Biomaterials Processing and Characterization Laboratory, Department of Materials Science and Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, Uttar Pradesh, India.
Department of Textile Technology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
Mater Sci Eng C Mater Biol Appl. 2018 Jul 1;88:13-24. doi: 10.1016/j.msec.2018.02.014. Epub 2018 Mar 1.
Post-implantation, vicinity acquired oxidative stress and bacterial infections lead to apoptosis with eventual bone-resorption and implant failure, respectively. Thus, in order to combat aforementioned complications, present research aims in utilizing antioxidant ceria (CeO) and antibacterial silver (Ag) reinforced hydroxyapatite (HA) composite with enhanced mechanical and cytocompatible properties. Highly dense (>90%) spark plasma sintered HA-based composites elicits enhanced elastic modulus (121-133 GPa) in comparison to that of HA. The antioxidant activity is quantified using ceria alone, wherein HA-ceria and HA-ceria-Ag pellets exhibits 36 and 30% antioxidant activity, respectively, accrediting ceria as a scavenger of reactive oxygen species, which was corroborated with the % Ce change quantified by X-ray photoelectron spectroscopy. The HA-Ag pellet shows antibacterial efficacy of ~61% for E. coli and ~53% for S. aureus, while a reduction of ~59% for E. coli and ~50% for S. aureus is observed for HA-ceria-2.5Ag pellet, affirming Ag reinforcement as an established bactericidal agent. The enhanced hydrophobicity on all the HA-based composites affords a high protein adsorption (24 h incubation). Further, elevated hFOB cell count (6.7 times for HA-ceria-Ag on day 7) with filopodial extensions (60-150 μm) and matrix-like deposition reflect cell-substrate intimacy. Thus, synergistic antioxidant ceria and antibacterial Ag reinforcement with enhanced mechanical integrity can potentially serve as cytocompatible porous bone scaffolds or bioactive coatings on femoral stems.
种植体植入后，周围环境中产生的氧化应激和细菌感染分别导致细胞凋亡、最终发生骨吸收和植入物失败。因此，为了应对上述并发症，本研究旨在利用具有增强的机械性能和细胞相容性的抗氧化铈（CeO）和抗菌银（Ag）增强的羟基磷灰石（HA）复合材料。与 HA 相比，高度致密（>90%）的火花等离子体烧结 HA 基复合材料具有更高的弹性模量（121-133 GPa）。单独使用 CeO2 来量化抗氧化活性，其中 HA-CeO2 和 HA-CeO2-Ag 小球分别表现出约 36%和 30%的抗氧化活性，证明 CeO2 是活性氧物质的清除剂，这与 X 射线光电子能谱定量的%Ce 变化一致。HA-Ag 小球对大肠杆菌的抗菌效果约为 61%，对金黄色葡萄球菌的抗菌效果约为 53%，而 HA-CeO2-2.5Ag 小球对大肠杆菌的抗菌效果降低约 59%，对金黄色葡萄球菌的抗菌效果降低约 50%，证实了 Ag 增强作为一种已确立的杀菌剂。所有基于 HA 的复合材料的增强疏水性赋予其高蛋白质吸附能力（24 小时孵育）。此外，HA-CeO2-Ag 上的 hFOB 细胞计数（第 7 天约增加 6.7 倍）升高，并有丝状伪足延伸（60-150 μm）和基质样沉积，反映了细胞与基底的亲密关系。因此，具有增强的机械完整性的协同抗氧化铈和抗菌 Ag 增强作用可能作为细胞相容性多孔骨支架或股骨柄上的生物活性涂层。
