Fabrication of a Bioactive Human Adipose Extracellular Matrix Allograft Using Supercritical Carbon Dioxide.
Academic Article
Overview
abstract
PURPOSE: Autologous fat grafting is widely used for soft tissue augmentation but hindered by unpredictable volume retention and donor site morbidity. Decellularized adipose extracellular matrix (DAM) represents a promising alternative. Herein we evaluate an injectable, human-derived DAM decellularized via supercritical carbon dioxide (scCO2, sDAM), promising a gentler, more eco-friendly isolation of matrix components than conventional chemical decellularization. METHODS: Human adipose tissue was homogenized, delipidated, then underwent scCO2 cleansing, two cycles of scCO2 decellularization, cryomilling, and scCO2 terminal sterilization. The sDAM was injected into dorsal flank and cranial subcutaneous pockets of immunocompetent C57BL/6 mice (400 mm3 of 0.5 g sample/mL PBS). Commercially available hyaluronic acid (HA) was injected (400 mm3) for comparison. Samples were explanted after 1, 3 and 6 months. RESULTS: sDAM demonstrated a mean of 47 ng DNA/mg of dry weight, below the 50 ng/mg "complete" decellularization threshold. After 6 months, adipose flank volume was 307 mm3 (77% of initial volume), adipose cranial was 273 mm3 (68%), and HA flank was 1393 mm3 (348%), due to its hydrophilic nature. sDAM explants demonstrated significantly higher cellular density over HA explants (p < 0.0001). Perilipin expression revealed adipocytes developing within sDAM after 3 months, increasing in density and size by 6 months; few cells were noted in HA explants. Similarly, CD31 expression demonstrated neo-vascularization in sDAM only. Picrosirius red staining of sDAM demonstrated deposition of new fibrillar collagen after 1 month, which became more aligned over time. CONCLUSION: We present the first description of scCO2 DAM preparation foregoing the use of detergents and enzymatic chemicals with successful volume preservation and adipose tissue regeneration in vivo.
