Constructing three-dimensional nanofibrous bioglass/gelatin nanocomposite scaffold for enhanced mechanical and biological performance

- A BG/Gel scaffold was made by coating a bare BG scaffold with gelatin layers.
- The BG/Gel scaffold has 3D porous nanostructure of pristine bacterial cellulose.
- The BG/Gel scaffold has desirable porosity and tri-modal pore size.
- The BG/Gel shows enhanced mechanical and biological performance over bare BG.

The unique properties of bioactive glasses (BGs) make them promising for bone regeneration. Unfortunately, their brittleness greatly limits their clinical application. Combining BGs with polymers is an ideal solution such that their advantages (toughness of the polymers and bioactivity of BGs) can be combined. In this work, a novel nanocomposite biomaterial consisting of BG nanofibers with a diameter of only 31 nm and gelatin coating has been developed for bone regeneration. The BG nanofibrous scaffold was synthesized via a template-assisted sol-gel method by using natural three-dimensional (3D) bacterial cellulose as the template. The BG nanofibers were subsequently coated with gelatin followed by crosslinking with proanthocyanidin (PA) to yield the BG/gelatin nanocomposite scaffolds. Characterizations with scanning electron microscope (SEM), transmission electron microscope (TEM), atomic force microscope (AFM), mercury intrusion porosimetry, nitrogen adsorption-desorption, and mechanical testing reveal that the as-obtained BG/gelatin scaffolds maintain the 3D interconnected porous nanofibrous structure of pristine BC, show tri-modal pore structure (20-60 μm, 1-2 μm, 3-32 nm), and exhibit improved mechanical strength over bare BG scaffold. Cell studies using primary osteoblasts demonstrate more favorable cell growth, higher alkaline phosphatase (ALP) activity, and more calcium deposition on the BG/gelatin scaffold than other nanocomposite scaffolds as well as bare BG scaffold, strongly indicating a coating thickness-dependent synergistic effect between BGs and gelatin. This novel type of BG/gelatin scaffold has great potential in applications of bone regeneration.

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