Gokcekaya Ozkan, Ergun Celaletdin, Webster Thomas J, Bahadir Abdurrahman, Ueda Kyosuke, Narushima Takayuki, Nakano Takayoshi
Division of Materials and Manufacturing Science, Osaka University, Suita 565-0871, Japan.
Faculty of Mechanical Engineering, Istanbul Technical University, 34437 Istanbul, Turkey.
Materials (Basel). 2021 Jun 8;14(12):3158. doi: 10.3390/ma14123158.
Ag-containing hydroxyapatite (HA) can reduce risks associated with bacterial infections which may eventually require additional surgical operations to retrieve a failed implant. The biological properties of HA in such applications are strongly affected by its composition in terms of dopants as well as Ca/P stoichiometry, which can be easily controlled by altering processing parameters, such as precursor concentrations. The objective of this in vitro study was to understand the effect of variations in HA precursor solutions on antibacterial properties against and for promoting osteoblast (bone-forming cell) adhesion on Ag incorporated HA (AgHA) which has not yet been investigated. For this, two groups of AgHAs were synthesized via a precipitation method by adjusting precursor reactants with a stoichiometric value of 1.67, being either (Ca + Ag)/P (Ca-deficient) or Ca/(P + Ag) (P-deficient), and were characterized by XRD, FTIR, and SEM-EDS. Results showed that Ag incorporated into the Ca sites was associated with a corresponding OH vacancy. Additional incorporation of CO into PO sites occurred specifically for the P-deficient AgHAs. While antibacterial properties increased, osteoblast adhesion decreased with increasing Ag content for the Ca-deficient AgHAs, as anticipated. In contrast, significant antibacterial properties with good osteoblast behavior were observed on the P-deficient AgHAs even with a lower Ag content, owing to carbonated HA. Thus, this showed that by synthesizing AgHA using P-deficient precursors with carbonate substitution, one can keep the antibacterial properties of Ag in HA while reducing its toxic effect on osteoblasts.
含银羟基磷灰石（HA）可降低与细菌感染相关的风险，而细菌感染最终可能需要额外的外科手术来取出失败的植入物。在这类应用中，HA的生物学特性在很大程度上受到其掺杂剂组成以及钙磷化学计量比的影响，而这可以通过改变诸如前驱体浓度等加工参数轻松控制。这项体外研究的目的是了解HA前驱体溶液的变化对针对[此处原文缺失相关细菌名称]的抗菌性能以及促进成骨细胞（骨形成细胞）在尚未被研究的含银HA（AgHA）上黏附的影响。为此，通过沉淀法合成了两组AgHA，通过调整前驱体反应物使其化学计量值为1.67，分别为（钙+银）/磷（缺钙型）或钙/（磷+银）（缺磷型），并通过X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）和扫描电子显微镜-能谱仪（SEM-EDS）进行表征。结果表明，掺入钙位点的银与相应的羟基空位相关。缺磷型AgHA中特别发生了额外的碳酸根掺入磷氧位点的情况。正如预期的那样，对于缺钙型AgHA，随着银含量的增加，抗菌性能增强，但成骨细胞黏附性下降。相比之下，即使银含量较低，缺磷型AgHA由于碳酸化的HA，仍表现出显著的抗菌性能且成骨细胞行为良好。因此，这表明通过使用缺磷前驱体并进行碳酸根取代来合成AgHA，可以在保持HA中银的抗菌性能的同时降低其对成骨细胞的毒性作用。
