ABSTRACT
OBJECTIVE: To study the preparation and characteristics of silver-loaded nano-titania coating so as to develop a bioactive implant material with antibacterial property. METHODS: Plasma sprayed nano-titania coatings were immersed in 1%, 5%, and 9% AgNO3 solution to load silver. The loaded silver and its distribution were evaluated by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). After optimizing the preparation process, the release rate of silver from the nano-titania coating was measured in deionized water, its corresponding in vitro cytotoxicity and antibacterial activity were also examined. RESULTS: The loaded silver was in proper quantity and distributed evenly on the nano-titania coatings after immersion in 5% AgNO3. A burst release of the silver could be detected. The quick release of silver from the titania coatings sustained about 12 days in deionized water, which had no obvious influence on the surface morphology of titania coatings. The loaded silver did not inhibit the osteoblast proliferation (P = 0.1) and alkaline phosphatase expression (P = 0.06), however, it effectively inhibited the survival and growth of Staphylococcus aureus for 12 days: the zone of inhibition reached 3.81 +/- 0.8 mm with a bacteria killing rate of 100%. CONCLUSIONS: It is economical and effective to prepare the silver-loaded nano-titania coatings by 5% AgNO3 solution. The loaded silver has good antibacterial function, and shows no obvious effect on the physical and biological properties of nano-titania coatings.
Subject(s)
Anti-Bacterial Agents/pharmacology , Coated Materials, Biocompatible/pharmacology , Silver/chemistry , Titanium/pharmacology , Anti-Bacterial Agents/chemistry , Cell Proliferation/drug effects , Cell Survival/drug effects , Cells, Cultured , Coated Materials, Biocompatible/chemistry , Humans , Materials Testing , Microbial Sensitivity Tests , Nanoparticles/chemistry , Nanoparticles/ultrastructure , Orthopedic Procedures/instrumentation , Osteoblasts/cytology , Osteoblasts/drug effects , Prostheses and Implants , Staphylococcus aureus/drug effects , Staphylococcus aureus/growth & development , Titanium/chemistryABSTRACT
OBJECTIVE: To develop antibacterial coatings for orthopedic implants with a sustained release of drugs. METHODS: Wollastonite coatings were deposited on the titanium substrates by an atmospheric plasma spray system. After soaking in weight percent of 5% AgNO(3) solution for 24 h, the wollastonite coatings loading silver were obtained. Gentamicin were loaded on the wollastonite coatings by collagen grafting process. The release rates of drugs from wollastonite coatings were investigated by the in vitro solution soaking test. One strain of S. aureus was used in zone of inhibition test to evaluate the antibacterial properties of drug loaded wollastonite coatings, and the cell culture test was used to evaluate their cytotoxicity. RESULTS: Silver and gentamicin loaded wollastonite coatings were successfully prepared. The release of silver ions from the silver loaded wollastonite coatings lasted 50 d in deionized water, effectively inhibiting the growth of S. aureus for 40 d. While an initial burst release of gentamicin was found during the in vitro solution soaking test. The gentamicin released from gentamicin loaded wollastonite coatings can inhibit the growth of S. aureus for 18 d. Both the two kinds of antibacterial wollastonite coatings showed no adverse effect on cellular adhesion, proliferation and alkaline phosphatase expression. CONCLUSIONS: Compared with gentamicin loaded wollastonite coatings, silver loaded wollastonite coatings may have more promising clinical applications due to the even and long-time antibacterial agent release.
