Functionalized mesoporous bioactive glass scaffolds for enhanced bone tissue regeneration

Abstract

Event Abstract Back to Event Functionalized mesoporous bioactive glass scaffolds for enhanced bone tissue regeneration Deliang Zeng1 and Xinquan Jiang1 1 The Ninth People’s Hospital affiliated to Shanghai Jiao Tong University, School of Mediceine, Department of Prosthodontics, China Introduction: Mesoporous bioactive glass (MBG), which possesses excellent bioactivity and biocompatibility, has played an important role in bone tissue regeneration. However, it is difficult to prepare MBG scaffolds with sufficient compressive strength for bone regeneration, which greatly hinder its development and applications. Materials and Methods: a simple powder processing technique has been successfully developed to fabricate a novel kind of MBG scaffolds (MBGS). The resultant MBGS not only possesses higher compressive strength up to 0.3 MPa and interconnected macro- structure with pore diameter of 100-300 μm, but also inherits the highly ordered mesoporous structure from MBG. Furthermore, amino or carboxylic groups could be successfully grafted (donated as N-MBGS and C-MBGS, respectively) through a post-grafting process. Results and Discussion: It is revealed that both MBGS and functionalized MBGSs could significantly promote the proliferation and osteogenic differentiation of bone marrow stromal cells (bMSCs) by improving their bone-related gene expression (runt-related transcription factor 2 (runx2), alkaline phosphatase (ALP), bone sialoprotein (BSP) and osteocalcin (OCN)). Due to the positively charged surface, N-MBGS presented the highest in vitro osteogenic capability among three samples. Moreover, the in vivo testing results in a rabbit femur defect model demonstrated that N-MBGS could result in more bone regeneration, in comparison with MBGS and C-MBGS. In addition to the surface characteristics, it is believed that the decreased degradation rate of N-MBGS plays a vital role in the bone regeneration. Conclusions: MBGS modified with amino groups not only provided suitable surface for cell to proliferate and differentiate, but also decreased the degradation rate to adapt new bone formation. And the novel surface characteristics of N-MBGS combined with bMSCs exhibited the largest newly formed bone area in the rabbit femur defects model. These indicate that the N-MBGS scaffold facilely fabricated by combining the powder processing technique has practical application potentials for bone regeneration. Figure 1: Effective scaffold system for enhanced bone regeneration. Figure 2: (A) Digital microscopic photograph, (B) Reverse color photograph, (C) SEM image and (D) SEM image in high magnification of MBGS, E) The compressive strength and porosity of MBGS and the contrast. (*MBG scaffolds prepared by the polyurethane foam template method) Figure 3: The color images represent sequential fluorescent labeling of AL, CA and the cross sections of rabbit femurs implanted (Histological observation of new bone formation in three kinds of scaffolds after 12 weeks). We thank Pro. Yongsheng Li and PhD. Xingdi Zhang for their involvement in the present study. And this work was financially supported by the 973 Program (Grant No. 2012CB933600); the National Natural Science Foundation of China (Grant Nos. 81300853)