Polycaprolactone scaffold modified with galactosylated chitosan for hepatocyte culture

A suitable extracellular matrix that can maintain long-term proliferation and liver-specific functions of hepatocytes is essential for both extracorporeal bioartificial liver (BAL) assist systems and implantable cell-scaffold constructs. In this work, a polycaprolactone (PCL) scaffold was modified with galactosylated chitosan (GC) to achieve better bioactivity and mechanical stability. The PCL scaffold, prepared by a method of gelatin particle leaching, was hydrolyzed to produce carboxylic groups that were utilized to react with the amine groups of the GC, which was synthesized by grafting the galactose to chitosan. Results showed that the content of carboxylic groups was increased initially with the hydrolysis time until 10 min, at which a COOH density of 2.0x10(-5) mol/mg scaffold was reached. The incorporated GC amount showed a positive relationship with the COOH density and finally reached a 100 mu g/mg scaffold with a hydrolysis time of 15 min. The incorporated GC was rather stable against incubation in the medium, and could significantly enhance the compression strength of the PCL scaffold in a wet state. With the galactose ligands on the surface, the PCL scaffold could be better recognized by hepatocytes, and show better cell viability, spheroid formation and long-term maintenance of liver-specific functions such as albumin secretion.