Cunha Alexandre, Zouani Omar Farouk, Plawinski Laurent, Botelho do Rego Ana Maria, Almeida Amélia, Vilar Rui, Durrieu Marie-Christine
Instituto Superior Técnico-Universidade de Lisboa, CeFEMA-Centro de Física e Engenharia de Materiais Avançados, Av. Rovisco Pais, 1049 001 Lisbon, Portugal.
Nanomedicine (Lond). 2015;10(5):725-39. doi: 10.2217/nnm.15.19.
The aim of the present work was to investigate ultrafast laser surface texturing as a surface treatment of Ti-6Al-4V alloy dental and orthopedic implants to improve osteoblastic commitment of human mesenchymal stem cells (hMSCs).
MATERIALS & METHODS: Surface texturing was carried out by direct writing with an Yb:KYW chirped-pulse regenerative amplification laser system with a central wavelength of 1030 nm and a pulse duration of 500 fs. The surface topography and chemical composition were investigated by scanning electron microscopy and x-ray photoelectron spectroscopy, respectively. Three types of surface textures with potential interest to improve implant osseointegration can be produced by this method: laser-induced periodic surface structures (LIPSSs); nanopillars (NPs); and microcolumns covered with LIPSSs, forming a bimodal roughness distribution. The potential of the laser treatment in improving hMSC differentiation was assessed by in vitro study of hMSCs spreading, adhesion, elongation and differentiation using epifluorescence microscopy at different times after cell seeding, after specific stainings and immunostainings.
Cell area and focal adhesion area were lower on the laser-textured surfaces than on a polished reference surface. Obviously, the laser-textured surfaces have an impact on cell shape. Osteoblastic commitment was observed independently of the surface topography after 2 weeks of cell seeding. When the cells were cultured (after 4 weeks of seeding) in osteogenic medium, LIPSS- and NP- textured surfaces enhanced matrix mineralization and bone-like nodule formation as compared with polished and microcolumn-textured surfaces.
The present work shows that surface nanotextures consisting of LIPSSs and NPs can, potentially, improve hMSC differentiation into an osteoblastic lineage.
本研究旨在探讨超快激光表面织构化作为一种对Ti-6Al-4V合金牙科和骨科植入物的表面处理方法，以改善人间充质干细胞（hMSCs）的成骨细胞定向分化。
使用中心波长为1030nm、脉冲持续时间为500fs的Yb:KYW啁啾脉冲再生放大激光系统通过直接写入进行表面织构化。分别通过扫描电子显微镜和X射线光电子能谱研究表面形貌和化学成分。通过这种方法可以产生三种可能有助于改善植入物骨整合的表面织构：激光诱导周期性表面结构（LIPSSs）；纳米柱（NPs）；以及覆盖有LIPSSs的微柱，形成双峰粗糙度分布。在细胞接种后的不同时间，通过落射荧光显微镜对hMSCs进行铺展、黏附、伸长和分化的体外研究，并进行特定染色和免疫染色，评估激光处理在改善hMSC分化方面的潜力。
激光织构化表面的细胞面积和粘着斑面积低于抛光的参考表面。显然，激光织构化表面对细胞形状有影响。细胞接种2周后，无论表面形貌如何，均观察到成骨细胞定向分化。当细胞在成骨培养基中培养（接种4周后）时，与抛光和微柱织构化表面相比，LIPSSs和NP织构化表面增强了基质矿化和骨样结节形成。
本研究表明，由LIPSSs和NPs组成的表面纳米织构有可能改善hMSC向成骨细胞谱系的分化。
