Abstract


Over the past three decades, there has been a growing interest in the use of oxygen therapy to promote wound healing. Although the most commonly recognized oxygen therapy for the treatment of chronic wounds is hyperbaric oxygen therapy, topical oxygen therapy has a greater level of evidence supporting its use in chronic wound care. Still, it is imperative that these two treatment modalities be recognized not merely as competitors, but as distinct therapeutic entities. Through personal experience and a thorough literature review, we investigated the use of topical oxygen therapy in the management of chronic wounds. The benefits of using topical oxygen therapy have been demonstrated in patients with diabetic foot ulcers, ischemic ulcers, post-revascularization ulcers, and pressure ulcers. There are several topical oxygen devices currently on the market that are versatile, relatively low-risk, and generally well-tolerated by patients. While these devices have been used in the treatment of chronic wounds at different locations and of different etiologies, other uses of these devices are still being investigated. Topical oxygen therapy is yet another tool in our arsenal to be used in treating difficult to heal chronic wounds and could potentially be used more readily.

Abstract


It is generally thought that dermal fibroblasts from chronic wounds are in a state of senescence, which contributes to the failure to heal. This assumption, based on limited experimental evidence, has led to the widespread use of therapeutic approaches focused on delivering new fibroblasts and/or increasing resident fibroblast activity to promote healing. In this study, we decided to re-visit the evidence for the relative inactivity of resident chronic wound fibroblasts. We therefore evaluated the proliferative and migratory activities of matching, patient-derived dermal fibroblasts from a chronic wound (wound dermal fibroblasts, or WDF), ipsilateral thigh newly created acute wound dermal fibroblasts (ADF, Day-3 after wounding the normal thigh skin), and ipsilateral thigh normal dermal skin fibroblasts (NDF). This approach was used in each of 10 consecutive non-selected individual patients with a venous leg ulcer, and allowed us to determine whether WDF are intrinsically less active than NDF and AWD. Cell migration and proliferation were quantified by a live-cell analysis system and MTT assay, respectively, in low (0.5%) or high (10%) levels of fetal bovine serum (FBS). In addition, the ability of patient-derived fibroblasts to modulate wound re-epithelialization in vivo was analyzed by transplantation in a mouse tail full-thickness wound model. Wnt5a mRNA, its ROR1 co-receptors, and ROR2 mRNA levels were determined by qRT-PCR. We report that WDF had increased -SMA and increased levels of Wnt5a. Moreover, using live-cell imaging in a scratch assay monolayer model, WDF showed baseline migratory activity similar to those of NDF and ADF, and such activity was not stimulated by FBS. WDF showed the same capacity to increase wound re-epithelialization as NDF and ADF. Together, these results suggest that WDF are not actually less "active" than NDF and ADF. This enhanced activity of chronic wound fibroblasts may lead to high energy requirements that contribute to a failure to heal. The findings may represent a new paradigm for wound chronicity, impaired healing, and high recurrence rates.

Abstract


Debridement is a standard part of wound care that is used on both acute and chronic wounds. Current methods of wound debridement include: autolytic based on the natural immune response, surgical, enzymatic based on application of exogenous proteases, mechanical using water jets and ultrasound, and biological using live organisms such as maggots. The choice of individual methods involves a trade-off between speed of treatment, selectivity, and pain. Irreversible electroporation via the application of pulsed electric fields has been used as a novel approach for deep tissue ablation, sometimes in conjunction with chemotherapy, as in the case of tumors, and also in cases where high precision is needed in otherwise very fragile tissues, such as for treating diabetic neuropathy and in epicardial atrial ablation. This method could be readily extended to wound care as it is both rapid and relatively painless, and it is also effective at decreasing bacterial load and clearing biofilms. Furthermore, the process primarily targets cells leaving the extracellular matrix relatively intact, thus providing a suitable natural scaffold for host cellular invasion and regrowth. A unique aspect of the use of pulsed electric fields is that around the region where ablation is perfomed, electric fields of lower energy are dissipated into the healthy tissue. There is a range of electric fields that are known to stimulate cellular functions, in particular migration and proliferation, and that may contribute to the healing process after electroporation. While irreversible electroporation is a potentially useful alternative to other debridement methods, future clinical application awaits technological advances in electrode design that will enable precise delivery of the therapy in wounds of various sizes and depths.

Abstract


Preparation of the wound bed is a key step in the use of cell- and tissue-based therapy (CTP). In particular, good pre-application debridement is an essential component of CTP. However, there are many situations in which the wound bed is not adequately debrided, including trauma, burn, and in cases of chronic wounds with significant biofilm. In the setting of inadequate wound bed preparation, the use of a CTP that has either added or intrinsic antimicrobial properties is attractive. Some CTPs include added antimicrobial agents such as PHMB or silver, while others have intrinsic antimicrobial components, such as Omega 3 fatty acids. In addition, some wound-covering dressings are completely synthetic, and therefore simply do not become infected. A full understanding of the basic science and clinical data supporting the use of these therapies is important for the advanced wound care practitioner.