Study of chondrogenesis of umbilical cord mesenchymal stem cells in curdlan- poly(vinyl alcohol) composite hydrogels and its mechanical properties of freezing-thawing treatments

The curdlan gel is a natural material produced by bacteria. It utilizes chemical cross -linking reactions to form a 3D porous composite hydrogel, increasing its porosity and water content, and improving its mechanical properties. It can be used in tissue repair and regenerative medicine. Curdlan-Poly(vinyl alcohol) (PVA) composite hydrogel can rapidly swell within 1 min due to its porous structure. Compression tests confirmed that it still maintains its original mechanical strength, even after five repeated freeze -thaw (FT) processes, making it suitable for long-term cryopreservation. The purpose of this study is to transplant umbilical cord mesenchymal stem cells (UC-MSCs) on Curdlan-PVA composite hydrogel and observe the chondrocytes on the material. The results of using 4 ' ,6-diamidino-2-phenylindole (DAPI), hematoxylin and eosin (H &E), calcein-acetoxymethyl ester (calcein AM), and Collagen type II - Fluorescein isothiocyanate (FITC) staining, confirmed that UC-MSCs can attach and differentiate into chondrocytes on 3D Curdlan-PVA composite hydrogel.