The influence of solvent formulations on thermosensitive hydroxybutyl chitosan hydrogel as a potential delivery matrix for cell therapy

Many cell delivery matrices have been developed due to the low transplantation efficiency of cell therapy. In the present study, thermosensitive hydroxybutyl chitosan (HBC) hydrogels were prepared with different formulations' solvent (Dulbecco's modified eagle's medium/phosphate buffered saline [DMEM/PBS], 0:100, 30:70, 50:50, 70:30, 100:0 [v/v]). Their gelation temperature was raised with DMEM ratio increase (from 9.5 °C to 20.9 °C). Pore sizes of HBC hydrogels treated with high ionic strength solutions became smaller. HUVECs cultured with HBC hydrogels exhibited proliferation in high DMEM ratio groups, and the optimal solvent formulation was DMEM/PBS 70:30 (v/v). Upon exposure to PBS, HUVECs encapsulated in HBC hydrogels could survive better than that when seeded on the surface of HBC hydrogels. These results demonstrated that HBC hydrogel could be a potential cell delivery matrix for cell therapy applications, especially when DMEM proportion in solvent formulations was higher than 50% (DMEM/PBS > 50:50 [v/v]).