2Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia
* To whom correspondence should be addressed.
Received November 3, 2010; Revision received November 23, 2010
Microparticles containing recombinant human insulin and its analogs aspart and lispro were prepared using an alternate adsorption of chitosan and dextran sulfate from solutions onto microaggregates of proteindextran sulfate insoluble complex. The following properties of polyelectrolyte hormone-containing microparticles were studied: pH stability, surface charge, mucoadhesive properties, Ca2+ binding, degradation under the influence of proteases (trypsin, chymotrypsin). The influence of the self-association ability of encapsulated insulins on the form of protein releasing from microparticles was studied. Insulins aspart and lispro released from the microparticles as monomers were more liable to proteolysis than human insulin released as a hexamer. The combined effect of properties of polyelectrolyte microparticles and of encapsulated recombinant proteins on the bioavailability of insulin under peroral administration is discussed.
KEY WORDS: polyelectrolyte microparticles, human insulin, insulin lispro and aspart, mucoadhesive properties, Ca2+ binding, proteolysis