Electrospun fibers immobilized with bone forming peptide-1 derived from BMP7 for guided bone regeneration

The development of ideal barrier membranes with appropriate porosity and bioactivity is essential for the guidance of new bone formation in orthopedic and craniomaxillofacial surgery. In this study, we developed bioactive electrospun fibers based on poly (lactide-co-glycolic acid) (PLGA) by immobilizing bone-forming peptide 1 (BFP1) derived from the immature region of bone morphogenetic protein 7 (BMP7). We exploited polydopamine chemistry for the immobilization of BFP1; polydopamine (PD) was coated on the electrospun PLGA fibers, on which BFP1 was subsequently immobilized under weakly basic conditions. The immobilization of BFP1 was verified by characterizing the surface chemical composition and quantitatively measured by fluorescamine assay. The immobilization of BPF1 on the electrospun fibers supported the compact distribution of collagen I and the spreading of human mesenchymal stem cells (hMSCs). SEM micrographs demonstrated the aggregation of globular mineral accretions, with significant increases in ALP activity and calcium deposition when hMSCs were cultured on fibers immobilized with BFP1 for 14 days. We then implanted the prepared fibers onto mouse calvarial defects and analyzed bone formation after 2 months. Semi-quantification of bone growth from representative X-ray images showed that the bone area was approximately 20% in the defect-only group, while the group implanted with PLGA fibers showed significant improvements of 44.27 ± 7.37% and 57.59 ± 15.24% in the groups implanted with PD-coated PLGA and with BFP1-coated PLGA, respectively. Based on these results, our approach may be a promising tool to develop clinically-applicable bioactive membranes for guided bone regeneration."