Additive Manufactured Macroporous Chambers Facilitate the Regeneration of Large Volume Soft Tissue from Adipose-Derived Extracellular Matrix

Breast tissue engineering is considered to be a promising alternative intervention for breast reconstruction. Decellularized adipose tissue (DAT) can potentially regenerate adipose tissue in vivo owing to its low immunogenicity and well-preserved adipogenic microenvironment. Nevertheless, the volume of adipose tissue regenerated from DAT can hardly satisfy the demand for breast reconstruction. Numerous studies have shown that tissue engineering chamber (TEC) is an effective technique for generation of a large volume of adipose tissue. However, application of TEC necessitates reoperation to remove non-degradable plastic chambers and harvest autologous tissue, which prolongs the operation time and causes potential damage to the donor site. In this study, we improved the TEC strategy by combining biodegradable polycaprolactone (PCL) chambers and decellularized adipose tissue (DAT). A miniaturized porous PCL chamber based on the scaling difference between a human and rabbit chest was fabricated and basic fibroblast growth factor (bFGF)-binding DAT was successfully prepared. In rabbit models, highly vascularized adipose tissue that nearly filled up the PCL chamber (5 mL) was generated de novo from 0.5 mL DAT. Moreover, the newly formed tissue had significantly higher expression of adipogenic genes compared to endogenous adipose tissues. The concept described here can be exploited to improve breast tissue engineering in clinical applications.