Micronized Cross-Linked Human Acellular Dermal Matrices: An Effective Scaffold for Collagen Synthesis and Promising Material for Tissue Augmentation

Micronized cross-linked human acellular dermal matrices (ADMs) contain the extracellular components necessary for cell integration and tissue remodeling, and have high tensile strength and durability. We hypothesized that such material could serve as a scaffold to enhance the survival of adipocytes in grafted fat. Nude mice (n = 15) were randomly assigned to three groups, each receiving different subcutaneous injections into two dorsal paravertebral areas: fat and saline (control), fat and micronized ADM (E1), and fat and diluted micronized ADM (E2). Digital photographs were taken at 2-week intervals, and the grafted fat volumes and weights were examined after 10 weeks. A histological analysis of the grafted fat was performed, and the expression of vascular endothelial growth factor (VEGF) was examined. The grafted fat volumes decreased over time in all groups; however, at 10 weeks, the grafted fat was better preserved in both experimental groups, with significantly greater weights than in the group C (both, p < 0.001). In the experimental groups, there was more regular arrangement of collagen in the graft tissue, whereas relatively thin, disorderly collagen deposition was observed in the control group. In addition, VEGF expression was significantly greater in the experimental groups than in the control group (p < 0.001). These results are the first to show that micronized cross-linked human ADMs are an excellent scaffold for promoting adipocyte survival and may be an option for maintaining or promoting the in vivo survival of grafted fat.