Optimized Synthesis and Characterization of N-Triethyl Chitosan

Chitosan exhibits poor solubility at pH values above 6 which prevents its enhancing effects at drugs absorption of sites. In the present work, N-triethylated chitosan (TEC) was prepared based on a modified one-step process via a 22 factorial design to optimize the preparative conditions. TEC polymer with different degree of quaternization for pharmacological and pharmaceutical experiments was achieved. Ethyl iodide and sodium hydroxide concentrations were chosen as independent variables. The degree of deacetylation of the starting chitosan was predetermined by pH-metric titration, infrared, and NMR methods. TEC chloride was fully characterized using FTIR and 1H-NMR spectroscopies. Based on NMR calculations, a high degree of quaternization was achieved through the optimized one-step process. These highly N-triethylated chitosan chlorides were soluble in water at room temperature.

Enhanced Cellular Cytotoxicity and Antibacterial Activity of 18-β-Glycyrrhetinic Acid by Albumin-conjugated PLGA Nanoparticles

The aim of the present work was to encapsulate 18-β-Glycyrrhetinic acid (GLA) in albumin conjugated poly(lactide-co-glycolide) (PLGA) nanoparticles by a modified nanoprecipitation method. Nanoparticles (NPs) were prepared by different drug to polymer ratios, human serum albumin (HSA) content, dithiothreitol (as producer of free thiol groups) content, and acetone (as non-solvent in nanoprecipitation). NPs with a size ranging from 126 to 174 nm were achieved. The highest entrapment efficiency (89.4±4.2%) was achieved when the ratio of drug to polymer was 1:4. The zeta potential of NPs was fairly negative (-8 to -12). Fourier transform infrared spectroscopy and differential scanning calorimetry proved the conjugation of HSA to PLGA NPs. In vitro release profile of NPs showed 2 phases: an initial burst for 4 h (34-49%) followed by a slow release pattern up to the end. The antibacterial effects of NPs against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa were studied by microdilution method. The GLA-loaded NPs showed more antibacterial effect than pure GLA (2-4 times). The anticancer MTT test revealed that GLA-loaded NPs were approximately 9 times more effective than pure GLA in Hep G2 cells.

Reform in medical and health sciences educational system: a Delphi study of faculty members' views at Shiraz University of Medical Sciences

Despite the strengths in the Iranian medical and health sciences educational system, areas in need of improvement have been noted. The purpose of this study was to understand the views of faculty members at Shiraz University of Medical Sciences about current and future needs for medical and health sciences education, with the goal of improving the quality of the educational system. The data were collected using a Delphi consensus method. Analysis of the findings identified the following key themes among the factors likely to contribute to medical and health sciences education and training: adding and/or increasing student numbers in higher degrees in preference to associate degrees; providing more interactive, student-centred teaching methods; improving the educational content with more practical and research-based courses tailored to society's needs; and an emphasis on outcome-based student evaluation techniques. These changes aim to respond to health trends in society and enhance the close relationship between medical education and the needs of the Iranian society.