Abstract: Objective To construct collagen/hyaluronic acid polyeletrolyte multilayer films on the surface of pure titanium disc and to evaluate its biocompatibility. Methods Pure titanium disc was first ground, polished and acid-etched with a mixture of H2SO4/H2O2, and then a basal surface with plenty of hydroxy group was obtained (set as control group). Collagen type Ⅰand hyaluronic acid was introduced onto this basal surface using layer by layer technique (set as test group). Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and contact angle measurement were used for surface characterization. Pre-osteoblasts were seeded on these 2 groups’ discs, and then cell attachment, cell proliferation and cell differentiation were evaluated. Results SEM analysis demonstrated that the pure titanium discs in the 2 groups both had very smooth surfaces, and were also covered with different granules in nano size. However, the nanoparticle of the control group was much bigger than that of the test group. XPS analysis showed that the element nitrogen content of the test surface dramatically increased with deposition number. Contact angle measurement showed that surface wettability of the test surface was dramatically altered with the deposition number. Nevertheless, the contact angle of the test surface was less than that of the control surface. Cell attachment and cell proliferation were much stimulated in the test group. Meanwhile, the cells grew on the surface of test group showed much stronger differentiation ability. Conclusions Collagen typeⅠand hyaluronic acid was successfully constructed on the titanium surface, and this coating promoted cell growth, showing good biocompatibility.

Key words: collagen type Ⅰ, hyaluronic acid , layer by layer technique.