Construction And Property Study Of The Extracellular Matrix On The Surface Of Titanium Oxide With Nanotubes And Micro Grooves

Currently, the biomedical devices and materials used for the implantation treatment of cardiovascular diseases would would unavoidably bring damages to vascular intima, thus causing restenosis. It is generally regarded that endothelialization of devices surfaces is an important approach for solving this problem. Rencently, it is found that mesenchymal stem cells (MSC) could differentiate into vascular cells with the improvement of researches on stem cell functions. The early results by our team showed that MSC could be induced to differentiate towards smooth muscle cell class. Our further research will foucus on the improvement of materials surface properties and the regulation of MSC differentiation toward endothelial cells (EC). Meanwhile, it is concerned that the extracellular matrix secreed by endothelial cells possesses good biocompatibility and the possibility of inducing MSCs differentiate toward endothelial cells. Hence, extracellular matrix (ECM) modification was applicated on micro/nano structures, and the cell behavior was evaluated in this article, which provides a possible method for endotheliazation.Firstly, photolithography and anodic oxidation technology are used to prepare the samples:TiO2, nanotube sample (nano), two-dimentional micro/nano composite structure sample (gro-nano), micro groove sample (topo) and three-dimentional nano/micro composite structure sample (topo-nano). After that, EC ECM is obtained on the five types of samples by decellularization, and name as ECM/TiO2、ECM/nano、ECM/gro-nano、ECM/topo、 ECM/topo-nano samples. Optical microscope, fluorescence microscope, fourier transform infrared spectral, water contact angle and scanning electron microscope are used for sample characterization. Hemocompatibility, inflammatory reaction and EC culture are evaluated, and the influence toMSC is further researched.Results of material characterization shows that width of micro-ridges/grooves is 20μm/10μm, and the diameter of nanotubes is about 70nm. The EC ECM is observed on the modificated surface, the adhesion and spreading is investigated by ColIV staining.Our results demonstrate that the modification of ECM can greatly improve the hemocompatibiliy and decrease the inflammation reaction. EC culture shows that ECM can promote the adhesion and proliferation of ECs. The induction of cell oriented growth of gro-nano is weakened by ECM, but topo and topo-nano are not affected.The results of MSC culture indicate that after short time (5 days) culture, CD44 is positive while a-sma and vWF are negative. After long time (2 weeks) culture, ECMs on the surface of nano, gro-nano, topo and topo-nano tend of differentiate into smooth muscle cells, while ECM/TiO2、ECM/nano、ECM/gro-nano、ECM/topo、ECM/topo-nano show the trend of differentiation into ECs.