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 400microm (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 66nM insulin, 100nM cortisol and 1microg/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.