Titanium‐Adhesive Polymer Nanoparticles as a Surface‐Releasing System of Dual Osteogenic Growth Factors

Abstract A titanium (Ti)‐adhesive nanoparticle is developed as a surface‐releasing system for dual osteogenic growth factors. The Ti‐adhesive nanoparticle is prepared by self‐assembly of a poly(L‐lactide‐co‐glycolide) (PLGA)‐grafted hyaluronic acid (HA) copolymer, followed by conjugation of catechol groups on nanoparticle surfaces. The nanoparticles consist of Ti‐adhesive peripheral catechol groups, anionic HA shells, and hydrophobic PLGA inner cores. The immobilization of the nanoparticles onto Ti substrates is successfully verified using various analytical tools including field‐emission scanning electron microscopy (Fe‐SEM), contact angle measurement, and X‐ray photoelectron spectroscopy (XPS). Positively charged dual growth factors, bone morphogenetic protein‐2 (BMP‐2) and insulin‐like growth factor‐1 (IGF‐1) are readily loaded onto the negatively charged HA shells of surface‐immobilized nanoparticles, which is confirmed by fluorescence microscopy. The Ti substrates with dual growth factor‐loaded nanoparticle‐immobilized nanoparticles remarkably promote the attachment, proliferation, spreading, and alkaline phosphatase (ALP) activity of human adipose‐derived stem cells (hADSCs).