Abou Talib

Facile synthesis of gold nanohexagons on graphene templates in Raman spectroscopy for biosensing cancer and cancer stem cells.

Several surface enhanced Raman spectroscopy (SERS) substrates were prepared based on in situ nucleation of gold nanohexagons (Au) on graphene (G) nanosheets (Au@G), G, Au nanoparticles and Au conjugated G nanomaterials. These were applied to enhance Raman scattering and to differentiate human breast normal, cancer and cancer stem cells. These SERS substrates at concentrations of 100 µg/1 × 10(4) cells led to 5.4 fold increase in detecting breast cancer cells (BCCs) and 4.8 fold of sensitivity for detecting breast cancer stem cells (BCSCs) and they were able to identify and differentiate between normal cells, cancer cells and cancer stem cells. These approaches are rapid, simple and reliable for healthy normal cells, cancer cells and cancer stem cell detection which have a huge potential for cancer research for medical or biomedicine applications.

Synthesis of highly fluorescent hydrophobic carbon dots by hot injection method using Paraplast as precursor.

We have reported synthesis of bright blue colored hydrophobic carbon dots (hC-dots) using highly pure blend of polymers called Paraplast. We developed a hot injection method for making nearly monodispersed hC-dots with a diameter in a range: 5-30nm as confirmed by high resolution transmission electron microscopy (HRTEM). The involvement of various functional groups was confirmed by Fourier transform infra-red (FTIR) spectroscopy. These hC-dots were incubated with breast cancer stem cells in order to check the entry as well as biological imaging. The cells were analyzed using epifluorescent microscopy. hC-dots showed concentration dependent cytotoxicity (LD50: 50mg/ml) and could be used for bioimaging even at lower concentration (0.5mg/ml). hC-dots were found to be versatile agents for peeping inside the cells which could also be used for delivery of water insoluble chemotherapeutic agents to variety of solid tumors.

Controlled delivery of dopamine hydrochloride using surface modified carbon dots for neuro diseases.

Delivery of therapeutic agents using water-soluble, highly biocompatible Carbon dots (C-dots) is an efficient strategy to control drug release under physiological milieu. Dopamine hydrochloride (DA), the most important inotropic vasopressor agent used in neurological diseases. In our study DA is anchored to water-soluble carbon dots for controlled release under mimicked in vitro physiological conditions. The tenure of the DA release at pH 7.4 was greatly extended to 60 h for C-dots-DA, in comparison with the control DA alone. The statistical calculation was used to comprehend the release pattern of the DA, which exhibited the pattern of Hixson-Crowell model of release. In order to understand the impact of the C-dots-DA conjugate under physiological conditions, Neuro 2A cells were taken under consideration. The conjugate C-dots-DA was found to be biocompatible against Neuro 2A cells. The survival rate was found to be 74% at maximum concentration of 9 μg mL(-1). In vivo toxicity was studied using thin section of tissues after staining with Hematoxyline and Eosin Yellow (H&E). As per microscopic observations, conjugates did not inflict any anatomical distortions or hostile effects on tissues. Body weight of mice was also taken into consideration after injecting 20 μg mL(-1) of nano-conjugates via tail vein. The impact of nano-conjugate on body weight was found to be negligible after 45 days of observation.

Tellurium platinate nanowires for photothermal therapy of cancer cells

Among the most celebrated modes of cancer treatment, photothermal therapy has been the most promising tool over the past few years. In spite of the introduction of many novel nanomaterials for photothermal therapy, there is still plenty of room for exploration of naïve materials. We have explored the photothermal properties of metal chalcogenides, namely tellurium platinate nanowires (TePt NWrs), in this work. Upon irradiation with a laser (Ti:sapphire laser, 808 nm) the temperature of the aqueous suspension of TePt NWrs was found to increase to ∼62 °C from room temperature at optimum concentrations. This was due to the stability and high photothermal transduction efficiency of nanorods (NRs) i.e.∼47%. The power to ablate tumor cells was studied using A549 cells and tumor grafted experimental mice models. After an initial exposure for 10 min (808 nm laser at 1 W cm-2), the cells were killed mainly by the process of apoptosis as confirmed by a flow cytometry assisted cell sorting system (FACS; PI-FITC-Annexin V staining). Tumor growth was significantly reduced after photothermal therapy via a combination of TePt NRs and laser, thus proving the importance of this new nanomaterial for cancer photothermal therapy. The current approach has introduced a highly potential photothermal therapy method for applications in the medical world in the near future.

Synthesis of mesoporous titanium oxide for release control and high efficiency drug delivery of vinorelbine bitartrate

The present study reports a facile method for fabrication of mesoporous titanium oxide (mTiO2) and its application for delivery of the potential anticancer drug vinorelbine bitartrate (VB) under physiological conditions. The mTiO2 was functionalized with hexamethylene tetramine (HMTA), which can release formaldehyde in the acidic environment of cancer cells. Due to the highly porous nature of mTiO2, the drug loading capacity of mTiO2-HMTA was extremely high (about 73%) and the release of the drug was consistent for a long time (about 72 h). The release of VB was pH dependent and found to be higher under slightly acidic conditions thus mimicking a cancer environment. The role of HMTA in the present context is to trigger the release of formaldehyde under acidic conditions (pH 6.5), which was responsible for killing cancer cells, whereas working synergistically with VB. The toxicity of the conjugate was assessed using HeLa and Vero cells. In the case of normal cells, the nano-conjugates were completely biocompatible (>75%). In vivo-toxicity was checked by staining thin slices of the tumor tissues using H&A staining. More damage was found in the case of the tumor cells due to inimical action of formaldehyde.

Graphene oxide@gold nanorods for chemo-photothermal treatment and controlled release of doxorubicin in mice Tumor

Graphene oxide (GO) is a close derivative of graphene has unlocked many pivotal steps in drug delivery due to their inherent biocompatibility, excellent drug loading capacity, and shows antibacterial, antifungal properties etc. We used a novel plant material called Gum arabic (GA) to increase the solubility of GO as well as to chemically reduce it in the solution. GA functionalized GO (fGO) exhibited increased absorption in near infra-red region (NIR) which was exploited in photothermal therapy for cancer. In order to understand the shape and size effect of GO which may affect their rheological properties, we have conjugated them with gold nanorods (GNRs) using in situ synthesis of GO@GNRs via seed mediated method. To the above conjugate, Doxorubicin (DOX) was attached at ambient temperature (28±2°C). The release kinetics of DOX with the effect of NIR exposure was also carefully studied via in vitro photothermal killing of A549 cell lines. The enhancement in NIR induced drug release and photothermal property was observed which indicates that the fGO@GNRs-DOX method is an ideal choice for chemotherapy and photothermal therapy simultaneously.

Folic Acid navigated Silver Selenide nanoparticles for photo-thermal ablation of cancer cells

Photothermal ablation of the cancer cells is a non-invasive technique for cancer treatment, involving cellular assassination in presence of photothermal agent. We are reporting silver selenide (Ag2Se) nanoparticles for photothermal therapy using folic acid for selective targeting. The material, when exposed to 808nm laser, the temperature got boosted to 54°C in 6.5min, thus proving its potential for photothermal ablation. The material was highly biocompatible (95%) at highest concentration (10μg/mL) against A 549 cells. However, in presence of laser, the cellular killing was 55%. The mode of death was analyzed using MALDI-TOF MS.

Laser-assisted synthesis of multi-colored protein dots and their biological distribution in experimental mice using a dye tracking method

We report a novel method for the synthesis of ultra-bright green and red colored protein dots (Pr-dots) using continuous and pulse lasers (λ = 534 and 1064 nm) with lysozyme as a precursor in ethanol. The quantum yield of the Pr-dotsRed was calculated to be ∼13% and that of the Pr-dotsGreen was ∼15%. A shift in the fluorescent intensity and the fluorescence color of the Pr-dots under UV light (λem = 365 nm) with respect to changes in the repetition frequency of the laser was observed. After successful synthesis of the Pr-dots, their in vivo bio-kinetics were studied using 5 week old ICR mouse models. The highest accumulation of multi-Pr-dots was observed in the brains of the mice. This method has opened a new door to pursue the application of Pr-dots to ferry drugs across blood–brain barrier (BBB) which is considered very difficult to achieve. Another vital application of the Pr-dots in biological imaging was explored. These multi-colored Pr-dots were used as effective fluorescence probes for the imaging of Vero cells as well as MCF 7 cancer stem cells.