Randomized trial of topically applied repifermin (recombinant human keratinocyte growth factor-2) to accelerate wound healing in venous ulcers

Clinical efficacy of blood derivatives on wound healing: A systematic review and network meta-analysis

This study aims to evaluate the clinical effects of different blood derivatives on wound healing using network meta-analysis. PubMed, Embase, OVID, Web of Science, SCOPUS and Cochrane Central were searched to obtain studies about blood derivatives on wound healing until October 2023. R 4.2.0 and Stata 15.0 softwares were used for data analysis. Forty-four studies comprising 5164 patients were included. The results of network meta-analysis showed that the healing area from high to low was GF + ORCCB, ORCCB, GF, PRF, Unnas paste dressing, APG, PRP injection, PRP, PRP + thrombin gel, PPP, HPL, CT. The healing time from low to high was PRP + thrombin gel, GF, PRP, PC + K, PC, APG, PRF, CT, Silver sulfadiazine ointment. The number of patients cured from high to low was APG, PRP injection, PRP, Aurix, PRF, Leucopatch, HPL, Antimicrobial Ointment Dressing, CT, 60 μg/cm2 repifermin, 120 μg/cm2 repifermin, AFG, PPP. The order of analgesic effect from high to low was AFG, Aminogam gel, PRF, PRP, Oxidised oil, APG, GF, CT. The order of the number of wound infection cases from low to high is APG, 20 μg/cm2 repifermin, 60 μg/cm2 repifermin, PRP, LeucoPatch, CT, PPP, Antiseptic ointment dressing. Healing area: GF + ORCCB had the best effect; Healing time: PRP + thrombin gel took the shortest time. The number of cured patients and the reduction of wound infection: APG has the best effect. Analgesic effect: AFG has the best effect. More studies with large sample sizes are needed to confirm the above findings.

The effects of injectable platelet-rich fibrin application on wound healing following gingivectomy and gingivoplasty operations: single-blind, randomized controlled, prospective clinical study

OBJECTIVES

The aim of this study was to evaluate the effects of wound healing using injectable platelet-rich fibrin (IPRF) after gingivectomy and gingivoplasty.

MATERIALS AND METHODS

In this clinical study, 46 systemically healthy patients with chronic inflammatory gingival enlargement were randomly treated with gingivectomy-gingivoplasty + I-PRF (n=23) or gingivectomy-gingivoplasty alone (n=23). The primary outcome was to evaluate the effect of I-PRF on wound healing over a 3-week follow-up period. Samples collected from gingival crevicular fluid (GCF) were processed using enzyme-linked immunosorbent assay (ELİSA) to measure VEGF and FGF-10 biomarkers. The surgical areas were stained with Mira-2 tone and evaluated in ImageJ. Wound healing was evaluated with Modified Manchester Scar (MMS) scale and Landry, Turnbull, and Howley (LTH) index.

RESULTS

VEGF values of the control group at baseline, week 2, and week 3 were significantly higher than the test group. In weeks 2 and 3, FGF-10 values were found to be significantly higher in the control group than the test group. The amount of staining was found to be significantly higher in the control group than in the test group on days 3, 7, and 14. LTH values of the control group were significantly lower than the test group and MMS values were significantly higher than those of the test group.

CONCLUSIONS

I-PRF applications revealed positive effects on epithelial wound healing after gingivectomy and gingivoplasty operations.

CLINICAL RELEVANCE

Platelet concentrates such as I-PRF accelerate wound healing and contribute to the patient's comfort and quality of life. I-PRF application may have positive effects on wound healing after gingivectomy and gingivoplasty operations.

Approaches for Regenerative Healing of Cutaneous Wound with an Emphasis on Strategies Activating the Wnt/β-Catenin Pathway

Significance: In adult mammals, spontaneous repair of a cutaneous wound occurs slowly and leaves a scar with skin adnexa deficiencies. To accelerate cutaneous wound-healing rates and avoid scar formation, current studies have focused on regenerative therapies. Recent Advances: Emerging therapeutics for regenerative wound healing often focus on the use of growth factors and stem cells. However, these therapeutic approaches have limited routine clinical use due to high costs and technical requirements. Critical Issue: Understanding the molecular mechanisms involved in the signaling pathways for cutaneous wound healing and neogenic synthesis of the skin components is important for identification of novel targets for the development of regenerative wound-healing agents. Future Directions: The Wnt/β-catenin pathway is a well-known key player for enhancement of the overall healing process involving tissue regeneration via crosstalk with other signaling pathways. Strategies that activate the Wnt/β-catenin pathway via modulation of the pathway-controlling regulatory factors could provide effective therapeutic approaches for regenerative wound healing.

Fibroblast growth factor in the treatment of burns: A systematic review

INTRODUCTION

A burn is a trauma that breaks the skin barrier, causing local and systemic responses. Treatment is complex, multiprofessional and expensive. In addition to surgical treatment, topical dressings can be used to keep the wound moist, reduce the risk of infection and stimulate healing. Clinical studies show that topical use of fibroblast growth factors may accelerate healing. An assessment of the quality of the available evidence and its strength of recommendation is necessary.

OBJECTIVE

This study aimed to evaluate the effectiveness and safety of topical use of fibroblast growth factor, compared to other topical treatments or placebo, in the healing of burns, to determine the strength of recommendation.

METHOD

Based on a defined search strategy, randomized and quasi-randomized clinical trials, available in electronic databases, were gathered. These compare the topical use of FGF versus other topical or non-treatment. The primary outcome was healing and as adverse effects: pain, infection and mortality. The systematic review protocol was registered on the PROSPERO platform (CRD42018089556), developed in accordance with the "Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) 2015" and within the "SWiM guideline 2019". GRADEpro was used for the critical analysis of the methodology of the studies.

RESULTS

Four clinical trials were found, in which FGF reduced the healing time and improved the appearance of the scar. Two trials were determined to be of low strength, while two others have a moderate recommendation strength.

CONCLUSION

This review gathered available evidence, between low and moderate recommendation strength for the use of FGF as a topical dressing. Further rigorous trials are needed to improve the strength of recommendation for topical use of FGF for burns.

Growth factors for treating chronic venous leg ulcers: A systematic review and meta-analysis

Chronic venous leg ulcers (VLU) are wounds that commonly occur due to venous insufficiency. Many growth factors have been introduced over the past two decades to treat VLU. This systematic review and meta-analysis evaluates the impact of growth factor treatments of VLU in comparison to control for complete wound healing, percent reduction in wound area, time to wound healing, and adverse events. A systematic review and meta-analysis of randomised trials was conducted. MEDLINE and EMBASE were searched up to December 2020. Studies were included if they compared a growth factor versus placebo or standard care in patients with VLU. From 1645 articles, 13 trials were included (n = 991). There was a significant difference between any growth factor and placebo in complete wound healing (P = 0.04). Any growth factor compared to placebo significantly increased the likelihood of percent wound reduction by 48.80% (P = <0.00001). There was no difference in overall adverse event rate. Most comparisons have low certainty of evidence according to Grading of Recommendations, Assessment, Development, and Evaluation. This meta-analysis suggests that growth factors have a beneficial effect in complete wound healing of VLU. Growth factors may also increase percent reduction in wound area. The suggestion of benefit for growth factors identified in this review is not a strong one based on the low quality of evidence.

Controlled release of KGF-2 for regulation of wound healing by KGF-2 complexed with "lotus seedpod surface-like" porous microspheres

Keratinocyte growth factor-2 (KGF-2) can regulate the proliferation and differentiation of keratinocyte, which plays a remarkable role in maintaining normal tissue structure and promoting wound healing. As an effective strategy, KGF-2 solution is widely used in the treatment of wounds in clinical applications. However, KGF-2 in solution cannot achieve sustained release, which results in drug loss and unnecessary waste. Polysaccharide hemostasis microspheres (PHMs) are an ideal drug loading platform due to their special "lotus seedpod surface-like" morphology and structure. Herein, to realize the controllable release of KGF-2, PHMs loaded with KGF-2 (KGF-2@PHMs) were prepared. It was found that the bioavailability of KGF-2 was improved greatly. Most importantly, KGF-2@PHMs can reduce inflammation and accelerate the wound healing process due to the controlled release of KGF-2. KGF-2@PHMs might be a potential alternative strategy for wound healing in future clinical applications.

Targeting Drugs Against Fibroblast Growth Factor(s)-Induced Cell Signaling

BACKGROUND

The fibroblast growth factor (FGF) family is comprised of 23 highly regulated monomeric proteins that regulate a plethora of developmental and pathophysiological processes, including tissue repair, wound healing, angiogenesis, and embryonic development. Binding of FGF to fibroblast growth factor receptor (FGFR), a tyrosine kinase receptor, is facilitated by a glycosaminoglycan, heparin. Activated FGFRs phosphorylate the tyrosine kinase residues that mediate induction of downstream signaling pathways, such as RAS-MAPK, PI3K-AKT, PLCγ, and STAT. Dysregulation of the FGF/FGFR signaling occurs frequently in cancer due to gene amplification, FGF activating mutations, chromosomal rearrangements, integration, and oncogenic fusions. Aberrant FGFR signaling also affects organogenesis, embryonic development, tissue homeostasis, and has been associated with cell proliferation, angiogenesis, cancer, and other pathophysiological changes.

OBJECTIVE

This comprehensive review will discuss the biology, chemistry, and functions of FGFs, and its current applications toward wound healing, diabetes, repair and regeneration of tissues, and fatty liver diseases. In addition, specific aberrations in FGFR signaling and drugs that target FGFR and aid in mitigating various disorders, such as cancer, are also discussed in detail.

CONCLUSION

Inhibitors of FGFR signaling are promising drugs in the treatment of several types of cancers. The clinical benefits of FGF/FGFR targeting therapies are impeded due to the activation of other RTK signaling mechanisms or due to the mutations that abolish the drug inhibitory activity on FGFR. Thus, the development of drugs with a different mechanism of action for FGF/FGFR targeting therapies is the recent focus of several preclinical and clinical studies.

Evidence supporting wound care end points relevant to clinical practice and patients' lives. Part 3: The Patient Survey

The 2006 U.S. Food and Drug Administration Guidance for Industry emphasizes wound closure as the primary outcome for clinical trials in wound healing. Wound care professionals understand that complete wound healing is not always achievable when evaluating new treatments. FDA, Association for the Advancement of Wound Care, and Wound Healing Society are working collaboratively to identify scientifically achievable, clinically relevant, and patient-centered endpoints with sufficient support to serve as primary outcomes for clinical trials. The Opinion Survey from People with Wounds presented here addresses an important but understudied issue: the gap between clinician, healthcare insurance companies, government agencies, and patient perspectives regarding clinically meaningful and scientifically achievable primary endpoints for wound care. The survey, adapted from the clinician survey with adjustment for health literacy, was pilot tested and revised based on a limited number of patients in a single clinic. After central IRB approval, the on-line survey was administered in English and Spanish and submitted anonymously to a server with the cooperation of multiple wound clinics and societies. Four hundred and thirty-eight patients and caregivers from across the United States responded over a 10-month period. Based on this survey, the most valuable clinical endpoints were reduced infection, recurrence, and amputation. The most valuable quality of life outcomes were increased independence, reduced social isolation, and pain. The top five endpoints in terms of usefulness for measuring clinical trial success were time to heal, wound size, infection, recurrence, and pain. Narrative responses from wound patients emphasized the inability to perform activities of daily living and pain as major factors that impacted their daily lives. Engagement of patients in clinical trials and evaluation of potential treatments is critical to improving wound care. This survey provides insight into the needs of patients with wounds and provides a roadmap for structuring future clinical trials to better meet those needs.

Autologous platelet-rich plasma injection enhances healing of chronic venous leg ulcer: A prospective randomised study

Our aim was to compare the efficacy and safety of platelet-rich plasma (PRP) application versus PRP injection for chronic venous leg ulcer (VLU) healing compared with compression therapy as a control. From July 2018 to December 2019, 90 chronic VLU patients were randomly assigned to PRP dressings (n = 30), local PRP injections (n = 30), and compression therapy alone (n = 30). Standard compression accompanied both PRP groups. The main endpoints were ulcer healing and area reduction within 3, 6, and 12 months. Complications and ulcer recurrence were also recorded. The study included 72 (80.0%) males and 18 (20.0%) females aged 22 to 66 years, having VLUs for 1 to 11 years. PRP injection promoted healing (24/30, 80%) more than PRP application (20/30, 66.7%) and compression (14/30, 46.7%), P = .007. Healing time was significantly shorter after PRP injection compared with the other two groups. A greater area reduction was observed after PRP injection compared with compression at all follow-up visits, P = .013, .002, and < .001, and compared with PRP application only at 3 months post-treatment, P = .016. Recurrence and complications were comparable among the groups. PRP injection enhances the healing of chronic venous ulcers more than each of PRP application and compression therapy. All had comparable recurrence and safety.

Therapeutic advances in wound healing

Wound healing is a complex physiological process that occurs in the human body involving the sequential activation of multiple cell types and signaling pathways in a coordinated manner. Chronic wounds and burns clearly decrease quality of life of the patients since they are associated with an increase in physical pain and socio-economical complications. Furthermore, incidence and prevalence of chronic wounds (unlike burns) have been increasing mainly due to population aging resulting in increased costs for national health systems. Thus, the development of new and more cost-effective technologies/therapies is not only of huge interest but also necessary to improve the long-term sustainability of national health systems. This review covers the current knowledge on recent technologies/therapies for skin regeneration, such as: wound dressings; skin substitutes; exogenous growth factor based therapy and systemic therapy; external tissue expanders; negative pressure; oxygen; shock wave, and photobiomodulation wound therapies. Associated benefits and risks as well as the clinical use and availability are all addressed for each therapy. Moreover, future trends in wound care including novel formulations using metallic nanoparticles and topical insulin are herein presented. These novel formulations have shown to be promising therapeutic options in the near future that may change the wound care paradigm.

Characterization of the local wound environment following treatment of chronic leg ulcers with SIS wound matrix

BACKGROUND

The SIS Wound Matrix (SISWM) has been shown to improve healing of chronic ulcers over standard of care. In this study, we tested the hypothesis that chronic venous ulcers responsive to treatment with SISWM would more closely mimic an acute wound state as opposed to unresponsive ulcers.

METHODS

Serum and wound exudate were collected at baseline and then weekly for up to 12 weeks from 12 patients receiving multiple applications of the SISWM. Levels of matrix metalloproteinases (MMP-1, MMP-2, MMP-3, MMP-9, and MMP-12), pro-inflammatory cytokines (IL-1β, TNF-α, IL-8), and transforming growth factor beta (TGF-β1) were evaluated. A variety of Th1/Th2 cytokines were also assayed, as were systemic anti-SIS and anti-α-gal antibody titers.

RESULTS

Seven of the 12 patients eventually healed their wounds. Results showed significant decreases in MMP-1, MMP-2, MMP-3, MMP-9, TNF-α and IL-8, and significant increases in TGF-β1 in wounds responding to treatment with the SISWM versus wounds that did not respond to treatment. None of the 12 patients formed a measurable serum antibody response to the SISWM.

CONCLUSIONS

These data show that SISWM does not lead to immune system recognition or sensitization to the matrix and that wounds that went on to heal following treatment were characterized by a more acute wound state. The study confirms that the wound environment is important to healing and that turning a wound toward an acute biochemical state is key to the healing process.

Drug therapies and delivery mechanisms to treat perturbed skin wound healing

Acute wound healing is an orderly process of four overlapping events: haemostasis, inflammation, proliferation and remodelling. A drug delivery system with a temporal control of release could promote each of these events sequentially. However, acute wound healing normally proceeds very well in healthy individuals and there is little need to promote it. In the elderly and diabetics however, healing is often slow and wounds can become chronic and we need to promote their healing. Targeting the events of acute wound healing would not be appropriate for a chronic wound, which have stalled in the proinflammatory phase. They also have many additional problems such as poor circulation, low oxygen, high levels of leukocytes, high reactive oxygen species, high levels of proteolytic enzymes, high levels of proinflammatory cytokines, bacterial infection and high pH. The future challenge will be to tackle each of these negative factors to create a wound environment conducive to healing.

Treatment of venous ulcers with growth factors: systematic review and meta-analysis

OBJECTIVE

To identify evidence about the effects of growth factor application on venous ulcer healing.

METHOD

Systematic review and meta-analysis, including Randomized Clinical Trials. Searches: Ovid MEDLINE, EMBASE, CINAHL, Cochrane CENTRAL, LILACS, Web of Science, Digital Library of Theses and Dissertations; Google Scholar and list of references.

RESULTS

802 participants were recruited from the 10 included studies: 472 in the intervention group (growth factors) and 330 as control. The relative risk for the complete healing outcome was 1.06 [95% CI 0.92-1.22], p = 0.41. Participants who received Platelet-Rich Plasma and Epidermal Growth Factor showed a slight tendency to achieve complete healing, but without statistical relevance (p <0.05). Most of the studies were classified as moderate risk of bias.

CONCLUSION

The effect of the application of growth factors for complete healing in venous ulcers is not clear, and clinical trials with methodological quality are required for more accurate recommendations.

Stem cell therapies for wound healing

INTRODUCTION

Aberrant wound healing is a significant healthcare problem, posing a substantial burden on patients, their families, and the healthcare system. Existing treatment options remain only moderately effective and often fail to promote the closure of non-healing wounds in susceptible populations, such as aging and diabetic patients. Stem cell therapy has emerged as a promising treatment modality, with the potential to restore tissue to its pre-injured state. Of particular interest are mesenchymal stromal cells, which have been shown to accelerate wound healing by modulating the immune response and promoting angiogenesis.

AREAS COVERED

This review provides an overview of wound healing and current methods for the management of chronic wounds, as well as the current state and considerations for optimizing stem cell therapy. Considerations include stem cell types, tissue source, donor selection, cell heterogeneity, delivery methods, and genetic engineering.

EXPERT OPINION

A growing body of evidence has shown that delivery of stem cells, particularly mesenchymal stromal cells, has the potential to effectively improve the rate and quality of wound healing. However, significant additional basic and clinical research must be performed to optimize cell therapy, such as further elucidation of the therapeutic mechanisms of stem cells and standardization of clinical trial guidelines.

Advances in surgical applications of growth factors for wound healing

Growth factors have recently gained clinical importance for wound management. Application of recombinant growth factors has been shown to mimic cell migration, proliferation, and differentiation in vivo, allowing for external modulation of the healing process. Perioperative drug delivery systems can enhance the biological activity of these growth factors, which have a very short in vivo half-life after topical administration. Although the basic mechanisms of these growth factors are well understood, most have yet to demonstrate a significant impact in animal studies or small-sized clinical trials. In this review, we emphasized currently approved growth factor therapies, including a sustained release system for growth factors, emerging therapies, and future research possibilities combined with surgical procedures. Approaches seeking to understand wound healing at a systemic level are currently ongoing. However, further research and consideration in surgery will be needed to provide definitive confirmation of the efficacy of growth factor therapies for intractable wounds.

Healing Chronic Wounds: Current Challenges and Potential Solutions

PURPOSE OF REVIEW

The purpose of this review is to raise awareness, examine the challenges faced by wound care researchers and explore opportunities for potential improvements.

RECENT FINDINGS

Chronic wounds are associated with significant morbidity and mortality, and they represent a major medical and financial burden. Despite this, no new therapy has received FDA efficacy approval for the treatment of chronic wounds since 1997. Previous preclinical studies using animal models did not translate to human wounds due to inherent limitations of experimental models, variability in assessment methods and overall experimental design. Clinical trials continued to be challenged by the balance of the inclusion and exclusion criteria, the high cost and time expenditure of the trials, and the constraint of a single FDA-acceptable outcome of complete wound closure.

SUMMARY

Wound research faces multiple challenges in both pre-clinical and clinical research that slowed progress and development of efficacious therapies. Solutions to such challenges will provide new opportunities for improved study design in the future.

FGF Family: From Drug Development to Clinical Application

Fibroblast growth factor (FGF) belongs to a large family of growth factors. FGFs use paracrine or endocrine signaling to mediate a myriad of biological and pathophysiological process, including angiogenesis, wound healing, embryonic development, and metabolism regulation. FGF drugs for the treatment of burn and ulcer wounds are now available. The recent discovery of the crucial roles of the endocrine-acting FGF19 subfamily in maintaining homeostasis of bile acid, glucose, and phosphate further extended the activity profile of this family. Here, the applications of recombinant FGFs for the treatment of wounds, diabetes, hypophosphatemia, the development of FGF receptor inhibitors as anti-neoplastic drugs, and the achievements of basic research and applications of FGFs in China are reviewed.

Dressings and topical agents for treating venous leg ulcers

BACKGROUND

Venous leg ulcers are open skin wounds on the lower leg which can be slow to heal, and are both painful and costly. The point prevalence of open venous leg ulcers in the UK is about 3 cases per 10,000 people, and many people experience recurrent episodes of prolonged ulceration. First-line treatment for venous leg ulcers is compression therapy, but a wide range of dressings and topical treatments are also used. This diversity of treatments makes evidence-based decision-making challenging, and a clear and current overview of all the evidence is required. This review is a network meta-analysis (NMA) which assesses the probability of complete ulcer healing associated with alternative dressings and topical agents.

OBJECTIVES

To assess the effects of (1) dressings and (2) topical agents for healing venous leg ulcers in any care setting and to rank treatments in order of effectiveness, with assessment of uncertainty and evidence quality.

SEARCH METHODS

In March 2017 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also scanned reference lists of relevant included studies as well as reviews, meta-analyses, guidelines and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting. We updated this search in March 2018; as a result several studies are awaiting classification.

SELECTION CRITERIA

We included published or unpublished randomised controlled trials (RCTs) that enrolled adults with venous leg ulcers and compared the effects of at least one of the following interventions with any other intervention in the treatment of venous leg ulcers: any dressing, or any topical agent applied directly to an open venous leg ulcer and left in situ. We excluded from this review dressings attached to external devices such as negative pressure wound therapies, skin grafts, growth factors and other biological agents, larval therapy and treatments such as laser, heat or ultrasound. Studies were required to report complete wound healing to be eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, 'Risk of bias' assessment and data extraction. We conducted this NMA using frequentist meta-regression methods for the efficacy outcome; the probability of complete healing. We assumed that treatment effects were similar within dressings classes (e.g. hydrocolloid, foam). We present estimates of effect with their 95% confidence intervals (CIs) for individual treatments focusing on comparisons with widely used dressing classes, and we report ranking probabilities for each intervention (probability of being the best, second best, etc treatment). We assessed the certainty (quality) of the body of evidence using GRADE for each network comparison and for the network as whole.

MAIN RESULTS

We included 78 RCTs (7014 participants) in this review. Of these, 59 studies (5156 participants, 25 different interventions) were included in the NMA; resulting in 40 direct contrasts which informed 300 mixed-treatment contrasts.The evidence for the network as a whole was of low certainty. This judgement was based on the sparsity of the network leading to imprecision and the general high risk of bias in the included studies. Sensitivity analyses also demonstrated instability in key aspects of the network and results are reported for the extended sensitivity analysis. Evidence for individual contrasts was mainly judged to be low or very low certainty.The uncertainty was perpetuated when the results were considered by ranking the treatments in terms of the probability that they were the most effective for ulcer healing, with many treatments having similar, low, probabilities of being the best treatment. The two most highly-ranked treatments both had more than 50% probability of being the best (sucralfate and silver dressings). However, the data for sucralfate was from one small study, which means that this finding should be interpreted with caution. When exploring the data for silver and sucralfate compared with widely-used dressing classes, there was some evidence that silver dressings may increase the probability of venous leg ulcer healing, compared with nonadherent dressings: RR 2.43, 95% CI 1.58 to 3.74 (moderate-certainty evidence in the context of a low-certainty network). For all other combinations of these five interventions it was unclear whether the intervention increased the probability of healing; in each case this was low- or very low-certainty evidence as a consequence of one or more of imprecision, risk of bias and inconsistency.

AUTHORS' CONCLUSIONS

More research is needed to determine whether particular dressings or topical agents improve the probability of healing of venous leg ulcers. However, the NMA is uninformative regarding which interventions might best be included in a large trial, largely because of the low certainty of the whole network and of individual comparisons.The results of this NMA focus exclusively on complete healing; whilst this is of key importance to people living with venous leg ulcers, clinicians may wish to take into account other patient-important outcomes and factors such as patient preference and cost.

Platelet rich plasma and growth factors cocktails for diabetic foot ulcers treatment: State of art developments and future prospects

Current advances in diabetic foot ulcers (DFU) treatment are discussed. Normal and pathological wound healing process are observed and the role of growth factors (GFs) is elucidated. Current techniques involving GFs and platelet rich plasma (PRP) are compared. Up-to-date research suggests that treatment with single growth factor (GF) could be insufficient and not encompassing all pathological changes in DFU bed. Efficiency of PRP is rather controversial and lacks evidence. Thus the use of cocktail of particular GFs is suggested. Pro et contra of each approach are discussed.

Publicly Reported Wound Healing Rates: The Fantasy and the Reality

Significance: We compare real-world data from the U.S. Wound Registry (USWR) with randomized controlled trials and publicly reported wound outcomes and develop criteria for honest reporting of wound outcomes, a requirement of the new Quality Payment Program (QPP). Recent Advances: Because no method has existed by which wounds could be stratified according to their likelihood of healing among real-world patients, practitioners have reported fantastically high healing rates. The USWR has developed several risk-stratified wound healing quality measures for diabetic foot ulcers (DFUs) and venous leg ulcers (VLUs) as part of its Qualified Clinical Data Registry (QCDR). This allows practitioners to report DFU and VLU healing rates in comparison to the likelihood of whether the wound would have healed. Critical Issues: Under the new QPP, practitioners must report at least one practice-relevant outcome measure, and it must be risk adjusted so that clinicians caring for the sickest patients do not appear to have worse outcomes than their peers. The Wound Healing Index is a validated risk-stratification method that can predict whether a DFU or VLU will heal, leveling the playing field for outcome reporting and removing the need to artificially inflate healing rates. Wound care practitioners can report the USWR DFU and VLU risk-stratified outcome measure to satisfy the quality reporting requirements of the QPP. Future Directions: Per the requirements of the QPP, the USWR will begin publicly reporting of risk-stratified healing rates once quality measure data have met the reporting standards of the Centers for Medicare and Medicaid Services. Some basic rules for data censoring are proposed for public reporting of healing rates, and others are needed, which should be decided by consensus among the wound care community.

Mesenchymal stem cell in venous leg ulcer: An intoxicating therapy

Venous leg ulcers (VLU) are a prevalent and reoccurring type of complicated wound, turning as a considerable public healthcare issue, with critical social and economic concern. There are both medical and surgical therapies to treat venous leg ulcers; however, a cure does not yet exist. Mesenchymal stem cells (MSC) are capable and proved of accelerating wound healing in vivo and their study with human chronic wounds is currently awaited. MSCs are a promising source of adult progenitor cells for cellular therapy and have been demonstrated to differentiate into various mesenchymal cell lineages. They have a crucial and integral role in native wound healing by regulating immune response and inflammation. Improved understanding of the cellular and molecular mechanisms at work in delayed wound healing compels to the development of cellular therapy in VLU. This review focuses on the current treatment option of VLU and further emphasizing the role of MSCs in accelerating the healing process. With further understanding of the mechanism of action of these cells in wound improvement and, the involvement of cytokines can also be revealed that could be used for the therapeutic purpose for VLU healing. Clinical uses of MSCs have been started already, and induced MSCs are surely a promising tool or compelling therapy for VLU.

Innovative Therapies in Wound Healing

Background:

Apligraf is a bioengineered skin product composed of neonatal fibroblasts and keratinocytes. The FDA has approved Apligraf for the treatment of chronic venous ulcers and diabetic ulcers.

Objective:

We review the development of bioengineered skin, examine the cellular activities of various growth factors that may facilitate wound healing, and discuss the results of clinical trials with a particular construct, Apligraf, as proof of principle.

Conclusion:

Bioengineered skin acts as a “smart” delivery system for growth factors and other stimulatory substances. Not only does it present a novel treatment for chronic and diabetic ulcers, but it could also be considered for application to other types of acute wounds.

End points in dermatologic clinical trials: A review for clinicians

Clinical trials are critical for the development of new therapies in dermatology, and their results help determine US Food and Drug Administration (FDA) approval and guide care. Of special relevance is the clinical trial efficacy end point, the metric from which statistically significant outcome is derived. Clinicians' understanding of a clinical trial's end point is necessary for critical analysis of the trial results and for applying those results to daily practice. This review provides practical knowledge and critical evaluation of end points used in treatment approvals by the FDA. The end points for actinic keratosis, acne vulgaris, atopic dermatitis, onychomycosis, and cutaneous ulcer serve as examples.

Keratinocyte growth factor-2 inhibits bacterial infection with Pseudomonas aeruginosa pneumonia in a mouse model

To determine protective effects of concurrent administration of Keratinocyte growth factor-2 (KGF-2) with Pseudomonas aeruginosa (P. aeruginosa) inoculation on the induced pneumonia. KGF-2 (5 mg/kg) was concurrently administered into the left lobe of 55 mice with P. aeruginosa PAO1 (5 × 10(6) CFU, half-lethal dose); 55 mice in the control group were concurrently administered PBS with the PAO1. We detected and analyzed: body temperature; amount of P. aeruginosa in homogenates; count of total number of nucleated cells and of mononuclear macrophages; protein concentration in bronchoalveolar lavage fluid (BALF); lung wet-to-dry weight ratio; cytokines in BALF and blood; and lung morphology. To study survival rate, concurrent administration of KGF-2 (experimental group) versus PBS (control) with a lethal dose of PAO1 (1 × 10(7) CFU was performed, and survivorship was documented for 7 days post-inoculation. The bacterial CFU in lung homogenates was significantly decreased in the KGF-2 group compared to the control group. There were significantly more mononuclear macrophages in the BALF from the KGF-2 group than from the control group (p < 0.05). KGF-2 increased the surfactant protein and GM-CSF mRNA in lung at 6 h and 72 h after inoculation. Significant reduction of lung injury scores, protein concentrations, lung wet-to-dry weight ratio, and IL-6 and TNF-α levels was noted in the KGF-2 treated rats at 72 h after inoculation (p < 0.05). The 7-day survival rate of the KGF-2 group was significantly higher than that of the control group (p < 0.05). Concurrent administration of KGF-2 facilitates the clearance of P. aeruginosa from the lungs, attenuates P. aeruginosa-induced lung injury, and extends the 7-day survival rate in mice model with P. aeruginosa pneumonia.

Role of fibroblast growth factors in organ regeneration and repair

In its broad sense, regeneration refers to the renewal of lost cells, tissues or organs as part of the normal life cycle (skin, hair, endometrium etc.) or as part of an adaptive mechanism that organisms have developed throughout evolution. For example, worms, starfish and amphibians have developed remarkable regenerative capabilities allowing them to voluntarily shed body parts, in a process called autotomy, only to replace the lost parts afterwards. The bizarre myth of the fireproof homicidal salamander that can survive fire and poison apple trees has persisted until the 20th century. Salamanders possess one of the most robust regenerative machineries in vertebrates and attempting to draw lessons from limb regeneration in these animals and extrapolate the knowledge to mammals is a never-ending endeavor. Fibroblast growth factors are potent morphogens and mitogens that are highly conserved among the animal kingdom. These growth factors play key roles in organogenesis during embryonic development as well as homeostatic balance during postnatal life. In this review, we provide a summary about the current knowledge regarding the involvement of fibroblast growth factor signaling in organ regeneration and repair. We also shed light on the use of these growth factors in previous and current clinical trials in a wide array of human diseases.

Challenges in the Treatment of Chronic Wounds

Significance: Chronic wounds include, but are not limited, to diabetic foot ulcers, venous leg ulcers, and pressure ulcers. They are a challenge to wound care professionals and consume a great deal of healthcare resources around the globe. This review discusses the pathophysiology of complex chronic wounds and the means and modalities currently available to achieve healing in such patients. Recent Advances: Although often difficult to treat, an understanding of the underlying pathophysiology and specific attention toward managing these perturbations can often lead to successful healing. Critical Issues: Overcoming the factors that contribute to delayed healing are key components of a comprehensive approach to wound care and present the primary challenges to the treatment of chronic wounds. When wounds fail to achieve sufficient healing after 4 weeks of standard care, reassessment of underlying pathology and consideration of the need for advanced therapeutic agents should be undertaken. However, selection of an appropriate therapy is often not evidence based. Future Directions: Basic tenets of care need to be routinely followed, and a systematic evaluation of patients and their wounds will also facilitate appropriate care. Underlying pathologies, which result in the failure of these wounds to heal, differ among various types of chronic wounds. A better understanding of the differences between various types of chronic wounds at the molecular and cellular levels should improve our treatment approaches, leading to better healing rates, and facilitate the development of new more effective therapies. More evidence for the efficacy of current and future advanced wound therapies is required for their appropriate use.

Wound management of chronic diabetic foot ulcers: from the basics to regenerative medicine

BACKGROUND

Hospital-based studies have shown that mortality rates in individuals with diabetic foot ulcers are about twice those observed in individuals with diabetes without foot ulcers.

OBJECTIVE

To assess the etiology and management of chronic diabetic foot ulcers.

STUDY DESIGN

Literature review.

METHODS

Systematic review of the literature discussing management of diabetic foot ulcers. Since there were only a few randomized controlled trials on this topic, articles were selected to attempt to be comprehensive rather than a formal assessment of study quality.

RESULTS

Chronic nonhealing foot ulcers occur in approximately 15% of patients with diabetes. Many factors contribute to impaired diabetic wound healing. Risk factors include peripheral neuropathy, peripheral arterial disease, limited joint mobility, foot deformities, abnormal foot pressures, minor trauma, a history of ulceration or amputation, and impaired visual acuity. With the current treatment for nonhealing diabetic foot ulcers, a significant number of patients require amputation.

CONCLUSION

Diabetic foot ulcers are optimally managed by a multidisciplinary integrated team. Offloading and preventative management are important. Dressings play an adjunctive role. There is a critical need to develop novel treatments to improve healing of diabetic foot ulcers. The goal is to have wounds heal and remain healed.

CLINICAL RELEVANCE

Diabetic neuropathy and peripheral arterial disease are major factors involved in a diabetic foot ulcer. Despite current treatment modalities for nonhealing diabetic foot ulcers, there are a significant number of patients who require amputations. No known therapy will be effective without concomitant management of ischemia, infection, and adequate offloading.

Clinical application of growth factors and cytokines in wound healing

Wound healing is a complex and dynamic biological process that involves the coordinated efforts of multiple cell types and is executed and regulated by numerous growth factors and cytokines. There has been a drive in the past two decades to study the therapeutic effects of various growth factors in the clinical management of nonhealing wounds (e.g., pressure ulcers, chronic venous ulcers, diabetic foot ulcers). For this review, we conducted an online search of Medline/PubMed and critically analyzed the literature regarding the role of growth factors and cytokines in the management of these wounds. We focused on currently approved therapies, emerging therapies, and future research possibilities. In this review, we discuss four growth factors and cytokines currently being used on and off label for the healing of wounds. These include granulocyte-macrophage colony-stimulating factor, platelet-derived growth factor, vascular endothelial growth factor, and basic fibroblast growth factor. While the clinical results of using growth factors and cytokines are encouraging, many studies involved a small sample size and are disparate in measured endpoints. Therefore, further research is required to provide definitive evidence of efficacy.

Growth factor therapy in patients with partial-thickness burns: a systematic review and meta-analysis

Growth factor (GF) therapy has shown promise in treating a variety of refractory wounds. However, evidence supporting its routine use in burn injury remains uncertain. We performed this systematic review and meta-analysis assessing randomised controlled trials (RCTs) to investigate efficacy and safety of GFs in the management of partial-thickness burns. Electronic searches were conducted in PubMed and the Cochrane databases. Endpoint results analysed included wound healing and scar formation. Thirteen studies comprising a total of 1924 participants with 2130 wounds (1131 GF receiving patients versus 999 controls) were identified and included, evaluating the effect of fibroblast growth factor (FGF), epidermal growth factor (EGF) and granulocyte macrophage-colony stimulating factor (GM-CSF) on partial-thickness burns. Topical application of these agents significantly reduced healing time by 5·02 (95% confidence interval, 2·62 to 7·42), 3·12 (95% CI, 1·11 to 5·13) and 5·1 (95% CI, 4·02 to 6·18) days, respectively, compared with standard wound care alone. In addition, scar improvement following therapy with FGF and EGF was evident in terms of pigmentation, pliability, height and vascularity. No significant increase in adverse events was observed in patients receiving GFs. These results suggested that GF therapy could be an effective and safe add-on to standard wound care for partial-thickness burns. High-quality, adequately powered trials are needed to further confirm the conclusion.

Which dressings reduce inflammation and improve venous leg ulcer healing

Chronic venous leg ulcers (VLU) affect around 1% of the adult population in the Western world. The impact of VLU is both social and economic, with significant expenditures on active venous ulcers to provide medical treatment and eventual healing. At the core of VLU is venous hypertension which affects the venous macrocirculation. The changes incurred in venous hemodynamics leads to microcirculatory changes affecting the postcapillary venule and surrounding tissues. Inflammation by leukocytes affecting the venous endothelium, promotes a complex cascade and activation of adhesion molecules expression, chemokines and cytokines released, altered growth factor responses, and activation of protease (e.g. tPA) and proteinase (e.g. MMPs) activity that causes dysregulation and compromise of tissue integrity with eventual dermal damage and ulcer development. A critical component to treating VLU is correcting the abnormal venous hemodynamics and compression therapy. Unfortunately, VLU recurrence ranges between 30–70%, and other modalities in therapy along with compression are required. The goal for adjuvant products is to restore the balance from an inflammatory chronic wound to that of a reparative wound that will promote provisional matrix and epithelialization. There are many products on the market that can be used as adjuvant to compression therapy, but it must be recognized that there is a paucity of clinical trials that have evaluated the clinical effectiveness of specific products with clearly defined end points, and most importantly a healed VLU with a low recurrence rate. This review will discuss the fundamentals of VLU inflammation, and evaluate the available literature that may have benefit in reducing inflammation and lead to effective VLU healing.

Food and Drug Administration (FDA) drug approval end points for chronic cutaneous ulcer studies

The rising costs of caring for chronic cutaneous ulcers (CCUs) and recent appreciation of the mortality of CCUs have led to consideration of the reasons for the failure to have new drug therapies. No new chemical entities to heal CCUs have been approved by the Food and Drug Administration (FDA) in over a decade, in part due to an inability to reach the FDA accepted end point of "complete wound closure." The frequent failure to reach the complete closure end point brings forward the question of the relevance of other healing end points such as improved quality of life, or partial healing. Because CCUs carry a prognosis and mortality rate worse than many cancers, it is reasonable to compare the FDA trial end points for cancer drug approval with those for CCUs. And the difference is quite striking. While there is only one end point for CCUs, there are five surrogate and three direct end points for cancers. In contrast to cancer, surrogate end points and partial healing are not acceptable for therapies aimed at CCUs. For example, making tumors smaller is an acceptable end point, but making CCUs smaller is not and improvement in the signs and symptoms of cancer is an acceptable end point for cancers but not CCUs. As CCUs carry a prognosis and mortality rate worse than many cancers, we believe a reconsideration of end points for CCUs is highly warranted.

Chronic wounds - is cellular 'reception' at fault? Examining integrins and intracellular signalling

As with all physiologic processes, chronic wounds are associated with unique intracellular and cellular/extracellular matrix (ECM) receptor types and signalling messages. These cellular receptors mediate responses of the epidermis to provisional wound matrix and change in form and number in cases of impaired wound healing. Integrins are the major cell-surface receptors for cell adhesion and migration and epidermal keratinocytes express several integrins that bind ECM ligands in provisional wound ECM. Integrin receptors and more particularly integrin clusters and focal adhesion points appear to influence epidermal and dermal cell matrix interactions, cell motility, cell phenotype and ultimate healing trajectory. In chronic wounds, a variety of changes in receptors have been identified: decreased integrin α5β1 receptors affect the integration of fibronectin and subsequent keratinocyte migration; integrin αvβ6 stimulate transforming growth factor (TGF)-β and may increase the susceptibility to ulceration and fibrosis; however, TGF-β signal receptors have been found to be dysfunctional in many chronic wounds; additionally receptor interactions result in increased senescent cells including fibroblasts, myofibroblasts and even keratinocytes - this produces a degradative ECM and wound bed and corrosive chronic wound fluid. The activation or inhibition of integrin receptors by various agents may provide an excellent means of influencing wound healing. This process offers an earlier intervention into the wound healing cascade promoting intrinsic healing and elaboration of growth factors and ECM proteins, which may be more cost effective than the traditional attempts at extrinsic addition of these agents.

Fgf10 overexpression enhances the formation of tissue-engineered small intestine

Short bowel syndrome (SBS) is a morbid and mortal condition characterized in most patients by insufficient intestinal surface area. Current management strategies are inadequate, but tissue-engineered small intestine (TESI) offers a potential therapy. A barrier to translation of TESI is the generation of scalable mucosal surface area to significantly increase nutritional absorption. Fibroblast growth factor 10 (Fgf10) is a critical growth factor essential for the development of the gastrointestinal tract. We hypothesized that overexpression of Fgf10 would improve the generation of TESI. Organoid units, the multicellular donor tissue that forms TESI, were derived from Rosa26(rtTA/+), tet(o)Fgf10/(-) or Fgf10(Mlc-nlacZ-v24) (hereafter called Fgf10(lacZ)) mice. These were implanted into the omentum of NOD/SCID γ-chain-deficient mice and induced with doxycycline in the case of tet(o)Fgf10/(-). Resulting TESI were explanted at 4 weeks and studied by histology, quantitative RT-PCR and immunofluorescence. Four weeks after implantation, Fgf10 overexpressing TESI was larger and weighed more than the control tissues. Within the mucosa, the villus height was significantly longer and crypts contained a greater percentage of proliferating epithelial cells. A fully differentiated intestinal epithelium with enterocytes, goblet cells, enteroendocrine cells and Paneth cells was identified in the Fgf10-overexpressing TESI, comparable to native small intestine. β-Galactosidase expression was found in both the epithelium and the mesenchyme of the TESI derived from the Fgf10(LacZ) duodenum. However, this was not the case with TESI generated from jejunum and ileum. We conclude that Fgf10 enhances the formation of TESI.

Wound bed preparation for chronic diabetic foot ulcers

The escalating incidence of diabetic mellitus has given rise to the increasing problems of chronic diabetic ulcers that confront the practice of medicine. Peripheral vascular disease, neuropathy, and infection contribute to the multifactorial pathogenesis of diabetic ulcers. Approaches to the management of diabetic ulcers should start with an assessment and optimization of the patient's general conditions, followed by considerations of the local and regional factors. This paper aims to address the management strategies for wound bed preparation in chronic diabetic foot ulcers and also emphasizes the importance of preventive measures and future directions. The “TIME” framework in wound bed preparation encompasses tissue management, inflammation and infection control, moisture balance, and epithelial (edge) advancement. Tissue management aims to remove the necrotic tissue burden via various methods of debridement. Infection and inflammation control restores bacterial balance with the reduction of bacterial biofilms. Achieving a moist wound healing environment without excessive wound moisture or dryness will result in moisture balance. Epithelial advancement is promoted via removing the physical and biochemical barriers for migration of epithelium from wound edges. These systematic and holistic approaches will potentiate the healing abilities of the chronic diabetic ulcers, including those that are recalcitrant.

Innovative approaches in wound healing: trajectory and advances

Wound is one of the oldest suffering associated with the mankind and its history is as old as humanity. Advances in the field of medical sciences created a pile of knowledge and paved the path for the development of a separate branch specifically devoted for wound healing. The understanding and treatment strategies for wound healing have gone through a great revolution. This article reviews all the aspects of wound healing including the pathway, types and recent advances made in the wound care management in particular moist wound dressings using natural polymers, skin grafts, debridement, growth factor and drug delivery.

Acute and impaired wound healing: pathophysiology and current methods for drug delivery, part 2: role of growth factors in normal and pathological wound healing: therapeutic potential and methods of delivery

This is the second of 2 articles that discuss the biology and pathophysiology of wound healing, reviewing the role that growth factors play in this process and describing the current methods for growth factor delivery into the wound bed.

Wound bed preparation from a clinical perspective

Wound bed preparation has been performed for over two decades, and the concept is well accepted. The ‘TIME’ acronym, consisting of tissue debridement, infection or inflammation, moisture balance and edge effect, has assisted clinicians systematically in wound assessment and management. While the focus has usually been concentrated around the wound, the evolving concept of wound bed preparation promotes the treatment of the patient as a whole. This article discusses wound bed preparation and its clinical management components along with the principles of advanced wound care management at the present time. Management of tissue necrosis can be tailored according to the wound and local expertise. It ranges from simple to modern techniques like wet to dry dressing, enzymatic, biological and surgical debridement. Restoration of the bacterial balance is also an important element in managing chronic wounds that are critically colonized. Achieving a balance moist wound will hasten healing and correct biochemical imbalance by removing the excessive enzymes and growth factors. This can be achieved will multitude of dressing materials. The negative pressure wound therapy being one of the great breakthroughs. The progress and understanding on scientific basis of the wound bed preparation over the last two decades are discussed further in this article in the clinical perspectives.

Potential clinical application of KGF-2 (FGF-10) for acute lung injury/acute respiratory distress syndrome

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is an acute life-threatening form of hypoxemic respiratory failure with a high mortality rate, and there is still a great need for more effective therapies for such a severe and lethal disease. Dysfunction of endothelial and epithelial barriers is one of the most important mechanisms in hypoxia-associated ALI/ARDS. The acceleration of the epithelial repair process in the injured lung may provide an effective therapeutic target. KGF-2, a potent alveolar epithelial cell mitogen, plays an important role in organ morphogenesis and epithelial differentiation, and modulates a variety of mechanisms recognized to be important in alveolar repair and resolution in ALI/ARDS. Preclinical and clinical studies have suggested that KGF-2 may be the candidate of novel therapies for alveolar epithelial damage during ALI/ARDS.

[Hydroactive stage-adapted wound management]

The treatment of subacute and chronic wounds is not only a major medical challenge but because of demographic developments and the concurrent increase in predisposing diseases, such as diabetes mellitus and arterial occlusive disease is also a relevant socioeconomic challenge. The principle of modern, moist wound care can now be regarded as established. In daily practice there are nevertheless significant treatment problems which are, among other things due to the vast variety of products available. As evidence-based guidelines for the treatment of chronic wounds were until recently lacking and many question were left unanswered, standards of care represent an appropriate means of orientation. In addition to improved quality of care in this way costs can also be reduced. Furthermore, criteria can be illustrated by which the selection of appropriate wound dressings can be facilitated and established.

The vascular endothelial growth factor (VEGF)-E encoded by orf virus regulates keratinocyte proliferation and migration and promotes epidermal regeneration

Vascular endothelial growth factor (VEGF)-A, a key regulator of cutaneous blood vessel formation, appears to have an additional role during wound healing, enhancing re-epithelialization. Orf virus, a zoonotic parapoxvirus, induces proliferative skin lesions that initiate in wounds and are characterized by extensive blood vessel formation, epidermal hyperplasia and rete ridge formation. The vascular changes beneath the lesion are largely due to viral-expressed VEGF-E. This study investigated using mouse skin models whether VEGF-E can induce epidermal changes such as that seen in the viral lesion. Injection of VEGF-E into normal skin increased the number of endothelial cells and blood vessels within the dermis and increased epidermal thickening and keratinocyte number. Injection of VEGF-E into wounded skin, which more closely mimics orf virus lesions, increased neo-epidermal thickness and area, promoted rete ridge formation, and enhanced wound re-epithelialization. Quantitative RT-PCR analysis showed that VEGF-E did not induce expression of epidermal-specific growth factors within the wound, but did increase matrix metalloproteinase (MMP)-2 and MMP-9 expression. In cell-based assays, VEGF-E induced keratinocyte migration and proliferation, responses that were inhibited by a neutralizing antibody against VEGF receptor (VEGFR)-2. These findings demonstrate that VEGF-E, both directly and indirectly, regulates keratinocyte function, thereby promoting epidermal regeneration.

Sugar-coating wound repair: a review of FGF-10 and dermatan sulfate in wound healing and their potential application in burn wounds

Thousands of patients suffer from burn injuries each year, yet few therapies have been developed to accelerate the wound healing process. Most fibroblast growth factors (FGFs) have been extensively evaluated but only a few have been found to participate in the wound healing process. In particular, FGF-10 is robustly increased in the wound microenvironment after injury and has demonstrated some ability to promote wound healing in vitro and in vivo. Glycosaminoglycans are linear carbohydrates that participate in wound repair by influencing cytokine/growth factor localization and interaction with cognate receptors. Dermatan sulfate (DS) is the most abundant glycosaminoglycan in human wound fluid and has been postulated to be directly involved in the healing process. Recently, the combination of FGF-10 and DS demonstrated the potential to accelerate wound healing via increased keratinocyte proliferation and migration. Based on these preliminary studies, DS may serve as a cofactor for FGF-10, and together they are likely to expedite the healing process by stimulating keratinocyte activity. As a specific subtype of wounds, the overall healing process of burn injuries does not significantly differ from other types of wounds, where optimal repair results in matrix regeneration and complete reepithelialization. At present, standard burn treatment primarily involves topical application of antimicrobial agents, while no routine therapies target acceleration of reepithelialization, the key to wound closure. Thus, this novel therapeutic combination could be used in conjunction with some of the current therapies, but it would have the unique ability to initiate wound healing by stimulating keratinocyte epithelialization.

Engineering the growth factor microenvironment with fibronectin domains to promote wound and bone tissue healing

Although growth factors naturally exert their morphogenetic influences within the context of the extracellular matrix microenvironment, the interactions among growth factors, their receptors, and other extracellular matrix components are typically ignored in clinical delivery of growth factors. We present an approach for engineering the cellular microenvironment to greatly accentuate the effects of vascular endothelial growth factor-A (VEGF-A) and platelet-derived growth factor-BB (PDGF-BB) for skin repair, and of bone morphogenetic protein-2 (BMP-2) and PDGF-BB for bone repair. A multifunctional recombinant fragment of fibronectin (FN) was engineered to comprise (i) a factor XIIIa substrate fibrin-binding sequence, (ii) the 9th to 10th type III FN repeat (FN III9-10) containing the major integrin-binding domain, and (iii) the 12th to 14th type III FN repeat (FN III12-14), which binds growth factors promiscuously, including VEGF-A165, PDGF-BB, and BMP-2. We show potent synergistic signaling and morphogenesis between α5β1 integrin and the growth factor receptors, but only when FN III9-10 and FN III12-14 are proximally presented in the same polypeptide chain (FN III9-10/12-14). The multifunctional FN III9-10/12-14 greatly enhanced the regenerative effects of the growth factors in vivo in a diabetic mouse model of chronic wounds (primarily through an angiogenic mechanism) and in a rat model of critical-size bone defects (through a mesenchymal stem cell recruitment mechanism) at doses where the growth factors delivered within fibrin only had no significant effects.

Human pilot studies reveal the potential of a vitronectin: growth factor complex as a treatment for chronic wounds

Several different advanced treatments have been used to improve healing in chronic wounds, but none have shown sustained success. The application of topical growth factors (GFs) has displayed some potential, but the varying results, high doses and high costs have limited their widespread adoption. Many treatments have ignored the evidence that wound healing is driven by interactions between extracellular matrix proteins and GFs, not just GFs alone. We report herein that a clinical Good Manufacturing Practice-grade vitronectin:growth factor (cVN:GF) complex is able to stimulate functions relevant to wound repair in vitro, such as enhanced cellular proliferation and migration. Furthermore, we assessed this complex as a topical wound healing agent in a single-arm pilot study using venous leg ulcers, as well as several 'difficult to heal' case studies. The cVN:GF complex was safe and re-epithelialisation was observed in all but 1 of the 30 patients in the pilot study. In addition, the case studies show that this complex may be applied to several ulcer aetiologies, such as venous leg ulcers, diabetic foot ulcers and pressure ulcers. These findings suggest that further evaluation is warranted to determine whether the cVN:GF complex may be an effective topical treatment for chronic wounds.