Chondrogenic Differentiation Potential of Human Adipose Stem Cell Spheroid Forming on Glycol Chitosan and Gelatin Hydrogel

The repair of damaged cartilage is a challenge due to its hard self-repair in cartilage tissue engineering. Human adipose stem cells are proved that have the ability to differentiate into different linage including adipogenic, osteogenic and chondrogenic lineage. They are considered to be the cell sources in cartilage tissue engineering. Glycol chitosan, which is a soluble derivative of chitosan, is studied for cartilage repairing due to its similar structure to glycosaminoglycans in cartilage and keeps the properties of biocompatibility and degradability as chitosan. In this study, the hydrogel was combined by glycol chitosan and gelatin which made cells able to attach on and its performance in cell culture was researched. This hydrogel could make cells adhere on its surface and make the hASCs form a sphere structure after culturing for several days. The formation of spheroids was attributed to the releasing of gelatin and the main material, glycol chitosan. These spheroids were observed by SEM and fluorescence and tested their properties and gene expression of differentiation. There were studies showing that the stem cells in spheroids were viable mostly and had better differentiation ability. Moreover, the material we used was usually studied for cartilage tissue engineering. Therefor the chondrogenic differentiation potential of cells in spheroids was researched. We hope the GAGs-like glycol chitosan in hydrogel and formation of spheroids are able to promote the chondrogenic differentiation. The results showed the chondrogenic differentiation performance appeared in spheroids. Moreover, the spheroids formed with induction medium were larger and had more complete shape of sphere. They also had higher performance in chondrogenic differentiation.