فهرست نشریات علمی دسترسی آزاد ایران

In this work PLGA copolymers with different high molecular weight and up to 95 per cent efficiency are economically synthesised using a novel ring opening as the heart of process and then with micro double emulsion technique in which nanoparticles size are below 60 nanometer is obtained. Conditions under that we were successful to such synthesis are discussed later. At first, characterisation tests are accomplished for all polymers/copolymers to choice the best sample to be thermo-stable enough and also have more stability in the human body and with higher molecular weight. Double micro emulsion method with very polar solvent propylene carbonate and a co-solvent PVA and DMAB as the main surfactant are used to produce nanoparticles. Some critical parameters like homogeniser speed and ultrasonic device to look into nanoparticles size, as well as surfactant type are explored whilst homogeniser worked from 5000 to 30000 rpm, surfactant was DMAB and ultrasound worked with  8 min at 75% amplitude sonicator. It is found that copolymer concentration and surfactant type affected sharply on the nanoparticles size. Meanwhile, show that ultrasound operation is not suitable to give fine nanoparticles, likely, due to high momently temperature rise in/around/surface the emulsion. For this reason a powerful homogeniser is employed so that very fine nanoparticles are reached under low temperature. Characterisation tests such as DLS and SEM verify fine size and show a vast particle size distribution with an average 40-60 nanometer particles which is very valuable through others work because of its fine particle size. Former works have been reported large PLGA nanoparticles (up to 150 nm), perhaps to, usage of low molecular weight polymer/copolymer or sonication condition. As another novelty is that we did not buy PLGA form any company but we synthesise/purify high molecular weight (above 1000000) type of copolymers according to 10 year of our experience in this field. This was the key of our success. Our next work would be focus on the drug delivery system with PLGA nano carrier and smart nanoparticles that would be reported later.