Bio-inspired immobilization of Lactoferrin on nanofiber guided membranes for engineering bone regeneration

Abstract

Induced bone regeneration indicates the process such that bone defects could be regenerated by facilitated healing through the use of osteoinductive signaling molecules such as small molecules, peptides or growth factors. In this thesis, we used lactoferrin, a multifunctional glycoprotein that has been recognized as an osteoinductive molecule with abilities was used to increase osteoblast survival, proliferation and differentiation for improved bone regeneration. Polydopamine coating would be a method to immobilize the protein onto scaffold because it successfully immobilized the proteins through Shiff’s base reaction and Michael addition. Given that, we prepared 50 g/mL lactoferrin immobilized PLLA electrospun nanofiber sheet using polydopamine coating method and investigated the effect of polydopamine coating time on immobilized amount of lactoferrin. After that, human adipose derived stem cells (hADSCs) were seeded on the scaffold to investigate the function of immobilized lactoferrin on cell adhesion, proliferation and osteogenic differentiation. As results, lactoferrin successfully activated the proliferation and increased osteogenic differentiation. Specifically, osteopontin (OPN) gene expression, which is an osteogenic marker, increased 6.85 ± 2.29 folds in the lactoferrin immobilized group. Also, anti-inflammatory effect was induced by lactoferrin. Tumor Necrosis Factor - alpha (TNF- gene expression inducing inflammatory response, 0.25 ± 0.10 folds decreased in lactoferrin immobilized group. In conclusion, low dosage of lactoferrin mediated by polydopamine showed significantly enhanced osteogenic potential of hADSCs when it was immobilized on the nanofiber and demonstrated anti-inflammatory effect in in vivo.