Ectopic adipogenesis of preconditioned adipose-derived stromal cells in an alginate system

Soft tissue substitutes are increasingly needed in reconstructive and plastic surgery, although difficulties arise when autografts or allografts have to provide long-term satisfactory replacement in soft tissue restoration. Adipose tissue engineering has highlighted the possibility of soft tissue restoration by using regeneration strategies. As few reports exist regarding adipose regeneration with alginate systems mixed with adipose-derived stromal cells (ASCs), the present study has attempted to evaluate the adipogenic differentiation of ASCs isolated from BALB/c mice in vitro and to define the potential of ASCs to form ectopic adipose tissue in an alginate system with subcutaneous implantation in nude mice. After 10 days induction in vitro, prediferentiated ASCs were seeded in an alginate gel system and implanted subcutaneously into the dorsum of nude mice. Adipogenesis of the newly formed tissue at 8 weeks post-implantation was confirmed by oil red O staining, reverse transcription/polymerase chain reaction, and Western blot analysis. This study thus provides evidence that the alginate system has the ability to form ectopic adipose tissue when mixed with predifferentiated ASCs. The results also supply clues for improving adipose tissue engineering and soft tissue defects repair in adults.