Pulyala Praneetha, Singh Akshay, Dias-Netipanyj Marcela Ferreira, Cogo Sheron Compos, Santos Luciane S, Soares Paulo, Gopal Vasanth, Suganthan V, Manivasagam Geetha, Popat Ketul C
School of Electronics Engineering, Vellore Institute of Technology, Vellore, Tamil Nadu, India; Department of Mechanical Engineering/School of Biomedical Engineering, Colorado State University, Fort Collins, CO, USA.
Department of Mechanical Engineering/School of Biomedical Engineering, Colorado State University, Fort Collins, CO, USA; Pós-graduação em Ciências da Saúde, Escola de Medicina, Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil.
Mater Sci Eng C Mater Biol Appl. 2017 Jun 1;75:1305-1316. doi: 10.1016/j.msec.2017.02.175. Epub 2017 Mar 10.
The goal of this work was to enhance the mechanical strength and fracture toughness of brittle hydroxyapatite (HAP) by reinforcing it with nanocomposites such as graphene oxide (GO), carbon nanotubes (CNT) and Titania. The goal was also to evaluate the cytotoxicity and the cellular adhesion/proliferation of these composites. The composites were characterized for their crystallinity, functionality, morphology and mechanical properties. Altering the composition by adding 1wt% GO and CNT significantly altered the wettability, hardness and roughness. Further, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FITR) and X-ray photoelectron spectroscopy (XPS) results confirm the crystal structure, bulk chemical composition and surface elemental composition respectively of the composites. The bulk hardness of HAP with CNT was significantly higher than that of HAP. The wettability of HAP with GO was significantly lower than that of HAP with GO and Titania. Adipose Derived Stem Cells (ADSCs) were used for this study to evaluate cytotoxicity and viability. HAP with CNT and HAP with CNT and Titania were found to be least cytotoxic compared to other composites as evaluated by Lactate Dehydrogenase (LDH) assay and alamarBlue assay. ADSC adhesion and proliferation was investigated after 1, 4 and 7days of culture using fluorescence microscopy. All the composites nurtured ADSC adhesion and proliferation, however, distinct morphological changes were observed by using Scanning Electron Microscopy (SEM). Overall, these composites have the potential to be used as bone graft substitutes.
这项工作的目标是通过用氧化石墨烯（GO）、碳纳米管（CNT）和二氧化钛等纳米复合材料增强脆性羟基磷灰石（HAP）来提高其机械强度和断裂韧性。该目标还包括评估这些复合材料的细胞毒性以及细胞黏附/增殖情况。对这些复合材料的结晶度、功能、形态和机械性能进行了表征。通过添加1wt%的GO和CNT改变成分，显著改变了润湿性、硬度和粗糙度。此外，X射线衍射（XRD）、傅里叶变换红外光谱（FITR）和X射线光电子能谱（XPS）结果分别证实了复合材料的晶体结构、整体化学成分和表面元素组成。含有CNT的HAP的整体硬度显著高于HAP。含有GO的HAP的润湿性显著低于含有GO和二氧化钛的HAP。本研究使用脂肪干细胞（ADSCs）来评估细胞毒性和活力。通过乳酸脱氢酶（LDH）测定和alamarBlue测定评估发现，与其他复合材料相比，含有CNT的HAP以及含有CNT和二氧化钛的HAP的细胞毒性最小。在培养1、4和7天后，使用荧光显微镜研究了ADSC的黏附和增殖情况。所有复合材料都促进了ADSC的黏附和增殖，然而，通过扫描电子显微镜（SEM）观察到了明显的形态变化。总体而言，这些复合材料有潜力用作骨移植替代物。
