Graphene quantum dots decorated with imatinib for leukemia treatment.

The use of graphene quantum dots as biomedical device and drug delivery system has been increasing. This nanoplatform of pure carbon has showed unique properties and showed to be safe for human use. The imatinib is a molecule designed to specifically inhibit the tyrosine kinase, used for leukemia treatment. In this study, we successfully decorated the graphene quantum dots (GQDs@imatinb) by a carbodiimide crosslinking reaction. The GQDs@imatinb were characterized by FTIR and AFM. The nanoparticles' in vitro behaviors were evaluated by cellular trafficking (internalization) assay and cell viability and apoptosis assays in various cancer cell lines, including suspension (leukemia) cells and adherent cancer cells. The results showed that the incorporation of the imatinib on the surface of the graphene quantum dots did not change the nanoparticles' morphology and properties. The GQDs@imatinb could be efficiently internalized and kill cancer cells via the induction of apoptosis. The data indicated that the prepared GQDs@imatinb might be a great drug nano-platform for cancer, particularly leukemia treatments.

Radioactive polymeric nanoparticles for biomedical application.

Nowadays, emerging radiolabeled nanosystems are revolutionizing medicine in terms of diagnostics, treatment, and theranostics. These radionuclides include polymeric nanoparticles (NPs), liposomal carriers, dendrimers, magnetic iron oxide NPs, silica NPs, carbon nanotubes, and inorganic metal-based nanoformulations. Between these nano-platforms, polymeric NPs have gained attention in the biomedical field due to their excellent properties, such as their surface to mass ratio, quantum properties, biodegradability, low toxicity, and ability to absorb and carry other molecules. In addition, NPs are capable of carrying high payloads of radionuclides which can be used for diagnostic, treatment, and theranostics depending on the radioactive material linked. The radiolabeling process of nanoparticles can be performed by direct or indirect labeling process. In both cases, the most appropriate must be selected in order to keep the targeting properties as preserved as possible. In addition, radionuclide therapy has the advantage of delivering a highly concentrated absorbed dose to the targeted tissue while sparing the surrounding healthy tissues. Said another way, radioactive polymeric NPs represent a promising prospect in the treatment and diagnostics of cardiovascular diseases such as cardiac ischemia, infectious diseases such as tuberculosis, and other type of cancer cells or tumors.

Cytotoxic Activity of the Mesoionic Compound MIH 2.4Bl in Breast Cancer Cell Lines.

In this work, we report the synthesis of a new 1,3-thiazolium-5-thiolate derivative of a mesoionic compound (MIH 2.4Bl) and the characterization of its selective cytotoxicity on a panel of breast cancer cells lines. The cytotoxic effect of MIH 2.4Bl on breast cancer cell lines was determined by XTT and crystal violet assays, flow cytometry analysis, electron microscopy characterization, and terminal deoxynucleotidyl transferase (TdT) deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) apoptosis assays. As determined using XTT cell growth and survival assays, MIH 2.4Bl exhibited growth inhibition activity on most breast cancer cell lines tested, compared with normal human mammary epithelial cells. Three breast cancer cell lines (MCF-7, T-47D, and ZR-75-1) showed a more potent sensitivity index to growth inhibition by MIH 2.4Bl than the other breast cancer cell lines. Interestingly, these 3 cell lines were derived from tumors of Luminal A origin and have ER (estrogen receptor), PR (progesterone receptor), and HER2 (human epidermal growth factor receptor 2) positive expression. Additional analysis of cytotoxicity mediated by MIH 2.4Bl was performed using the MCF-7 cell line. MCF-7 cells displayed both time- and dose-dependent decreases in cell growth and survival, with a maximum cytotoxic effect observed at 72 and 96 hours. The MCF-7 cells were also characterized for cell cycle changes upon treatment with MIH 2.4Bl. Using flow cytometry analysis of cell cycle distribution, a treatment-dependent effect was observed; treatment of cells with MIH 2.4Bl increased the G2/M population to 34.2% compared with 0.1% in untreated (control) cells. Ultrastructural analysis of MFC-7 cells treated with MIH 2.4Bl at 2 different concentrations (37.5 and 75 µM) was performed by transmission electron microscopy. Cells treated with 37.5 µM MIH 2.4Bl showed morphologic changes beginning at 6 hours after treatment, while cells treated with 75 µM showed changes beginning at 3 hours after treatment. These changes were characterized by an alteration of nuclear morphology and mitochondrial degeneration consistent with apoptotic cell death. Results of a TUNEL assay performed on cells treated for 96 hours with MIH 2.4Bl supported the observation of apoptosis. Together, these results suggest that MIH 2.4Bl is a promising candidate for treating breast cancer and support further in vitro and in vivo investigation.

Characterization and application of a lanthanide-based metal-organic framework in the development and validation of a matrix solid-phase dispersion procedure for pesticide extraction on peppers (Capsicum annuum L.) with gas chromatography-mass spectrometry.

The metal-organic framework [(La0.9 Sm0.1 )2 (DPA)3 (H2 O)3 ]∞ was synthetized and characterized by X-ray diffractometry, differential thermogravimetric analysis, and infrared spectroscopy. The material was tested for the development and validation of a matrix solid-phase dispersion procedure for extraction of atrazine, bifenthrin, bromuconazole, clofentezine, fenbuconazole, flumetralin, procymidone, and pirimicarb, from peppers, with analysis using gas chromatography with mass spectrometry in the selected ion monitoring mode. The method developed was linear over the range tested (50.0-1000.0 µg/kg for procymidone and 200.0-1000.0 µg/kg for all other pesticides), with correlation coefficients ranging from 0.9930 to 0.9992. Experiments were carried out at 250.0, 500.0, and 1000.0 µg/kg fortification levels, and resulted in recoveries in the range of 52.7-135.0%, with coefficient of variation values between 5.2 and 5.4%, respectively, for [(La0.9 Sm0.1 )2 (DPA)3 (H2 O)3 ]∞ sorbent. Detection and quantification limits ranged from 16.0 to 67.0 µg/kg and from 50.0 to 200.0 µg/kg, respectively, for the different pesticides studied. The results were compared with literature data. The developed and validated method was applied to real samples. The analysis detected the presence of residues of pesticides procymidone, fenbuconazole, flumetralin, clofentezine, atrazine, and bifenthrin.

Evaluation of a novel metal-organic framework as an adsorbent for the extraction of multiclass pesticides from coconut palm (Cocos nucifera L.): An analytical approach using matrix solid-phase dispersion and liquid chromatography.

We report the synthesis, characterization, and application of [Zn(1,4-benzenedicarboxylate)(H2 O)2 ]n , Zn(1,4-benzenedicarboxylate)0.99 (NH2 -1,4-benzenedicarboxylate)0.01 (H2 O)2 ]n , [Zn(1,4-benzenedicarboxylate)0.95 (NH2 -1,4-benzenedicarboxylate)0.05 (H2 O)2 ]n , and [Zn(1,4-benzenedicarboxylate)0.9 (NH2 -1,4-benzenedicarboxylate)0.1 (H2 O)2 ]n as sorbents for the extraction of multiclass pesticides from coconut palm. Liquid chromatography with ultraviolet diode array detection was used as the analysis technique, and the experiments were performed at one fortification level (0.1 µg/g). The recoveries were 47-67, 51-70, 58-72, and 64-76% for [Zn(1,4-benzenedicarboxylate)(H2 O)2 ]n , Zn(1,4-benzenedicarboxylate)0.99 (NH2 -1,4-benzenedicarboxylate)0.01 (H2 O)2 ]n , [Zn(1,4-benzenedicarboxylate)0.95 (NH2 -1,4-benzenedicarboxylate)0.05 (H2 O)2 ]n , and [Zn(1,4-benzenelate)0.95 (NH2 -1,4-benzenedicarboxylate)0.05 (H2 O)2 ]n , and [Zn(1,4-benzenedicarboxylate)0.9 (NH2 -1,4-benzenedicarboxylate)0.1 (H2 O)2 ]n , respectively, with relative standard deviation ranging from 1 to 7% (n = 3). Detection and quantification limits were 0.01-0.05 and 0.05-0.2 µg/g, respectively, for the different pesticides studied. The method developed was linear over the range tested (0.01-10.0 µg/g) with r2  > 0.9991. A direct comparison of [Zn(1,4-benzenedicarboxylate)0.9 (NH2 -1,4-benzenedicarboxylate)0.1 (H2 O)2 ]n with the commercially available neutral alumina showed that [Zn(1,4-benzenedicarboxylate)0.9 (NH2 -1,4-benzenedicarboxylate)0.1 (H2 O)2 ]n was a similar extracting phase for the pesticides investigated.