Construction Of Novel Thermo-Sensitive Hydrogel Culture System For Study Of BMSCs Adhesion And Detachment

Objective: To construct a novel thermo-sensitive hydrogel culture system using biomimetic method,and then investigate the optimum condition for adhesion and detachment of BMSCs sheet,providing experimental basis for biological tissue engineering.Methods:1)Dopamine(DA)monomer was dissolved in Tris-HCl buffer(0.01 mol/L,p H 8.5),then the solution was added and spread uniformly over tissue culture polystyrene(TCPS)surface at 60 ?C.After oxidation and self-polymerization of DA,polydopamine film was then deposited on TCPS surface.PNIPAM-NH2 was grafted on PDA-TCPS via schiff reaction or michael addition reaction to create PNIPAM-PDA-TCPS thermo-sensitive hydrogel culture system.The morphology,structure and composition of the composite films were observed by SEM and FTIR.The hydrophilicity of hydrogel films was measured via water contact angle measurement.2)BMSCs were cultured on TCPS and PNIPAM-PDA-TCPS thermo-sensitive hydrogel culture system at 37 ?C,5% CO2,and detachment at 20 ?C.Inverted microscope and MTT assay were used to investigate the growth condition and characteristic of BMSCs sheet,along with the cell sheet structure and optimum condition during detachment.Results and Conclusion:1)FTIR spectra showed characteristic absorption peaks of PDA and PNIPAM;The morphology of PDA-TCPS was observed by SEM which showed granular PNIPAM hydrogel grafted on PDA-TCPS surface;At 37 ?C,the PNIPAM-PDA-TCPS surface was relatively hydrophobic,while at 20 ?C,the hydrogel culture system exhibited relatively hydrophilic.2)MTT assay showed there was no statistical difference in cell viability between PNIPAMPDA-TCPS and TCPS groups,which demonstrated that PNIPAM-PDA-TCPS can be used for cell culture and related purposes.3)The culture of BMSCs showed that BMSCs can attach,grow and proliferate on PNIPAMPDA-TCPS at 37 ?C.After formation of compact sheet,intact BMSCs sheet can be detached from the thermo-sensitive hydrogel culture system,making it possible for construction of the engineered tissues.