| Paper description |
Re-infection of implants during the service life troubles the patients. Traditionally physical loading or chemical bonding of antibacterial agents on implant surfaces can't settle the repeated bacteria invasion after a period time of implantation. In this work, a pH-responsive ECM coating was fabricated on Ti. It is consisted of hydroxyapatite (HA) nanorods, antimicrobial peptide (AMP) cross-linked collagen I nanonets (CA nanonets) and physically loaded AMPs. CA nanonets formed in the interspaces of HA nanorods have an average pore size of 46.5 nm. With the increased weight ratio of AMP cross-linkers in collagen I (from 0 to 1:3), isoelectric points of CA nanonets increased. CA nanonets linked with 50 Wt% of AMPs (HCA1) had the isoelectric point of about 7, and its zeta potential shifted from electronegativity to electropositivity when pH value changed from 7.4 to 6.0. Compared with other nanonets, HCA1 showed pH-responsively blast releasing of physically loaded AMPs. It is due to the electrostatic repulsion between the physically absorbed AMPs and HCA1 after potential shifted. In vitro, all the CA nanonets were cytocompatible and exhibited significantly short-term antibacterial performance, however, just HCA1 showed outstanding long-time responsive antibacterial activity; in vivo, HCA1 inhibit bacterial infection and suppresses inflammatory response, especially in a re-infected model, indicating its potential application on Ti implants in the risk of re-infection. |
(创新港)
