Physicochemical and molecularbiological modification of artificial joint surfaces used the compromised patients

关节功能受损患者行全关节置换术后并发症发生率较高。可以推测，表面自由能的降低将降低人工关节表面的摩擦系数和细菌的吸附。氟烷基化是降低表面自由能的表面改性方法之一，人们推测，对用于全关节置换表面的生物材料进行改性，可以降低表面自由能，从而降低摩擦系数（CF）和细菌吸附。本研究的目的是验证这一假设，评估改性超高分子量聚乙烯（UHMWPE）和多晶氧化铝陶瓷（PCAC）的CF。UHMWPE和PCAC使用氟烷基封端的硅烷偶联剂进行氟烷基化。证实了生物材料的表面自由能降低和氟烷基化。用机械光谱仪使用圆盘几何形状随角速度变化测量UHMWPE和PCAC（对照或改性）之间的CF。在圆盘上施加250 kPa的垂直载荷。氟烷基化是一种简单的表面改性方法，它是在材料表面聚合一层很薄的氟烷基基团。氟烷基化生物材料有可能在临床上用于解决全关节置换术后的并发症。

Total joint replacement for the compromised patients has the higher ratio of complication. It can be speculated that the reduction of surface free energy would decrease friction coefficient of artificial joint surfaces and adsorption of bacterium. Fluoroalkylation is one of the surface modification methods, decreasing surface free energy.It has been hypothesized that modification of biomaterial used for total replacement joint surfaces may decrease coefficient of friction (CF) and adsorption of bacterium as a result of decreasing surface free energy. The purpose of this study is to test this hypothesis, assessing the CF of modified Ultra-High Molecular Weight Polyethylene (UHMWPE) and Polycrystal Alumina Ceramic (PCAC).UHMWPE and PCAC were fluoroalkylated using fluoroalkyl end-capped silane coupler. Decreasing surface free energy and fluoroalkylation for biomaterial were confirmed. CF between UHMWPE and PCAC (control or modified) was measured with a mechanical spectrometer using disc on disc geometry with changing of angular velocity. A vertical load was applied on the disc at 250 kPa. CF of modified PCAC against UHMWPE was significantly decreased at all range of angular velocity.Fluoroalkylation is an easy method of surface modification that polymerizes fluoroalkyl group on material surface in very thin layer. There has a possibility of clinical use in fluoroalkylation for biomaterial to resolve complications following total joint arthroplasty.