Human Adipose-Derived Microvessel Fragments: A Natural Vascularization Units for Ischemic Diseases

In plastic surgery tissue transplantation, tissue ischemia limits transplanted tissue survival. Adipose-derived stem cells (ASCs) and stromal vascular fraction (SVF) show potential for promoting angiogenesis and rescuing ischemic conditions. However, when SVF and ASC suspensions are utilized without the protection of extracellular matrix, the retention rate of transplanted cells tends to be diminished, leading to an unsatisfactory therapeutic outcome. To overcome this, adipose tissue-derived microvascular fragments (ad-MVFs) have emerged as a promising solution. We conducted enzymatic digestion on human adipose tissue to generate ad-MVFs. These fragments underwent a thorough characterization process, utilizing electron microscopy to assess their structural attributes and enabling a detailed analysis of their intricate morphology. Furthermore, our team investigated the cellular composition of these microvascular fragments, subsequently confirming their ability to enhance the viability of ischemic skin flaps. The resulting product primarily comprised fragments with sizes ranging from 20 to 50 µm, and some exhibited a sophisticated network-like structure. Electron microscopy examination revealed the presence of collagen components in the product. Additionally, flow cytometry analysis indicated a substantial abundance of adipose-derived stem cells and endothelial cells within these microvascular fragments. Significantly, when tested in treating an ischemic skin flap in a nude mouse model, the product exhibited superior therapeutic efficacy compared to SVF cell suspension. We have successfully generated human ad-MVFs and established standardized procedures. Compared with SVF, Ad-MVFs have a better effect in the treatment of ischemic diseases. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .