Xinyu Zong,1,2,* Shangying Xiao,3,* Haishan Xia,3 Dan Guo,1 Jiaping Wu,1 Manjiao Zhuang,3 Lei Rao1 

1Guangdong Provincial Key Laboratory of Utilization and Conservation of Food and Medicinal Resources in Northern Region, Medical College, Shaoguan University, Shaoguan, 512005, People’s Republic of China; 2School of Pharmacy, Anhui Medical University, Hefei, Anhui, 230032, People’s Republic of China; 3School of Pharmacy, Guangdong Medical University, Dongguan, Guangdong, 523808, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Lei Rao, Guangdong Provincial Key Laboratory of Utilization and Conservation of Food and Medicinal Resources in Northern Region, Medical college, Shaoguan University, Shaoguan, 512005, People’s Republic of China, Email 591617735@qq.com Manjiao Zhuang, School of Pharmacy, Guangdong Medical University, Dongguan, Guangdong, 523808, People’s Republic of China, Email man.jiao@163.com

Background: BAY55-9837, a potential therapeutic peptide for the treatment of type 2 diabetes mellitus (T2DM), can induce glucose (GLC)-dependent insulin secretion. Our previous study has demonstrated that the use of superparamagnetic iron oxide nanoparticle-decorated exosome (exosome-SPION) and external magnetic force (MF) enables BAY 55-9837 to target pancreatic islets. However, the initial burst release of BAY 55-9837 loaded within exosome-SPION shortens its in vivo half-life and consequently reduces the frequency of GLC responsiveness. Therefore, in our study, the transmembrane hydrophobic structure of the exosome signature protein CD81 was fused with BAY 55-9837 to obtain MBAY with sustained-release capability.
Methods: MBAY was fabricated via genetic engineering, and the dissociation constant (Kd) was determined to assess its affinity for vasoactive intestinal peptide receptor type 2 (VPACII). Subsequently, MABY was incorporated into exosomes through electroporation to obtain MBAY-exosome, and SPOIN was adorned on MBAY-exosome by means of the self-assembly of transferrin (Tf) and the transferrin receptor (TfR). The in vitro release profile and in vivo pharmacokinetic profile of MBAY-Exosome-SPION were detected using high-performance liquid chromatography (HPLC). The L9(34) orthogonal design approach was utilized to optimize the drug administration mode in vivo. The therapeutic effect of MBAY-exosome-SPIONs/MF on T2DM was assessed both in vitro and in vivo.
Results: In vitro studies showed that the release rate of MBAY from exosome-SPION was slower compared with BAY 55-9837. Meanwhile, MBAY still maintained high affinity and selectivity for VPAC II and MBAY-exosome-SPIONs/MF could effectively promote insulin secretion in response to elevated GLC as BAY-exosome-SPIONs/MF. In vivo studies indicated that MBAY-exosome-SPIONs had a prolonged half-life and improved pharmacokinetic parameters compared to BAY-exosome-SPIONs, which further alleviated the symptoms of T2DM model mice.
Conclusion: Thus, the reconstructed MBAY loaded in SPION-exosome realized sustained-release and exosomes-SPIONS achieved pancreatic targeting which led to ideal therapeutic effect in T2DM mice.

Keywords: type 2 diabetes mellitus, exosome, BAY 55-9837, sustained-release