Mocanu Aura-Cătălina, Miculescu Florin, Stan George E, Pandele Andreea-Mădălina, Pop Mihai Alin, Ciocoiu Robert Cătălin, Voicu Ștefan Ioan, Ciocan Lucian-Toma
Department of Metallic Materials Science, Physical Metallurgy, University Politehnica of Bucharest, 313 Splaiul Independentei, J Building, RO-060042 Bucharest, Romania.
National Institute of Materials Physics, 405A Atomistilor Street, RO-077125 Măgurele, Romania.
Materials (Basel). 2021 Apr 25;14(9):2198. doi: 10.3390/ma14092198.
A successful bone-graft-controlled healing entails the development of novel products with tunable compositional and architectural features and mechanical performances and is, thereby, able to accommodate fast bone in-growth and remodeling. To this effect, graphene nanoplatelets and -fibers were chosen as mechanical reinforcement phase and sacrificial template, respectively, and incorporated into a hydroxyapatite and brushite matrix derived by marble conversion with the help of a reproducible technology. The bio-products, framed by a one-stage-addition polymer-free fabrication route, were thoroughly physico-chemically investigated (by XRD, FTIR spectroscopy, SEM, and nano-computed tomography analysis, as well as surface energy measurements and mechanical performance assessments) after sintering in air or nitrogen ambient. The experiments exposed that the coupling of a nitrogen ambient with the graphene admixing triggers, in both compact and porous samples, important structural (i.e., decomposition of β-Ca(PO) into α-Ca(PO) and α-CaPO) and morphological modifications. Certain restrictions and benefits were outlined with respect to the spatial porosity and global mechanical features of the derived bone scaffolds. Specifically, in nitrogen ambient, the graphene amount should be set to a maximum 0.25 wt.% in the case of compact products, while for the porous ones, significantly augmented compressive strengths were revealed at all graphene amounts. The sintering ambient or the graphene addition did not interfere with the ability to generate 3D-channels-arrays at high temperatures. It can be concluded that both and graphene agents act as adjuvants under nitrogen ambient, and that their incorporation-ratio can be modulated to favorably fit certain foreseeable biomedical applications.
成功的骨移植控制愈合需要开发具有可调节成分、结构特征和机械性能的新型产品，从而能够适应快速的骨生长和重塑。为此，分别选择石墨烯纳米片和纳米纤维作为机械增强相和牺牲模板，并借助可重现技术将它们掺入通过大理石转化得到的羟基磷灰石和透钙磷石基质中。这些生物产品采用一步添加无聚合物制造路线制备，在空气或氮气环境中烧结后，对其进行了全面的物理化学研究（通过XRD、FTIR光谱、SEM、纳米计算机断层扫描分析以及表面能测量和机械性能评估）。实验表明，在致密和多孔样品中，氮气环境与石墨烯混合的耦合会引发重要的结构（即β-Ca(PO)分解为α-Ca(PO)和α-CaPO）和形态变化。针对所得骨支架的空间孔隙率和整体机械特性概述了某些限制和益处。具体而言，在氮气环境中，对于致密产品，石墨烯的含量应设定为最大0.25 wt.%，而对于多孔产品，在所有石墨烯含量下均显示出显著提高的抗压强度。烧结环境或石墨烯添加不会干扰在高温下生成三维通道阵列的能力。可以得出结论，在氮气环境下，二者和石墨烯试剂均作为佐剂，并且它们的掺入比例可以进行调节，以有利地适应某些可预见的生物医学应用。
