Fabrication of gelatin/calcium phosphate composite nanofibrous membranes by biomimetic mineralization

Based on the principles of biomimetic mineralization, biocomposite nanofibrous membranes were fabricated by the growth of CaP crystals on electrospun gelatin nanofibers to mimic both the physical architecture and chemical composition of natural bone ECM. Plenty more CaP crystals formed on the nanofibrous membrane containing Ca2+ ion precursors, in which these crystals were also observed on the inner side of membrane. The release rate of Ca2+ ion precursors from the nanofibrous membrane was slower than that of PO43− ion precursors, suggesting the existence of more strong intermolecular interaction between gelatin and Ca2+ ions. ATR-FTIR and XRD results clearly revealed the formation of CaP crystals mixed with apatite and CaCO3, or apatite and TCP on the membranes. The Ca/P molar ratio of crystals obtained from the XPS data was 2.03 and 1.60, which depended on the mineralization conditions. Higher amount of CaP crystals significantly accelerated the deposit rate of bone-like apatite on the surface of composite membrane, meaning to the improved in vivo bone bioactivity.

► Biocomposite membranes were fabricated by electrospinning and mineralization.
► The existence of strong intermolecular interaction between gelatin and Ca2+ ions was observed.
► The Ca/P molar ratio of crystals depended on the mineralization conditions.
► Higher amount of CaP crystals accelerated the deposit rate of bone-like apatite.