Preparation and Characterization of CS/γ-PGA/PC Complex Nanoparticles for Insulin Oral Delivery

In recent years, natural polyelectrolyte complex chitosan/poly-γ-glutamic acid (CS/γ-PGA) has emerged as a promising nanocarrier delivery system for drug delivery due to its non-toxic and easily degradable properties. However, tightly bound CS/γ-PGA complexes often lead to lower encapsulation efficiency of peptide drugs without coordination of metal ions. In this investigation, we find that procyanidin (PC), as a cross-linking agent, is able to combine with CS and insulin through hydrogen bonding, which significantly improve encapsulation efficiency of insulin up to 90