A narrative review of the epidemiology and economics of chronic wounds

VOLKSMED Database: A Source for Forgotten Wound Healing Plants in Austrian Folk Medicine

The global increase in the incidence of wounds is concerning and fuels the search for new treatment options. The use of traditional medicinal plants in wound healing represents an appreciated available therapeutic possibility. This work introduces the VOLKSMED database, which contains plants and other materials used in Austrian folk medicine, either as monographs or mixtures. This work focuses on the monographs of the database. Concerning wound healing, Hypericum sp., Arnica montana, Calendula officinalis, Plantago sp., and Malva sp. are the most commonly used plants. The focus of this paper is set on selected lesser-known plants (Abies alba, Anthyllis vulneraria, Brassica sp., Gentiana sp., Larix decidua, Picea abies, Sambucus sp., Sanicula europaea) and their status quo in literature concerning wound healing. A systematic search using the databases SciFinder, SCOPUS, and PubMed yielded substantial evidence for the wound healing potential of Brassica sp., Gentiana sp., the Pinaceae A. abies, L. decidua, and P. abies, as well as Sambucus nigra. In vivo and clinical studies substantiate their use in Austrian folk medicine. According to the literature, especially A. vulneraria, Sambucus racemosa, and S. europaea would be worth investigating in-depth since data concerning their wound healing effects - even though scarce - are convincing. In conclusion, the VOLKSMED database contains promising opportunities for further treatment options in the field of wound healing. Future research should consider the listed plants to support their traditional use in Austrian folk medicine and possibly promote the implementation of old knowledge in modern medicine.

Pressure ulcer point prevalence, classification, locations, and preventive measures: Insights from a Norwegian nursing home survey

OBJECTIVE

To report data from a point pressure ulcer (PU) prevalence survey on prevalence, PU categories, locations and preventive interventions at one Norwegian nursing home.

METHODS

A cross-sectional research design was used. One nursing home in Norway participated in the prevalence survey in 2020. The data were collected on one selected day. A total of 74 out of 88 residents (84.1%) participated. Descriptive statistical analyses were run.

RESULTS

The overall prevalence of PUs was 27% amongst all participants in the nursing home, who together had a total of 57 PUs categorised as category I-III. One major finding was that the most common site of the PUs was on the residents' toes. Interestingly, the prevalence of PUs in the residents' sacrum was considerably low. The most frequently used PU preventive interventions were foam chair cushions, nutritional supplements and pressure-reducing heel protection.

CONCLUSION

This study identified a high prevalence of PUs, predominantly on residents' toes. Although preventive strategies were implemented, their application appeared limited. Implementing obligatory care packages and annual nationwide PU surveys might be worth considering in municipalities.

IL-17 in wound repair: bridging acute and chronic responses

Chronic wounds, resulting from persistent inflammation, can trigger a cascade of detrimental effects including exacerbating inflammatory cytokines, compromised blood circulation at the wound site, elevation of white blood cell count, increased reactive oxygen species, and the potential risk of bacterial infection. The interleukin-17 (IL-17) signaling pathway, which plays a crucial role in regulating immune responses, has been identified as a promising target for treating inflammatory skin diseases. This review aims to delve deeper into the potential pathological role and molecular mechanisms of the IL-17 family and its pathways in wound repair. The intricate interactions between IL-17 and other cytokines will be discussed in detail, along with the activation of various signaling pathways, to provide a comprehensive understanding of IL-17's involvement in chronic wound inflammation and repair.

Antimicrobial liposomes-in-nanofiber wound dressings prepared by a green and sustainable wire-electrospinning set-up

Increasing prevalence of infected and chronic wounds demands improved therapy options. In this work an electrospun nanofiber dressing with liposomes is suggested, focusing on the dressing's ability to support tissue regeneration and infection control. Chloramphenicol (CAM) was the chosen antibiotic, added to the nanofibers after first embedded in liposomes to maintain a sustained drug release. Nanofibers spun from five different polymer blends were tested, where pectin and polyethylene oxide (PEO) was identified as the most promising polymer blend, showing superior fiber formation and tensile strength. The wire-electrospinning setup (WES) was selected for its pilot-scale features, and water was applied as the only solvent for green electrospinning and to allow direct liposome incorporation. CAM-liposomes were added to Pectin-PEO nanofibers in the next step. Confocal imaging of rhodamine-labelled liposomes indicated intact liposomes in the fibers after electrospinning. This was supported by the observed in vitroCAM-release, showing that Pectin-PEO-nanofibers with CAM-liposomes had a delayed drug release compared to controls. Biological testing confirmed the antimicrobial efficacy of CAM and good biocompatibility of all CAM-nanofibers. The successful fiber formation and green production process with WES gives a promising outlook for industrial upscaling.

Multifunctional antibacterial hydrogels for chronic wound management

Chronic wounds have gradually evolved into a global health challenge, comprising long-term non-healing wounds, local tissue necrosis, and even amputation in severe cases. Accordingly, chronic wounds place a considerable psychological and economic burden on patients and society. Chronic wounds have multifaceted pathogenesis involving excessive inflammation, insufficient angiogenesis, and elevated reactive oxygen species levels, with bacterial infection playing a crucial role. Hydrogels, renowned for their excellent biocompatibility, moisture retention, swelling properties, and oxygen permeability, have emerged as promising wound repair dressings. However, hydrogels with singular functions fall short of addressing the complex requirements associated with chronic wound healing. Hence, current research emphasises the development of multifunctional antibacterial hydrogels. This article reviews chronic wound characteristics and the properties and classification of antibacterial hydrogels, as well as their potential application in chronic wound management.

Porous Functionally Graded Scaffold prepared by a single-step freeze-drying process. A bioinspired approach for wound care

Nowadays, chronic wounds are the major cause of morbidity worldwide and the healthcare costs related to wound care are a billion-dollar issue; chronic wounds involve a non-healing process that makes necessary the application of advanced wound dressings to promote skin integrity recovery. Functionally Graded Scaffolds (FGSs) are currently driving interest as promising candidates in mimicking the skin tissue environment and, thus, in enhancing a faster and more effective wound healing process. Aim of the present work was to design and develop a porous FGS based on κ-carrageenan (κCG) for the management of chronic skin wounds; a freeze-drying process was optimized to obtain in a single-step a three-layered FGS characterized by a pore size gradient functional to mimic the structure of native skin tissue. In addition to κCG, arginine and whey protein isolate were used as multifunctional agents for FGS preparation; these substances can not only intervene in some stages of wound healing but are able to establish non-covalent interactions with κCG, which were responsible for the production of layers with different pore size, water content capability and mechanical properties. Cell migration, adhesion and proliferation within the FGS structure were evaluated in vitro on fibroblasts and FGS wound healing potential was also studied in vivo on a murine model.

Multiomics Analysis Unravels Alteration in Molecule and Pathways Involved in Nondiabetic Chronic Wounds

The prevalence of chronic wounds (CW) continues to grow. A thorough knowledge of the mechanism of CW formation remains elusive due to a lack of relevant studies. Furthermore, most previous studies concentrated on diabetic ulcers with relatively few investigations on other types. We performed this multiomics study to investigate the proteomic and metabolomic changes in wound and surrounding tissue from a cohort containing 13 patients with nondiabetic CW. Differentially expressed proteins (DEPs) and metabolites (DEMs) were filtered out and analyzed through multiomic profiling. The DEPs were further confirmed with the use of parallel reaction monitoring. Compared with the surrounding tissue, there were 82 proteins and 214 metabolites altered significantly in wound tissue. The DEPs were mainly enriched in focal adhesion (FA), extracellular matrix-receptor interaction (ERI), and the PI3K-Akt (PA) signaling pathway. Moreover, the DEMs were significantly enriched in amino sugar and nucleotide sugar metabolism and biosynthesis of nucleotide sugar pathways. In correlation analysis, we discovered that the PA signaling pathway, as well as its upstream and downstream pathways, coenriched some DEPs and DEMs. Additionally, we found that FBLN1, FBLN5, and EFEMP1 (FBLN3) proteins dramatically elevated in wound tissue and connected with the above signaling pathways. This multiomics study found that changes in FA, ERI, and PA signaling pathways had an impact on the cellular activities and functions of wound tissue cells. Additionally, increased expression of those proteins in wound tissue may inhibit vascular and skin cell proliferation and degrade the extracellular matrix, which may be one of the causes of CW formation.

An enzyme-responsive hydrogel of ferrocene-grafted carboxymethyl chitosan as a soft electrochemical sensor for MMP-9 detection

Matrix metalloproteinase 9 (MMP-9) plays an important role in wound healing. However, overexpression of MMP-9 leads to the degradation of the newly formed extracellular matrix, which delays wound healing, ultimately leading to chronic wounds. Therefore, timely monitoring of the MMP-9 activity using simple, cost-effective methods is important to prevent the formation of chronic wounds. In this work, ferrocene-modified MMP-9 cleavage peptide (Fc-MG) modified carboxymethyl chitosan hydrogels were prepared as electrochemical biosensors. In the presence of MMP-9, the peptide chain is sheared, and the electrochemically active ferrocene segment is released. Therefore, analyzing the electrochemical activity of hydrogels using differential pulse voltammetry (DPV) can be used to determine MMP-9 activity. The results showed that the DPV peaks were correlated with the MMP-9 concentration in phosphate-buffered saline (PBS, pH 7.4) and Dulbecco's modified Eagle's medium (DMEM). Specifically, the corresponding coefficient of determination (R2) were 0.918 and 0.993. The limit of detections were 73.08 ng/mL and 131.71 ng/mL, respectively. Compared with the enzyme-linked immunosorbent assay, the hydrogel biosensor determined the concentration of MMP-9 in solution with simpler steps. This study demonstrates a novel strategy based on Fc-MG-modified hydrogels to monitor MMP-9 activity in cell secretion samples and shows the potential application in chronic wounds.

M.O.I.S.T. Concept for the Local Therapy of Chronic Wounds: An International Update

Chronic wounds remain a significant clinical challenge both for those affected and for healthcare systems. The treatment is often comprised and complex. All patients should receive wound care that is integrated into a holistic approach involving local management that addresses the underlying etiology and provides for gold standard therapy to support healing, avoid complications and be more cost effective. There have been significant advances in medicine over the last few decades. The development of new technologies and therapeutics for the local treatment of wounds is also constantly increasing. To help standardize clinical practice with regard to the multitude of wound products, the M.O.I.S.T. concept was developed by a multidisciplinary expert group. The M stands for moisture balance, O for oxygen balance, I for infection control, S for supporting strategies, and T for tissue management. Since the M.O.I.S.T. concept, which originated in the German-speaking countries, is now intended to provide healthcare professionals with an adapted instrument to be used in clinical practice, and a recent update to the concept has been undertaken by a group of interdisciplinary experts to align it with international standards. The M.O.I.S.T. concept can now be used internationally both as an educational tool and for the practical implementation of modern local treatment concepts for patients with chronic wounds and can also be used in routine clinical practice.

A review of the current state of natural biomaterials in wound healing applications

Skin, the largest biological organ, consists of three main parts: the epidermis, dermis, and subcutaneous tissue. Wounds are abnormal wounds in various forms, such as lacerations, burns, chronic wounds, diabetic wounds, acute wounds, and fractures. The wound healing process is dynamic, complex, and lengthy in four stages involving cells, macrophages, and growth factors. Wound dressing refers to a substance that covers the surface of a wound to prevent infection and secondary damage. Biomaterials applied in wound management have advanced significantly. Natural biomaterials are increasingly used due to their advantages including biomimicry of ECM, convenient accessibility, and involvement in native wound healing. However, there are still limitations such as low mechanical properties and expensive extraction methods. Therefore, their combination with synthetic biomaterials and/or adding bioactive agents has become an option for researchers in this field. In the present study, the stages of natural wound healing and the effect of biomaterials on its direction, type, and level will be investigated. Then, different types of polysaccharides and proteins were selected as desirable natural biomaterials, polymers as synthetic biomaterials with variable and suitable properties, and bioactive agents as effective additives. In the following, the structure of selected biomaterials, their extraction and production methods, their participation in wound healing, and quality control techniques of biomaterials-based wound dressings will be discussed.

Fabrication of Quercetin-Functionalized Morpholine and Pyridine Motifs-Laden Silk Fibroin Nanofibers for Effective Wound Healing in Preclinical Study

Choosing suitable wound dressings is crucial for effective wound healing. Spun scaffolds with bioactive molecule functionalization are gaining attention as a promising approach to expedite tissue repair and regeneration. Here, we present the synthesis of novel multifunctional quercetin with morpholine and pyridine functional motifs (QFM) embedded in silk fibroin (SF)-spun fibers (SF-QFM) for preclinical skin repair therapies. The verification of the novel QFM structural arrangement was characterized using ATR-FTIR, NMR, and ESI-MS spectroscopy analysis. Extensive characterization of the spun SF-QFM fibrous mats revealed their excellent antibacterial and antioxidant properties, biocompatibility, biodegradability, and remarkable mechanical and controlled drug release capabilities. SF-QFM mats were studied for drug release in pH 7.4 PBS over 72 h. The QFM-controlled release is mainly driven by diffusion and follows Fickian's law. Significant QFM release (40%) occurred within the first 6 h, with a total release of 79% at the end of 72 h, which is considered beneficial in effectively reducing bacterial load and helping expedite the healing process. Interestingly, the SF-QFM-spun mat demonstrated significantly improved NIH 3T3 cell proliferation and migration compared to the pure SF mat, as evidenced by the complete migration of NIH 3T3 cells within 24 h in the scratch assay. Furthermore, the in vivo outcome of SF-QFM was demonstrated by the regeneration of fresh fibroblasts and the realignment of collagen fibers deposition at 9 days post-operation in a preclinical rat full-thickness skin defect model. Our findings collectively indicate that the SF-QFM electrospun nanofiber scaffolds hold significant capability as a cost-effective and efficient bioactive spun architecture for use in wound healing applications.

Anticipation and Verification of Dendrobium-Derived Nanovesicles for Skin Wound Healing Targets, Predicated Upon Immune Infiltration and Senescence

Background

Dendrobium, with profound botanical importance, reveals a rich composition of bioactive compounds, including polysaccharides, flavonoids, alkaloids, and diverse amino acids, holding promise for skin regeneration. However, the precise mechanism remains elusive. Seeking a potent natural remedy for wound healing, exocyst vesicles were successfully isolated from Dendrobium.

Aims of the Study

This investigation aimed to employ bioinformatics and in vivo experiments to elucidate target genes of Dendrobium-derived nanovesicles in skin wound healing, focusing on immune infiltration and senescence characteristics.

Materials and Methods

C57 mice experienced facilitated wound healing through Dendrobium-derived nanovesicles (DDNVs). Bioinformatics analysis and GEO database mining identified crucial genes by intersecting immune-related, senescence-related, and PANoptosis-associated genes. The identified genes underwent in vivo validation.

Results

DDNVs remarkably accelerated skin wound healing in C57 mice. Bioinformatics analysis revealed abnormal expression patterns of immune-related, senescence-related, and pan-apoptosis-related genes, highlighting an overexpressed IL-1β and downregulated IL-18 in the model group, Exploration of signaling pathways included IL-17, NF-kappa B, NOD-like receptor, and Toll-like receptor pathways. In vivo experiments confirmed DDNVs' efficacy in suppressing IL-1β expression, enhancing wound healing.

Conclusion

Plant-derived nanovesicles (PDNV) emerged as a natural, reliable, and productive approach to wound healing. DDNVs uptake by mouse skin tissues, labeled with a fluorescent dye, led to enhanced wound healing in C57 mice. Notably, IL-1β overexpression in immune cells and genes played a key role. DDNVs intervention effectively suppressed IL-1β expression, accelerating skin wound tissue repair.

Unique combination of hyaluronic acid and amino acids in the management of patients with a range of moderate-to-severe chronic wounds: Evidence from international clinical trials

Chronic wounds present a prolonged burden to patients, their families and healthcare systems. There is evidence that the unique combination of hyaluronic acid (HA) and amino acids (Vulnamin®) promotes re-epithelialization of wounds and stimulates activation and proliferation of fibroblasts with a significant increase in the regeneration of epithelial cells. Tissue regeneration and tissue repair are considered to be the fundamental activities of this unique combination of HA and amino acids that distinguishes it from other wound healing products. A review of trials over the last 15 years indicates distinct advantages of the unique combination of HA and amino acids, in terms of healing rate and induction of granulation tissue production compared with HA alone.

Green synthesis of epigallocatechin gallate-ferric complex nanoparticles for photothermal enhanced antibacterial and wound healing

Bacterial infections are a significant global health concern, particularly in the context of skin infections and chronic wounds, which was further exacerbated by the emerging of antibiotic resistance. Therefore, there are urgent needs to develop alternative antibacterial strategies without inducing significant resistance. Photothermal therapy (PTT) is a promising alternative approach but usually faces limitations such as the need for stable and environmental-friendly PTT agents and ensuring biocompatibility with living tissues, necessitating ongoing research for its clinical advancement. Herein, in this study, with the aim to develop a green synthesized PTT agent for photothermal enhanced antibacterial and wound healing, we proposed a facile one-pot method to prepare epigallocatechin gallate-ferric (EGCG-Fe) complex nanoparticles. The obtained nanoparticles showed improved good size distribution and stability with high reproducibility. More importantly, EGCG-Fe complex nanoparticles have additional photothermal conversion ability which can give photothermal enhanced antibacterial effect on various pathogens, including Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) strains. EGCG-Fe complex nanoparticles also showed powerful biofilm prevention and destruction effects with promoted antibacterial and wound healing on mice model. In conclusion, EGCG-Fe complex nanoparticles can be a robust green material with effective and novel light controllable antibacterial properties for photothermal enhanced antibacterial and wound healing applications.

Smart Responsive and Controlled-Release Hydrogels for Chronic Wound Treatment

Chronic wounds are a major health challenge that require new treatment strategies. Hydrogels are promising drug delivery systems for chronic wound healing because of their biocompatibility, hydration, and flexibility. However, conventional hydrogels cannot adapt to the dynamic and complex wound environment, which involves low pH, high levels of reactive oxygen species, and specific enzyme expression. Therefore, smart responsive hydrogels that can sense and respond to these stimuli are needed. Crucially, smart responsive hydrogels can modulate drug release and eliminate pathological factors by changing their properties or structures in response to internal or external stimuli, such as pH, enzymes, light, and electricity. These stimuli can also be used to trigger antibacterial responses, angiogenesis, and cell proliferation to enhance wound healing. In this review, we introduce the synthesis and principles of smart responsive hydrogels, describe their design and applications for chronic wound healing, and discuss their future development directions. We hope that this review will inspire the development of smart responsive hydrogels for chronic wound healing.

Effects of home-based chronic wound care training for patients and caregivers: A systematic review

We aimed to review and synthesise the evidence of the interventions of patients' and informal caregivers' engagement in managing chronic wounds at home. The research team used a systematic review methodology based on an updated guideline for reporting systematic reviews (PRISMA) and recommendations from the Synthesis Without Meta-analysis. Cochrane Central Register of Controlled Trial of the Cochrane Library, Pubmed, Embase, CINAHL, Wanfang (Chinese), and CNKI database (Chinese) were searched from inception to May 2022. The following MESH terms were used: wound healing, pressure ulcer, leg ulcer, diabetic foot, skin ulcer, surgical wound, educational, patient education, counselling, self-care, self-management, social support, and family caregiver. Experimental studies involving participants with chronic wounds (not at risk of wounds) and their informal caregivers were screened. Data were extracted and the narrative was synthesised from the findings of included studies. By screening the above databases, 790 studies were retrieved, and 16 met the inclusion and exclusion criteria. Studies were 6 RCTs and ten non-RCTs. Outcomes of chronic wound management included patient indicators, wound indicators, and family/caregiver indicators. Home-based interventions of patients or informal caregivers' engagement in managing chronic wounds at home may effectively improve patient outcomes and change wound care behaviour. What's more, educational/behavioural interventions were the primary type of intervention. Multiform integration of education and skills training on wound care and aetiology-based treatment was delivered to patients and caregivers. Besides, there are no studies entirely targeting elderly patients. Home-based chronic wound care training was important to patients with chronic wounds and their family caregivers, which may advance wound management outcomes. However, the findings of this systematic review were based on relatively small studies. We need more exploration of self and family-oriented interventions in the future, especially for older people affected by chronic wounds.

The hemostatic effect and wound healing of novel collagen-containing polyester dressing

Collagen plays an important role in hemostasis and tissue repair processes. Traditional passive wound dressings like gauze, bandage, and cotton wool could hardly fit the open wounds and exerted no active effect on wound healing. Even worse, they would adhere to the skin tissue, causing dehydration and second injury upon replacement. Polyester is commonly used in the medical field and is a safe and inexpensive polymer. Due to the hydrophobic surface, polyester does not adhere to tissue; however, polyester does not have the hemostatic properties. We designed a material composed of collagen and polyester, encapsulated hydrolyzed collagen in polyester particles, and made collagen-polyester non-woven fabric by melt blowing method, The collagen content was 1% and the collagen-polyester dressing exhibited a hydrophobic nature, preventing moisture from sticking to its surface. The purpose of this study was to compare the hemostatic effect of collagen-polyester nonwovens with conventional polyester pads, and to observe the adhesion of the pads to the wound. The wound healing and shrinkage rates of collagen-polyester dressings and conventional pads were compared in a rat wound healing test. The hemostatic test showed that the polyester pads containing 1% collagen significantly shortened the bleeding time compared with the traditional polyester pads, and retained the hydrophobicity and non-adhesion properties. The collagen-polyester dressing had better angiogenesis and granulation degree than the control group on the 14th day, and reduced the wound shrinkage rate. Collagen polyester dressings have excellent hemostasis, regeneration, shrinkage reduction and non-adhering for wounds. Overall, the novel collagen-containing polyester dressing is ideal choice for wound dressings.

Chronic wounds in a multiethnic Asian population: a cost of illness study

OBJECTIVE

To estimate the 'cost of illness' arising from chronic wounds in Singapore.

DESIGN

Incidence-based cost of illness study using evidence from a range of sources.

SETTING

Singapore health services.

PARTICIPANTS

We consider 3.49 million Singapore citizens and permanent residents. There are 16 752 new individuals with a chronic wound in 2017, with 598 venous ulcers, 2206 arterial insufficiency ulcers, 6680 diabetic ulcers and 7268 pressure injuries.Primary outcome measures expressed in monetary terms are the value of all hospital bed days lost for the population; monetary value of quality-adjusted life years (QALYs) lost in the population; costs of all outpatient visits; and costs of all poly clinic, use of Community Health Assist Scheme (CHAS) and emergency departments (EDs) visits. Intermediate outcomes that inform the primary outcomes are also estimated.

RESULTS

Total annual cost of illness was $350 million (range $72-$1779 million). With 168 503 acute bed days taken up annually (range 141 966-196 032) that incurred costs of $139 million (range 117-161 million). Total costs to health services were $184 million (range $120-$1179 million). Total annual costs of lost health outcomes were 2077 QALYs (range -2657 to 29 029) valued at $166 million (range -212 to 2399 million).

CONCLUSIONS

The costs of chronic wounds are large to Singapore. Costs can be reduced by making positive investments for comprehensive wound prevention and treatment programmes.

Lignin-Cobalt Nano-Enabled Poly(pseudo)rotaxane Supramolecular Hydrogel for Treating Chronic Wounds

Chronic wounds (CWs) are a growing issue for the health care system. Their treatment requires a synergic approach to reduce both inflammation and the bacterial burden. In this work, a promising system for treating CWs was developed, comprising cobalt-lignin nanoparticles (NPs) embedded in a supramolecular (SM) hydrogel. First, NPs were obtained through cobalt reduction with phenolated lignin, and their antibacterial properties were tested against both Gram-negative and Gram-positive strains. The anti-inflammatory capacity of the NPs was proven through their ability to inhibit myeloperoxidase (MPO) and matrix metalloproteases (MMPs), which are enzymes involved in the inflammatory process and wound chronicity. Then, the NPs were loaded in an SM hydrogel based on a blend of α-cyclodextrin and custom-made poly(ether urethane)s. The nano-enabled hydrogel showed injectability, self-healing properties, and linear release of the loaded cargo. Moreover, the SM hydrogel's characteristics were optimized to absorb proteins when in contact with liquid, suggesting its capacity to uptake harmful enzymes from the wound exudate. These results render the developed multifunctional SM material an interesting candidate for the management of CWs.

Oxygen-releasing biomaterials for chronic wounds breathing: From theoretical mechanism to application prospect

Chronic wounds have always been considered as "gordian knots" in medicine, in which hypoxia plays a key role in blocking healing. To address this challenge, although tissue reoxygenation therapy based on hyperbaric oxygen therapy (HBOT) has been performed clinically for several years, the bench to bedside still urges the evolution of oxygen-loading and -releasing strategies with explicit benefits and consistent outcome. The combination of various oxygen carriers with biomaterials has gained momentum as an emerging therapeutic strategy in this field, exhibiting considerable application potential. This review gives an overview of the essential relationship between hypoxia and delayed wound healing. Further, detailed characteristics, preparation methods and applications of various oxygen-releasing biomaterials (ORBMs) will be elaborated, including hemoglobin, perfluorocarbon, peroxide, and oxygen-generating microorganisms, those biomaterials are applied to load, release or generate a vast of oxygen to relieve the hypoxemia and bring the subsequent cascade effect. The pioneering papers regarding to the ORBMs practice are presented and trends toward hybrid and more precise manipulation are summarized.

Implementation of a patient-centered remote wound monitoring system for management of diabetic foot ulcers

Background

Regular clinical assessment is critical to optimize lower extremity wound healing. However, family and work obligations, socioeconomic, transportation, and time barriers often limit patient follow-up. We assessed the feasibility of a novel, patient-centered, remote wound management system (Healthy.io Minuteful for Wound Digital Management System) for the surveillance of lower extremity wounds.

Methods

We enrolled 25 patients from our outpatient multidisciplinary limb preservation clinic with a diabetic foot ulcer, who had undergone revascularization and podiatric interventions prior to enrollment. Patients and their caregivers were instructed on how to use the digital management system and asked to perform one at-home wound scan per week for a total of 8 weeks using a smartphone application. We collected prospective data on patient engagement, smartphone app useability, and patient satisfaction.

Results

Twenty-five patients (mean age 65.5 ± 13.7 years, 60.0% male, 52.0% Black) were enrolled over 3 months. Mean baseline wound area was 18.0 ± 15.2 cm2, 24.0% of patients were recovering from osteomyelitis, and post-surgical WiFi stage was 1 in 24.0%, 2 in 40.0%, 3 in 28.0%, and 4 in 8.00% of patients. We provided a smartphone to 28.0% of patients who did not have access to one that was compatible with the technology. Wound scans were obtained by patients (40.0%) and caregivers (60.0%). Overall, 179 wound scans were submitted through the app. The mean number of wound scans acquired per patient was 0.72 ± 0.63 per week, for a total mean of 5.80 ± 5.30 scans over the course of 8 weeks. Use of the digital wound management system triggered an early change in wound management for 36.0% of patients. Patient satisfaction was high; 94.0% of patients reported the system was useful.

Conclusion

The Healthy.io Minuteful for Wound Digital Management System is a feasible means of remote wound monitoring for use by patients and/or their caregivers.

PRP of T2DM Patient Immobilized on PCL Nanofibers Stimulate Endothelial Cells Proliferation

Diabetic foot ulcers (DFU) are a common complication of Type 2 Diabetes Mellitus (T2DM). Development of bioactive wound healing covers is an important task in medicine. The use of autologous platelet-rich plasma (PRP) consisting of growth factors, cytokines and components of extracellular matrix is a perspective approach for DFU treatment, but we previously found that some T2DM PRP samples have a toxic effect on mesenchymal stem cells (MSCs) in vitro. Here, we covalently immobilized T2DM PRP proteins on polycaprolactone (PCL) nanofibers, and the growth of endothelial cells on the PCL-COOH-PRP was investigated. Additionally, the level of NO reflecting the cytotoxic effects of PRP, angiogenin, and VEGF levels were measured in T2DM PRP samples. The results showed that the application of PCL-COOH-PRP nanofibers allows to remove the cytotoxicity of T2DM PRP and to improve endothelial cell adhesion and proliferative activity. We showed that the origin of T2DM PRP (the level of PRP toxicity or presence/absence of DFU) does not influence the efficiency of cell growth on PCL-COOH-PRP, and on the level of angiogenin, vascular epidermal growth factor (VEGF) in PRP itself.

The biological and physiological impact of the performance of wound dressings

Chronic wounds affect millions globally and are a huge financial burden. Whilst there are many wound dressings commercially available to manage these wounds, the complexity of the repair process makes it difficult to select the right dressing for the right wound at the right time. Thus, in this narrative review, we have examined reasons why wounds fail to heal, summarised the pathophysiology of the chronic wound environment and provided an evidence-based, clinically-relevant compilation of the published literature relevant to dressing design and evaluation. This has highlighted the need for a deeper understanding of wound exudates, how exudates change throughout the healing process, and how they are impacted by different dressing materials. Studies assessing biochemical and biophysical changes in exudates throughout the healing process are extremely valuable in this regard, enhancing both our understanding of the wound healing process and the ability to assess dressing performance. In addition, this knowledge allows us to replicate various wound conditions in the laboratory, and develop clinically-relevant models for testing current and new dressings, therefore providing a more comprehensive understanding of how and when they should be used. This approach makes the use of dressings more effective, thereby improving outcomes, and reducing the economic burden of chronic wounds.

Human In Vitro Skin Models for Wound Healing and Wound Healing Disorders

Skin wound healing is essential to health and survival. Consequently, high amounts of research effort have been put into investigating the cellular and molecular components involved in the wound healing process. The use of animal experiments has contributed greatly to the knowledge of wound healing, skin diseases, and the exploration of treatment options. However, in addition to ethical concerns, anatomical and physiological inter-species differences often influence the translatability of animal-based studies. Human in vitro skin models, which include essential cellular and structural components for wound healing analyses, would improve the translatability of results and reduce animal experiments during the preclinical evaluation of novel therapy approaches. In this review, we summarize in vitro approaches, which are used to study wound healing as well as wound healing-pathologies such as chronic wounds, keloids, and hypertrophic scars in a human setting.

Advances in Zebrafish for Diabetes Mellitus with Wound Model

Diabetic foot ulcers cause great suffering and are costly for the healthcare system. Normal wound healing involves hemostasis, inflammation, proliferation, and remodeling. However, the negative factors associated with diabetes, such as bacterial biofilms, persistent inflammation, impaired angiogenesis, inhibited cell proliferation, and pathological scarring, greatly interfere with the smooth progress of the entire healing process. It is this impaired wound healing that leads to diabetic foot ulcers and even amputations. Therefore, drug screening is challenging due to the complexity of damaged healing mechanisms. The establishment of a scientific and reasonable animal experimental model contributes significantly to the in-depth research of diabetic wound pathology, prevention, diagnosis, and treatment. In addition to the low cost and transparency of the embryo (for imaging transgene applications), zebrafish have a discrete wound healing process for the separate study of each stage, resulting in their potential as the ideal model animal for diabetic wound healing in the future. In this review, we examine the reasons behind the delayed healing of diabetic wounds, systematically review various studies using zebrafish as a diabetic wound model by different induction methods, as well as summarize the challenges and improvement strategies which provide references for establishing a more reasonable diabetic wound zebrafish model.

Extracellular Vesicle-Based Hydrogels for Wound Healing Applications

Hydrogels and extracellular vesicle-based therapies have been proposed as emerging therapeutic assets in wound closure. The combination of these elements has given good results in managing chronic and acute wounds. The intrinsic characteristics of the hydrogels in which the extracellular vesicles (EVs) are loaded allow for overcoming barriers, such as the sustained and controlled release of EVs and the maintenance of the pH for their conservation. In addition, EVs can be obtained from different sources and through several isolation methods. However, some barriers must be overcome to transfer this type of therapy to the clinic, for example, the production of hydrogels containing functional EVs and identifying long-term storage conditions for EVs. The aim of this review is to describe the reported EV-based hydrogel combinations, along with the obtained results, and analyze future perspectives.

Centella asiatica and Its Metabolite Asiatic Acid: Wound Healing Effects and Therapeutic Potential

An intense effort has been focused on new therapeutic approaches and the development of technologies for more efficient and rapid wound healing. The research for plants used for long time in traditional medicine in the treatment of wound has become a promising strategy to obtain drugs therapeutically useful in the acute and chronic wound management. In this context, Centella asiatica (Apiaceae) has been used to treat a variety of skin diseases, such as leprosy, lupus, varicose ulcers, eczema and psoriasis, in Asiatic traditional medicine for thousands of years. Studies have shown that Centella asiatica extracts (CAE) display activity in tissue regeneration, cell migration and wound repair process by promoting fibroblast proliferation and collagen synthesis. Preliminary findings have shown that the asiatic acid is one of the main active constituents of C. asiatica, directly associated with its healing activity. Thus, this study discusses aspects of the effects of Centella asiatica and its active component, asiatic acid, in different stages of the healing process of cutaneous wounds, including phytochemical and antimicrobial aspects that contribute to its therapeutic potential.

Plasma-Functionalised Dressings for Enhanced Wound Healing

Fundamental knowledge about cell-surface interactions can be applied in the development of wound dressings and scaffolds to encourage wounds to heal. As surfaces produced with acid-functionalised monomers encourage keratinocyte adhesion, proliferation and migration, whilst amine functionalisation enhances fibroblast proliferation and migration in vitro, standard care wound dressings were plasma-coated with either acrylic acid or allylamine and applied to 6 mm excisional wounds on the backs of mice to test their effectiveness in vivo. At day 3, the rate of wound healing was increased in mice treated with dressings that were plasma-coated with allylamine compared to uncoated dressings, with a significantly reduced wound area. However, healing may be impaired following prolonged treatment with allylamine-functionalised dressings, with delayed re-epithelialisation and increased cellularisation of the wound site at later timepoints. Acrylic acid functionalisation, however, offered no early improvement in wound healing, but wounds treated with these dressings displayed increased collagen deposition at day 7 post wounding. These results suggest that plasma polymerisation may allow for the development of new dressings which can enhance wound closure by directing cell behaviour, but that the application of these dressings may require a timed approach to enhance specific phases of the wound healing response.

Polyhexanide-Releasing Membranes for Antimicrobial Wound Dressings: A Critical Review

The prevalence of chronic, non-healing skin wounds in the general population, most notably diabetic foot ulcers, venous leg ulcers and pressure ulcers, is approximately 2% and is expected to increase, driven mostly by the aging population and the steady rise in obesity and diabetes. Non-healing wounds often become infected, increasing the risk of life-threatening complications, which poses a significant socioeconomic burden. Aiming at the improved management of infected wounds, a variety of wound dressings that incorporate antimicrobials (AMDs), namely polyhexanide (poly(hexamethylene biguanide); PHMB), have been introduced in the wound-care market. However, many wound-care professionals agree that none of these wound dressings show comprehensive or optimal antimicrobial activity. This manuscript summarizes and discusses studies on PHMB-releasing membranes (PRMs) for wound dressings, detailing their preparation, physical properties that are relevant to the context of AMDs, drug loading and release, antibacterial activity, biocompatibility, wound-healing capacity, and clinical trials conducted. Some of these PRMs were able to improve wound healing in in vivo models, with no associated cytotoxicity, but significant differences in study design make it difficult to compare overall efficacies. It is hoped that this review, which includes, whenever available, international standards for testing AMDs, will provide a framework for future studies.

The role of allogeneic platelet-rich plasma in patients with diabetic foot ulcer: Current perspectives and future challenges

The frequency of chronic cutaneous wounds are sharply increasing in aging populations. Patients with age-related diseases, such as diabetes, tumors, renal failure and stroke are prone to soft tissue and skin injury, compounded by slowed healing in aging. Imbalance of wound inflammation, loss of growth factor secretion, and impairment of tissue repair abilities are all possible reasons for failed healing. Therefore, it is vital to explore novel approaches to accelerate wound healing. Platelet-rich plasma (PRP) as a cell therapy has been widely applied for tissue repair and regeneration. PRP promotes wound healing by releasing antimicrobial peptides, growth factors and micro-RNAs. Medical evidence indicates that autologous platelet-rich plasma (au-PRP) can promote wound healing effectively, safely and rapidly. However, its clinical application is usually restricted to patients with chronic cutaneous wounds, generally because of other severe complications and poor clinical comorbidities. Allogeneic platelet-rich plasma (al-PRP), with abundant sources, has demonstrated its superiority in the field of chronic wound treatment. Al-PRP could overcome the limitations of au-PRP and has promising prospects in clinical applications. The aim of this review is to summarize the current status and future challenges of al-PRP in chronic cutaneous wound management. We also summarized clinical cases to further describe the application of al-PRP for chronic wounds in clinical practice.

Bacterial Cellulose—Adaptation of a Nature-Identical Material to the Needs of Advanced Chronic Wound Care

Modern wound treatment calls for hydroactive dressings. Among the variety of materials that have entered the field of wound care in recent years, the carbohydrate polymer bacterial cellulose (BC) represents one of the most promising candidates as the biomaterial features a high moisture-loading and donation capacity, mechanical stability, moldability, and breathability. Although BC has already gained increasing relevance in the treatment of burn wounds, its potential and clinical performance for “chronic wound” indications have not yet been sufficiently investigated. This article focuses on experimental and clinical data regarding the application of BC within the indications of chronic, non-healing wounds, especially venous and diabetic ulcers. A recent clinical observation study in a chronic wound setting clearly demonstrated its wound-cleansing properties and ability to induce healing in stalling wounds. Furthermore, the material parameters of BC dressings obtained through the static cultivation of Komagataeibacter xylinus were investigated for the first time in standardized tests and compared to various advanced wound-care products. Surprisingly, a free swell absorptive capacity of a BC dressing variant containing 97% moisture was found, which was higher than that of alginate or even hydrofiber dressings. We hypothesize that the fine-structured, open porous network and the resulting capillary forces are among the main reasons for this unexpected result.

The performance of gelling fibre wound dressings under clinically relevant robotic laboratory tests

The effectiveness of wound dressing performance in exudate management is commonly gauged in simple, non‐realistic laboratory setups, typically, where dressing specimens are submersed in vessels containing aqueous solutions, rather than by means of clinically relevant test configurations. Specifically, two key fluid–structure interaction concepts: sorptivity—the ability of wound dressings to transfer exudate, including viscous fluids, away from the wound bed by capillary action and durability—the capacity of dressings to maintain their structural integrity over time and particularly, at removal events, have not been properly addressed in existing test protocols. The present article reviews our recent published research concerning the development of clinically relevant testing methods for wound dressings, focussing on the clinical relevance of the tests as well as on the standardisation and automation of laboratory measurements of dressing performance. A second objective of this work was to compile the experimental results characterising the performance of gelling fibre dressings, which were acquired using advanced testing methods, to demonstrate differences across products that apparently belong to the same “gelling fibre” family but differ remarkably in materials, structure and composition and, thereby, in performance.