Nanosilver-containing Hydroxyapatite Coatings By Electronical Deposition And Its Effects On Osteoblasts

As the increase of life quality, further improvements of bioactivity and safety of biomaterials are very much demanded. Hydroxyapatite (HAp) coated titanium is an ideal biomaterial commonly used for prosthesis and implants in surgery and orthopaedics. Hydroxyapatite, the main inorganic compound of natural bone, is osteoconductive and able to accelerate bone ingrowth. In addition, it is also selected as an attachment to the surface of implants during the early stages after implantation. Metallic titanium possesses high mechanical strength, excellent corrosion resistance, and good compatibility with bone, however, the bioactive environment on HAp may be also a soil for bacteria to propagate. Infection remains a leading cause of morbidity of injured patients. About 90% of all biomaterials still have bacteria after sterilization. Therefore, the antibacterial Hydroxyapatite-Nanosilver (HAp/Ag) composite coating on titanium has been attractive and valuable for clinical application.In this paper, the electrochemical deposition was employed to deposit a HAp/ Nanosilver composite coating on titanium. The experiments were carried out to study the conditions of preparation and properties (especially the antibacterial property) of the composite coating. The main results and progress of this work are listed as following:1. Preparation of Nanosilver-containing hydroxyapatite coatings by depositionObjective This research was aimed at the electrochemical deposition employed to deposit a HAp/Nanosilver composite coating on titanium surface. The electrodeposition was carried out to form a DCPD/Ag coating on the titanium plate in the solution containing CaCl2, NaH2PO4, AgNO3 and KI. The DCPD/Nanosilver composite coating was then transformed to HAp/Nanosilver by the treatment in 2.5M NaOH at 75℃for 3h. Scanning electro-microscope (SEM), X-ray diffraction (XRD), and X-ray energy dispersive spectrometer (EDS) were employed to characterize the obtained coating. Results The electrodeposition was successfully carried out to form a HAp/Nanosilver coating, and the diameter of Nanosilver was about 200～400nm. Conclusions The HAp/Nanosilver bioceramic coating on titanium surface was successfully carried out.2.The cell culturedThe isolated osteoblasts were cultured in DMEM medium until cells were lined up in one layer. Osteoblasts were identified by the ALP staining (Gomori Ca-Co method) and the bone nodule staining. The cell were trypsinized and removed from the flask and collected for next step.3. The effect of the HAp/Nanosilver coating on osteoblastsObjective The purpose of this study was to investigate the effect of the HAp/Nanosilver on osteoblasts. Methods Osteoblasts were cultured and identified in vitro. The reactions of osteoblasts on the coating were also evaluated by MTT assay and SEM observation. Results The HAp/Nanosilver bioceramic coating had good crystallization and homogeneousness on nano-scale surface morphology. Osteoblasts exhibited satisfactory bioactivity. Conclusions Due to the results of the study, the HAp/Nanosilver bioceramic coating on titanium surface is demonstrated to have promising prospects in the clinical future application.