiology, and understand dressing properties when making clinical decisions using wound management guidelines to ensure optimal patient outcomes. This review has highlighted there is lack of high quality evidence and the need for future well designed trials.

Sprayed in-situ synthesis of polyvinyl alcohol/chitosan loaded silver nanocomposite hydrogel for improved antibacterial effects

To overcome the practical limitations of hydrogel preparations, applications and strength-based problems, the present study utilizes the use of sprayers for preparing polyvinyl alcohol/chitosan (PVA/CH) hydrogels. The particle size, morphology, stability, release studies and antibacterial activity of silver nanoparticles (AgNPs) had been studied. The particle size of AgNPs was found to be in the range of 4.59-10 nm (75 °C) with a polydispersity index (PDI) of 0.84. The morphological images exhibited inter-connecting porous structure with pore size in submicron's (<1 µm). Major infra-red spectral peaks of PVA (2946.67 cm-1; stretching of CH, 1142.72 cm-1; CO stretching) and CH (3287.49 cm-1; OH stretching, 2917.48 cm-1; CH stretching) maintain their place in PVA/CH and PVA/CH/Ag hydrogels. In addition, X-ray diffraction (XRD) pattern showed peaks with 2θ values at 38.08°, 44.29° and 64.50° corresponding to the crystal planes of (1 1 1), (2 0 0) and (2 2 0), respectively, allocated to face-centered cubic crystalline structure of AgNPs. The drug release and antibacterial studies showed a maximum release of 91.83% from hydrogels and a concentration dependent zone of inhibition (ZOI) for >24 h, respectively. Thus, the newly developed sprayed hydrogels could turn out to be a suitable dressing material for wound healing applications.

Preparation of a novel asymmetric wettable chitosan-based sponge and its role in promoting chronic wound healing

Cutaneous chronic wounds are characterized by an impaired wound healing which may lead to infection. To surmount this problem, a novel quaternary ammonium chitosan nanoparticles (TMC NPs)/chitosan (CS)composite sponge with asymmetric wettability surfaces was successfully prepared. The optimum concentrations of TMC NPs and CS were 0.2 mg/mL and 2.0%, respectively. The incorporated TMC NPs could improve the antibacterial activity of the CS sponge. Asymmetric modification enables the CS sponge to have hydrophobic outer surface and hydrophilic inner surface. The hydrophobic surface of the sponge shows waterproof and anti-adhesion contaminant properties, whereas the hydrophilic surface preserves water-absorbing capability and efficiently inhibits the growth of bacteria. More importantly, in vivo chronic wound healing model evaluation reveals that TMC NPs/CS composite sponge promotes the wound healing and accelerates re-epithelialization and angiogenesis. And in vivo anti-infection test shows the TMC NPs/CS composite sponge could effectively prevent wound infection. These findings demonstrate that TMC NPs/CS composite sponge is a promising dressing material for chronic wounds.

Biopolymer-based biomaterials for accelerated diabetic wound healing: A critical review

Non-healing, chronic wounds place a huge burden on healthcare systems as well as individual patients. These chronic wounds especially diabetic wounds will ultimately lead to compromised mobility, amputation of limbs and even death. Currently, wounds and limb ulcers associated with diabetes remain significant health issues; the associated healthcare cost ultimately leads to the increased clinical burden. The presence of diabetes interrupts a highly coordinated cascade of events in the wound closure process. Advances in the understanding of pathophysiological conditions associated with diabetic wounds lead to the development of drug delivery systems which can enhance wound healing by targeting various phases of the impaired processes. Wound environments typically contain degradative enzymes, along with an elevated pH and demonstrate a physiological cascade involved in the regeneration of tissue, which requires the application of an effective delivery system. This article aims to review the pathophysiological conditions associated with chronic and diabetic wounds. The delivery systems, involved in their treatment are described, highlighting potential biomaterials and polymers for establishing drug delivery systems, specifically for the treatment of diabetic wounds and the promotion of the associated mechanisms involved in advanced wound healing. Emerging approaches and engineered devices for effective wound care are reported. The discussion will give insight into the mechanisms relevant to all stages of wound healing.

Borrowing From Nature: Biopolymers and Biocomposites as Smart Wound Care Materials

Wound repair is a complex and tightly regulated physiological process, involving the activation of various cell types throughout each subsequent step (homeostasis, inflammation, proliferation, and tissue remodeling). Any impairment within the correct sequence of the healing events could lead to chronic wounds, with potential effects on the patience quality of life, and consequent fallouts on the wound care management. Nature itself can be of inspiration for the development of fully biodegradable materials, presenting enhanced bioactive potentialities, and sustainability. Naturally-derived biopolymers are nowadays considered smart materials. They provide a versatile and tunable platform to design the appropriate extracellular matrix able to support tissue regeneration, while contrasting the onset of adverse events. In the past decades, fabrication of bioactive materials based on natural polymers, either of protein derivation or polysaccharide-based, has been extensively exploited to tackle wound-healing related problematics. However, in today's World the exclusive use of such materials is becoming an urgent challenge, to meet the demand of environmentally sustainable technologies to support our future needs, including applications in the fields of healthcare and wound management. In the following, we will briefly introduce the main physico-chemical and biological properties of some protein-based biopolymers and some naturally-derived polysaccharides. Moreover, we will present some of the recent technological processing and green fabrication approaches of novel composite materials based on these biopolymers, with particular attention on their applications in the skin tissue repair field. Lastly, we will highlight promising future perspectives for the development of a new generation of environmentally-friendly, naturally-derived, smart wound dressings.

Lomatuell Pro contact layer and its role in the wound-healing process

There is a plethora of wound contact layer dressings on the market each with its own properties to promote healing, which makes dressing selection complicated. An effective and efficient choice of dressing depends on holistic patient assessment, along with an understanding of the wound-healing process, moist wound healing and wound bed preparation. This paper, supported by clinical case studies, demonstrates the effectiveness of the Lomatuell® Pro dressing (Lohmann & Rauscher) in the management of graft wounds, although it is known to be effective in the management of dermal and deep dermal wounds as well. Lomatuell Pro offers benefits of conformability, open mesh gel-forming wound contact properties and a low risk of adhering to the wound bed. It enables moist wound healing by allowing exudate to be absorbed by a secondary dressing. Lomatuell® Pro demonstrates excellence in maintaining a moist wound environment, allows atraumatic dressing removal and encourages a healthy periwound area.

Functionalization of electrospun polymeric wound dressings with antimicrobial peptides

Wound dressings have evolved considerably since ancient times. Modern dressings are now important systems that combine the physical and biochemical properties of natural and synthetic polymers with active compounds that are beneficial to wound healing. Antimicrobial peptides (AMPs) are the most recent addition to these systems. These aim to control the microbial proliferation and colonization of pathogens and to modulate the host's immune response. In the last decade, electrospun wound dressings have been extensively studied and the electrospinning technique recognized as an efficient approach for the production of nanoscale fibrous mats. The control of the electrospinning processing parameters, the selection of the polymer and AMPs, and the definition of the most appropriate AMPs' functionalization method contribute to the successful treatment of acute and chronic wounds. Although the use of electrospinning in wound dressings' production has been previously reviewed, the increased development of AMPs and the establishment of functionalization methods for wound dressings over recent years has increased the need for such research. In the present review, we approach all these subjects and reveal the promising therapeutic potential of wound dressings functionalized with AMPs.

Wound Healing Concepts in Clinical Practice of OMFS

BACKGROUND

Wound healing is a complex and dynamic process and a thorough knowledge of the basics of physiology of wound healing is a must to implement principles of chronic wound care. Understanding wound healing at multiple levels-biochemical, physiologic, cellular and molecular provides the surgeon with a framework for basing clinical decisions aimed at optimizing the healing response.

OBJECTIVE

This review article describes the classification of wounds and aims to highlight the fundamentals of wound repair, enumerating the dressings used commonly and also, the newer concepts of wound healing.

MATERIALS AND METHODS

Search engines and medical databases were tapped to gather information on the subject. Search words employed were "Wounds", "wounds in OSMF", "Wound healing", "Repair", "Dressings in OMFS".

RESULTS

The search resulted in total of 153 articles which we reviewed to add to the literature the concepts of wound healing and to throw some light on recent advances in wound care.

CONCLUSIONS

Wound healing remains a challenging clinical problem and correct, efficient wound management is essential to positively influence the wound healing course and reduce potential complications.

Review of recent research on biomedical applications of electrospun polymer nanofibers for improved wound healing

Wound dressings play an important role in a patient's recovery from health problems, as unattended wounds could lead to serious complications such as infections or, ultimately, even death. Therefore, wound dressings since ancient times have been continuously developed, starting from simple dressings from natural materials for covering wounds to modern dressings with functionalized materials to aid in the wound healing process and enhance tissue repair. However, understanding the nature of a wound and the subsequent healing process is vital information upon which dressings can be tailored to ensure a patient's recovery. To date, much progress has been made through the use of nanomedicine in wound healing due to the ability of such materials to mimic the natural dimensions of tissue. This review provides an overview of recent studies on the physiology of wound healing and various wound dressing materials made of nanofibers fabricated using the electrospinning technique.

Imparting commercial antimicrobial dressings with low-adherence to burn wounds

The objective of our study was to decrease the wound adherence of commercial silver based wound dressings by depositing a non-adherent layer. Our hypothesis was that this non-adherent layer will lower the dressing's adherence to burn wounds without compromising the antimicrobial activity or increasing the cytotoxicity. A polyacrylamide (PAM) hydrogel layer was grafted on two commercial silver antimicrobial dressings (silver nanocrystal dressing (NC) and silver plated dressing (SP)) using a proprietary technique. The grafted PAM served as the non-adherent layer. Dressing adherence was measured with a previously published in vitro gelatin model using an Instron mechanical force testing instrument. The dressings were challenged with two clinically retrieved bacterial strains (Methicillin-resistant Staphylococcus aureus (MRSA) and multidrug resistant (MDR) Pseudomonas aeruginosa) with both a disk diffusion test, and a suspension antibacterial test. The cytotoxicity of samples to human neonatal fibroblast cells was evaluated with 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay. Both untreated dressings showed high peeling energy: 2070±453J/m(2) (NC) and 669±68J/m(2) (SP), that decreased to 158±119J/m(2) (NC) and 155±138J/m(2) (SP) with the PAM deposition. Addition of the PAM caused no significant difference in zone of inhibition (ZOI) (disk diffusion test) or antibacterial kinetics (suspension test) against both bacteria (p>0.05, n=6) in either dressing. Survival of fibroblasts was improved by the PAM grafting from 48±5% to 60±3% viable cells in the case of NC and from 55±8% to 61±4% viable cells in SP (p<0.05, n=12). It was concluded that PAM as a non-adherent layer significantly decreases the adherence of these two commercial antimicrobial dressings in an in vitro gelatin model while preserving their antimicrobial efficacy, and reducing their cytotoxicity.

Effects of wound dressings on cultured primary keratinocytes

Autologous cell-spray grafting of non-cultured epidermal cells is an innovative approach for the treatment of severe second-degree burns. After treatment, wounds are covered with dressings that are widely used in wound care management; however, little is known about the effects of wound dressings on individually isolated cells. The sprayed cells have to actively attach, spread, proliferate, and migrate in the wound for successful re-epithelialization, during the healing process. It is expected that exposure to wound dressing material might interfere with cell survival, attachment, and expansion. Two experiments were performed to determine whether some dressing materials have a negative impact during the early phases of wound healing. In one experiment, freshly isolated cells were seeded and cultured for one week in combination with eight different wound dressings used during burn care. Cells, which were seeded and cultured with samples of Adaptic(®), Xeroform(®), EZ Derm(®), and Mepilex(®) did not attach, nor did they survive during the first week. Mepitel(®), N-Terface(®), Polyskin(®), and Biobrane(®) dressing samples had no negative effect on cell attachment and cell growth when compared to the controls. In a second experiment, the same dressings were exposed to pre-cultured cells in order to exclude the effects of attachment and spreading. The results confirm the above findings. This study could be of interest for establishing skin cell grafting therapies in burn medicine and also for wound care in general.

Smart Dressings Based on Nanostructured Fibers Containing Natural Origin Antimicrobial, Anti-Inflammatory, and Regenerative Compounds

A fast and effective wound healing process would substantially decrease medical costs, wound care supplies, and hospitalization significantly improving the patients' quality of life. The search for effective therapeutic approaches seems to be imperative in order to avoid the aggravation of chronic wounds. In spite of all the efforts that have been made during the recent years towards the development of artificial wound dressings, none of the currently available options combine all the requirements necessary for quick and optimal cutaneous regeneration. Therefore, technological advances in the area of temporary and permanent smart dressings for wound care are required. The development of nanoscience and nanotechnology can improve the materials and designs used in topical wound care in order to efficiently release antimicrobial, anti-inflammatory and regenerative compounds speeding up the endogenous healing process. Nanostructured dressings can overcome the limitations of the current coverings and, separately, natural origin components can also overcome the drawbacks of current antibiotics and antiseptics (mainly cytotoxicity, antibiotic resistance, and allergies). The combination of natural origin components with demonstrated antibiotic, regenerative, or anti-inflammatory properties together with nanostructured materials is a promising approach to fulfil all the requirements needed for the next generation of bioactive wound dressings. Microbially compromised wounds have been treated with different essential oils, honey, cationic peptides, aloe vera, plant extracts, and other natural origin occurring antimicrobial, anti-inflammatory, and regenerative components but the available evidence is limited and insufficient to be able to draw reliable conclusions and to extrapolate those findings to the clinical practice. The evidence and some promising preliminary results indicate that future comparative studies are justified but instead of talking about the beneficial or inert effects of those natural origin occurring materials, the scientific community leads towards the identification of the main active components involved and their mechanism of action during the corresponding healing, antimicrobial, or regenerative processes and in carrying out systematic and comparative controlled tests. Once those natural origin components have been identified and their efficacy validated through solid clinical trials, their combination within nanostructured dressings can open up new avenues in the fabrication of bioactive dressings with outstanding characteristics for wound care. The motivation of this work is to analyze the state of the art in the use of different essential oils, honey, cationic peptides, aloe vera, plant extracts, and other natural origin occurring materials as antimicrobial, anti-inflammatory and regenerative components with the aim of clarifying their potential clinical use in bioactive dressings. We conclude that, for those natural occurring materials, more clinical trials are needed to reach a sufficient level of evidence as therapeutic agents for wound healing management.

Clinical and Antibiofilm Efficacy of Antimicrobial Hydrogels

Significance: Hydrogels have been shown to have a significant role to play in wound healing. Hydrogels are used to assist in the management of dry, sloughy, or necrotic wounds. However, recent scientific evidence has shown that biofilms delay wound healing and increase a wound propensity to infection. It is therefore essential that hydrogels incorporating antimicrobials demonstrate efficacy on biofilms. Consequently, it is the aim of this article to review the efficacy of hydrogels, incorporating antimicrobials, on wounds with specific reference to their efficacy on biofilms. Recent Advances: Technologies being developed for the management of wounds are rapidly expanding. In particularly next-generation hydrogels, incorporating copolymers, have been reported to enable the smart release of antimicrobials. This has led to the development of a more tailored patient-specific antimicrobial hydrogel therapy. Critical Issues: Evidence relating to the efficacy of hydrogels, incorporating antimicrobials, on biofilms within both the in vitro and in vivo environments is lacking. Future Direction: Studies that investigate the efficacy of antimicrobial hydrogel wound dressings on both in vivo and in vitro biofilms are important. However, there is a significant need for better and more reproducible in vivo biofilm models. Until this is possible, data generated from appropriate and representative in vitro models will help to assist researchers and clinicians in evaluating antimicrobial and antibiofilm hydrogel technology for the extrapolation of efficacy data relevant to biofilms present in the in vivo environment.