Self-assembly pH-sensitive chitosan/alginate coated polyelectrolyte complexes for oral delivery of insulin

Abstract

Polyelectrolyte complexes (PEC) provide new opportunities for controlled release system of drugs, and have potentials to address challenges on the way to effective oral insulin delivery. Here, an innovative pH-sensitive PEC for insulin oral administration was developed, which was formed by self-assembly of two oppositely charged nanoparticles (chitosan-coated nanoparticles and alginate-coated nanoparticles) through electrostatic interaction via optimised double emulsion method. The encapsulation efficiency of insulin-loaded alginate-coated and chitosan-coated nanoparticles were 81.5 ± 7.4% and 55.2 ± 7.0%, respectively, and the particle size of these nanoparticles were in 200–300 nm range. The pH-dependent morphology of PEC was observed by transmission electron microscopy. The PEC exhibited insulin release profile triggered by pH in vitro and was non-cytotoxicity against Caco-2 cell. The insulin-loaded PEC could decrease blood glucose levels effectively and prolong insulin release after oral administration to diabetic rats. The results illustrated that the as-prepared PEC may be employed as a potential oral insulin delivery system.

Keywords:

• Polyelectrolyte complexes
• self-assembly
• insulin
• nanoparticles
• oral drug delivery
• pH-sensitive

Acknowledgements

The authors acknowledge the equipment support provided by Guangdong Institute of Microbiology for Transmission Electron Microscope.

Disclosure statement

The authors report no conflict of interest.

Availability of data and materials

The datasets supporting the conclusions of this article are included within the article.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China under Grant [number 81373365]; Guangdong Science and Technology Project under Grant [number 2015A010105014].