Nanocomposite scaffolds incorporated with hydrophobically-functionalized mesoporous nanocarriers for the effective loading and long-term delivery of osteogenic drugs

Development of scaffolds with a delivery potential of drugs in a sustained and controlled manner is of special importance to achieve favorable tissue responses and to maximize tissue regeneration capacity. Here we design novel nanocomposite fibrous scaffolds made of polycaprolactone (PCL) biopolymer incorporating surface-functionalized mesoporous nanospheres which are to carry hydrophobic osteogenic drug for a long-term therapeutic purpose in bone regeneration. After tailoring the surface of nanospheres hydrophobically, the target drug dexamethasone (Dex) was shown to incorporate effectively (as high as similar to 10 wt% loading efficiency), which was essentially released over a-week-period. When the Dex-nanoparticle complex was incorporated within PCL fiber matrix, the Dex release was continued over a month without showing an initial burst effect. The designed scaffolds sustainably delivering Dex drug demonstrated the therapeutic efficacy in vitro. Bone marrow mesenchymal stem cells cultured on the Dex-loaded scaffolds were substantially stimulated in the initial proliferation phase. Furthermore, osteogenic differentiation and cellular mineralization were significantly improved by the Dex delivery over a culture period of 21 days. Results demonstrated the novel nanocomposite fiber scaffolds are effective in loading hydrophobic Dex at large quantity and subsequently deliver over a long-term period, ultimately finding a potential therapeutic scaffold platform for bone regeneration.