Nanosponges as protein delivery systems: Insulin, a case study

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Nanotechnology

Background:

• Oral delivery of peptides and proteins, like insulin, is challenging due to degradation and poor absorption.
• Cyclodextrin-based nanosponges offer potential as advanced drug carriers.

Purpose of the Study:

• To investigate the potential of beta-cyclodextrin nanosponges for oral insulin delivery.
• To characterize the physicochemical properties and evaluate the in vitro and in vivo performance of insulin-loaded nanosponges.

Main Methods:

• Synthesis of beta-cyclodextrin nanosponges using pyromellitic dianhydride.
• Physicochemical characterization including size, zeta potential, mucoadhesion, and swelling.
• In vitro release studies at different pH values and Caco-2 cell permeability assays.
• In vivo studies in rats and diabetic mice to assess insulin presence and hypoglycemic effect.

Main Results:

• The nanosponges were approximately 250 nm with high negative zeta potential, mucoadhesion, and swelling.
• High loading capacity (14%) and encapsulation efficiency (>90%) were achieved.
• pH-sensitive insulin release was observed, with negligible release at gastric pH and sustained release at intestinal pH.
• Enhanced intestinal permeation of insulin and significant hypoglycemic effect in diabetic mice were confirmed.

Conclusions:

• Beta-cyclodextrin nanosponges are a promising technology for oral insulin delivery.
• The nanosponge system exhibits suitable properties for protecting insulin and enhancing its oral bioavailability.
• Further research is warranted to explore this technology for other protein-based therapeutics.