Tissue engineering of white adipose tissue using hyaluronic acid-based scaffolds. I: in vitro differentiation of human adipocyte precursor cells on scaffolds

Background and aim of the study: Reconstruction of soft tissue defects is a challenge in plastic surgery and there is clinical need for adequate solutions. Aim of this study was to develop a biohybrid construct consisting of hyaluronic acid-based scaffolds and human adipocyte precursor cells as a soft tissue filler. Methods: Human adipocyte precursor cells were obtained by collagenase digestion of adipose tissue samples and seeded on hyaluronic acid-based spongy scaffolds of various degrees of esterification and pore size using different techniques. After cell attachment, adipose differentiation was induced by defined adipogenic factors under serum-free culture conditions. Results: Among the five different scaffold types under investigation the highest cell attachment rate was observed for the HYAFF® scaffold with 100% esterification and a mean pore size of 400 μm (HYAFF® 11lp). For inoculation of human adipocyte precursor cells on hyaluronic acid-based scaffolds a “drop-on” technique and low-pressure centrifugation using a Speed Vac® airfuge were compared. With respect to efficacy, cell distribution and simpleness the drop-on method proved to be the method of choice. In a serum-free medium supplemented with 66 n insulin, 100 n cortisol and 1 μg/ml troglitazone a substantial proportion of cells underwent adipose differentiation as assessed by lipid accumulation and emergence of glycerol-3-phosphate dehydrogenase activity, a lipogenic marker enzyme. Conclusion: Hyaluronic acid-based scaffolds appear to be a suitable three-dimensional carrier for the culture and in vitro differentiation of human adipocyte precursor cells.