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

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.