Poly (hexamethylene biguanide), adsorbed onto Ti-Al-V alloys, kills slime-producing Staphylococci and Pseudomonas aeruginosa without inhibiting SaOs-2 cell differentiation

Abstract

Antimicrobial coating of implant material with poly(hexamethylene biguanide) hydrochloride (PHMB) may be an eligible method for preventing implant-associated infections. In the present study, an antibacterial effective amount of PHMB is adsorbed on the surface of titanium alloy after simple chemical pretreatment. Either oxidation with 5% H2O2 for 24 hr or processing for 2 hr in 5 M NaOH provides the base for the subsequent formation of a relatively stable self-assembled PHMB layer. Compared with an untreated control group, adsorbed PHMB produces no adverse effects on SaOs-2 cells within 48 hr cell culture, but promotes the initial attachment and spreading of the osteoblasts within 15 min. Specimens were inoculated with slime-producing bacteria to simulate a perioperative infection. Adsorbed PHMB reacts bactericidally against Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa after surface contact. Adhered SaOs-2 cells differentiate and produce alkaline phosphatase and deposit calcium within 4 days in a mineralization medium on PHMB-coated Ti6Al4V surfaces, which have been precontaminated with S. epidermidis. The presented procedures provide a simple method for generating biocompatibly and antimicrobially effective implant surfaces that may be clinically important.