Controlled SPION-Exosomes Loaded with Quercetin Preserves Pancreatic Beta Cell Survival and Function in Type 2 Diabetes Mellitus

Manjiao Zhuang,1,* Lei Rao,2,3,* Yadi Chen,1 Shangying Xiao,1 Haishan Xia,1 Jiangyong Yang,2 Xiaohua Lv,1 Dongyun Qin,1 Chunjie Zhu1 1Guangdong Provincial Key Laboratory of Research and Development of Natural Drugs, and School of Pharmacy, Guangdong Medical University, Dongguan, 523808, People’s Republic of China; 2Medical College, Shaoguan University, Shaoguan, 512026, People’s Republic of China; 3Department of Biomedicine, Chengdu Medical College, Chengdu, 610500, People’s Republic of China*These authors contributed equally to this workCorrespondence: Manjiao Zhuang, Guangdong Provincial Key Laboratory of Research and Development of Natural Drugs, and School of Pharmacy, Guangdong Medical University, Dongguan, 523808, People’s Republic of China, Email manjiao@163.com Chunjie Zhu, School of Basic Medicine, Guangdong Medical University, Dongguan, 523808, People’s Republic of China, Email zhuchunjie718@163.comIntroduction: Quercetin has an ideal therapeutic effect on islet function improvement in type 2 diabetes mellitus (T2DM). However, the therapeutic benefit of quercetin is hindered by its poor bioavailability and limited concentration in pancreatic islets. In this study, superparamagnetic iron oxide nanoparticle (SPION)-modified exosomes were prepared to load quercetin, hoping to endow quercetin with enhanced water solubility and active targeting capacity with the help of magnetic force (MF).Methods: Transferrin-modified SPIONs (Tf-SPIONs) were synthesized by exploiting N-hydroxysuccinimidyl (NHS) conjugation chemistry, and quercetin-loaded exosomes (Qu-exosomes) were acquired by electroporation. Tf-SPION-modified quercetin-loaded exosomes (Qu-exosome-SPIONs) were generated by the self-assembly of transferrin (Tf) and the transferrin receptor (TfR). The solubility of quercetin was determined by high-performance liquid chromatography (HPLC) analysis. The pancreatic islet targeting capacity and insulin secretagogue and antiapoptoti