Development and in vitro assessment of novel decellularised adipose sheets for adipose tissue regeneration

Background: Decellularised adipose tissue (DAT) is a potential regenerative treatment for adipose tissue regeneration; however, decellularisation often involves methods that compromise the integrity of the extracellular matrix architecture. This study aimed to develop a protocol to produce a sheet form of porcine-derived DAT and to assess the cellular response to DAT.

Methods: A novel method of producing DAT was assessed using histology and biochemical assays to confirm decellularisation. An extract cytotoxicity assay was used to detect whether DAT was cytotoxic towards 3T3 and L929 cells. Following this, the DAT was cultured with 3T3 and 3T3-L1 (preadipocyte) cell lines for 28 days. Cell metabolism, viability and differentiation potential were investigated using alamarBlueTM, live/dead and BODIPY 493/503 staining. Finally, the angiogenic potential of DAT was assessed using a chick chorioallantoic membrane (CAM) assay.

Results: DAT was successfully produced in sheet form (from n = 6 pigs) with 7.96% lipid (relative to native tissue), 0.047 µg/mg sodium dodecyl sulphate and 0.50 ng DNA/mg of tissue remaining. The DAT was demonstrated to be non-cytotoxic to both 3T3 and L929 cells, supporting the attachment and migration of 3T3 and 3T3-L1 cell lines in vitro. DAT also supported the accumulation of lipids within 3T3-L1 cells and the directional growth of blood vessels ex ovo.

Conclusions: A suitable method for producing DAT has been developed, resulting in DAT sheets that are non-cytotoxic, cytocompatible, and have the potential to support adipogenic differentiation and angiogenesis in vivo.