Lysozyme-dextran core-shell nanogels prepared via a green process.

A novel method has been developed for preparing nanogels with a lysozyme core and dextran shell. The method involves the Maillard dry-heat process and heat-gelation process. First, lysozyme-dextran conjugates were produced through the Maillard reaction. Then, the conjugate solution was heated above the denaturation temperature of lysozyme to produce nanogels. The nanogels are of spherical shape having a hydrodynamic diameter of about 200 nm and swelling ratio of about 30. The nanogel solutions are stable against long-term storage as well as changes in pH and ionic strength. Ibuprofen has been used as a drug model to study the electrostatic and hydrophobic interactions with these nanogels at different pH values. The study reveals that the nanogels are more suitable for loading protonated ibuprofen. We have verified that the knowledge of the formation mechanism of lysozyme-dextran nanogels can be applied to prepare other globular protein-dextran nanogels.