Preparation and HL-7702 cell functionality of titania/chitosan composite scaffolds

Titania/chitosan composite scaffolds were prepared through a freeze-drying technique. The composite scaffolds were highly porous with the average pore size of 120-300 microm, and the titania (TiO(2)) powders were uniformly dispersed on the surface of the pore walls. The compressive strength of the composite scaffolds was significantly improved compared to that of pure chitosan scaffolds. Composite scaffold with 0.3 of TiO(2)/chitosan weight ratio showed the maximum compressive strength of 159.7 +/- 21 kPa. Hepatic immortal cell line HL-7702 was used as seeding cells on the scaffolds, and after different culture periods, cell attachment and function was analyzed. HL-7702 cells attached on the pore walls of the scaffolds with the spheroid shape after 1 day of culture, but more cell aggregations formed within the TiO(2)/chitosan composite scaffolds as compared to pure chitosan scaffolds. Liver-specific functions, albumin secretion and urea synthesis were detected using a spectrometric method. The results showed that albumin secretion and urea synthesis rate of HL-7702 cells slightly decreased with the culture time, and there was no significant difference between composite scaffolds and pure chitosan scaffolds. In conclusion, the TiO(2)/chitosan composite scaffolds possessed an improved mechanical strength compared to pure chitosan scaffolds and supported the attachment and functional expression of hepatocyte, implying their potential application in liver tissue engineering.