Journal of Nanomedicine Research Graphene Oxide for Biomedical Applications Submit Manuscript | http://medcraveonline.com Volume 5 Issue 6 - 2017 School of Engineering Sciences and Technology, University of Hyderabad, India *Corresponding author: Pradip Paik, School of Engineering Sciences and Technology, University of Hyderabad, Telangana, India, Tel: +91-040-2313-4457 (O); Email: Received: June 5, 2017 | Published: July 12, 2017 Mini Review J Nanomed Res 2017, 5(6): 00136 Abstract Graphene oxide (GO) is one of the most promising functional materials used in various applications like energy storage (batteries and supercapacitors) sensors, photocatalysis, electronics and in biomedicine. The last 10 years literature on GO for biomedical applications revealed and confirmed the scope of its potential capabilities as biomaterial. GO alone and its modified form with different materials (surface functionalization, immobilization of nanoparticles and composite formation) also proved as a multifunctional candidate for medical biotechnology. A material for its use in biomedical applications must be biocompatible and nontoxic to the living cells.. Although there are some concerns about the toxicity of the GO in specific cases, a dosage range and size effects reported in the literature to use it as a nontoxic materials. In view of all these points, an effort has been made to review and emphasize the scope of GO as a biomedical agent for the applications like targeted drug delivery, cancer theranostics, bioimaging and biosensors etc. Further, potential applications along with the future scope and limitations of GO have also been highlighted in this review. Keywords: Graphene oxide; Nanocomposites; Toxicity; Biosensors; Biomedicine; Cancer; Drug delivery Introduction GO is mainly used in biomedicine such as for drug delivery, cancer therapy, imaging and biosensors because of its physico chemical properties and biocompatibiliy. GO possesses unique structure i.e., graphene basal plane is attached with various biocompatible functional groups like carboxylic (COOH) and hydroxyl (OH) etc. The attached functional groups lead to further functionalization and conjugation or immobilization of other nanoparticles on its surface. Further, the size (number of layers, lateral dimension) and shape of GO plays an important role in deciding its properties that can be used in various applications. Thickness gradient of the GO sheets showed various functionality and tunable properties. Based on the reported literature in the past decade, a comprehensive review on the GO’s applications in the biomedicine has been summarized in to four main categories, such as a. Drug delivery and Cancer therapy. b. Biosensors. c. Bio-Imaging. d. Antibacterial activities and the Toxicity effects have also been discussed in the separate section. Discussion Drug delivery and cancer therapy Research on GO nanocomposites was reported extensively for its uses in drug delivery and cancer therapy. GO played a significant role in sorting out the drawbacks in dealing with cancer treatment. The extensive loading of anticancer drugs on GO is essentially influenced by the pi-pi stacking interactions. A hybrid nanocomposite of Hypocrellin B (HB) stacked GO can be synthesized through pi-pi interaction. This nanocomposite generates reactive oxygen species (ROS) efficiently and accelerate the killing of tumor cells under radiation [1]. Gold (Au) nanorods vesicle@ reduced graphene oxide (rGO) hybrid nanocomposite showed excellent drug release, enhanced photo thermal and photo acoustic effect to treat the cancer cells when loaded with commonly used anticancer drug doxorubicin (DOX). DOX release can be controlled by the near infrared (NIR) photothermal effect in intracellular acidic environment. This nanocomposite enables efficient inhibition of tumor growth due to sequential drug release and killing of infected cells [2]. GO on integration with NIR radiation produce heat inside cancer cells. Further it is reported that radionuclide I-131 labeled PEG with rGO can be used in potential combined therapies, e.g., photo thermal therapy (PTT) and radio therapy to treat the cancer cells. GO on excitation with NIR radiation, induce the photothermal effect while I-131 emits X-rays to kill the cancer cells. Due to this multiple effects the efficient elimination of tumor cells is possible. However, there is a concern on toxicity of this nanocomposites [3]. A core-shell nanocomposite of chitosan based polyseudorotaxane shell and (Fe 3 O 4 @GO@mSiO 2 ) core showed excellent pH dependent release. The extent of drug release can be controlled by changing the pH and the bursting of shell at 5.5 pH showed maximum release. Furthermore, this core- shell nanocomposite is quite soluble and formed stable colloid in biological fluids [4]. Hydrophobic drugs can also be delivered to the tumor cells using GO. Water insoluble anticancer drug SN38 (hydrophobic aromatic molecules including a camptothecin (CPT) analogue) can be made soluble for treating cancer cells efficiently