Turk Mert, Deliormanlı Aylin M
Faculty of Engineering, Department of Metallurgical and Materials Engineering, Manisa Celal Bayar University, Manisa, Turkey.
J Biomater Appl. 2017 Jul;32(1):28-39. doi: 10.1177/0885328217709608. Epub 2017 May 25.
In this study, electrically conductive, borate-based, porous 13-93B3 bioactive glass composite scaffolds were prepared using a polymer foam replication technique. For this purpose, a slurry containing 40 vol% glass particles and 0-10 wt% graphene nanoplatelets was prepared by dispersing the particles in ethanol in the presence of ethyl cellulose. Composite scaffolds were subjected to a controlled heat treatment, in air atmosphere, to decompose the foam and sinter the glass particles into a dense network. It was found that the applied heat treatment did not influence the structure of graphene in the glass network. Graphene additions did not negatively affect the mechanical properties and enhanced the electrical conductivity of the glass scaffolds. In X-ray diffraction analysis, the crystalline peak corresponding to hydroxyapatite was observed in all the samples suggesting that all of the samples were bioactive after 30 days of immersion in simulated body fluid. However, Fourier transform infrared spectroscopy analysis and scanning electron microscope observations revealed that hydroxyapatite formation rate decreased with increasing graphene concentration especially for samples treated in simulated body fluid for shorter times. Based on the cytotoxicity assay findings, the MC3T3-E1 cell growth was significantly inhibited by the scaffolds containing higher amount of graphene compared to bare glass scaffolds. Best performance was obtained for 5 wt% graphene which yielded an enhancement of electrical conductivity with moderate cellular response and in vitro hydroxyapatite forming ability. The study revealed that the electrically conductive 13-93B3 graphene scaffolds are promising candidates for bone tissue engineering applications.
在本研究中，采用聚合物泡沫复制技术制备了具有导电性的硼酸盐基多孔13-93B3生物活性玻璃复合支架。为此，通过在乙基纤维素存在下将颗粒分散在乙醇中，制备了一种含有40体积%玻璃颗粒和0-10重量%石墨烯纳米片的浆料。将复合支架在空气气氛中进行可控热处理，以分解泡沫并将玻璃颗粒烧结成致密网络。结果发现，所施加的热处理不影响玻璃网络中石墨烯的结构。添加石墨烯不会对机械性能产生负面影响，反而提高了玻璃支架的导电性。在X射线衍射分析中，在所有样品中均观察到对应于羟基磷灰石的结晶峰，这表明所有样品在模拟体液中浸泡30天后均具有生物活性。然而，傅里叶变换红外光谱分析和扫描电子显微镜观察表明，随着石墨烯浓度的增加，羟基磷灰石的形成速率降低，特别是对于在模拟体液中处理时间较短的样品。基于细胞毒性试验结果，与裸玻璃支架相比，含有较高量石墨烯的支架显著抑制了MC3T3-E1细胞的生长。对于5重量%的石墨烯，获得了最佳性能，其提高了导电性，同时具有适度的细胞反应和体外羟基磷灰石形成能力。该研究表明，导电的13-93B3石墨烯支架是骨组织工程应用的有前途的候选材料。
