J.C. Ku1, G.M. Abd4, K. Bailey2, H. Pan4, R.G. Sawyer3, Y. Li4 1Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, MI, USA 2Western Michigan University Homer Stryker MD School of Medicine, Research Histology Laboratory, Kalamazoo, MI, USA 3Western Michigan University Homer Stryker MD School of Medicine, Department Of Surgery, Kalamazoo, MI, USA 4Western Michigan University Homer Stryker MD School of Medicine, Department Of Biomedical Engineering, Kalamazoo, MI, USA
Introduction: Blood clots play a critical role in initiating tissue regeneration following injury. However, the potential of ex vivo-generated blood clots in wound healing has been underexplored. Autologous blood clots (ABC), with their 3D fibrin architecture and rich reservoir of growth factors, present a biocompatible and cost-effective therapeutic vehicle that can be easily created without the regulatory hurdles associated with FDA approval required for many other treatments. We hypothesize that ABC conjugated with mesenchymal stem cells (MSC) and antibiotics can effectively prevent infection, promote angiogenesis, and accelerate overall skin wound healing.
Methods: ABC were generated from 10mL of blood drawn from Domestic Yorkshire pigs via the jugular vein. The clots were conjugated with porcine bone marrow MSC (5 x 106) and gentamicin (5.0 mg/mL). Partial excisional skin wounds (2.5cm x 2.5cm) were created on the dorsum of each animal, and the wounds were treated topically with ABC alone, ABC+gentamicin, and ABC+MSC. Wounds were evaluated on Days 3, 5, 8, 10 for wound closure and contraction. Blood flow was assessed using laser speckle imaging (LSI). Skin biopsies were collected for histological analysis.
Results: The results demonstrated a significant improvement in skin wound healing across all treated conditions compared to the untreated control group. The ABC+MSC treatment showed the most significant wound closure and contraction. Histological analysis confirmed tissue regeneration across all treatment groups. On Day 5, the ABC group showed dermal regeneration, the ABC+gentamicin group displayed early signs of epithelial regrowth, while the ABC+MSC group exhibited enhanced dermal growth with a deeper extension into the connective tissue. By Day 10, ABC alone showed marked healing, while the ABC+MSC group achieved the most pronounced epithelial regeneration, evidenced by the well-defined ridges. LSI indicated increased perfusion across all treatment groups, with peak blood flow signals at Day 5.
Conclusion:
This preclinical pilot study provides compelling evidence that ABC, especially when combined with MSC, offer a powerful and innovative approach to enhancing skin wound healing. ABC not only accelerated wound closure and contraction, but also significantly promoted dermal and epithelial regeneration, with improved perfusion. The simplicity of the methodology, low cost, and exemption from FDA approval further underscore the potential of this therapeutic strategy as a valuable addition to clinical management of complex wounds, potentially leading to improved outcomes in patients with challenging wound healing scenarios.