Robust and Antibacterial Polymer/Mechanically Exfoliated Graphene Nanocomposite Fibers for Biomedical Applications

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.