Fabrication And Properties Of Galactosylated Chitosan/Polycaprolactone Hybrid Material For Bioartificial Liver

Tissue engineering for liver treatment has two major applications.One is the application in extracorporeal bioartificial liver(BLA) assist system,and the other one is for liver regeneration with implantable cell-scaffold constructs.A suitable extracellular matrix which can sustain long-term hepatocytes proliferation and maintenance of liver-specific functions is essential for both applications.In this work,a kind of galatosylated chitosan(GC) was prepared by coupling Lactobionic Acid(LA) to chitosan under the catalyzation of 1-Ethyl-3-(3-dimethyl aminopropyl) carbodiimide(EDC) and N-hydroxysuccinimide(NHS).The obtained GC having galatose moieties was characterized by infrared spectroscopy(IR), nuclear magnetic resonance(NMR) and elemental analysis,confirming the resultant molecular structure.Polycaprolactone(PCL) membrane was hydrolyzed in alkaline solution to introduce carboxyl groups which can react with GC to form a GC/PCL hybrid materials for hepatocytes culture.The results showed that hydrolysis could increase the density of carboxyl on the PCL membrane,which was controled by the concentration of solution,reaction time and reaction temperature.The hydrolysis could also change hydrophilicity of the PCL membrane due to the change of these surface chemical and physical properties.The amount of immobilized GC on the membrane could be altered by the change of hydrolysis time.Next,a hybrid porous three-dimensional scaffold was fabricated by using the same method.The polycaprolactone(PCL) scaffold was firstly prepared by a particle leaching method,which was then integrated with galactosylated chitosan(GC) via a method of hydrolysis to obtain a hybrid GC/PCL scaffold.The micro morphology, the density of carboxyl,the GC content and mechanical property of the hybrid scaffold were analyzed as well.In vitro culture of HepG2 cells on the hybrid scaffold demonstrated a good cell viability and long-term maintenance of liver-specific functions.All the results suggest that the GC/PCL scaffold could be a potential candidate applied for scaffolds bioreactor in bioartificial liver assist system.