Ginkgo biloba: a natural reducing agent for the synthesis of cytocompatible graphene.
BACKGROUND
Graphene is a novel two-dimensional planar nanocomposite material consisting of rings of carbon atoms with a hexagonal lattice structure. Graphene exhibits unique physical, chemical, mechanical, electrical, elasticity, and cytocompatible properties that lead to many potential biomedical applications. Nevertheless, the water-insoluble property of graphene restricts its application in various aspects of biomedical fields. Therefore, the objective of this work was to find a novel biological approach for an efficient method to synthesize water-soluble and cytocompatible graphene using Ginkgo biloba extract (GbE) as a reducing and stabilizing agent. In addition, we investigated the biocompatibility effects of graphene in MDA-MB-231 human breast cancer cells.


METHODS
Synthesized graphene oxide (GO) and GbE-reduced GO (Gb-rGO) were characterized using various sequences of techniques: ultraviolet-visible (UV-vis) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), scanning electron microscopy (SEM), atomic force microscopy (AFM), and Raman spectroscopy. Biocompatibility of GO and Gb-rGO was assessed in human breast cancer cells using a series of assays, including cell viability, apoptosis, and alkaline phosphatase (ALP) activity.


RESULTS
The successful synthesis of graphene was confirmed by UV-vis spectroscopy and FTIR. DLS analysis was performed to determine the average size of GO and Gb-rGO. X-ray diffraction studies confirmed the crystalline nature of graphene. SEM was used to investigate the surface morphologies of GO and Gb-rGO. AFM was employed to investigate the morphologies of prepared graphene and the height profile of GO and Gb-rGO. The formation of defects in Gb-rGO was confirmed by Raman spectroscopy. The biocompatibility of the prepared GO and Gb-rGO was investigated using a water-soluble tetrazolium 8 assay on human breast cancer cells. GO exhibited a dose-dependent toxicity, whereas Gb-rGO-treated cells showed significant biocompatibility and increased ALP activity compared to GO.


CONCLUSIONS
In this work, a nontoxic natural reducing agent of GbE was used to prepare soluble graphene. The as-prepared Gb-rGO showed significant biocompatibility with human cancer cells. This simple, cost-effective, and green procedure offers an alternative route for large-scale production of rGO, and could be used for various biomedical applications, such as tissue engineering, drug delivery, biosensing, and molecular imaging.
Department of Animal Biotechnology, Konkuk University, Seoul, South Korea.
Sangiliyandi
S
Gurunathan
Department of Animal Biotechnology, Konkuk University, Seoul, South Korea.
Jae Woong
JW
Han
Department of Animal Biotechnology, Konkuk University, Seoul, South Korea.
Jung Hyun
JH
Park
Department of Animal Biotechnology, Konkuk University, Seoul, South Korea.
Vasuki
V
Eppakayala
Department of Animal Biotechnology, Konkuk University, Seoul, South Korea.
Jin-Hoi
JH
Kim
D001672:Biocompatible Materials / Q000138:chemical synthesis* / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000473:pathology / Q000503:physiopathology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D020441:Ginkgo biloba / Q000737:chemistry*; D006108:Graphite / Q000138:chemical synthesis* / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000737:chemistry
D001672:Biocompatible Materials; D010936:Plant Extracts; D006108:Graphite
Fourier-transform infrared spectroscopy; Raman spectroscopy; UV-visible spectroscopy; alkaline phosphatase activity; atomic force microscopy; biocompatibility; cell viability; graphene; scanning electron microscopy