ABSTRACT
Among the numerous nanosized drug delivery systems currently under investigation, carbon nanotubes [CNTs], regardless of being single or multiple-walled, offer several advantages and are considered as promising candidates for drug targeting. Despite the valuable potentials of CNTs in drug delivery, their toxicity still remains an important issue. After the PEGylation of single-walled CNTs [SWCNTs] with phospholipid-PEG [Pl-PEG] conjugates to prepare water-dispersible nanostructures, the present study was designed to evaluate whether the functionalization with Pl-PEG derivatives could alter the cytotoxic response of cells in culture, affect their viability and proliferation. In-vitro cytotoxicity screens were performed on cultured Jurkat cells. The SWCNTs samples used in this exposure were pristine SWCNTs, Pl-PEG 2000/5000-SWCNTs at various concentrations. Jurkat cells were first incubated for 3 h at 37°C with test materials and seeded in 6-well culture plates at a given concentration. The plates were then incubated for 24, 48 and 72 h at 37°C in a 5% CO[2] humidified incubator. Cell Viability and proliferation assay were performed using trypan blue exclusion test and the cell cycle kinetic status of Jurkat cells was analyzed by flow cytometry. Cell morphology was finally studied using double staining technique and a fluorescence microscope. We found that, regardless of the duration of exposure, functionalized SWCNTs were substantially less toxic, compared to pure SWCNTs and that the molecular weight of Pl-PEGs played an important role at higher concentrations. In conclusion, our noncovalent protocol seemed to be effective for increasing SWCNTs biocompatibility
ABSTRACT
Organophosphorous [OP] chemical warfare nerve agents mainly sarin and tabun were used during the Iran-Iraq war with high mortalities. In addition to atropine and oximes, the followings have recently been used successfully for the treatment of OP poisoning. 1. Sodium Bicarbonate: Infusion of high doses of sodium bicarbonate [5 mEq/kg in 60 min. followed by 5-6 mEq/kg/day to obtain arterial blood pH of 7.45 to 7.55] revealed positive effects in patients with acute OP poisoning in Mashhad. 2. Magnesium Sulfate: Intravenous magnesium sulfate in a dose of 4 g only on the first day after admission was also effective in acute human OP poisoning. 3. Antioxidants: The toxicity of OP compounds is mediated by generation of nitric oxide and other free radicals. These toxic molecules can be counteracted by antioxidants such as vitamins C and E, spin traps, melatonin and low molecule weight thiols. The latter compounds can also increase the synthesis of glutathione, which can both ameliorate the OP-induced oxidative stress and enhance OP detoxification. It is concluded Sodium bicarbonate, Magnesium sulfate and the antioxidants should be added to the standard treatment of OP poisonings