Overcoming Multiple Absorption Barrier for Insulin Oral Delivery Using Multifunctional Nanoparticles Based on Chitosan Derivatives and Hyaluronic Acid

Zuxian Chen,1,* Shangcong Han,1,* Xiaotang Yang,1 Lisa Xu,1 Hong Qi,2 Guizhou Hao,3 Jie Cao,1 Yan Liang,1 Qingming Ma,1 Guimin Zhang,3 Yong Sun1 1Department of Pharmaceutics, School of Pharmacy, Qingdao University, Qingdao 266021, People’s Republic of China; 2Department of General Surgery, Qingdao Municipal Hospital, Qingdao 266071, People’s Republic of China; 3Department of Scientific Research, Lunan Pharmaceutical Corporation, Linyi 276001, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yong Sun Tel +86-532-82991203Email sunyong@qdu.edu.cnBackground: Although dynamics and uses of modified nanoparticles (NPs) as orally administered macromolecular drugs have been researched for many years, measures of molecule stability and aspects related to important transport-related mechanisms which have been assessed in vivo remain as relatively under characterized. Thus, our aim was to develop a novel type of oral-based delivery system for insulin and to overcome barriers to studying the stability, transport mechanisms, and efficacy in vivo of the delivery system.Methods: NPs we developed and tested were composed of insulin (INS), dicyandiamide-modified chitosan (DCDA-CS), cell-penetrating octaarginine (r8), and hydrophilic hyaluronic acid (HA) and were physically constructed by electrostatic self-assembly techniques.Results: Compared to free-insulin, levels of HA-DCDA-CS-r8-INS NPs were retained at more desirable measures of biological activity in our study. Further, our assessments of the mechanisms for NPs suggested that there were high measures of cellular uptake that mainly achieved through active transport via lipid rafts and the macropinocytosis pathway. Furthermore, investigations of NPs indicated their involvement in caveolae-mediated transport and in the DCDA-CS-mediated paracellular pathway, which contributed to increasing the efficiency of sequential transportation from the apical to basolatera