Ibasco Suzette, Tamimi Faleh, Meszaros Robert, Nihouannen Damien Le, Vengallatore Srikar, Harvey Edward, Barralet Jake E
McGill University, Montreal, QC, Canada.
Acta Biomater. 2009 Jul;5(6):2338-47. doi: 10.1016/j.actbio.2009.03.006. Epub 2009 Mar 14.
Osteoconductive coatings may improve the clinical performance of implanted metallic biomaterials. Several low-temperature coating methods have been reported where a supersaturated solution is used to deposit typically apatitic materials. However, due to the very low solubility of apatite, the concentration of calcium and phosphate ions attainable in a supersaturated solution is relatively low ( approximately 1-2mM), thus coating formation is slow, with several solution changes required to form a uniform and clinically relevant coating. In order to avoid this problem, we present a novel method where substrates were initially sputter coated with pure magnesium metal and then immersed in differing phosphate solutions. In this method, upon immersion the implant itself becomes the source of cations and only the anions to be incorporated into the coating are present in solution. These ions react rapidly, forming a continuous coating and avoiding problems of premature non-localized precipitation. The different coatings resulting from varying the phosphate solutions were then characterized in terms of morphology and composition by microscopy and chemical analyses. Upon immersion of the sputter-coated metals into ammonium phosphate solution, it was found that a uniform struvite (MgNH(4)PO(4).6H(2)O) coating was formed. Upon subsequent immersion into a calcium phosphate solution, stable coatings were formed. The coated surfaces also enhanced both osteoblastic cellular adhesion and cell viability compared to bare titanium. The concept of sputter-coating a reactive metal to form an adherent inorganic metal coating appears promising in the field of developing rapid-forming low-temperature bioceramic coatings.
骨传导涂层可改善植入金属生物材料的临床性能。已经报道了几种低温涂层方法，其中使用过饱和溶液来沉积典型的磷灰石材料。然而，由于磷灰石的溶解度非常低，过饱和溶液中可达到的钙和磷酸根离子浓度相对较低（约1-2mM），因此涂层形成缓慢，需要多次更换溶液才能形成均匀且与临床相关的涂层。为了避免这个问题，我们提出了一种新方法，即首先用纯镁金属对基底进行溅射涂层，然后将其浸入不同的磷酸盐溶液中。在这种方法中，浸入后植入物本身成为阳离子的来源，而溶液中仅存在要掺入涂层的阴离子。这些离子迅速反应，形成连续涂层并避免过早的非局部沉淀问题。然后通过显微镜和化学分析对因改变磷酸盐溶液而产生的不同涂层的形态和成分进行表征。将溅射涂层金属浸入磷酸铵溶液中后，发现形成了均匀的鸟粪石（MgNH(4)PO(4).6H(2)O）涂层。随后浸入磷酸钙溶液后，形成了稳定的涂层。与裸露的钛相比，涂层表面还增强了成骨细胞的粘附和细胞活力。在开发快速形成的低温生物陶瓷涂层领域，溅射涂覆活性金属以形成附着的无机金属涂层的概念似乎很有前景。
