Effects of femtosecond laser micropatterning on the surface properties and cellular response of biomedical tantalum-blended composites

Abstract

Poly(ε-caprolactone) (PCL) holds unique bioresorbability and competent biomechanical properties for tissue-engineering application. However, PCL is hydrophobic intrinsically and poor in cell-biomaterial interaction. In this study, we prepared a composite based on PCL and bioactive tantalum (Ta) to understand the effects of direct laser micropatterning on composite surface properties. The PCL/Ta composite after preparation was surface-patterned by femtosecond laser and characterized with surface morphology, crystal structure, chemical composition, wettability and cellular response of fibroblast. It was found that laser micropatterning enlarged the difference of wetting properties (∼15°) on PCL and PCL/Ta surfaces. The wetting changes was dependent on both material composition and laser-machined geometry. The blending of Ta enhanced surface wettability with prolonged contact time on the laser-machined line and rectangle microarrays. In vitro culture results showed beneficial effects of laser micropatterning on cell morphology of the fibroblasts. On the PCL/Ta surfaces with line and rectangle microarrays, the cells were more likely to bridge the sidewalls of the microgrooves, showing adaptive 3D morphologies to the micro/nano topographies on the sidewalls. These findings are envisaged to facilitate surface design and micropattern optimization for favorable tuning the cell response to biomedical PCL/Ta composites.

摘要

聚己内酯(PCL)具有良好的生物相容性、可降解性和优异的力学性能，广泛用于组织工程。然 而，PCL 的表面疏水性使生物蛋白附着困难。为了提升PCL 的表面性能，本文制备了钽(Ta)掺杂的 PCL复合薄膜(PCL/Ta)，并采用飞秒激光直写技术在其表面制备微图案阵列。本文的材料表征手段包 括:表面形貌分析、物相结构分析、化学组分分析、润湿性能测试和成纤维细胞的生物活性测试。润 湿性测试结果表明:钽掺杂和激光表面修饰都有助于提升膜材料表面的亲水性能和生物黏附性。细胞 实验结果表明:激光微图案表面修饰极大改善了成纤维细胞的细胞形貌;在微线阵列和微矩形阵列修 饰的复合薄膜表面，细胞更易于在微凹槽侧壁的杂合微纳结构上黏附和增殖。本研究通过材料组分设 计和微图案表面修饰实现了PCL/Ta 复合生物医用材料表面细胞生长的调控和优化，为深入理解细胞-材料的相互作用提供了新思路和新方法。