Surface characterization and biocompatibility of isotropic microstructure prepared by UV laser

• 作者: Yifei Wang Jing Zhang Kangmei Li Jun Hu
• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2021,（35）
• 页码范围: 136-146
• 页数: 11页
• 语种: 英文

摘要

To construct a structure with a structure-inducing function favors the personalized design and processing of the implant.Pulse lasers provide convenient conditions for the preparation of functional structures.The laser with a wavelength of 355 nm and pulse width of 50 ns was employed to prepare the structure with cauliflower-like (C_f),sputtered droplets (S_d),and lattice (L_t) characteristics.We analyzed the influence of laser process parameters on the formation of morphology,roughness,surface chemical composition(X-ray photoelectron spectroscopy,XPS),phase,and wettability of titanium alloys.We ascertained the proliferation and osteogenic differentiation of mesenchymal stem cells (MSCs) on C_f,S_d,and L_t struc-tures.The results showed that multiple depositions,aggregation,and oxidation of droplets with a thick oxide layer played an essential role in forming the C_f.With the reduction of scanning speed (v) and pitch(Dy),pollutants containing O-C=O were removed,and the chemical composition of the surface gradually transformed from Ti,Ti2O3,and TiO2 to complete TiO2.The rough C_f structure had super-hydrophilic and underwater oleophobic properties,and the near-surface was mostly rutile.Nevertheless,the high in-terfacial tension and fractal dimension inhibited cell adhesion and proliferation.Interestingly,the stem cells had outstanding osteogenic differentiation on the surface of the S_d structure with higher hardness(450 HV) and appropriate roughness (Sa=1μm).The L_t had a gradient of roughness and hardness at low laser spot overlap.Stem cells adhered and migrated to the ablation ring under locally amplified traction,and there was excellent osteogenic differentiation through mechanotransduction.