PEGylation of shellac-based nanocarriers for enhanced colloidal stability.

Shellac is a biomaterial obtained from secretion of lac insects. Nanoparticles based on shellac are prepared by nanoprecipitation and miniemulsion techniques. The corrosion inhibitor 2-mercaptobenzothiazole can be efficiently encapsulated in nanoparticles. Release kinetics of the inhibitor from the nanocarriers is controlled by pH of the surrounding environment as well as the introduction of other biopolymers such as lignin and zein. To overcome the low colloidal stability of shellac nanoparticles in saline conditions, shellac is conjugated with poly(ethylene glycol) moieties. After PEGylation, nanoparticles with higher critical aggregation concentration are obtained and provide release kinetics of 2-mercaptobenzothiazole similar to shellac nanoparticles.