Leng Yongxiang

Antithrombogenic investigation and biological behavior of cultured human umbilical vein endothelial cells on Ti-O film

Our previous research results have shown that the Ti-O films with appropriate characteristics possess great potentials for biomaterials application. In this paper, using plasma immersion ion implantation and deposition (PIII-D), titanium oxide thin films are fabricated onto silicon wafer. The antithrombogenesis of films is evaluated in vitro through the platelet adhesion investigation. The biological behavior of human umbilical vein endothelial cells (HUVEC) on the film surface is investigated in vitro by endothelial cell (EC) culture. Our results reveal that the crystalline Ti-O films exhibit attractive blood compatibility. The in vitro HUVEC-cultured investigation of Ti-O film surface has justified that the biological behavior of HUVECs on different structure surfaces is significantly different. The adherence, growth and proliferation of HUVECs to the crystalline Ti-O film surface are in order, by forming a perfect single layer, preserving the natural original shape and displaying the cobblestone road metal rank, and obviously superior to that on the amorphous Ti-O film surface. According to our study, the crystalline Ti-O film, with proper microstructure, is helpful for seeding ECs and can be used as a functional surface for the adherence and growth of ECs.

Microstructure and Mechanical Properties of Ti(Cr)SiC(O)N Coatings Deposited by Plasma Enhanced Magnetron Sputtering

Abstract TiSiCN, TiSiCON, TiCrSiCN, TiCrSiCON, CrSiCN and CrSiCON coatings have been deposited on WC-Co substrates and Si wafers using plasma enhanced magnetron sputtering (PEMS) technique. The microstructure, composition and mechanical properties of the non-oxygen coatings and oxygen-containing coatings were studied by XRD, SEM, EDS and load-depth-sensing indentation. The tribological behavior of the coatings against Al2O3 balls was conducted by pin-on-disc tests. The results show that TiSiCON, TiCrSiCON and CrSiCON coatings exhibit the face center cubic (fcc) TiN-type (or CrN-type) structure. The existence of oxygen will induce loose structure and more defects for TiSiCON, TiCrSiCON and CrSiCON coatings compared with TiSiCN, TiCrSiCN and CrSiCN, respectively. The addition of oxygen element would lead to the decrease of the hardness (H) and elasticity of Ti(Cr)SiCN coatings. TiCrSiCON and CrSiCON coatings with oxygen element have lower friction coefficients and wear rate compared with TiCrSiCN and CrSiCN coatings without oxygen, respectively. The TiSiCON with higher friction coefficient and wear rate shows poor abrasive wear resistance than TiSiCN.