表面图案化生物可降解聚膦腈制备及对成骨细胞的黏附

Preparation of surface-patterned biodegradable poly(organophosphazene) and its affinity to osteoblasts

背景:纳/微米尺度的拓扑结构可影响细胞在基体上的黏附和增殖。目的:改变制备条件,考察表面图案化聚(甘氨酸乙酯-丙氨酸乙酯)膦腈(PGAP)膜的表面性质对成骨细胞黏附和增殖的影响。方法:将PGAP溶于氯仿配成不同浓度溶液,在25℃、20%或80%湿度下浇铸成膜。采用SEM、AFM、XRD和水接触角进行表征,通过体外培养,采用黏附、增殖和细胞形态等评价膜表面特性对成骨细胞生物学行为的影响。结果与结论:高相对湿度环境有利于形成图案化表面,溶液浓度升高使图案化结构变得更加规整。溶液质量浓度120g/L时,可得到一种蜂巢结构表面,但当其升至160g/L后,反而不利于图案化表面的形成。高湿度环境下得到的膜表现出极性磷和氮原子在表面富集的现象。这些特性使表面图案化的PGAP膜更易于吸附蛋白质,从而使成骨细胞更易在其上黏附,增殖速度更快,细胞铺展状态也更好。说明溶液浓度和环境湿度是一种简便、可用于控制PGAP膜表面性质的方法,可用于对成骨细胞生物学行为的调控。

BACKGROUND： It has been identified that surface topographical structures in nano- or micro-scale can significantly affect the adhesion and proliferation of cells on artificial matrixes, and promote cell behaviors. OBJECTIVE： To investigate the effect of preparation parameters on the surface characteristics of poly（glycine ethyl ester-coalaine ethyl ester）phosphazene （PGAP） films, and the osteoblasts behaviors on PGAP films. METHODS： PGAP was dissolved in chloroform and polymeric solutions with different concentrations were obtained. Then the solutions were cast onto PTFE plates under relative humidity （RH） of 20% or 80% at 25 ℃. After 2 hours of solvent evaporation, the samples were vacuum-dried at 25 ℃ to constant weight. The resulted films were characterized with scanning electron microscope, atomic force microscope, and X-ray diffraction and water contact angle measurement to determine their surface morphology, composition and hydrophilicity. Mouse osteoblast-like cells OCT-1 were seeded onto the PGAP films, and the effect of surface features of PGAP films on cell behaviors were evaluated via determination of cell adhesion efficiency, proliferation and morphology. RESULTS AND CONCLUSION： The surface morphology and composition of solvent-cast PGAP films depended closely on the solution concentration and environmental RH. In comparison with smooth PGAP films prepared under low RH, surface-patterned PGAP films were obtained under high RH which contributed high surface roughness. The porous structure turned more regular as the solution concentration increasing, a kind of honeycomb structure was observed at the concentration of 120 g/L. However, the surface pattern was blurred when the solution concentration was further increased to 160 g/L, owing to the increased viscosity and the slowed solvent evaporation. Accumulation of polar phosphorous and nitrogen atoms on film surface has been found in the cases of PGAP films prepared under RH of 80%, which resulted in high protein absorption ability in combination with the increased surface roughness. These features facilitated the adhesion, spread and proliferation of mouse osteoblast-like cells OCT-1. All the results suggested that parameters like RH and solution concentration could be an easy way to alter the surface properties of PGAP films and thus could be used in the study of cell-matrix interaction.