Nanoporous structured carbon nanofiber-bioactive glass composites for skeletal tissue regeneration

Bioactive glass (BG) decorated nanoporous composite carbon nanofibers (PCNF-BG) were prepared for the purpose of obtaining effective substrates for skeletal tissue regeneration. The preparation was conducted by electrospinning of polyacrylonitrile (PAN)-polymethylmethacrylate (PMMA) blends with the addition of sol-gel precursors of 58s-type (mol%: 58% SiO₂-38% CaO-4% P₂O₅) BG, followed by high temperature thermal treatment. The removal of PMMA during the carbonization of PAN generated numerous slit-like nanoporous structures along CNFs, leading to a significant enhancement in the specific surface area, surface roughness and pore volume, which was confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) characterizations. PCNF-BG composites with different specific surface areas were biologically evaluated by experiments of biomineralization in simulated body fluid (SBF), in vitro MC3T3-E1 osteoblast proliferation and osteogenic differentiation. Compared to non-porous CNF/BG, the nanoporous structure distinctively enlarged the interfacial reaction area of the BG component with a medium environment and thus enhanced the bioactivity of CNFs by accelerating the dissolution of the BG component and providing abundant nucleation sites for hydroxyapatite depositions. The released ions displayed distinct promotion in proliferation and osteogenic differentiation of osteoblast cells, which promoted the osteocompatibility of carbon-based materials significantly.