Dadong Guo

Synergistic cytotoxic effect of different sized ZnO nanoparticles and daunorubicin against leukemia cancer cells under UV irradiation.

Failure of chemotherapy to the malignant tumor is usually induced by multidrug resistance (MDR). The development of anti-MDR agents for efficient drug delivery is of great importance in cancer therapy. Recent reports have demonstrated that some anticancer drugs could be readily self-assembled on some biocompatible nanomaterials covalently or non-covalently, which could effectively afford the sustained drug delivery for the target cancer cells and reduce the relevant toxicity towards normal cells and tissues. Thus these biocompatible nanomaterials may play an important role in the relevant biological and biomedical system. In this paper, we have explored the cytotoxic effect of anticancer drug daunorubicin on leukemia cancer cells in the absence and presence of different sized ZnO nanoparticles via fluorescence microscopy, UV-Vis absorption spectroscopy, electrochemical analysis as well as MTT assay. Meanwhile, the cytotoxicity suppression of daunorubicin together with different sized ZnO nanoparticles in the absence and presence of UV irradiation on leukemia cancer cells were also investigated using MTT assay. The results indicate that the combination of the different sized ZnO nanoparticles and daunorubicin under UV irradiation could have synergistic cytotoxic effect on leukemia cancer cells, indicating the great potential of ZnO nanoparticles in relevant clinical and biomedical applications.

Poly(lactic acid) (PLA) based nanocomposites?a novel way of drug-releasing

In this communication, poly(lactic acid) nanofibers have been fabricated by electrospinning and then poly(lactic acid) (PLA) based nanocomposites have been prepared by accumulating anticancer drug daunorubicin on PLA nanofibers combined with TiO2 nanoparticles. Our atomic force microscopy (AFM) and laser-scanning confocal microscope (LSCM) studies demonstrate that the respective drug molecules could be readily self-assembled on the surface of the blends of nano-TiO2 with PLA polymer nanocomposites, which could further efficiently facilitate the drug permeation and accumulation on the target leukemia K562 cells. Besides, the respective new nanocomposites have good biocompatibility, ease of surface chemistry modification and very high surface area, which may afford the possibility for their promising application in pharmacology and biomedical engineering areas.

The Photodynamic Effect of Different Size ZnO Nanoparticles on Cancer Cell Proliferation In Vitro

Nanomaterials have widely been used in the field of biological and biomedicine, such as tissue imaging, diagnosis and cancer therapy. In this study, we explored the cytotoxicity and photodynamic effect of different-sized ZnO nanoparticles to target cells. Our observations demonstrated that ZnO nanoparticles exerted dose-dependent and time-dependent cytotoxicity for cancer cells like hepatocellular carcinoma SMMC-7721 cells in vitro. Meanwhile, it was observed that UV irradiation could enhance the suppression ability of ZnO nanoparticles on cancer cells proliferation, and these effects were in the size-dependent manner. Furthermore, when ZnO nanoparticles combined with daunorubicin, the related cytotoxicity of anticancer agents on cancer cells was evidently enhanced, suggesting that ZnO nanoparticles could play an important role in drug delivery. This may offer the possibility of the great potential and promising applications of the ZnO nanoparticles in clinical and biomedical areas like photodynamic cancer therapy and others.

Novel Nanocomposite of Nano Fe3O4 and Polylactide Nanofibers for Application in Drug Uptake and Induction of Cell Death of Leukemia Cancer Cells

Novel nanocomposites of polylactide (PLA) nanofibers and tetraheptylammonium-capped Fe3O4 magnetic nanoparticles have been prepared and utilized to realize the efficient accumulation of anticancer drug daunorubicin in target cancer cells. The observations of optical microscopy and confocal fluorescence microscopy indicate that the PLA nanofibers and Fe3O4 nanoparticles may contribute to their beneficial effects on intracellular drug uptake of leukemia K562 cell lines in which the efficiently enhanced accumulation of anticancer drug daunorubicin on the membrane of cancer cells could be observed. Meanwhile, the electrochemical detection and the microculture tetrazolium studies were also explored to probe the effect of the relevant nanomaterials on the drug uptake of cancer cells. The results illustrate that the nanocomposites could effectively facilitate the interaction of daunorubicin with leukemia cells and remarkably enhance the permeation and drug uptake of anticancer agents in the cancer cells, which could readily lead to the induction of the cell death of leukemia cells. This observation suggests a new perspective for the targeted therapeutic approaches of cancers.

The incorporation of daunorubicin in cancer cells through the use of titanium dioxide whiskers

Porous nanostructure with its unique properties is found to be able to hold promise in drug delivery. We fabricated the one-dimensional titanium dioxide whiskers (TiO2 Ws) and designed a strategy to explore their drug delivery application and anti-tumor function combined with daunorubicin (DNR). We observed good biocompatibility of TiO2 Ws and noted better photocatalytic activity. In human hepatocarcinoma cells (SMMC-7721 cells), TiO2 Ws can obviously increase the intracellular concentration of DNR and enhance its potential anti-tumor efficiency, indicating TiO2 Ws could produce an efficient drug delivery carrier effect importing DNR into target cells. Furthermore, its photocatalysis further led to the enhanced mortality of cancer cells under UV irradiation. These findings reveal that TiO2 Ws-based delivery of anticancer drugs represents a promising approach in cancer therapy.

Ligand-based neutral ruthenium(II) arene complex: selective anticancer action.

Two new ruthenium(II) arene complexes, 2a (C(24)H(34)B(10)FeRuS(2)) and 2b (C(15)H(26)B(10)O(2)RuS(2)), bearing a carborane unit and other different functional groups were synthesized, and their cytostatic effects on cancerous cells were evaluated. Our observations illustrate that a structural change from a ferrocene unit to a carboxyl group could lead to high selectivity toward cancer cells and facilitate the efficient inhibition of the proliferation of target cells, indicating that the tuning of the overall properties of the ruthenium(II) arene complex by appropriate ligand tagging is critical to creating a selective antineoplastic agent.

New potential anticancer agent of carborane derivatives: selective cellular interaction and activity of ferrocene-substituted dithio-o-carborane conjugates.

The large diversity of structures and unique bonding modes of organometallic complexes make them possible to act as promising candidate therapeutic agents. In this study, the new type of ferrocene-substituted dithio-o-carborane conjugates (FcSB1, FcSB2, and FcSBCO) has been synthesized, and their in vitro antineoplastic activities have been explored by means of the electrochemical study, the real time cell electronic sensing (RT-CES) system, and biological assays. The conjugate-cell interactions were first monitored by electrochemistry, and the results show different cell uptake efficiency for FcSB1, FcSB2, and FcSBCO toward target cells. Both the highly hydrophobic ferrocenyl and carboranyl groups render the conjugates able to rapidly enter cells and exert acute cytotoxicity after 4 h incubation in serum-free media. However, FcSB1, FcSB2, and FcSBCO display different inhibition efficiencies toward SMMC-7721 and HepG2 cancer cells via the G(0)/G(1) arrest mechanism in a physiological environment. The anticancer activity is in the order FcSB2 > FcSB1 > FcSBCO, which is parallel to the order of the redox potentials of the ferrocenyl groups in the three complexes. In particular, FcSB1 and FcSB2 display a potent selective inhibition effect on the proliferation of the cancer cell lines SMMC-7721 and HepG2, but almost no effect on the normal cell line, the human embryonic lung fibroblast (HELF) cells. Thus, these results may provide some clues for use of the ferrocene-carborane conjugates in developing anticancer drugs.

Rapid identification and high sensitive detection of cancer cells on the gold nanoparticle interface by combined contact angle and electrochemical measurements

In this study, we have proposed a novel strategy for the rapid identification and high sensitive detection of different kinds of cancer cells by means of electrochemical and contact angle measurements. A simple, unlabeled method based on the functionalized Au nanoparticles (GNPs) modified interface has been utilized to distinguish the different cancer cells, including lung cancer cells, liver cancer cells, drug sensitive leukemia K562/B.W cells and drug resistant leukemia K562/ADM cells. The relevant results indicate that under optimal conditions, this method can provide the quantitative determination of cancer cells, with a detection limit of approximately 10(3)cells mL(-1). Our observations demonstrate that the difference in the hydrophilic properties for target cellular surfaces and in the uptake efficiency of the anticancer drug daunorubicin for different cancer cells could be readily chosen as the elements of cancer identification and sensitive detection. This raises the possibility to advance the promising clinic diagnosis and monitoring of tumors with the aim of successful chemotherapy of human cancers.

Synergistic Effect of Functionalized Nickel Nanoparticles and Quercetin on Inhibition of the SMMC-7721 Cells Proliferation

The effect of functionalized nickel (Ni) nanoparticles capped with positively charged tetraheptylammonium on cellular uptake of drug quercetin into hepatocellular carcinoma cells (SMMC-7721) has been explored in this study via microscopy and electrochemical characterization as well as MTT assay. Meanwhile, the influence of Ni nanoparticles and/or quercetin on cell proliferation has been further evaluated by the real-time cell electronic sensing (RT-CES) study. Our observations indicate that Ni nanoparticles could efficiently improve the permeability of cancer cell membrane, and remarkably enhance the accumulation of quercetin in SMMC-7721 cells, suggesting that Ni nanoparticles and quercetin would facilitate the synergistic effect on inhibiting proliferation of cancer cells.

The application of poly(N-isopropylacrylamide)-co-polystyrene nanofibers as an additive agent to facilitate the cellular uptake of an anticancer drug.

In this paper, we have fabricated poly(N-isopropylacrylamide)-co-polystyrene (PNIPAM-co-PS) nanofibers by electrospinning and explored the possibility to utilize the PNIPAM-co-PS nanofibers to enhance the permeation and uptake of the anticancer drug daunorubicin in drug-sensitive and drug-resistant leukemia K562 cells. Our MTT assay and electrochemical studies demonstrate that PNIPAM-co-PS nanofibers could play an important role in facilitating the cell track and drug delivery to the cancer cells. Meanwhile, the observations of atomic force microscopy (AFM) and confocal fluorescence microscopy indicate that the relevant interaction of the PNIPAM-co-PS nanofibers with bioactive molecules on the membrane of leukemia cell lines could affect the intracellular drug uptake positively and lead to the efficient accumulation of daunorubicin in drug-sensitive and drug-resistant cancer cells.