Simvastatin-loaded nanotubular mesoporous bioactive glass scaffolds for bone tissue engineering

Nanofibrous scaffolds with drug delivery functions are highly demanded in promoting tissue regeneration. Herein, we report a novel type of three-dimensional (3D) mesoporous bioactive glass (MBG) scaffolds. Such MBG scaffolds are consisted of 3D MBG nanotubes with highly ordered mesopores. The MBG nanotubes were prepared by template-assisted sol-gel procedure using bacterial cellulose (BC) as template and the mesopores were obtained using nonionic block copolymer (P123) as structure-directing agent. To improve bone regeneration capability, we loaded the nanotubular MBG scaffolds with simvastatin (SIM), as a representative small molecule, rather than commonly used growth factors which are large-sized, expensive, and fragile and may lead to serious side effects. By seeding human bone marrow stromal cells (hBMSCs) on the SIM-loaded nanotubular MBG scaffolds, the biocompatibility and bone regeneration were assessed by observing cell morphology, measuring cell viability and osteogenic-related gene expression. We found that SIM was successfully loaded into the nanotubular MBG scaffolds with a high loading efficiency of approximately 50%, and the nanotubular MBG scaffolds exhibited a sustained release of SIM. More importantly, the SIM-loaded nanotubular MBG scaffolds exhibited improved proliferation, ALP activity and osteogenic-related gene expression of hBMSCs over the bare MBG scaffold. We believe that the SIM-loaded nanotubular MBG scaffolds have great potential application in bone tissue regeneration.