Preparation, structural characterization, and in vitro cell studies of three-dimensional SiO-CaO binary glass scaffolds built ofultra-small nanofibers.

Three-dimensional (3D) nanofibrous scaffolds hold great promises in tissue engineering and regenerative medicine. In this work, for the first time, 3D SiO-CaO binary glass nanofibrous scaffolds have been fabricated via a combined method of template-assisted sol-gel and calcination by using bacterial cellulose as the template. SEM with EDS, TEM, and AFM confirm that the molar ratio of Ca to Si and fiber diameter of the resultant SiO-CaO nanofibers can be controlled by immersion time in the solution of tetraethyl orthosilicate and ethanol. The optimal immersion time was 6h which produced the SiO-CaO binary glass containing 60at.% Si and 40at.% Ca (named 60S40C). The fiber diameter of 60S40C scaffold is as small as 29nm. In addition, the scaffold has highly porous 3D nanostructure with dominant mesopores at 10.6nm and macropores at 20μm as well as a large BET surface area (240.9mg), which endow the 60S40C scaffold excellent biocompatibility and high ALP activity as revealed by cell studies using osteoblast cells. These results suggest that the 60S40C scaffold has great potential in bone tissue regeneration.