HHC-36 antimicrobial peptide loading on silk fibroin (SF)/hydroxyapatite (HA) nanofibrous-coated titanium for the enhancement of osteoblast and bactericidal functions

Improving osseointegration together with preventing infections are the main challenges of using titanium-based implants in joint replacement surgeries. In this study, a hybrid composite of silk fibroin (SF)/hydroxyapatite (HA) nanofibrous mats was directly electrospun on titanium plates in order to mimic the bone extracellular structure and improve osteoconductivity. Afterwards, HHC-36 antimicrobial peptide (AMP) was immobilized on the fabricated mats using dopamine as a linker. The morphology, bioactivity, and adhesive strength of the coating were characterized, and the cellular responses and antimicrobial activity of the modified titanium plates were assessed. The results exhibited a strong interfacial attachment and homogenously dispersed HA nanoparticles in the electrospun nanofibers. No cytotoxicity was observed for MG-63 cells and the coating could effectively induce cell differentiation. The cumulative release profile of HHC-36 showed a burst release within first 3 h, followed by a slow and steady release over 48 h. Finally, AMP could eradicate the representative Gram-positive and Gram-negative bacteria within 3 h while maintaining the antimicrobial activity for up to 21 days. [GRAPHICS] .