We have developed a chitosan-based melanocyte patch to improve the drawbacks encountered in autologous melanocyte transplantation for vitiligo treatment by use of melanocyte suspension. Melanocytes spontaneously grow into three dimensional spheroids on chitosan-coated surface and melanocyte spheroids show a better survival in growth factor and serum-deprived condition. Hence, preculturing melanocytes into spheroids on chitosan surface can provide melanocytes a survival advantage in stringent conditions. Up to date, the mechanism of the melanocyte spheroid formation is not clear. It has been shown that certain factors in serum are crucial for multicellular spheroid formation in cancer cell lines. In this work, we investigate the effect of serum concentration on the melanocyte spheroid formation. The trend for melanocyte spheroid formation is gradually decreased when serum concentration is serially increased from 0% to 20%. Our result shows that melanocyte spheroid formation is not inhibited in the absence of serum and serum deprivation accelerates melanocyte spheroid formation. However, melanocyte growth is greatly reduced when serum is completely removed. Our results suggest that melanocyte spheroid formation on chitosan is not dependent on serum factors. However, the presence of serum contributes to the cell growth on chitosan-coated surface. This result is important in the future development of serum free culture system for spheroidal melanocyte patch.
Tuning microenvironment for multicellular spheroid formation in thermo-responsive anionic microgel scaffolds
