Synthesis, toxicity, biocompatibility, and biomedical applications of graphene and graphene-related materials

Abstract

Graphene is a two-dimensional atomic crystal, and since its development it has been applied in many novel ways in both research and industry. Graphene possesses unique properties, and it has been used in many applications including sensors, batteries, fuel cells, supercapacitors, transistors, components of high-strength machinery, and display screens in mobile devices. In the past decade, the biomedical applications of graphene have attracted much interest. Graphene has been reported to have antibacterial, antiplatelet, and anticancer activities. Several salient features of graphene make it a potential candidate for biological and biomedical applications. The synthesis, toxicity, biocompatibility, and biomedical applications of graphene are fundamental issues that require thorough investigation in any kind of applications related to human welfare. Therefore, this review addresses the various methods available for the synthesis of graphene, with special reference to biological synthesis, and highlights the biological applications of graphene with a focus on cancer therapy, drug delivery, bio-imaging, and tissue engineering, together with a brief discussion of the challenges and future perspectives of graphene. We hope to provide a comprehensive review of the latest progress in research on graphene, from synthesis to applications.

Keywords: biomedical applications; cancer therapy; drug delivery; graphene; graphene-related materials; tissue engineering; toxicity.

Figure 1

Antibacterial activity of GO and GO reduced by Evolvulus alsinoides leaf extract in Pseudomonas aeruginosa and Staphylococcus aureus. Notes: Cells were incubated with GO and rGO (100 μg/mL) separately. Samples were withdrawn at 4 hours and streaked on nutrient agar plates and incubated at 37°C for 24 hours. The differential toxicity of GO and rGO was observed both in Gram-negative and Gram-positive bacteria. Abbreviations: CON, control; GO, graphene oxide; rGO, reduced graphene oxide.

Figure 2

Toxicity of GO and Ta-rGO to human ovarian cancer cells. Notes: The morphology of human ovarian cancer cells was determined after 24 hours of exposure to GO and Ta-rGO (50 μg/mL). Images were captured by interference contrast light microscopy. Abbreviations: CON, control; GO, graphene oxide; rGO, reduced graphene oxide; Ta-rGO, GO reduced by Typha angustifolia leaf extract.

Figure 3

Biocompatibility of GO and G-rGO with human ovarian cancer cells. Notes: Human breast cancer cells were treated with GO and G-rGO (50 μg/mL) for 24 hours, and then the cells were imaged by light microscopy. Representative microscopic images of GO- and G-rGO-treated cells (50 μg/mL). Abbreviations: CON, control; G-rGO, glutathione-reduced GO; GO, graphene oxide; rGO, reduced graphene oxide.

Figure 4

Graphene and graphene-related materials can be used as probes for whole-body functional in vivo bio-imaging of live animals.

Figure 5

Effect of GO and A-rGO on the survival of MEFs. Notes: Micrographs showing PMEFC attachment and growth on a non-coated dish (control), a dish coated with GO, and a dish coated with A-rGO. All coated dishes and a control uncoated dish were placed in the same culture conditions and allowed to incubate for 24 hours at 37°C. GO and A-rGO were good substrates for cell growth. Abbreviations: CON, control; GO, graphene oxide; rGO, reduced graphene oxide; A-rGO, protein-reduced GO; MEFs, primary mouse embryonic fibroblast cells.