Microbial degradation of azo dye carmoisine in aqueous medium using Saccharomyces cerevisiae ATCC 9763.

Carmoisine is an azo dye widely used in many industries, and therefore frequently occurs in the effluent of many factories. To our knowledge, biological degradation of carmoisine has received little attention. The present study investigates the capability of Saccharomyces cerevisiae ATCC 9763 for degradation of carmoisine. Spectrophotometry data indicates that carmoisine (50 mg/l) was eliminated from the aqueous medium after approximately 7 h of incubation with Saccharomyces under anaerobic shaking conditions. Thin layer chromatography (TLC) revealed the removal of carmoisine as well as the appearance of aromatic amines in samples collected from the decolourized medium by S. cerevisiae and this was subsequently confirmed by Fourier transform infrared (FTIR) spectroscopy. Liquid chromatography mass spectrometry (LC/MS) was carried out on fractions from consecutive column chromatography and two-dimensional (2D) chromatography. LC/MS indicated degradation of carmoisine into its constituent aromatic amines. In addition, investigating the effect of environmental conditions on the decolourization process indicated that yeast extract could positively affect decolourization rates; shaking significantly accelerated decolourization and shortened the time required for complete biodecolourization from ≃ 8 days to ≃ 7 h; and Saccharomyces was able to consume sucrose as a carbon source and remove the carmoisine despite the presence of sunset yellow, which remained unaffected.

Sugar-conjugated dendritic mesoporous silica nanoparticles as pH-responsive nanocarriers for tumor targeting and controlled release of deferasirox.

In this work, a new pH-responsive nanocarrier based on mesoporous silica nanoparticle which was functionalized by polyamidoamine dendrimer with sugar conjugation was designed for targetable and controllable delivery of deferasirox to cancer cells. To obtain the optimum conditions for the preparation of drug-loaded nanocarrier, the response surface method was employed. The effect of drug/silica ratio, temperature, and operation time on loading efficiency of deferasirox was evaluated, and high loading content achieved under optimized condition. The in vitro drug release studies at different pHs proved the pH-sensitivity of the nanocarrier. Due to the open state of dendritic structure in acidic pH, the maximum release observed at pH 4.5 (lysosomal pH). In the presence of the sugar decorated carrier, cytotoxicity of retinoblastoma cell line Y79 was enhanced which confirmed that tumor cell uptake was improved. These results suggested that this nanocarrier has the potential for treatment of cancer.

Synthesis of thermosensitive magnetic nanocarrier for controlled sorafenib delivery.

Allyl glycidyl ether/N-isopropylacrylamide-grafted magnetic nanoparticles were prepared using silica-coated magnetic nanoparticles as a substrate for radical copolymerization of allyl glycidyl ether and N-isopropylacrylamide. Chitosan was coupled with the prepared nanoparticles by opening the epoxy ring of the allyl glycidyl ether. The thermosensitive magnetic nanocarrier (TSMNC) obtained can be applied as a potent drug carrier. The TSMNC structure was characterized using Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry, vibrating sample magnetometer, and elemental analysis. Its morphology and size were investigated using field emission scanning electron microscopy, transmission electron microscopy and dynamic light scattering. The feasibility of employing the TSMNC for adsorption and in vitro controlled release of the chemotherapeutic agent sorafenib was tested. The effect of the adsorption parameters of pH, temperature, and loading time of sorafenib onto TSMNC was evaluated. The adsorption data was fitted to the Langmuir and Freundlich isotherms and the relevant parameters derived. The drug release profile indicated that 88% of the adsorbed drug was released within 35h at 45°C and drug release was Fickian diffusion-controlled. The results confirmed that the TSMNC has a high adsorption capacity at low temperature and good controlled release in a slow rate at a high temperature and could be developed for further application as a drug nanocarrier.