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Emerging Glycolysis Targeting and Drug Discovery from Chinese Medicine in Cancer Therapy
Zhiyu Wang,Neng Wang,Jianping Chen,Jiangang Shen
Evidence-Based Complementary and Alternative Medicine , 2012, DOI: 10.1155/2012/873175
Abstract: Molecular-targeted therapy has been developed for cancer chemoprevention and treatment. Cancer cells have different metabolic properties from normal cells. Normal cells mostly rely upon the process of mitochondrial oxidative phosphorylation to produce energy whereas cancer cells have developed an altered metabolism that allows them to sustain higher proliferation rates. Cancer cells could predominantly produce energy by glycolysis even in the presence of oxygen. This alternative metabolic characteristic is known as the “Warburg Effect.” Although the exact mechanisms underlying the Warburg effect are unclear, recent progress indicates that glycolytic pathway of cancer cells could be a critical target for drug discovery. With a long history in cancer treatment, traditional Chinese medicine (TCM) is recognized as a valuable source for seeking bioactive anticancer compounds. A great progress has been made to identify active compounds from herbal medicine targeting on glycolysis for cancer treatment. Herein, we provide an overall picture of the current understanding of the molecular targets in the cancer glycolytic pathway and reviewed active compounds from Chinese herbal medicine with the potentials to inhibit the metabolic targets for cancer treatment. Combination of TCM with conventional therapies will provide an attractive strategy for improving clinical outcome in cancer treatment.
Achieving ultrahigh carrier mobility and photo-responsivity in solution-processed perovskite/carbon nanotubes phototransistors  [PDF]
Hong Wang,Feng Li,Dominik Kufer,Weili Yu,Erkki Alarousu,Chun Ma,Yangyang Li,Zhixiong Liu,Changxu Liu,Nini Wei,Yin Chen,Fei Wang,Lang Chen,Omar F. Mohammed,Andrea Fratalocchi,Gerasimos Konstantatos,Tom Wu
Physics , 2015,
Abstract: Organolead trihalide perovskites have drawn substantial interest for applications in photovoltaic and optoelectronic devices due to their low processing cost and remarkable physical properties. However, perovskite thin films still suffer from low carrier mobility, limiting their device performance and application potential. Here we report that embedding single-walled carbon nanotubes into halide perovskite films can significantly enhance the hole and electron mobilities to record-high values of 595.3 and 108.7 cm2 V-1 s-1, respectively. In the ambipolar phototransistors with such hybrid channels, photo-carriers generated in the light-absorbing perovskite matrix are transported by the carbon nanotubes, leading to ultrahigh detectivity of 6 * 1014 Jones and responsivity of 1 * 104 A W-1. We find that the perovskite precursor in dimethylformamide solution serve as an excellent stabilizer for the dispersion of carbon nanotubes, which potentially extend the scope of applications of perovskites in solution-processed functional composites. The unprecedented high performances underscore the perovskite/carbon nanotubes hybrids as an emerging class of functional materials in optoelectronic and other applications.
Engineered cellular carrier nanoerythrosomes as potential targeting vectors for anti-malarial drug  [cached]
Agnihotri Jaya,Gajbhiye Virendra,Jain Narendra
Asian Journal of Pharmaceutics , 2010,
Abstract: The present investigation was aimed at developing and exploring the use of nanoerythrosomes (nEs) for targeted delivery of anti-malarial drug, pyrimethamine (PMA). The formulation was prepared by the extrusion method and drug was conjugated to nEs with the help of gluteraldehyde used as a cross-linking agent. The nEs formulation was optimized for drug concentration, surface morphology, viscosity, and sedimentation volume. The drug-loaded nEs showed delayed in vitro release, good stability at 4±1°C, and controlled in vivo release. Tissue distribution studies showed higher accumulation of drug in liver (17.34±1.3 μg/ml) at 3 h in the case of nEs as compared to free drug (12.82±0.7 μg/ml). A higher amount of drug i.e. 13.14±0.9 μg/ml was found after 24 h in liver in the case of nEs as compared to free drug concentration of 9.72±0.5 μg/ml. Data showed that developed PMA-loaded nEs hold promise for targeting and controlling the release of drug and improve treatment of malaria.
CARBON NANOTUBES: AN APPROACH TO NOVEL DRUG DELIVERY SYSTEM
M. H. Alai et al.
International Journal of Pharmaceutical Sciences and Research , 2012,
Abstract: Carbon nanotubes are cylindrical carbon molecules have novel properties, making them potentially useful in many applications in nanotechnology, electronics, optics, and other fields of material science as well as potential uses in architectural fields. They have unique electronic, mechanical, optical and chemical properties that make them good candidates for a wide variety of applications, including drug transporters, new therapeutics, delivery systems and diagnostics. Their unique surface area, stiffness, strength and resilience have led to much excitement in the field of pharmacy. Nanotubes are categorized as single-walled nanotubes, multiple walled nanotubes. Various techniques have been developed to produce nanotubes in sizeable quantities, including arc discharge, laser ablation, chemical vapor deposition. They can pass through membranes, carrying therapeutic drugs, vaccines and nucleic acids deep into the cell to targets previously unreachable. Purification of the tubes can be divided into a couple of main techniques: oxidation, acid treatment, annealing, sonication, filtering and functionalization techniques. The main problem of insolubility in aqueous media has been solved by developing a synthetic protocol that allows highly water-soluble carbon NTs to be obtained. The modifications are done to improve efficiency of carbon nanotubes by formulating luminescent carbon nanotubes, ultrathin carbon nanoneedles, magnetically guided nanotubes. The application of carbon nanotube in tissue engineering, drug carrier release system, wound healing, in cancer treatment and as biosensor. Researchers have recently developed a new approach to Boron Neutron Capture Therapy in the treatment of cancer using substituted Carborane-Appended Water-Soluble single-wall carbon nanotubes.
Mobility in semiconducting carbon nanotubes at finite carrier density  [PDF]
Vasili Perebeinos,J. Tersoff,Phaedon Avouris
Physics , 2005, DOI: 10.1021/nl052044h
Abstract: Carbon nanotube field-effect transistors operate over a wide range of electron or hole density, controlled by the gate voltage. Here we calculate the mobility in semiconducting nanotubes as a function of carrier density and electric field, for different tube diameters and temperature. The low-field mobility is a non-monotonic function of carrier density, and varies by as much as a factor of 4 at room temperature. At low density, with increasing field the drift velocity reaches a maximum and then exhibits negative differential mobility, due to the non-parabolicity of the bandstructure. At a critical density $\rho_c\sim$ 0.35-0.5 electrons/nm, the drift velocity saturates at around one third of the Fermi velocity. Above $\rho_c$, the velocity increases with field strength with no apparent saturation.
Contactless Probing of the Intrinsic Carrier Transport in Single-Walled Carbon Nanotubes  [PDF]
Yize Stephanie Li,Jun Ge,Jinhua Cai,Jie Zhang,Wei Lu,Jia Liu,Liwei Chen
Physics , 2014, DOI: 10.1007/s12274-014-0522-z
Abstract: Intrinsic carrier transport properties of single-walled carbon nanotubes are probed by two parallel methods on the same individual tubes: the contactless dielectric force microscopy (DFM) technique and the conventional field-effect transistor (FET) method. The dielectric responses of SWNTs are strongly correlated with electronic transport of the corresponding FETs. The DC bias voltage in DFM plays a role analogous to the gate voltage in FET. A microscopic model based on the general continuity equation and numerical simulation is built to reveal the link between intrinsic properties such as carrier concentration and mobility and the macroscopic observable, i.e. dielectric responses, in DFM experiments. Local transport barriers in nanotubes, which influence the device transport behaviors, are also detected with nanometer scale resolution.
Simulation of carrier transport through Single Wall Carbon Nanotubes(SWNT)
Rajesh Kumar,Ramlal Singh
International Journal of Engineering Science and Technology , 2011,
Abstract: In this paper, it is observed & verified that the simulation of carrier transport through Carbon Nanotubes (CNTs) can be explained with the help of tool, “the Boltzmann transport simulator for CNTs”.By using this simulator, we examine the electronic transport quantities of SWNTs such as electric current, electric field, steady state potential, resistance of CNTs and (I-V) curve which is useful in device modeling of nanodevices and the transport quantities as a function of different parameters like electric field, temperature, length of carbon tubes and applied potential. Because of the reduced scattering effect, the SWNTs can transport huge current density (max. 109 A per cm2) without being damaged.
Carbon Nanotubes in Cancer Therapy and Drug Delivery  [PDF]
Abdelbary M. A. Elhissi,Waqar Ahmed,Israr Ul Hassan,Vinod. R. Dhanak,Antony D'Emanuele
Journal of Drug Delivery , 2012, DOI: 10.1155/2012/837327
Abstract: Carbon nanotubes (CNTs) have been introduced recently as a novel carrier system for both small and large therapeutic molecules. CNTs can be functionalized (i.e., surface engineered) with certain functional groups in order to manipulate their physical or biological properties. In addition to the ability of CNTs to act as carriers for a wide range of therapeutic molecules, their large surface area and possibility to manipulate their surfaces and physical dimensions have been exploited for use in the photothermal destruction of cancer cells. This paper paper will discuss the therapeutic applications of CNTs with a major focus on their applications for the treatment of cancer.
Biexciton, single carrier, and trion generation dynamics in single-walled carbon nanotubes  [PDF]
Bertrand Yuma,Stéphane Berciaud,Jean Besbas,Jonah Shaver,Silvia M. Santos,Saunab Gosh,R. Bruce Weisman,Laurent Cognet,Mathieu Gallart,Marc Ziegler,Bernd H?nerlage,Brahim Lounis,Pierre Gilliot
Physics , 2013, DOI: 10.1103/PhysRevB.87.205412
Abstract: We present a study of free carrier photo-generation and multi-carrier bound states, such as biexcitons and trions (ionized excitons), in semiconducting single-walled carbon nanotubes. Pump-and-probe measurements performed with fs pulses reveal the effects of strong Coulomb interactions between carriers on their dynamics. Biexciton formation by optical transition from exciton population results in an induced absorption line (binding energy 130 meV). Exciton-exciton annihilation process is shown to evolve at high densities towards an Auger process that can expel carriers from nanotubes. The remaining carriers give rise to an induced absorption due to trion formation (binding energy 190 meV). These features show the dynamics of exciton and free carriers populations.
Phonon-limited carrier mobility and resistivity from carbon nanotubes to graphene  [PDF]
Jing Li,Henrique Pereira Coutada Miranda,Yann-Michel Niquet,Luigi Genovese,Ivan Duchemin,Ludger Wirtz,Christophe Delerue
Physics , 2015, DOI: 10.1103/PhysRevB.92.075414
Abstract: Under which conditions do the electrical transport properties of one-dimensional (1D) carbon nanotubes (CNTs) and 2D graphene become equivalent? We have performed atomistic calculations of the phonon-limited electrical mobility in graphene and in a wide range of CNTs of different types to address this issue. The theoretical study is based on a tight-binding method and a force-constant model from which all possible electron-phonon couplings are computed. The electrical resistivity of graphene is found in very good agreement with experiments performed at high carrier density. A common methodology is applied to study the transition from 1D to 2D by considering CNTs with diameter up to 16 nm. It is found that the mobility in CNTs of increasing diameter converges to the same value, the mobility in graphene. This convergence is much faster at high temperature and high carrier density. For small-diameter CNTs, the mobility strongly depends on chirality, diameter, and existence of a bandgap.
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