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Thakur M.,University of Mumbai | Thakur M.,Nsn Research Center For Nanotechnology And Bio Nanotechnology | Mewada A.,Nsn Research Center For Nanotechnology And Bio Nanotechnology | Mewada A.,Walchand Center for Research in Nanotechnology and Bio nanotechnology b | And 5 more authors.
Materials Science and Engineering C | Year: 2016

An economical green-chemistry approach was used for the synthesis of aqueous soluble graphene quantum dots (GQDs) from cow milk for simultaneous imaging and drug delivery in cancer. The GQDs synthesized using one-pot microwave-assisted heating were multi-fluorescent, spherical in shape having a lateral size of ca. 5 nm. The role of processing parameters such as heating time and ionic strength showed a profound effect on photoluminescence properties of GQDs. The GQDs were N-doped and oxygen-rich as confirmed by X-ray photoelectron spectroscopy (XPS) analysis. Cysteamine hydrochloride (Cys) was used to attach an anti-cancer drug berberine hydrochloride (BHC) on GQDs forming GQDs@Cys-BHC complex with c.a. 88% drug loading efficiency. In vitro drug release was studied at the acidic-basic environment and drug kinetics was studied using pharmacokinetic statistical models. The GQDs were biocompatible on L929 cells whereas theranostic GQDs@Cys-BHC complex showed a potent cytotoxic effect on different cancerous cell line models: cervical cancer cell lines such as HeLa cells and breast cancer cells such as MDA-MB-231 confirmed by Trypan blue and MTT-based cytotoxic assays. Furthermore, multi-excitation based cellular bioimaging was demonstrated using confocal laser scanning microscopy (CLSM) and fluorescence microscopy using GQDs as well as GQDs@Cys-BHC complex. Thus, drug delivery (therapeutic) and bioimaging (diagnostic) properties of GQDs@Cys-BHC complex are thought to have a potential in vitro theranostic application in cancer therapy. © 2016 Elsevier B.V. Source


Dharmatti R.,Nsn Research Center For Nanotechnology And Bio Nanotechnology | Phadke C.,Nsn Research Center For Nanotechnology And Bio Nanotechnology | Mewada A.,Nsn Research Center For Nanotechnology And Bio Nanotechnology | Thakur M.,Nsn Research Center For Nanotechnology And Bio Nanotechnology | And 2 more authors.
Materials Science and Engineering C | Year: 2014

We present synthesis of biogenic gold nano triangles (GNTs) using Azadirachta indica leaf extract at inherent pH (5.89) and its application in efficient drug delivery of doxorubicin (DOX) (anticancer drug). The main idea was to take advantage of large surface area of GNTs which has 3 dimensions and use the plant peptides coated on these triangles as natural linkers for the attachment of DOX. Sucrose density gradient centrifugation (SDGC) and dialysis methods were used for separation of the GNT from mixture of GNPs. Flocculation parameter (FP) was used to check stability of GNT which was found to be exceptionally high (0-0.75) due to the biological capping agents. DOX attachment to GNT was verified using Fourier transformed infra-red (FTIR) spectroscopy. The complex thus formed was found to be less toxic to normal cells (MDCK cells) and significantly toxic for the cancerous cells (HeLa cells). Drug loading efficiency was found to be 99.81% and DOX release followed first order release kinetics. Percentage drug release was found to be more than 4.5% in both acidic (5.8) as well as physiological pH (7.2) which is suitable for tumor targeting. © 2014 Elsevier B.V. All rights reserved. Source


Mewada A.,Nsn Research Center For Nanotechnology And Bio Nanotechnology | Pandey S.,Nsn Research Center For Nanotechnology And Bio Nanotechnology | Oza G.,Nsn Research Center For Nanotechnology And Bio Nanotechnology | Shah R.,Nsn Research Center For Nanotechnology And Bio Nanotechnology | And 3 more authors.
Journal of Bionanoscience | Year: 2013

Impact of pH on the morphology of the Gold Nanoparticles (GNPs) synthesized using leaf extracts of Azadirachta indica is reported here. pH of the plant extract significantly affected the morphology of the GNPs. At pH 2 along with the formation of spherical GNPs, initiation of the non-spherical morphology also occurred. The non-spherical GNPs developed into more distinct gold nano-cubes when the pH of the plant extract was adjusted to pH 4. At pH 6, the optical as well as morphological features of the triangles, hexagons and plates became more conspicuous. It must be mentioned here that there were presence of some spherical GNPs also in each case that could have been an initiator of different morphologies directed by the pH of the reaction mixture. Presence of the dual absorption maxima confirmed the formation of non-spherical GNPs. Formation of spherical as well as non spherical nanoparticles such as gold nano-prisms and nano-hexagons was observed at pH 8. To confirm the possible involvement of nitrate reductase; its activity as a catalyst and/or template to navigate the formation of anisotropic GNPs is also depicted. It was found that the activity of the NR was drastically reduced after the formation of GNPs. Copyright © 2013 American Scientific Publishers. All rights reserved. Source


Pandey S.,Nsn Research Center For Nanotechnology And Bio Nanotechnology | Mewada A.,Nsn Research Center For Nanotechnology And Bio Nanotechnology | Thakur M.,Nsn Research Center For Nanotechnology And Bio Nanotechnology | Pillai S.,Nsn Research Center For Nanotechnology And Bio Nanotechnology | And 3 more authors.
RSC Advances | Year: 2014

Due to the abundance of silica and carbon in rice (Oryza sativa) husk (RH), we exploited it for the synthesis of a mesoporous silica oxide micro-particles (meso-SiO2)/C-dot complex for biological imaging using a novel hot injection method commonly used for semiconductor quantum dots. Carbon dots (C-dots) with a high degree of green fluorescence were observed under UV-light they were found to be embedded to a significant extent in meso-SiO2 as confirmed by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The mesoporous nature of the complex was confirmed using N2 adsorption-desorption measurements. Surface functionalization was studied using Fourier transform infrared spectroscopy (FTIR). The synthesized meso-SiO2/C-dots complex was used for labeling yeast cells since the fungi closely represents eukaryotic organisms. Furthermore, the meso-SiO 2/C-dot complex was found to be highly bio-compatible for Vero cells. This study might help in the further utilization of the complex for the theranostic application of simultaneous cellular imaging and drug delivery. © 2014 The Royal Society of Chemistry. Source

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