Surface Modification Of Poly (ε-caprolactone)s And Its Influence On Cell Behaviour

Surface physiochemical properties of biomaterials can not only affect cell adhesion and proliferation, But also their differentiation capacity and, ultimately, the quality of new tissue formation. Poly(s-caprolactone) (PCL) has been intensively investigated in recent years due to its good biocompatibility and biodegradability, as well as its excellent mechanical properties and machinability. However, because of its intrinsic hydrophobic and laking of bioactive functional groups on the main chain, the interactions between cells and PCL materials were hindered, which result in a limited application as tissue engineering scaffolds. Therefore, Surface modification of PCL has now became a hot way to improve its long-term biocompatibility in tissue engineering.The purpose of this dissertation is to synthesis surface modified poly(ε-caprolactone)s, including inclusion of functional amino groups and the specific targeting galactose. And to create a good artificial extracellular matrix and imitate the ECM in vivo which is favourable to growth of cells and tissues. Followed by investigating the effect of surface modification on cell behaviours.The main contents of this dissertation are summarized below:1. A series of NPCL with different pendant amino groups densities were synthesized by altering the monomer compositions. The water contact angle measurer, XPS and AFM were used to study the surface wettability, chemical composition and morphology of the corresponding NPCL membranes. The inclusion of amino groups improved the hydrophilcity and surface roughness of the Poly(ε-caprolactone). hMSCs were adopted to evaluate the biocompatibility of NPCL and the effect of surface properties on cell behavior. Due to the improved surface hydrophilcity, morphology and the electrostatic interaction between the positively charged materials and negatively charged cells, the hMSCs exhibited a promoted cell cell adhesion, proliferation and differentiation on NPCL membranes and the NPCL can be served as a great candidate for tissue engineering scaffolds.2. Using lactobionic acid (LA) and NPCL as raw material, 1-Ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDC) and N-hydroxysulfosuccinimide (NHS) as crosslinking agent to synthesis a new galactosylated poly(ε-caprolactone) (GPCL) with pendant galactose residues. The structures of polymers were characterized by 1H NMR, FT-IR, GPC, and proved the lactobionic molecules have been successfully coupled onto NPCL. The crystallinity and thermal properties of GPCL were studied by WAXD and DSC.3. The newly synthesized GPCL were casted into membranes, the HepG2 cells hMSCs were adopted to evaluate the effect of the inclusion of galactose on cell behavior. blood count and F-actin staining were used to investigate the cell adhesion efficiency of HepG2 cells on the GPCL membranes. CCK-8 cells counting kit were used to study the cell proliferation of HepG2 cells, SEM and Live-Dead assays were used to study the cell morphology and viability of cells, albumin secretion of HepG2 cells were tested to study the liver Functional maintenance. The cell-scaffold interactions between immobilized galactose ligand on GPCL and ASGPR on the surface of HepG2 cells guieded cell adhesion and promoted the proliferation and viability of HepG2 cells...