Novel insights into negative pressure wound healing from an in situ porcine perspective

A method for temporal-spatial multivariate genomic analysis of acute wound healing via tissue stratification: a porcine negative pressure therapy pilot study

Introduction: Wound therapies are capable of modulating the complex molecular signaling profile of tissue regeneration. However traditional, bulk tissue analysis results in nonspecific expressional profiles and diluted signaling that lacks temporal-spatial information. Methods: An acute incisional porcine wound model was developed in the context of negative pressure wound therapy (NPWT). Dressing materials were inserted into wounds with or without NPWT exposure and evaluated over 8-hours. Upon wound explantation, tissue was stratified and dissected into the epidermis, dermis, or subcutaneous layer, or left undissected as a bulk sample and all groups processed for RNAseq. RNAseq of stratified layers provided spatial localization of expressional changes within defined tissue regions, including angiogenesis, inflammation, and matrix remodeling. Results: Different expressional profiles were observed between individual tissue layers relative to each other within a single wound group and between each individual layer relative to bulk analysis. Tissue stratification identified unique differentially expressed genes within specific layers of tissue that were hidden during bulk analysis, as well as amplification of weak signals and/or inversion of signaling between two layers of the same wound, suggesting that two layers of skin can cancel out signaling within bulk analytical approaches. Discussion: The unique wound stratification and spatial RNAseq approach in this study provides a new methodology to observe expressional patterns more precisely within tissue that may have otherwise not been detectable. Together these experimental data offer novel insight into early expressional patterns and genomic profiles, within and between tissue layers, in wound healing pathways that could potentially help guide clinical decisions and improve wound outcomes.

Engineered exosomes derived from miR-132-overexpresssing adipose stem cells promoted diabetic wound healing and skin reconstruction

The tissue reconstruction of diabetic wounds mainly depends on the proliferation and remodelling of cutaneous cells around wounds and the transplantation of random skin flaps, however, the proliferation of cells or survival of skin flaps are difficult due to the severe inflammation and other problems caused by diabetes. The stem cell-derived exosomes loaded with miRNA can be an effective therapeutic strategy for promoting diabetic wound healing. Therefore, in this study, the engineered exosomes derived from miR-132-overexpressing adipose stem cells (miR-132-exo) was obtained for promoting the healing of diabetic wounds and skin flaps. In vitro, the miR-132-exo promoted the proliferation and migration of human umbilical vein endothelial cells (HUVECs). In vivo, streptozotocin (STZ) induced diabetic mice were used to create full-thickness skin wounds and random skin flaps to further investigate the healing effect of miR-132-exo. The results showed miR-132-exo evidently enhanced the survival of skin flaps and promote diabetic wound healing, through reducing local inflammation, promoting angiogenesis and stimulating M2-macrophages polarization mediated by NF-κB signaling pathway. These novel findings demonstrated that engineered miR-132-exo can be a potent therapeutic for treating diabetic wounds and inflammatory-related disease.

On diabetic foot ulcer knowledge gaps, innovation, evaluation, prediction markers, and clinical needs

Diabetic foot ulcers (DFUs) remain a very prevalent and challenging complication of diabetes worldwide due to high morbidity, high risks of lower extremity amputation and associated mortality. Despite major advances in diabetes treatment in general, there is a paucity of FDA approved technologies and therapies to promote successful healing. Furthermore, accurate biomarkers to identify patients at risk of non-healing and monitor response-to-therapy are significantly lacking. To date, research has been slowed by a lack of coordinated efforts among basic scientists and clinical researchers and confounded by non-standardized heterogenous collection of biospecimen and patient associated data. Novel technologies, especially those in the single and 'multiomics' arena, are being used to advance the study of diabetic foot ulcers but require pragmatic study design to ensure broad adoption following validation. These high throughput analyses offer promise to investigate potential biomarkers across wound trajectories and may support information on wound healing and pathophysiology not previously well understood. Additionally, these biomarkers may be used at the point-of-care. In combination with national scalable research efforts, which seek to address the limitations and better inform clinical practice, coordinated and integrative insights may lead to improved limb salvage rates.

Evaluating polymeric biomaterials to improve next generation wound dressing design

Wound healing is a dynamic series of interconnected events with the ultimate goal of promoting neotissue formation and restoration of anatomical function. Yet, the complexity of wound healing can often result in development of complex, chronic wounds, which currently results in a significant strain and burden to our healthcare system. The advancement of new and effective wound care therapies remains a critical issue, with the current therapeutic modalities often remaining inadequate. Notably, the field of tissue engineering has grown significantly in the last several years, in part, due to the diverse properties and applications of polymeric biomaterials. The interdisciplinary cohesion of the chemical, biological, physical, and material sciences is pertinent to advancing our current understanding of biomaterials and generating new wound care modalities. However, there is still room for closing the gap between the clinical and material science realms in order to more effectively develop novel wound care therapies that aid in the treatment of complex wounds. Thus, in this review, we discuss key material science principles in the context of polymeric biomaterials, provide a clinical breadth to discuss how these properties affect wound dressing design, and the role of polymeric biomaterials in the innovation and design of the next generation of wound dressings.