pH in the Bacteria-Contaminated Wound and Its Impact on Clostridium histolyticum Collagenase Activity: Implications for the Use of Collagenase Wound Debridement Agents

Injectable Hydrogels with Integrated Ph Probes and Ultrasound-Responsive Microcapsules as Smart Wound Dressings for Visual Monitoring and On-Demand Treatment of Chronic Wounds

Hydrogel dressings capable of infection monitoring and precise treatment administration show promise for advanced wound care. Existing methods involve embedd ingorganic dyes or flexible electronics into preformed hydrogels, which raise safety issues and adaptability challenges. In this study, an injectable hydrogel based smart wound dressing is developed by integrating food-derived anthocyanidin as a visual pH probe for infection monitoring and poly(L-lactic acid) microcapsules as ultrasound-responsive delivery systems for antibiotics into a poly(ethylene glycol) hydrogel. This straightforwardly prepared hydrogel dressing maintains its favorable properties for wound repair, including porous morphology and excellent biocompatibility. In vitro experiments demonstrated that the hydrogel enabled visual assessment of pH within the range of 5 ∼ 9.Meanwhile, the release of antibiotics could be triggered and controlled by ultrasound. In vivo evaluations using infected wounds and diabetic wounds revealed that the wound dressing effectively detected wound infection by monitoring pH levels and achieved antibacterial effects through ultrasound-triggered drug release. This led to significantly enhanced wound healing, as validated by histological analysis and the measurement of inflammatory cytokine levels. This injectable hydrogel-based smart wound dressing holds great potential for use in clinical settings to inform timely and precise clinical intervention and in community to improve wound care management.

Bacterial Biofilm in Chronic Wounds and Possible Therapeutic Approaches

Wound repair and skin regeneration is a very complex orchestrated process that is generally composed of four phases: hemostasis, inflammation, proliferation, and remodeling. Each phase involves the activation of different cells and the production of various cytokines, chemokines, and other inflammatory mediators affecting the immune response. The microbial skin composition plays an important role in wound healing. Indeed, skin commensals are essential in the maintenance of the epidermal barrier function, regulation of the host immune response, and protection from invading pathogenic microorganisms. Chronic wounds are common and are considered a major public health problem due to their difficult-to-treat features and their frequent association with challenging chronic infections. These infections can be very tough to manage due to the ability of some bacteria to produce multicellular structures encapsulated into a matrix called biofilms. The bacterial species contained in the biofilm are often different, as is their capability to influence the healing of chronic wounds. Biofilms are, in fact, often tolerant and resistant to antibiotics and antiseptics, leading to the failure of treatment. For these reasons, biofilms impede appropriate treatment and, consequently, prolong the wound healing period. Hence, there is an urgent necessity to deepen the knowledge of the pathophysiology of delayed wound healing and to develop more effective therapeutic approaches able to restore tissue damage. This work covers the wound-healing process and the pathogenesis of chronic wounds infected by biofilm-forming pathogens. An overview of the strategies to counteract biofilm formation or to destroy existing biofilms is also provided.

Enzymes for dermatological use

Skin is the ultimate barrier between body and environment and prevents water loss and penetration of pathogens and toxins. Internal and external stressors, such as ultraviolet radiation (UVR), can damage skin integrity and lead to disorders. Therefore, skin health and skin ageing are important concerns and increased research from cosmetic and pharmaceutical sectors aims to improve skin conditions and provide new anti-ageing treatments. Biomolecules, compared to low molecular weight drugs and cosmetic ingredients, can offer high levels of specificity. Topically applied enzymes have been investigated to treat the adverse effects of sunlight, pollution and other external agents. Enzymes, with a diverse range of targets, present potential for dermatological use such as antioxidant enzymes, proteases and repairing enzymes. In this review, we discuss enzymes for dermatological applications and the challenges associated in this growing field.

Imperfect cross-linking of xanthan for pH-responsive bio-based composite moist wound dressings by stencil printing

The work addresses the use of bio-based and -degradable materials for the production of a moist, adaptive and anti-microbial wound dressing. The dressing is targeted to exhibit a pH-dependent active agent release. Xanthan hydrogel structures are coated on cellulose fabrics via stencil printing and subsequently cross-linked using glyoxal. By alteration of the cross-linker content from 1 to 6% by mass, the hydrogel elasticity can be tuned within a range of 2-16 kPa storage modulus. Increasing initial glyoxal concentrations also result in higher amounts of glyoxal release. Glyoxal, an anti-microbial agent with approval in veterinary medicine, is mostly released upon wound application supporting infection management. As wound simulation, normal saline, as pH 5 and pH 8 buffer solutions, were used. The release profile and magnitude of approx. 65%-90% glyoxal is pH-dependent. Increased release rates of glyoxal are present in pH 8 fluids, which mostly base on faster hydrogel swelling. Higher total glyoxal release is present in pH 5 fluid and normal saline after 3 days. Accordingly, a pH-dependent release profile was encountered. As glyoxal attacks any cell unselectively, it is expected to be effective against antibiotic resistant bacteria. By stencil printing the dressing size can be adjusted to minimize healthy glyoxal tissue exposure.

pH-sensitive bilayer electrospun nanofibers based on ethyl cellulose and Eudragit S-100 as a dual delivery system for treatment of the burn wounds; preparation, characterizations, and in-vitro/in-vivo assessment

A pH-sensitive bilayer electrospun nanofibrous mat containing both antibiotic (gentamicin sulfate, GEN) and non-steroidal anti-inflammatory (diclofenac sodium, DIC) drugs was fabricated for burn wound dressing by electrospinning technique, in which ethyl cellulose (EC) and ethyl cellulose/Eudragit S-100 (EC/ES-100) formed the top and bottom layers, respectively. The fabricated pH-sensitive bilayer electrospun nanofibrous mats were characterized from aspects of both structure and efficiency. Physicochemical properties were investigated via SEM, FTIR, and TGA. The swelling ratio and in vitro drug release of the fabricated nanofibrous mats were studied in different pHs. MTT was applied to assess the safety of the fiber mats. Finally, the in vivo efficiency of the designed pH-sensitive bilayer electrospun nanofibrous mats was examined on the male Wistar rats. Based on the histological analysis and wound healing test (in vivo animal experiments), the (ES100/EC-DIC/GEN)-(EC) pH-sensitive bilayer nanofibrous mat displayed faster wound healing than other bilayer nanofibrous mat. As a result, (ES100/EC-DIC/GEN)-(EC) bilayer nanofibrous mat with pH-responsion could accelerate the burn wound healing process via decreasing the adverse effects of GEN and DIC as topical antimicrobial and anti-inflammatory agents, receptively.

Recent Advances in Stimuli-Responsive Hydrogel-Based Wound Dressing

Polymeric materials have found increasing use in biomedical applications in the last decades. Among them, hydrogels represent the chosen class of materials to use in this field, in particular as wound dressings. They are generally non-toxic, biocompatible, and biodegradable, and they can absorb large amounts of exudates. Moreover, hydrogels actively contribute to skin repair promoting fibroblast proliferation and keratinocyte migration, allowing oxygen to permeate, and protecting wounds from microbial invasion. As wound dressing, stimuli-responsive systems are particularly advantageous since they can be active only in response to specific environmental stimuli (such as pH, light, ROS concentration, temperature, and glucose level). In this review, we briefly resume the human skin's structure and functions, as well as the wound healing phases; then, we present recent advances in stimuli-responsive hydrogels-based wound dressings. Lastly, we provide a bibliometric analysis of knowledge produced in the field.

Research progress of advanced microneedle drug delivery system and its application in biomedicine

Transdermal drug delivery is an effective way of drug delivery in addition to oral and intravenous administration. Among them, microneedle administration is a new type of subcutaneous drug delivery, which forms micron-level pores on the surface of the skin, making the drug enter the dermis through the cuticular layer of the skin in the least invasive way. This mode of drug delivery not only increases the permeation efficiency of transdermal drug delivery but also improves the bioavailability of drug delivery. At present, there are many kinds of research on microneedles, such as solid microneedles, hollow microneedles, soluble polymer microneedles, etc. However, some new microneedle drug delivery systems have been gradually developed and applied with the development of microneedle drug delivery technology, for meeting the more complex pathological environment. In this review, we focus on the principle, structure, and function of some new types of microneedles, such as stimulus-response microneedles, iontophoresis microneedles, and bionic microneedles. We summarize the effects of materials, geometry, and size on the properties of microneedles as well as their applications and potential developments in the field of biomedicine. We hope that this review can provide new ideas and help with the development of new microneedle drug delivery systems.

Multi-functional wound dressings based on silicate bioactive materials

Most traditional wound dressings passively offer a protective barrier for the wounds, which lacks the initiative in stimulating tissue regeneration. In addition, cutaneous wound healing is usually accompanied by various complicated conditions, including bacterial infection, skin cancer, and damaged skin appendages, bringing further challenges for wound management in clinic. Therefore, an ideal wound dressing should not only actively stimulate wound healing but also hold multi-functions for solving problems associated with different specific wound conditions. Recent studies have demonstrated that silicate bioceramics and bioglasses are one type of promising materials for the development of wound dressings, as they can actively accelerate wound healing by regulating endothelial cells, dermal fibroblasts, macrophages, and epidermal cells. In particular, silicate-based biomaterials can be further functionalized by specific structural design or doping with functional components, which endow materials with enhanced bioactivities or expanded physicochemical properties such as photothermal, photodynamic, chemodynamic, or imaging properties. The functionalized materials can be used to address wound healing with different demands including but not limited to antibacterial, anticancer, skin appendages regeneration, and wound monitoring. In this review, we summarized the current research on the development of silicate-based multi-functional wound dressings and prospected the development of advanced wound dressings in the future.

Persistent Production of Reactive Oxygen Species with Zn2GeO4:Cu Nanorod-Loaded Microneedles for Methicillin-Resistant Staphylococcus Aureus Infectious Wound Healing

Skin wound infection caused by methicillin-resistant Staphylococcus aureus (MRSA) is an urgent concern. Photodynamic therapy has emerged as a promising means of combating bacterial infection. However, continuous or repeated in situ light excitation is required for photosensitizers to produce reactive oxygen species (ROS), and most photosensitizers need sufficient oxygen to produce singlet oxygen (¹O₂), which greatly limits their clinical application. In this work, we report the preparation of Zn₂GeO₄:Cu²⁺ (ZGC) persistent luminescence nanorods with excellent ability for persistent ROS production after stopping excitation for MRSA infectious wound healing. The prepared ZGC nanorods were loaded into dissolvable microneedles (MNs) (ZGC@MNs) to penetrate biofilms and treat MRSA-infected wounds in a minimally invasive manner. ZGC showed a long-persistent photocatalytic effect to constantly produce multiple ROS (¹O₂, hydroxyl radical, and superoxide radical) accompanied by persistent luminescence after a pre-illumination. The MN tips of ZGC@MNs were rapidly dissolved to release ZGC for the continuous production of multiple ROS for at least 48 h with no need for in situ excitation and no special requirement on the amount of oxygen for eliminating MRSA biofilms. The developed ZGC@MN patches exhibited excellent antibacterial activity and biocompatibility for effectively reducing inflammation and promoting wound healing in vivo.

Stimuli-Responsive Microneedles as a Transdermal Drug Delivery System: A Demand-Supply Strategy

Microneedles are one of the most prominent approaches capable of physically disrupting the stratum corneum without devastating the deeper tissues to deliver both small molecules and macromolecules into the viable epidermis/dermis for local/systemic effects. Over the past two decades, microneedles have caught the attention of many researchers because of their outstanding advantages over oral and parenteral drug delivery systems such as self-administration, pain-free, steady-plasma concentration maintenance, avoidance of first-pass hepatic biotransformation, and so on. So far, scientists have reported various types of microneedle patches to deliver the loaded therapeutics as soon as the microneedles are inserted into the skin, regardless of the demand for therapeutics to treat a specific condition. This way of drug delivery can lead to potential risks such as poor therapeutic efficacy or drug overdose. The stimuli-responsive microneedles are the most predominant tool to achieve the on-demand/need-based drug delivery, leading to safe and effective treatment. Various natural and synthetic polymers that can undergo significant transitions such as swelling, shrinking, dissolution, or disintegration play a pivotal role in the development of stimuli-responsive microneedles. The current Review provides brief information about the history, emergence, type, and working principles of microneedles. Furthermore, it selectively discusses various exogenous and endogenous stimuli-responsive microneedles along with their mechanism of action involved in treating different disease conditions. Collaterally, the emergence of "closed-loop" combinatorial stimuli-responsive microneedle patches for precise delivery of therapeutics is meticulously canvassed. Subsequently, it covers the patents of different stimuli-responsive microneedles and further highlights the existing challenges and future perspectives concerning clinical application and large-scale production.

Nature-Inspired Hydrogel Network for Efficient Tissue-Specific Underwater Adhesive

Underwater adhesives with efficient, selective, and repeatable adhesion are urgently needed for biomedical applications. Catechol-containing hydrogel adhesives have aroused much interest, but the design of specific underwater adhesives to biotic surfaces is still a challenge. Here we report a facile way that recapitulates the adhesion mechanism of mussel and sea gooseberry for the development of robust and specific hydrogel adhesives. With an exquisite design of chemical bonding, catechol chemistry, and electrostatic interaction, the hydrogel consisting of poly(acrylic acid) grafted with N-hydroxysuccinimide ester (PAA-NHS ester), tea polyphenol (TP), chitosan (CS), and Al³⁺ exhibited fast, specific, and repeatable underwater adhesion to various biological tissues, such as porcine skin, intestine, liver, and shrimp. Furthermore, nanofibers-hydrogel composite (NF-HG) was prepared via the wicking effect of curcumin-loaded electrospun nanofibers. The NF-HG exhibited pH-responsive color changing properties, sustained drug release, and good cell viability, which made it suitable as a novel wound healing material. This strategy may provide great inspiration for designing multifunctional specific underwater adhesives.

Clostridium Collagenase Impact on Zone of Stasis Stabilization and Transition to Healthy Tissue in Burns

Clostridium collagenase has provided superior clinical results in achieving digestion of immediate and accumulating devitalized collagen tissue. Recent studies suggest that debridement via Clostridium collagenase modulates a cellular response to foster an anti-inflammatory microenvironment milieu, allowing for a more coordinated healing response. In an effort to better understand its role in burn wounds, we evaluated Clostridium collagenase’s ability to effectively minimize burn progression using the classic burn comb model in pigs. Following burn injury, wounds were treated with Clostridium collagenase or control vehicle daily and biopsied at various time points. Biopsies were evaluated for factors associated with progressing necrosis as well as inflammatory response associated with treatment. Data presented herein showed that Clostridium collagenase treatment prevented destruction of dermal collagen. Additionally, treatment with collagenase reduced necrosis (HMGB1) and apoptosis (CC3a) early in burn injuries, allowing for increased infiltration of cells and protecting tissue from conversion. Furthermore, early epidermal separation and epidermal loss with a clearly defined basement membrane was observed in the treated wounds. We also show that collagenase treatment provided an early and improved inflammatory response followed by faster resolution in neutrophils. In assessing the inflammatory response, collagenase-treated wounds exhibited significantly greater neutrophil influx at day 1, with macrophage recruitment throughout days 2 and 4. In further evaluation, macrophage polarization to MHC II and vascular network maintenance were significantly increased in collagenase-treated wounds, indicative of a pro-resolving macrophage environment. Taken together, these data validate the impact of clostridial collagenases in the pathophysiology of burn wounds and that they complement patient outcomes in the clinical scenario.

Synthesis of a novel nanocomposite containing chitosan as a three-dimensional printed wound dressing technique: Emphasis on gene expression

In this study, a highly porous three-dimensional (3D)-printed wound healing core/shell scaffold fabricated using poly-lactic acid (PLA). The core of scaffold was composed of hyaluronic acid (HA), copper carbon dots (Cu-CDs), rosmarinic acid, and chitosan hydrogel. Cu-CDs were synthesized using ammonium hydrogen citrate under hydrothermal conditions. Formulation containing 1 mg ml^-1 concentration of Cu-CDs showed an excellent antibacterial activity against gram bacteria. At 0.25 mg ml^-1 of Cu-CDs concentration, scaffold had a good biocompatibility as confirmed by cytotoxicity assay on L929 fibroblast stem cells. in vivo wound healing experiments on groups of rats revealed that after 15 days of treatment, the optimal formulation of composite scaffold significantly improves the wound healing process compared to the PLA scaffold. This finding was confirmed by histological analysis and the relative expression of PDGF, TGF-β, and MMP-1 genes. The biocompatible antibacterial CU-CDS/PLA/HA/chitosan/rosmarinic acid nanocomposite is a promising wound healing scaffold which highly accelerates the process of skin regeneration.

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.

Flexible pH sensor based on a conductive PANI membrane for pH monitoring

pH is a critical parameter used to specify the acidity or alkalinity of an aqueous solution in chemistry, food processing, and medical care. In this study, a conductimetric-type micro pH sensor has been achieved using PANI membrane fabricated on a flexible substrate film aiming to monitor wound healing. The sensor is based on the incorporation of a polyaniline (PANI) membrane, interdigital electrode, and polyimide (PI) substrate. PANI was doped with dodecyl benzene sulfonic acid (DBSA) to obtain good conductivity. The electrodes were patterned on the PI film by etching. The contact area between the PANI and interdigital electrodes improves the responsiveness of the pH sensor. A sensitivity of 58.57 mV per pH over the entire pH range from 5.45 to 8.62 was obtained experimentally, along with a superior repeatability of 8% FS (full scale) and a temperature drift of 6.8% FS. This micro flexible pH sensor aims to monitor the pH value of wound healing, which also facilitates the realization of online monitoring of the pH for telemedicine, food safety, and home health care.

A conductimetric flexible film pH sensor working in sensing materials of PANI membrane was developed for clinic wound monitoring.

A pH-regulated drug delivery dermal patch for targeting infected regions in chronic wounds

This work presents a low-cost, passive, flexible, polymeric pump for topical drug delivery which uses wound pH as a trigger for localized drug release. Its operation relies on a pH-responsive hydrogel actuator which swells when exposed to the alkaline pH of an infected wound. The pump enables slow release (<0.1 μL min-1) of aqueous anti-bacterial solution for up to 4 hours and sustains against up to 8 kPa of backpressure. Featuring a scalable layer-by-layer fabrication technique to expand the pump into a 2 × 2 array, the device can dispense 50 μl onto a 160 mm2 dermal coverage within 4 hours. Robustness tests show that when integrated within a medical adhesive, the device can be worn around the forearm and can withstand various daily activities (non-intensive) for up to 12 hours. In vitro experiments demonstrate a 58 times decrease of live P. aeruginosa after 24 hours of the pump assisted antibiotics treatment.

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.

Novel mechanisms of Collagenase Santyl Ointment (CSO) in wound macrophage polarization and resolution of wound inflammation

Collagenases are useful in enzymatic wound debridement. Clostridial collagenase, marketed as Collagenase Santyl Ointment (CSO), is FDA approved for such use. Building on the scientific premise that collagenases as well as collagen degradation products may regulate immune cell function, we sought to investigate the potential role of CSO in wound inflammation. We tested the hypothesis that in addition to enacting debridement, CSO contributes to the resolution of persistent wound inflammation. Wound macrophages were isolated from PVA sponges loaded with CSO or petrolatum and implanted in mice. Significant increase in pro-reparative and decrease in pro-inflammatory polarization was noted in macrophages of acute as well as diabetic wounds. Wound macrophages from CSO-treated group displayed increased production of anti-inflammatory cytokines IL-10 and TGF-β, and decreased levels of pro-inflammatory cytokines TNF-α and IL-1β. The active ingredient of CSO, CS-API, induced the expression of mϕ^heal /M(IL-4) polarization markers ex vivo. CS-API treatment attenuated transactivation of NF-κB and significantly induced STAT6 phosphorylation. A significant role of a novel PGE2-EP4 pathway in CS-API induced STAT6 activation and the mϕ^heal /M(IL-4) polarization was identified. Taken together, findings of this work reposition CSO as a potential agent that may be effective in resolving wound inflammation, including diabetic wounds.

Effects of pH on the Antibiotic Resistance of Bacteria Recovered from Diabetic Foot Ulcer Fluid An In Vitro Study

BACKGROUND

This study investigated the resistance of bacteria isolated from diabetic foot ulcers (DFUs) to antibiotics frequently used in the management of the diabetic foot infections, at a range of pH values (pH 6.5, 7.5, and 8.5) known to exist in DFU wound fluid. This study aimed to determine whether changes (or atypical stasis) in wound fluid pH modulate the antibiotic resistance of DFU isolates, with potential implications in relation to the suppression/eradication of bacterial infections in DFUs.

METHODS

Thirty bacterial isolates were recovered from DFU wound fluid, including Staphylococcus spp, Staphylococcus aureus, Escherichia coli, Streptococcus spp, Pseudomonas spp, and Pseudomonas aeruginosa. The resistances of these isolates to a panel of antibiotics currently used in the treatment of infected or potentially infected DFUs, ie, ciprofloxacin, amoxicillin-clavulanate, doxycycline, and piperacillin-tazobactam, at the previously mentioned pH values were determined by a modification of the Kirby-Bauer assay.

RESULTS

The resistance of DFU isolates to clinically relevant antibiotics was significantly affected by the pH levels in DFU wound fluid.

CONCLUSIONS

These findings highlight the importance of a more comprehensive understanding of the conditions in DFUs to inform clinical decision making in the selection and application of antibiotics in treating these difficult-to-heal wounds. The scale of the differences in the efficacies of antibiotics at the different pH values examined is likely to be sufficient to suggest reconsideration of the antibiotics of choice in the treatment of DFU infection.

Comparative Effectiveness of Clostridial Collagenase Ointment to Medicinal Honey for Treatment of Pressure Ulcers

Objective: Compare enzymatic debridement using clostridial collagenase ointment (CCO) with autolytic debridement using medicinal honey in the hospital outpatient setting for treating pressure ulcers (PUs).

Approach: Retrospective deidentified electronic health records from 2007–2013 were extracted from the U.S. Wound Registry. Propensity score matching followed by multivariable analyses was used to adjust for selection bias and assess treatment effects comparing CCO-treated versus honey-treated PUs. Key outcomes included 100% granulation and epithelialization at 1 year.

Results: Five hundred seventeen CCO-treated PUs (446 patients) were matched to corresponding honey-treated PUs (341 patients). The majority of PUs were stage III (CCO 56%, honey 55%). CCO users had significantly fewer total visits (9.1 vs. 12.6; p < 0.001), fewer total selective sharp debridements (2.7 vs. 4.4; p < 0.001), and fewer PUs receiving negative pressure wound therapy (29% vs. 38%; p = 0.002) compared with honey.

Innovation: CCO-treated PUs were 38% more likely to achieve 100% granulation compared to honey-treated PUs at 1 year, p = 0.018. Mean days to 100% granulation were significantly lower for CCO-treated PUs (255 vs. 282 days, p < 0.001). CCO-treated PUs were 47% (p = 0.024) more likely to epithelialize at 1 year compared to PUs treated with honey. Mean days to epithelialization were significantly lower for PUs treated with CCO at 1 year (288 vs. 308 days; p = 0.011).

Conclusion: All stages of PUs treated with CCO achieved faster rates of granulation and subsequent epithelialization compared to PUs treated with medicinal honey as measured by real-world data collected in the hospital outpatient department care setting.

Wound dressing application of pH-sensitive carbon dots/chitosan hydrogel

Monitoring the pH of wounds as an essential diagnosis factor during the healing process.

New Developments in Smart Bandage Technologies for Wound Diagnostics

The pH of wound fluid has long been recognized as an important diagnostic for assessing wound condition, but as yet there are few technological options available to the clinician. The availability of sensors that can measure wound pH, either in the clinic or at home could significantly improve clinical outcome - particularly in the early identification of complications such as infection. New material designs and electrochemical research strategies that are being targeted at wound diagnostics are identified and a critical overview of emerging research that could be pivotal in setting the direction for future devices is provided.

Photonic porous silicon as a pH sensor

Chronic wounds do not heal within 3 months, and during the lengthy healing process, the wound is invariably exposed to bacteria, which can colonize the wound bed and form biofilms. This alters the wound metabolism and brings about a change of pH. In this work, porous silicon photonic films were coated with the pH-responsive polymer poly(2-diethylaminoethyl acrylate). We demonstrated that the pH-responsive polymer deposited on the surface of the photonic film acts as a barrier to prevent water from penetrating inside the porous matrix at neutral pH. Moreover, the device demonstrated optical pH sensing capability visible by the unaided eye.

Clinical and economic assessment of diabetic foot ulcer debridement with collagenase: results of a randomized controlled study

BACKGROUND

Despite significant advances, the treatment of diabetic foot ulcers (DFUs) remains a major therapeutic challenge for clinicians, surgeons, and other health care professionals. There is an urgent need for new strategies with clinically effective interventions to treat DFUs to reduce the burden of care in an efficient and cost-effective way.

OBJECTIVE

This randomized trial evaluated and compared the clinical effectiveness, tolerability, and costs of clostridial collagenase ointment (CCO) debridement to that of debridement using saline moistened gauze (SMG) and selective sharp debridement for the treatment of DFUs.

METHODS

Randomized, controlled, parallel group, multicenter, open-label, 12-week study of 48 patients with neuropathic DFUs randomized to 4 weeks of treatment with either CCO or SMG after baseline surgical debridement. The primary end point was the condition of the ulcer bed at the end of treatment as measured using a standardized wound assessment tool. Secondary end points were the percentage of reduction in wound area and therapeutic response rates. Adverse events were monitored for the tolerability analysis. In addition, a comparative cost-effectiveness analysis was performed from the perspective of the Centers for Medicare and Medicaid Services as a payer.

RESULTS

Both the CCO and SMG groups had significantly improved wound assessment scores after 4 weeks of treatment (CCO, -2.5, P = 0.007; SMG, -3.4, P = 0.006). Only CCO treatment resulted in a statistically significant decrease from baseline in the mean wound area at the end of treatment (P = 0.0164) and at the end of follow-up (P = 0.012). In addition, the CCO group exhibited a significantly better response rate at the end of follow-up compared with the SMG group (0.92 vs 0.75, P < 0.05). Reported adverse events were similar between the 2 treatment groups. None of the reported adverse events were considered to be related to treatment. The economic analysis indicated that the direct mean costs per responder in the physician office setting of care were $832 versus $1042 for the CCO group versus the SMG group, whereas the direct mean costs per responder in the hospital outpatient department setting were $1607 versus $1980.

CONCLUSIONS

CCO treatment provides equivalent debridement of DFUs similar to SMG while fostering better progress toward healing as measured by decreasing wound area over time and improved response rates at the end of follow-up. In addition, CCO yields a more favorable cost-effectiveness ratio in both the physician office and hospital outpatient department settings of care. ClinicalTrials.gov identifier: NCT01056198.