Ho Sunita P, Nakabayashi Nobuo, Iwasaki Yasuhiko, Boland Thomas, LaBerge Martine
Department of Preventive and Restorative Dental Sciences, University of California San Francisco, Box 0758 D2254, San Francisco, CA 94143, USA.
Biomaterials. 2003 Dec;24(28):5121-9. doi: 10.1016/s0142-9612(03)00450-2.
A fundamental understanding of surface properties of the biomaterials at a nanometer scale should be generated in order to understand cellular responses of the tissue to biomaterials thereby minimizing or eliminating tissue trauma at a macrometer scale. In this study poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) ([poly(MPC-co-BMA]) was evaluated as a potential coating material for vascular applications to provide smooth catheterization using atomic force microscopy (AFM) techniques.A uniform coating of [poly(MPC-co-BMA] equivalent to a thickness of 2.5 microm on a polyurethane (PU) catheter material was provided using dip casting technique. Using a contact mode AFM, no significant difference in surface roughness (R(a)) and frictional force (f) between uncoated (R(a)=10.2+/-1.9 nm, f=0.907+/-0.02) and coated (R(a)=11.7+/-1.8 nm, f=0.930+/-0.06) surfaces was observed under dry conditions. However, under wet conditions the R(a) of the coated surface (3.4+/-1.0 nm) was significantly lower than uncoated PU surface (9.0+/-1.8 nm). The coating on PU substrate offered the least frictional resistance (f=0.004+/-0.001) illustrating enhanced boundary lubrication capability due to hydration of phosphorylcholine polymer as compared to a significantly higher f for uncoated PU (0.017+/-0.007) surfaces. These tribological and chemical characteristics of the [poly(MPC-co-BMA)] coating could increase the overall efficacy of PU for clinical applications.
为了理解组织对生物材料的细胞反应，从而在宏观尺度上最小化或消除组织创伤，需要对生物材料在纳米尺度上的表面特性有基本的了解。在本研究中，使用原子力显微镜（AFM）技术评估了聚（2-甲基丙烯酰氧基乙基磷酰胆碱-co-甲基丙烯酸正丁酯）（[聚（MPC-co-BMA）]）作为血管应用潜在涂层材料的性能，以实现平滑导管插入。采用浸铸技术在聚氨酯（PU）导管材料上制备了厚度相当于2.5微米的[聚（MPC-co-BMA）]均匀涂层。在干燥条件下，使用接触模式原子力显微镜观察到未涂层（R(a)=10.2±1.9 nm，f=0.907±0.02）和涂层（R(a)=11.7±1.8 nm，f=0.930±0.06）表面的表面粗糙度（R(a)）和摩擦力（f）没有显著差异。然而，在潮湿条件下，涂层表面的R(a)（3.4±1.0 nm）明显低于未涂层的PU表面（9.0±1.8 nm）。PU基材上的涂层提供了最小的摩擦阻力（f=0.004±0.001），这表明与未涂层PU表面（0.017±0.007）相比，磷酰胆碱聚合物的水合作用增强了边界润滑能力。[聚（MPC-co-BMA）]涂层的这些摩擦学和化学特性可以提高PU在临床应用中的整体效果。
