The actual use of many tissue engineering products is currently prevented by their inadequate long-term stability and dependence on animal derived-sera. Long-term stability is a prerequisite of maturation or time-dependent applications. Animal-derived sera are associated to high variations, the risk of contaminations and a cover-up of actual results 1. Artificially engineered adipose tissue is still highly needed to replace lost, damaged or burned subcutaneous soft tissue 2. Additionally adipose tissue test systems could serve to analyze (patho)physiological processes or screen for potential drugs 3. In the current study a novel soft, cellulose-based material was applied to enable efficient adipogenic differentiation of human primary adipose-derived stem cells (hASCs) and the long-term maturation of received adipocytes under chemically defined conditions.
HASCs were characterized in a serum-free environment. Adipogenic differentiation of hASCs was performed on a cellulose-based material with a chemically defined medium for 14 days. Subsequent maturation of the received adipocytes was accomplished with a chemically defined adipocyte maintenance medium for further 28 days. Results were compared to serum-containing controls and tissue culture polystyrene. Cell viability as well as adipocyte characteristics like accumulated lipids, expressed perilipin or released leptin were evaluated through various stains, western blot analysis and assays of cell supernatant.
With chemically defined media a differentiation of more than two thirds was achieved compared to serum-containing controls which was proven by accumulated lipids, expressed adipocyte markers as well as released leptin. Even after long-term maintenance of 28 days adipocytes were found to be adherent and viable on the cellulose-based material while cell-specific characteristics were preserved.
We developed defined media for the setup of adipose tissue and verified a maintaining effect of the cellulose-based material on cell adherence, viability and identity. The successful implementation of defined differentiation and maintenance is of fundamental character for all consecutive attempts and its transfer to the setup of other approaches will be of great value for the tissue engineering branch in general.