We prepared silver nanoparticles/polyethyleneimine-reduction graphene oxide (AgNP/rGO-PEI) composite materials, and evaluated their quality performance in our center. Firstly, we prepared AgNP/rGO-PEI, and then analysed its stability, antibacterial activity, and cellular toxicity by comparing the AgNP/rGO-PEI with the silver nanoparticles (PVP/AgNP) modified by polyvinylpyrrolidone. We found in the study that silver nanoparticles (AgNP) distributed relatively uniformly in AgNP/rGO-PEI surface, silver nanoparticles mass fraction was 4.5%, and particle size was 6-13 nm. In dark or in low illumination light intensity of 3 000 lx meter environment (lux) for 10 days, PVP/AgNP aggregation was more obvious, but the AgNP/rGO-PEI had good dispersibility and its aggregation was not obvious; AgNP/rGO-PEI had a more excellent antibacterial activity, biological compatibility and relatively low biological toxicity. It was concluded that AgNP/rGO-PEI composite materials had reliable quality and good performance, and would have broad application prospects in the future.
Graphene and its derivatives have good physical and chemical properties and biological properties, which can promote stem cell proliferation and osteogenic differentiation, and it has antibacterial properties and drug release property. Therefore, it has broad application prospects in the field of orthopedic biomaterials. This paper mainly introduces the research progress of graphene nanocomposite materials applied in the aspects of bone tissue engineering scaffold, bone repair, bone graft materials, etc. in order to provide desirable information for the future application basis and clinical research.
Objective To explore the construction and biocompatibility in vitro evaluation of the electrospun-graphene (Gr)/silk fibroin (SF) nanofilms. Methods The electrostatic spinning solution was prepared by dissolving SF and different mass ratio (0, 5%, 10%, 15%, and 20%) of Gr in formic acid solution. The hydrophilia and hydrophobic was analyzed by testing the static contact angle of electrostatic spinning solution of different mass ratio of Gr. Gr-SF nanofilms with different mass ratio (0, 5%, 10%, 15%, and 20%, as groups A, B, C, D, and E, respectively) were constructed by electrospinning technology. The structure of nanofilms were observed by optical microscope and scanning electron microscope; electrochemical performance of nanofilms were detected by cyclic voltammetry at electrochemical workstation; the porosity of nanofilms were measured by n-hexane substitution method, and the permeability were observed; L929 cells were used to evaluate the cytotoxicity of nanofilms in vitro at 1, 4, and 7 days after culture. The primary Sprague Dawley rats’ Schwann cells were co-cultured with different Gr-SF nanofilms of 5 groups for 3 days, the morphology and distribution of Schwann cells were identified by toluidine blue staining, the cell adhesion of Schwann cells were determined by cell counting kit 8 (CCK-8) method, the proliferation of Schwann cells were detected by EdU/Hoechst33342 staining. Results The static contact angle measurement confirmed that the hydrophilia of Gr-SF electrospinning solution was decreased by increasing the mass ratio of Gr. Light microscope and scanning electron microscopy showed that Gr-SF nanofilms had nanofiber structure, Gr particles could be dispersed uniformly in the membrane, and the increasing of mass ratio of Gr could lead to the aggregation of particles. The porosity measurement showed that the Gr-SF nanofilms had high porosity (>65%). With the increasing of mass ratio of Gr, the porosity and conductivity of Gr-SF nanofilm increased gradually, the value in the group A was significantly lower than those in groups C, D, and E (P<0.05). In vitro L929 cells cytotoxicity test showed that all the Gr-SF nanofilms had good biocompatibility. Toluidine blue staining, CCK-8 assay, and EdU/Hoechst33342 staining showed that Gr-SF nanofilms with mass ratio of Gr less than 10% could support the survival and proliferation of co-cultured Schwann cells. Conclusion The Gr-SF nanofilm with mass ratio of Gr less than 10% have proper hydrophilia, conductivity, porosity, and other physical and chemical properties, and have good biocompatibility in vitro. They can be used in tissue engineered nerve preparation.
Objective To review the research progress of graphene and its derivatives in repair of peripheral nerve defect. Methods The related literature of graphene and its derivatives in repair of peripheral nerve defect in recent years was extensively reviewed. Results It is confirmed by in vitro and in vivo experiments that graphene and its derivatives can promote cell adhesion, proliferation, differentiation and neurite growth effectively. They have good electrical conductivity, excellent mechanical properties, larger specific surface area, and other advantages when compared with traditional materials. The three-dimensional scaffold can improve the effect of nerve repair. Conclusion The metabolic pathways and long-term reaction of graphene and its derivatives in the body are unclear. How to regulate their biodegradation and explain the electric coupling reaction mechanism between cells and materials also need to be further explored.