Multi-functional graphene as an in vitro and in vivo imaging probe.
A strategy has been developed for the synthesis of multi-functional graphene (MFG) using green synthetic approach and explored its biomedical application as a promising fluorescent marker for in vitro and in vivo imaging. In-situ microwave-assisted reduction and magnetization process was adopted to convert the graphene oxide into magnetic graphene within 1 min, which was further covalently modified to build a polyacrylic acid (PAA) bridge for linking the fluorescein o-methacrylate (FMA) to yield MFG with water-dispersibility (∼2.5 g/l) and fluorescence property (emission maximum at 526 nm). The PAA bridges also functions to prevent graphene-induced fluorescence quenching of conjugated FMA. The extent of reduction, magnetization, and functionalization was confirmed with TEM, AFM, Raman, XPS, FT-IR, TGA, and SQUID measurements. In vitro cytotoxicity study of HeLa cells reveal that MFG could stand as a biocompatible imaging probe with an IC(50) value of ∼100 μg/ml; whereas in vivo zebrafish study does not induce any significant abnormalities nor affects the survival rate after microinjection of MFG. Confocal laser scanning microscopy images reveals that MFG locates only in the cytoplasm region and exhibits excellent co-localization and biodistribution from the head to tail in the zebrafish. Our results demonstrate the applicability of graphene based fluorescence marker for intracellular imaging and, more significantly, as well as whole-animal imaging. Hence, MFG could preferentially serve as a dual functional probe in biomedical diagnostics.
Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan.
Ganesh
G
Gollavelli
Yong-Chien
YC
Ling
D000818:Animals; D017304:Annexin A5 / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003952:Diagnostic Imaging / Q000379:methods*; D005434:Flow Cytometry; D005453:Fluorescence; D006108:Graphite / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity; D006367:HeLa Cells; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D018613:Microscopy, Confocal; D015335:Molecular Probes / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity; D017382:Reactive Oxygen Species / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry; D018675:Toxicity Tests; D015027:Zebrafish
D017304:Annexin A5; D015335:Molecular Probes; D017382:Reactive Oxygen Species; D006108:Graphite; D007770:L-Lactate Dehydrogenase