Built-in microscale electrostatic fields induced by anatase–rutile-phase transition in selective areas promote osteogenesis

• DOI: 10.1038/am.2016.9
• Publication Date: 2016-03-04T07:02:53Z
• Authors: Chengyun Ning; Peng Yu; Ye Zhu; Mengyu Yao; Xiaojing Zhu; Xiaolan Wang; Zefeng Lin; Weiping Li; Shuangying Wang; Guoxin Tan; Yu Zhang; Yingjun Wang; Chuanbin Mao
• Keywords: 01 natural sciences; Article; 0104 chemical sciences

Bone has a built-in electric field because of the presence of piezoelectric collagen. To date, only externally applied electric fields have been used to direct cell behavior; however, these fields are not safe or practical for in vivo use. In this work, for the first time, we use a periodic microscale electric field (MEF) built into a titanium implant to induce osteogenesis. Such a MEF is generated by the periodic organization of a junction made of two parallel semiconducting TiO2 zones: anatase and rutile with lower and higher electron densities, respectively. The junctions were formed through anatase-rutile-phase transition in selective areas using laser irradiation on the implants. The in vitro and in vivo studies confirmed that the built-in MEF was an efficient electrical cue for inducing osteogenic differentiation in the absence of osteogenic supplements and promoted bone regeneration around the implants. Our work opens up a new avenue toward bone repair and regeneration using built-in MEF.