Jia Mary S, Hash Shelby, Reynoso Wendy, Elsaadany Mostafa, Ibrahim Hamdy
Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR 72701, USA.
Department of Mechanical Engineering, University of Tennessee, Chattanooga, TN 37403, USA.
Bioengineering (Basel). 2023 Jun 25;10(7):757. doi: 10.3390/bioengineering10070757.
Magnesium (Mg) has been intensively studied as a promising alternative material to inert metallic alloys for orthopedic fixation devices due to its biodegradable nature inside the body and its favorable biocompatibility. However, the low mechanical strength and rapid corrosion of Mg in physiological environments represent the main challenges for the development of Mg-based devices for orthopedic applications. A possible solution to these limitations is the incorporation of a small content of biocompatible nanoparticles into the Mg matrix to increase strength and possibly corrosion resistance of the resulting nanocomposites. In this work, the effect of adding boron nitride (BN) nanoparticles (0.5 and 1.5 vol.%) on the mechanical properties, corrosion behavior, and biocompatibility of Mg-based nanocomposites was investigated. The properties of the nanocomposites fabricated using powder metallurgy methods were assessed using microstructure analyses, microhardness, compression tests, in vitro corrosion, contact angle, and cytotoxicity tests. A significant increase in the microhardness, strength, and corrosion rates of Mg-BN nanocomposites was detected compared with those of pure Mg (0% BN). Crystalline surface post-corrosion byproducts were detected and identified via SEM, EDX, and XRD. Biocompatibility assessments showed that the incorporation of BN nanoparticles had no significant impact on the cytotoxicity of Mg and samples were hydrophilic based on the contact angle results. These results confirm that the addition of BN nanoparticles to the Mg matrix can increase strength and corrosion resistance without influencing cytotoxicity in vitro. Further investigation into the chemical behavior of nanocomposites in physiological environments is needed to determine the potential impact of corrosive byproducts. Surface treatments and formulation methods that would increase the viability of these materials in vivo are also needed.
镁（Mg）因其在体内的生物可降解性及其良好的生物相容性，作为骨科固定装置惰性金属合金的一种有前景的替代材料，已得到深入研究。然而，镁在生理环境中的低机械强度和快速腐蚀是开发用于骨科应用的镁基装置的主要挑战。解决这些限制的一种可能方法是在镁基体中加入少量生物相容性纳米颗粒，以提高所得纳米复合材料的强度并可能提高其耐腐蚀性。在这项工作中，研究了添加氮化硼（BN）纳米颗粒（0.5体积%和1.5体积%）对镁基纳米复合材料的力学性能、腐蚀行为和生物相容性的影响。使用粉末冶金方法制备的纳米复合材料的性能通过微观结构分析、显微硬度、压缩试验、体外腐蚀、接触角和细胞毒性试验进行评估。与纯镁（0% BN）相比，检测到Mg-BN纳米复合材料的显微硬度、强度和腐蚀速率显著增加。通过扫描电子显微镜（SEM）、能谱仪（EDX）和X射线衍射仪（XRD）检测并鉴定了晶态表面腐蚀后产物。生物相容性评估表明，BN纳米颗粒的加入对镁基材料的细胞毒性没有显著影响，并且根据接触角结果，样品具有亲水性。这些结果证实，向镁基体中添加BN纳米颗粒可以提高强度和耐腐蚀性，而不会在体外影响细胞毒性。需要进一步研究纳米复合材料在生理环境中的化学行为，以确定腐蚀性副产物的潜在影响。还需要能够提高这些材料在体内活性的表面处理和配方方法。
