Angiogenesis: Aspects in wound healing

Manufacturing exosomes for wound healing: Comparative analysis of culture media

Mesenchymal stem cell (MSC)-derived exosomes (EXs) have emerged as promising therapeutic agents for wound healing. However, the optimal conditions for manufacturing MSC-derived EXs that maximize their wound-healing potential have yet to be established. Hence, we compared the efficacy of five different MSC culture media, including three different serum-free, a platelet-supplemented, and a fetal bovine serum-supplemented media, in exosome manufacturing for wound healing applications. Although umbilical cord-derived MSCs (UCMSCs) cultured in these media exhibited similar proliferation, morphology, MSC surface marker expression, and stemness, EXs derived from UCMSCs cultured in different culture media displayed varying levels of growth factors and cytokines. Notably, EXs derived from platelet-supplemented media (DM-PLT_EXs) exhibited significantly higher concentrations of keratinocyte growth factor (KGF), vascular endothelial growth factor (VEGF-A), platelet-derived growth factor (PDGF-BB), interleukin 6 (IL-6), interleukin 7 (IL-7), and interleukin 8 (IL-8) than EXs from other media. These differences correlated with the superior capability of DM-PLT_EXs to promote human skin fibroblast proliferation and stimulate angiogenesis of human umbilical vein endothelial cells, making them a more suitable choice for wound healing applications. Our findings emphasize the significance of the culture medium selection in tailoring the therapeutic potential of UCMSC-derived EXs for wound healing.

Cord Blood Platelet Lysate-Loaded Thermo-Sensitive Hydrogels for Potential Treatment of Chronic Skin Wounds

BACKGROUND/OBJECTIVES

Chronic skin wounds (CSWs) are a worldwide healthcare problem with relevant impacts on both patients and healthcare systems. In this context, innovative treatments are needed to improve tissue repair and patient recovery and quality of life. Cord blood platelet lysate (CB-PL) holds great promise in CSW treatment thanks to its high growth factors and signal molecule content. In this work, thermo-sensitive hydrogels based on an amphiphilic poly(ether urethane) (PEU) were developed as CB-PL carriers for CSW treatment.

METHODS

A Poloxamer 407®-based PEU was solubilized in aqueous medium (10 and 15% w/v) and added with CB-PL at a final concentration of 20% v/v. Hydrogels were characterized for their gelation potential, rheological properties, and swelling/dissolution behavior in a watery environment. CB-PL release was also tested, and the bioactivity of released CB-PL was evaluated through cell viability, proliferation, and migration assays.

RESULTS

PEU aqueous solutions with concentrations in the range 10-15% w/v exhibited quick (within a few minutes) sol-to-gel transition at around 30-37 °C and rheological properties modulated by the PEU concentration. Moreover, CB-PL loading within the gels did not affect the overall gel properties. Stability in aqueous media was dependent on the PEU concentration, and payload release was completed between 7 and 14 days depending on the polymer content. The CB-PL-loaded hydrogels also showed biocompatibility and released CB-PL induced keratinocyte migration and proliferation, with scratch wound recovery similar to the positive control (i.e., CB-PL alone).

CONCLUSIONS

The developed hydrogels represent promising tools for CSW treatment, with tunable gelation properties and residence time and the ability to encapsulate and deliver active biomolecules with sustained and controlled kinetics.

Angio-microRNAs in diabetic foot ulcer-: Mechanistic insights and clinical perspectives

Diabetic foot ulcers, as one of the chronic wounds, are a serious challenge in the global healthcare system which have shown notable growth in recent years. DFU is associated with impairment in various stages of wound healing, including angiogenesis. Aberrant expression of microRNAs (miRNAs) involved in the disruption of the balance between angiogenic and anti-angiogenic factors, plays a crucial role in angiogenesis dysfunction. Alteration in the expression of angiomiRNAs (angiomiRs) have the potential to function as biomarkers in chronic wounds. Additionally, considering the rising importance of therapeutic RNAs, there is potential for utilizing angiomiRs in wound healing to induce angiogenesis. This review aims to explore angiogenesis in chronic wounds and investigate the mechanisms mediated by pro- and anti-angiomiRs in the context of diabetic foot ulcers.

Biomaterials-Based Strategies to Enhance Angiogenesis in Diabetic Wound Healing

Amidst the present healthcare issues, diabetes is unique as an emerging class of affliction with chronicity in a majority of the population. To check and control its effects, there have been huge turnover and constant development of management strategies, and though a bigger part of the health care area is involved in achieving its control and the related issues such as the effect of diabetes on wound healing and care and many of the works have reached certain successful outcomes, still there is a huge lack in managing it, with maximum effect yet to be attained. Studying pathophysiology and involvement of various treatment options, such as tissue engineering, application of hydrogels, drug delivery methods, and enhancing angiogenesis, are at constantly developing stages either direct or indirect. In this review, we have gathered a wide field of information and different new therapeutic methods and targets for the scientific community, paving the way toward more settled ideas and research advances to cure diabetic wounds and manage their outcomes.

Omentum Extracellular Matrix-Silk Fibroin Hydroscaffold Promotes Wound Healing through Vascularization and Tissue Remodeling in the Diabetic Rat Model

Nonhealing diabetic wounds are often associated with significant mortality and cause economic and clinical burdens to the healthcare system. Herein, a biomimetic hydroscaffold is developed using omentum tissue-derived decellularized-extracellular matrix (dECM) and silk fibroin (SF) proteins that associate the behavior of a collagenous fibrous scaffold and a hydrogel to reproduce all aspects of the provisional skin tissue matrix. The chemical cross-linker-free in situ gelation property of the two types of SF proteins from Bombyx mori and Antheraea assamensis ensures the adherence of dECM with surrounding tissue on the wound bed, circumventing further suturing. The physicochemical and mechanical properties of the composite hydroscaffold (SF-dECM) were thoroughly evaluated. The hydroscaffolds were found to support the growth and proliferation of human dermal fibroblasts and influence the angiogenic potential of endothelial cells under in vitro conditions. Furthermore, the healing efficacy of the composites was evaluated by generating full-thickness wounds on a streptozotocin-induced diabetic rat model. The presence of dECM components in the composite facilitated the rate of wound closure, granulation tissue formation, and re-epithelialization by providing intrinsic cues to advance the inflammatory stage and stimulating angiogenesis. Collectively, as an off-the-shelf wound dressing requiring only a single topical administration, the SF-dECM hydroscaffold is a promising, cost-effective dressing for the management of chronic diabetic wounds.

The importance of periwound skin in wound healing: an overview of the evidence

DECLARATION OF INTEREST

The authors have no conflicts of interest.

Effects of the Chinese Herb Medicine Formula "She-Xiang-Yu-Hong" Ointment on Wound Healing Promotion in Diabetic Mice

Wound healing in diabetic patients is a difficult problem to be solved at present. In addition, patients with diabetes have an increased risk of postoperative wound complications. "She-Xiang-Yu-Hong" (SXYH) ointment is a type of traditional Chinese medicine (TCM) compound used to treat wounds. Over the past few years, SXYH has been applied in the Affiliated Hospital of Chengdu University of TCM (Chengdu, China) for the treatment of diabetic foot infections and bedsores, whereas there has been rare research on the effect of SXYH ointment on wound healing. In this study, SXYH ointment was first applied to streptozotocin (STZ)-triggered diabetic ICR mice (4-6 weeks, 20 ± 2 g) to observe the accelerated wound healing and the shortened wound healing period. As indicated by the histology and biochemistry analyses of skin biopsies, the wounds treated using SXYH ointment showed an increase in the granulation tissue. Moreover, SXYH also modulated the inflammation response by regulating affinity proinflammatory cytokines release (e.g., IL-6 and TNF-α). Furthermore, SXYH ointment obviously improved collagen fiber deposition and tissue on the wound surface. On the whole, this study indicated that SXYH ointment could accelerate wound healing, promote blood vessel formation, and suppress inflammations. Thus, the clinical potential of SXYH ointment was demonstrated in the treatment of diabetes and refractory wounds.