Institute of Material Science and Engineering, Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Key Laboratory of Special Function Materials and Structure Design of Ministry of Education, Lanzhou University , Lanzhou 730000, China.
Department of Chemical Engineering and Biointerfaces Institute, University of Michigan , Ann Arbor, Michigan 48109-2136, United States.
ACS Appl Mater Interfaces. 2018 Jan 24;10(3):3002-3010. doi: 10.1021/acsami.7b17835. Epub 2018 Jan 12.
With the increasing demand for composites of multifunctional and integrated performance, graphene-based nanocomposites have been attracting increasing attention in biomedical applications because of their outstanding physicochemical properties and biocompatibility. High product yields and dispersion of graphene in the preparation process of graphene-based nanocomposites have long been a challenge. Further, the mechanical properties and biosafety of final nanocomposites are very important for real usage in biomedical applications. Here, we presented a novel high-throughput method of graphene on mechanical exfoliation in a natural honey medium, and a yield of ∼91% of graphene nanoflakes can be easily achieved with 97.76% of single-layer graphenes. The mechanically exfoliated graphene (MEG) can be well-dispersed in the poly(vinyl alcohol) (PVA) matrix. The PVA/MEG nanocomposite fibers are obtained by gel spinning and stretched 20 times. As a candidate for monofilament sutures, the PVA/MEG nanocomposite fibers with 0.3 wt % of MEG have an ultrahigh ultimate tensile strength of 2.1 GPa, which is far higher than that of the neat PVA fiber (0.75 GPa). In addition, the PVA/MEG nanocomposite fibers also have antibacterial property, low cytotoxicity, and other properties. On the basis of the above-mentioned properties, the effects of a common surgical suture and PVA/MEG nanocomposite fibers on wound healing are evaluated. As a result, the wounds treated with PVA/MEG nanocomposite fibers with 0.3 wt % of MEG show the best healing after 5 days of surgery. It is possible that this novel surgical suture will be available in the market relying on the gentle, inexpensive method of obtaining nonoxidized graphene and the simple process of obtaining nanocomposite fibers.
随着对多功能和集成性能复合材料需求的增加，基于石墨烯的纳米复合材料由于其出色的物理化学性质和生物相容性而在生物医学应用中引起了越来越多的关注。在制备基于石墨烯的纳米复合材料的过程中，如何提高石墨烯的产率并使其均匀分散一直是一个挑战。此外，最终纳米复合材料的机械性能和生物安全性对于其在生物医学应用中的实际使用非常重要。在这里，我们提出了一种在天然蜂蜜介质中机械剥离石墨烯的高通量方法，通过该方法可以轻松获得约 91%的石墨烯纳米片，其中单层石墨烯的比例高达 97.76%。机械剥离的石墨烯（MEG）可以很好地分散在聚乙烯醇（PVA）基质中。通过凝胶纺丝和拉伸 20 倍获得 PVA/MEG 纳米复合纤维。作为单丝缝线的候选材料，含有 0.3wt%MEG 的 PVA/MEG 纳米复合纤维具有超高的极限拉伸强度 2.1GPa，远高于纯 PVA 纤维（0.75GPa）。此外，PVA/MEG 纳米复合纤维还具有抗菌、低细胞毒性等性能。基于上述性能，评估了普通缝线和 PVA/MEG 纳米复合纤维对线缝合的影响。结果表明，在手术后 5 天，用含有 0.3wt%MEG 的 PVA/MEG 纳米复合纤维处理的伤口愈合效果最好。这种新型手术缝线有可能凭借获得非氧化石墨烯的温和、廉价的方法和获得纳米复合材料纤维的简单工艺而推向市场。
