Abstract
Adipose tissue-derived stem/progenitor cells (ASCs) have attracted attention as a promising cell source that replaces marrow stromal cells (MSCs). In this study, we developed an improved method for the cryopreservation by changing the component of a freezing medium (three freezing mediums including 10% DMSO, culture medium-DMSO, CELLBANKER 2, and culture medium-DMSO (serum-free), 0.1mol/L maltose and 1% sericin). Sericin, a protein hydrolysate (with an average molecular weight of 30kDa) is very rich in serine and obtained from raw silk during the degumming process. We further measured the viability and the adipo/osteogenic potential of frozen human ASCs using three freezing mediums. After thawing of cryopreserved human ASCs in the freezing medium, the cell viabilitiy was shown to be more than 95% from the trypan blue dye exclusion test. The cell proliferation of thawed human ASCs in CELLBANKER 2, and culture medium-DMSO (serum-free), 0.1mol/L maltose and 1% sericin had higher rate in comparison to culture medium-DMSO. The adipogenic induction shows similar tendency as cell proliferation. Additionally, we investigated osteogenic differentiation of cryopreserved human ASCs for 4 weeks. The frozen human ASCs were positive for von Kossa staining, suggesting that the cells had osteogenic differentiation capabilities.
