Synthesis of surfactant-free hydroxypropyl methylcellulose nanogels for controlled release of insulin
Abstract
A facile controlled-release nanogels delivery system has been developed by using hydroxypropyl methylcellulose (HPMC) hybrid nanogels as encapsulation shell materials, which were synthesized by surfactant-free polymerization in aqueous solution. The effects of reaction time and cross-linker concentration on the size of the nanogels have been studied. The results showed that in a certain range, the particle size decreased with increasing reaction time and increasing concentration of cross-linker. Meanwhile, at the feeding ratio 0.05/1 of HPMC/methacrylic acid (MAA), the LCST of prepared nanogels at pH = 6 was close to the body temperature, which can be used as sustained insulin delivery system. Besides, the HPMC nanogels loaded with insulin had a high drug loading of 21.3% and a high entrapment efficiency of 95.7%. The release behavior of the insulin nanogels can be adjusted by pH and temperature which will have potential applications in controlled release delivery system.