Optimizing Wound Bed Preparation With Collagenase Enzymatic Debridement

The effect of inflammation management on pH, temperature, and bacterial burden

The aim of this feasibility study was to investigate the impact of inflammation management on wound pH, temperature, and bacterial burden, using the principles of TIME and Wound Bed Preparation. A quantitative non-comparative, prospective, descriptive observational design. Following ethical approval, 26 participants with 27 wounds of varying aetiologies were observed twice weekly for 2 weeks. Wounds were treated with cleansing, repeated sharp debridement, and topical cadexomer iodine. Wound pH (pH indicator strips), temperature (infrared camera), bacterial burden (fluorescence imaging) and size (ruler method) was monitored at each visit. The mean age of all participants was 47 years (SD: 20.3 years), and 79% (n = 19) were male, and most wounds were acute (70%; n = 19) and included surgical and trauma wounds, the remaining (30%; n = 8) were chronic and included vascular ulcers and non-healing surgical wounds. Mean wound duration was 53.88 days (SD: 64.49 days). Over the follow up period, pH values ranged from 6 to 8.7, temperature (centre spot) ranged from 28.4°C to 36.4°C and there was an average 39% reduction in wound size. Inflammation management had a positive effect on pH, temperature, bacterial burden, and wound size. This study demonstrated that it was feasible to practice inflammation management using a structured approach to enhance wound outcomes.

Perspective: The viscoelastic properties of biofilm infections and mechanical interactions with phagocytic immune cells

Biofilms are viscoelastic materials that are a prominent public health problem and a cause of most chronic bacterial infections, in large part due to their resistance to clearance by the immune system. Viscoelastic materials combine both solid-like and fluid-like mechanics, and the viscoelastic properties of biofilms are an emergent property of the intercellular cohesion characterizing the biofilm state (planktonic bacteria do not have an equivalent property). However, how the mechanical properties of biofilms are related to the recalcitrant disease that they cause, specifically to their resistance to phagocytic clearance by the immune system, remains almost entirely unstudied. We believe this is an important gap that is ripe for a large range of investigations. Here we present an overview of what is known about biofilm infections and their interactions with the immune system, biofilm mechanics and their potential relationship with phagocytosis, and we give an illustrative example of one important biofilm-pathogen (Pseudomonas aeruginosa) which is the most-studied in this context. We hope to inspire investment and growth in this relatively-untapped field of research, which has the potential to reveal mechanical properties of biofilms as targets for therapeutics meant to enhance the efficacy of the immune system.

Skin grafting treatment of adolescent lower limb avulsion injury

Background

Under the influence of various factors, the number of lower extremity avulsion injuries in adolescents is increasing year by year. The main modality of treatment is skin grafting. There are many types of skin grafting. Although many studies on skin grafting after avulsion injuries have been published in the past few decades, there are differences in the treatment options for adolescents with post avulsion injuries.

Main body

Thorough debridement and appropriate skin grafts are essential for the surgical management of avulsion injuries for optimal prognosis. In the acquisition of grafts, progress has been made in equipment for how to obtain different depths of skin. The severity of the avulsion injury varies among patients on admission, and therefore the manner and type of skin grafting will vary. Especially in adolescents, graft survival and functional recovery are of great concern to both patients and physicians. Therefore, many efforts have been made to improve survival rate and activity.

Conclusion

This review summarizes the principles of treatment of avulsion injuries, the historical development of skin grafts, and the selection of skin grafts, hoping to be helpful for future research.

Clinical outcome of multidisciplinary treatment of vulvar necrotising fasciitis

OBJECTIVE

Vulvar necrotising fasciitis (VNF) is a severe soft tissue infection associated with substantial morbidity and high mortality. At Stony Brook Medicine, US, patients with known or suspected VNF are treated by a structured multidisciplinary team consisting of members of the Departments of Emergency Medicine and Medicine, the Divisions of Gynecologic Oncology, Burn and Surgical Intensive Care Units, Infectious Disease and Plastic Surgery, and the nursing, nutrition, physical/occupational therapy and social work services.

METHOD

This is a retrospective review of patients presenting to Stony Brook University Hospital with VNF over an 18-month period.

RESULTS

A total of 10 patients were treated for VNF during the study period. All patients were treated by the structured multidisciplinary team, including extensive initial surgical debridement by the gynaecologic oncologists. All patients survived to discharge.

CONCLUSION

The results of this review demonstrated that prompt diagnosis, rapid implementation of appropriate antibiotic coverage, surgical debridement of necrotic tissue, and comprehensive care delivered by a structured multidisciplinary team contributed to positive clinical outcomes and decreased the risk of death from VNF.

Hyaluronic Acid/Collagenase Ointment in the Treatment of Chronic Hard-to-Heal Wounds: An Observational and Retrospective Study

Background: Wound bed preparation is an important concept in clinical practice and is related to adequate debridement. The use of proteolytic enzymes is an established method of enzymatic wound debridement, especially in hard-to-heal ulcers that are unresponsive to normal healing procedures and progress. The TIME framework (tissue, inflammation/infection, moisture balance, and edge of wound) offers an appropriate strategy to eliminate resistance to healing, as well as maximizing the healing process. Maintenance debridement, as opposed to sporadic debridement, may be proposed in preserving an adequate wound bed towards complete recovery. Collagenase has been effective in debridement due to its ability to degrade collagen and elastin. In this clinical context, collagenase taken from Vibrio alginolitycus is the most favorably expressed enzymatic debriding agent. Methods: This retrospective observational study evaluates the efficacy of an ointment based on hyaluronic acid and collagenase (Bionect Start^®), considering a reduced healing time and greater healing quality. We included 70 patients with chronic wounds of different etiologies, including diabetes mellitus (20), post-traumatic ulcers (35), chronic burns of degrees I and II (10), and pressure ulcers (5). We analyzed wound characteristics using the wound bed score (WBS) concept, healing time, as well as operator and patient satisfaction. Results: Frequency of debridement efficacy in terms of wound bed cleansing varied from 26% after 2 weeks to 93% after 4 weeks. We observed complete healing in 62 patients within an eight-week period. The overall operator and patient satisfaction after 8 weeks were 100% and 90%, respectively. Moreover, all patients reported less pain. Conclusions: A combined action of hyaluronic acid and collagenase ointment demonstrated a reduction in healing time while improving healing quality, with a decrease in pain.

[Collagen-based biological dressings in the treatment of chronic wounds in diabetic foot syndrome]

One of the end-organs of diabetes mellitus (DM) is the skin. Cellular and molecular disorders occurring in the skin due to chronic hyperglycemia, neuropathy, and micro- and macroangiopathy lead to poor-heling foot wounds in patients with diabetes. Consequently, treating wounds in diabetic foot syndrome (DFS) is prolonged, costly, and often ineffective. The research on wound healing and treating wounds in DM with stricter adherence to international guidelines and technological breakthroughs in developing biological materials provide new therapeutic opportunities to solve wound care problems. Collagen is one of the body's many proteins, essential throughout the healing phases for skin repair and remodeling. Collagen is one of the body's many proteins, essential throughout the healing phases for skin repair and remodeling. The article addresses the features of biological dressings based on the lyophilized native triple-helix (non-hydrolyzed) collagen formulation. Also, we present clinical cases of their use in different phases of wound healing in DM.

The effects of Brazilian chitosan-based biomaterials on wound healing in rats

The use of natural supplies is a resource to mimic an original extracellular matrix that allows for migration, proliferation, and cellular organization. Chitosan from Brazilian Atlantic Ocean had low protein, minerals percentage and excellent antibacterial activity. The aim of this study was to evaluate and to compare the effectiveness of different types of acids as solvents with Brazilian chitosan-membrane in the healing process of skin lesions. Experimental full-thickness 2 × 2 cm wounds were created on the dorsum skin of Wistar rats. The applied different treatments were saline, collagenase®, microcrystalline chitosan salt membrane (MCSM), microcrystalline chitosan acetic acid membrane (MCAAM), and microcrystalline chitosan hydrochloric acid membrane (MCHAM). The wound repairs were measured morphologically and histologically on days 0, 3, 7, 10, and 14. The exudate formation and the final wound contractions were similar in all of the groups. There were mild exudations in the groups with chitosan-membranes, despite the formation of crust under the membrane. This configured a serum hematic aspect, but there was no impact on the healing process. The MCHAM group had more favorable aspects that histologically showed the healing phases. A significant migration of neutrophils and macrophages seen by myeloperoxidade and Beta-N-Acetylglucosaminidase activities was evident in the chitosan groups, MCHAM and MCSM, respectively. Furthermore, the MCHAM group created its histological arrangement in a dense and more consistent manner.

Vacuum sealing drainage with instillation in the treatment of necrotising soft-tissue infection: a retrospective analysis

Objective:

Necrotising soft-tissue infection is a rare but life-threatening infectious disease with high morbidity and mortality. It is typically caused by toxin-producing bacteria and characterised clinically by a very rapid progression of the disease with significant local tissue destruction. In this study, we intend to explore effective wound management to control the invasive infection and to decrease the high mortality.

Method:

This retrospective analysis explored the wound management and mortality in patients with necrotising soft-tissue infection. Extensive debridement, vacuum sealing drainage (VSD) with normal saline instillation combined with broad-spectrum or sensitive antibiotics, and supportive therapies were used.

Results:

All 17 patients included in the analysis survived. The microbiology of 11 patients was found to be polymicrobial. Of the patients, 14 were discharged with completely healed wounds and three were transferred to a local hospital after the systemic and invasive wound infection was controlled.

Conclusion:

Our experiences revealed the outstanding effect of VSD with instillation in removing the debris of necrotising tissue on the wound bed, in the continual and complete drainage of wound exudates, and in prompting wound healing.

Enzymatic Debridement of Porcine Burn Wounds via a Novel Protease, SN514

Necrotic tissue generated by a thermal injury is typically removed via surgical debridement. However, this procedure is commonly associated with blood loss and the removal of viable healthy tissue. For some patients and contexts such as extended care on the battlefield, it would be preferable to remove devitalized tissue with a nonsurgical debridement agent. In this paper, a proprietary debridement gel (SN514) was evaluated for the ability to debride both deep-partial thickness (DPT) and full-thickness burn wounds using an established porcine thermal injury model. Burn wounds were treated daily for 4 days and visualized with both digital imaging and laser speckle imaging. Strip biopsies were taken at the end of the procedure. Histological analyses confirmed a greater debridement of the porcine burn wounds by SN514 than the vehicle-treated controls. Laser speckle imaging detected significant increases in the perfusion status after 4 days of SN514 treatment on DPT wounds. Importantly, histological analyses and clinical observations suggest that SN514 gel treatment did not damage uninjured tissue as no edema, erythema, or inflammation was observed on intact skin surrounding the treated wounds. A blinded evaluation of the digital images by a burn surgeon indicated that SN514 debrided more necrotic tissue than the control groups after 1, 2, and 3 days of treatment. Additionally, SN514 gel was evaluated using an in vitro burn model that used human discarded skin. Treatment of human burned tissue with SN514 gel resulted in greater than 80% weight reduction compared with untreated samples. Together, these data demonstrate that SN514 gel is capable of debriding necrotic tissue and suggest that SN514 gel could be a useful option for austere conditions, such as military multi-domain operations and prolonged field care scenarios.

Crustacean Proteases and Their Application in Debridement

Digestive proteases from marine organisms have been poorly applied to biomedicine. Exceptions are trypsin and other digestive proteases from a few cold-adapted or temperate fish and crustacean species. These enzymes are more efficient than enzymes from microorganism and higher vertebrates that have been used traditionally. However, the biomedical potential of digestive proteases from warm environment species has received less research attention. This review aims to provide an overview of this unrealised biomedical potential, using the debridement application as a paradigm. Debridement is intended to remove nonviable, necrotic and contaminated tissue, as well as fibrin clots, and is a key step in wound treatment. We discuss the physiological role of enzymes in wound healing, the use of exogenous enzymes in debridement, and the limitations of cold-adapted enzymes such as their poor thermal stability. We show that digestive proteases from tropical crustaceans may have advantages over their cold-adapted counterparts for this and similar uses. Differences in thermal stability, auto-proteolytic stability, and susceptibility to proteinase inhibitors are discussed. Furthermore, it is proposed that the feeding behaviour of the source organism may direct the evaluation of enzymes for particular applications, as digestive proteases have evolved to fill a wide variety of feeding habitats, natural substrates, and environmental conditions. We encourage more research on the biomedical application of digestive enzymes from tropical marine crustaceans.

Traditional and advanced therapeutic modalities for wounds in the paediatric population: an evidence-based review

OBJECTIVE

Children can have non-healing wounds due to a wide range of pathologies, including epidermolysis bullosa (EB), pilonidal disease and Stevens-Johnson syndrome, with some causes being iatrogenic, including extravasation injuries and medical device-related hospital-acquired pressure ulcers. Furthermore, paediatric wounds are vastly different from adult wounds and therefore require a different treatment approach. While there are numerous types of dressings, topical remedies, and matrices with high-tier evidence to support their use in adults, evidence is scarce in the neonatal and paediatric age groups. The purpose of this review is to discuss the basic principles in paediatric wound management, as well as to present new treatment findings published in the literature to date. The benefits and risks of using different types of debridement are discussed in this review. Various topical formulations are also described, including the need to use antibiotics judiciously.

METHOD

Databases were searched for relevant sources including Pubmed, Embase, Web of Science and DynaMed. Search terms used included 'wound care', 'wound management', 'paediatrics', 'children', 'skin substitutes', and 'grafts'. Additionally, each treatment and disease entity was searched for relevant sources, including, for example: 'Apligraf', 'dermagraft', 'Manuka honey', 'antibiotic', 'timolol', and 'negative pressure wound therapy' (NPWT).

RESULTS

Amniotic membrane living skin equivalent is a cellular matrix that has been reportedly successful in treating paediatrics wounds and is currently under investigation in randomised clinical trials. Helicoll is an acellular matrix, which shows promise in children with recessive dystrophic EB. NPWT may be used as a tool to accelerate wound closure in children; however, caution must be taken due to limited evidence to support its safety and efficacy in the paediatric patient population. Integra has been reported as a useful adjunctive treatment to NPWT as both may act synergistically. Hospitalised children and neonates frequently have pressure ulcers, which is why prevention in this type of wound is paramount.

CONCLUSION

Advancements in wound care are rapidly expanding. Various treatments for non-healing wounds in paediatric and neonatal patients have been reported, but high tier evidence in these populations is scarce. We hope to shed light on existing evidence regarding the different therapeutic modalities, from debridement techniques and dressing types to tissue substitutes and topical remedies. There have been promising results in many studies to date, but RCTs involving larger sample sizes are necessary, in order to determine the specific role these innovative agents play in paediatric wounds and to identify true safety and efficacy.

Collagenolytic Enzymes and their Applications in Biomedicine

Nowadays, enzymatic therapy is a very promising line of treatment for many different diseases. There is a group of disorders and conditions, caused by fibrotic and scar processes and associated with the excessive accumulation of collagen that needs to be catabolized to normalize the connective tissue content. The human body normally synthesizes special extracellular enzymes, matrix metalloproteases (MMPs) by itself. These enzymes can cleave components of extracellular matrix (ECM) and different types of collagen and thus maintain the balance of the connective tissue components. MMPs are multifunctional enzymes and are involved in a variety of organism processes. However, under pathological conditions, the function of MMPs is not sufficient, and these enzymes fail to deal with disease. Thus, medical intervention is required. Enzymatic therapy is a very effective way of treating such collagen-associated conditions. It involves the application of exogenous collagenolytic enzymes that catabolize excessive collagen at the affected site and lead to the successful elimination of disease. Such collagenolytic enzymes are synthesized by many organisms: bacteria, animals (especially marine organisms), plants and fungi. The most studied and commercially available are collagenases from Clostridium histolyticum and from the pancreas of the crab Paralithodes camtschatica, due to their ability to effectively hydrolyse human collagen without affecting other tissues, and their wide pH ranges of collagenolytic activity. In the present review, we summarize not only the data concerning existing collagenase-based medications and their applications in different collagen-related diseases and conditions, but we also propose collagenases from different sources for their potential application in enzymatic therapy.

Fundamental aspects of the local approach to cutaneous ulcers

Ulcers or wounds can be classified as acute or chronic. Their treatment involves overall assessment of the patient and choice of suitable local therapy, and the appropriate indication and use of products. Technological progress in the field of wound treatment has increased rapidly. Constant updating, with emphasis on available scientific evidence, is necessary to offer the best approaches to patients with acute and chronic wounds. A qualitative analysis of literature was conducted to identify scientific publications that update the concepts involved in local wound treatment, to present some resources that can aid the healing process and describe the different types of dressings available. This review includes wound assessment using the acronym TIME (tissue, infection/inflammation, moisture balance and edge of wound), cleaning and debridement, infection/inflammation control, exudate control, dressing types and main indications.

Effect of collagenase ointment versus moist exposed burn ointment on healing of full-thickness burns in mice by removing of necrotic tissue

The presence of necrotic tissue is one of the major problems that affect healing of burn wounds. The present study was designed to find the effectiveness of collagenase versus moist exposed burn ointment (MEBO) on removal of necrotic tissue of burns. Twenty mice randomly assigned and divided into four groups. For Group 1, burn wounds were treated with collagenase ointment only, Group 2 burn wounds were treated with MEBO, Group 3 burn wounds were treated with white vaseline alone, and Group 4 burn wounds were considered as control and left without treatment. In each group, the time of treatment was considered. The results indicated that the removal time of necrotic tissue and healing process was better in the case of using collagenase than using MEBO for treatment of burns.

An Update on Calciphylaxis

Calciphylaxis, also known as calcific uremic arteriolopathy and uremic small artery disease with medial wall calcification and intimal hyperplasia, is a multifactorial cutaneous vascular disease characterized by chronic, painful, non-healing wounds that occur frequently in patients with chronic kidney disease, predominantly in those with end-stage renal disease. The pathogenesis remains unclear, and the development of calciphylaxis lesions depends on medial calcification, intimal fibrosis of arterioles and thrombotic occlusion. Despite an increase in reports of calciphylaxis in the literature and clinical recognition of demographic characteristics and risk factors associated with calciphylaxis, it remains a poorly understood disease with high morbidity and mortality. In this review, we analyze and summarize the clinical manifestations, pathogenesis and pathophysiology, histopathology, differential diagnosis, diagnostic workup and treatment modalities for calciphylaxis. Because of the lack of consensus regarding the optimal approach to and treatment of this disorder, a high degree of clinical suspicion, early diagnosis, and multimodal and multidisciplinary treatment in collaboration with dermatology, nephrology, wound care, nutrition and pain management specialties may improve survival in patients with calciphylaxis.

Digesting a Path Forward: The Utility of Collagenase Tumor Treatment for Improved Drug Delivery

Collagen and hyaluronan are the most abundant components of the extracellular matrix (ECM) and their overexpression in tumors is linked to increased tumor growth and metastasis. These ECM components contribute to a protective tumor microenvironment by supporting a high interstitial fluid pressure and creating a tortuous setting for the convection and diffusion of chemotherapeutic small molecules, antibodies, and nanoparticles in the tumor interstitial space. This review focuses on the research efforts to deplete extracellular collagen with collagenases to normalize the tumor microenvironment. Although collagen synthesis inhibitors are in clinical development, the use of collagenases is contentious and clinically untested in cancer patients. Pretreatment of murine tumors with collagenases increased drug uptake and diffusion 2-10-fold. This modest improvement resulted in decreased tumor growth, but the benefits of collagenase treatment are confounded by risks of toxicity from collagen breakdown in healthy tissues. In this review, we evaluate the published in vitro and in vivo benefits and limitations of collagenase treatment to improve drug delivery.

Economic analysis and budget impact of clostridial collagenase ointment compared with medicinal honey for treatment of pressure ulcers in the US

Objectives

Pressure ulcer (PU) treatment poses significant clinical and economic challenges to health-care systems. The aim of this study was to assess the cost-effectiveness and budget impact of enzymatic debridement with clostridial collagenase ointment (CCO) compared with autolytic debridement with medicinal honey (MH) for PU treatment from a US payer/Medicare perspective in the hospital outpatient department setting.

Methods

A cost-effectiveness analysis using a Markov model was developed using a 1-week cycle length across a 1-year time horizon. The three health states were inflammation/senescence, granulation/proliferation (ie, patients achieving 100% granulation), and epithelialization. Data sources included the US Wound Registry, Medicare fee schedules, and other published clinical and cost studies about PU treatment.

Results

In the base case analysis over a 1-year time horizon, CCO was the economically dominant strategy (ie, simultaneously conferring greater benefit at less cost). Patients treated with CCO experienced 22.7 quality-adjusted life weeks (QALWs) at a cost of $6,161 over 1 year, whereas MH patients experienced 21.9 QALWs at a cost of $7,149. Patients treated with CCO achieved 11.5 granulation weeks and 6.0 epithelization weeks compared with 10.6 and 4.4 weeks for MH, respectively. The number of clinic visits was 40.1 for CCO vs 43.4 for MH, and the number of debridements was 12.3 for CCO compared with 17.6 for MH. Probabilistic sensitivity analyses determined CCO dominant in 72% of 10,000 iterations and cost-effective in 91%, assuming a benchmark willingness-to-pay threshold of $50,000/quality-adjusted life year ($962/QALW). The budget impact analysis showed that for every 1% of patients shifted from MH to CCO, a cost savings of $9,883 over 1 year for a cohort of 1,000 patients was observed by the payer.

Conclusion

The results of these economic analyses suggest that CCO is a cost-effective, economically dominant alternative to MH in the treatment of patients with PUs in the hospital outpatient department setting.

Effects of quinine on gastric ulcer healing in Wistar rats

Background Quinine (QT) is an important anti-malarial drug; however, there is little information about its effects on the gut. Therefore, this study aimed to investigate the effects of a therapeutic dose of QT on the healing of gastric ulcer in rats. Methods Male Wistar rats weighing 150-200 g were divided into three groups: control rats without ulcer (group 1), ulcerated rats treated with 1 mL/kg (p.o.) normal saline (NS) (group 2), and ulcerated rats treated with 10 mg/kg (p.o.) QT (group 3). Ulcers were induced by serosal application of 80 % acetic acid to the stomach of rats anaesthetized with 50 mg/kg thiopentone sodium and treatment was given three times daily. Healing was assessed on days 3, 7 and 10 after ulcer induction by macroscopic measurement of: ulcer area, histology, lipid peroxidation, superoxide dismutase activity and gastric mucus secretion. Results At day 3, there was no significant difference (p>0.05) in ulcer areas between NS- and QT-treated rats. By day 10, however, the percentage area healed in NS treated (59.6±2.35 %) was significantly higher (p<0.05) than in QT rats (49.0±2.20 %) and clearing of inflammatory cells and re-epithelization was greater in NS-treated group. By days 7 and 10, lipid peroxidation was significantly higher in QT animals, when compared with NS-treated rats and controls (p<0.05). Superoxide dismutase activity and mucus secretion were significantly (p<0.05) higher in NS-treated than QT-treated rats. Conclusions QT delayed ulcer healing by prolonging the inflammatory phase of healing, increasing oxidative stress, reducing antioxidant activity and gastric mucus secretion.

Cost effectiveness of adding clostridial collagenase ointment to selective debridement in individuals with stage IV pressure ulcers

OBJECTIVE

The purpose of this study was to determine the cost effectiveness (from a payer's perspective) of adding clostridial collagenase ointment (CCO) to selective debridement compared with selective debridement alone (non-CCO) in the treatment of stage IV pressure ulcers among patients identified from the US Wound Registry.

METHODS

A 3-state Markov model was developed to determine costs and outcomes between the CCO and non-CCO groups over a 2-year time horizon. Outcome data were derived from a retrospective clinical study and included the proportion of pressure ulcers that were closed (epithelialized) over 2 years and the time to wound closure. Transition probabilities for the Markov states were estimated from the clinical study. In the Markov model, the clinical outcome is presented as ulcer-free weeks, which represents the time the wound is in the epithelialized state. Costs for each 4-week cycle were based on frequencies of clinic visits, debridement, and CCO application rates from the clinical study. The final model outputs were cumulative costs (in US dollars), clinical outcome (ulcer-free weeks), and incremental cost-effectiveness ratio (ICER) at 2 years.

RESULTS

Compared with the non-CCO group, the CCO group incurred lower costs ($11,151 vs $17,596) and greater benefits (33.9 vs 16.8 ulcer-free weeks), resulting in an economically dominant ICER of -$375 per ulcer. Thus, for each additional ulcer-free week that can be gained, there is a concurrent cost savings of $375 if CCO treatment is selected. Over a 2-year period, an additional 17.2 ulcer-free weeks can be gained with concurrent cost savings of $6,445 for each patient.

CONCLUSIONS

In this Markov model based on real-world data from the US Wound Registry, the addition of CCO to selective debridement in the treatment of pressure ulcers was economically dominant over selective debridement alone, resulting in greater benefit to the patient at lower cost.

Identification and Characterization of Novel Matrix-Derived Bioactive Peptides: A Role for Collagenase from Santyl® Ointment in Post-Debridement Wound Healing?

Debridement, the removal of diseased, nonviable tissue, is critical for clinicians to readily assess wound status and prepare the wound bed for advanced therapeutics or downstream active healing. Removing necrotic slough and eschar through surgical or mechanical methods is less specific and may be painful for patients. Enzymatic debridement agents, such as Clostridial collagenase, selectively and painlessly degrade devitalized tissue. In addition to its debriding activities, highly-purified Clostridial collagenase actively promotes healing, and our past studies reveal that extracellular matrices digested with this enzyme yield peptides that activate cellular migratory, proliferative and angiogenic responses to injury in vitro, and promote wound closure in vivo. Intriguingly, while collagenase Santyl® ointment, a sterile preparation containing Clostridial collagenases and other non-specific proteases, is a well-accepted enzymatic debridement agent, its role as an active healing entity has never been established. Based on our previous studies of pure Clostridial collagenase, we now ask whether the mixture of enzymes contained within Santyl® produces matrix-derived peptides that promote cellular injury responses in vitro and stimulate wound closure in vivo. Here, we identify novel collagen fragments, along with collagen-associated peptides derived from thrombospondin-1, multimerin-1, fibronectin, TGFβ-induced protein ig-h3 and tenascin-C, generated from Santyl® collagenase-digested human dermal capillary endothelial and fibroblastic matrices, which increase cell proliferation and angiogenic remodeling in vitro by 50-100% over controls. Using an established model of impaired healing, we further demonstrate a specific dose of collagenase from Santyl® ointment, as well as the newly-identified and chemically-synthesized ECM-derived peptides significantly increase wound re-epithelialization by 60-100% over saline-treated controls. These results not only confirm and extend our earlier studies using purified collagenase- and matrix-derived peptides to stimulate healing in vitro and in vivo, but these Santyl®-generated, matrix-derived peptides may also represent exciting new opportunities for creating advanced wound healing therapies that are enabled by enzymatic debridement and potentially go beyond debridement.