Yan Wang,1,2,* Fengmei Li,1,2,* Shanshan Wei,1,2,* Wenqun Li,1,2 Junyong Wu,1,2 Shengnan Li,1,2 Xiongbin Hu,1,2 Tiantian Tang,1,2 Xinyi Liu1,2 

1Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, People’s Republic of China; 2Institution of Clinical Pharmacy, Central South University, Changsha, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Xinyi Liu, Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, People’s Republic of China, Tel +86-731-8529-2095, Email liuxinyi128@csu.edu.cn

Purpose: Mitochondrial damage may lead to uncontrolled oxidative stress and massive apoptosis, and thus plays a pivotal role in the pathological processes of myocardial ischemia-reperfusion (I/R) injury. However, it is difficult for the drugs such as puerarin (PUE) to reach the mitochondrial lesion due to lack of targeting ability, which seriously affects the expected efficacy of drug therapy for myocardial I/R injury.
Methods: We prepared triphenylphosphonium (TPP) cations and ischemic myocardium-targeting peptide (IMTP) co-modified puerarin-loaded liposomes (PUE@T/I-L), which effectively deliver the drug to mitochondria and improve the effectiveness of PUE in reducing myocardial I/R injury.
Results: In vitro test results showed that PUE@T/I-L had sustained release and excellent hemocompatibility. Fluorescence test results showed that TPP cations and IMTP double-modified liposomes (T/I-L) enhanced the intracellular uptake, escaped lysosomal capture and promoted drug targeting into the mitochondria. Notably, PUE@T/I-L inhibited the opening of the mitochondrial permeability transition pore, reduced intracellular reactive oxygen species (ROS) levels and increased superoxide dismutase (SOD) levels, thereby decreasing the percentage of Hoechst-positive cells and improving the survival of hypoxia-reoxygenated (H/R)-injured H9c2 cells. In a mouse myocardial I/R injury model, PUE@T/I-L showed a significant myocardial protective effect against myocardial I/R injury by protecting mitochondrial integrity, reducing myocardial apoptosis and decreasing infarct size.
Conclusion: This drug delivery system exhibited excellent mitochondrial targeting and reduction of myocardial apoptosis, which endowed it with good potential extension value in the precise treatment of myocardial I/R injury.

Keywords: mitochondrial targeting, triphenylphosphonium cations, puerarin, ischemic myocardium-targeting peptide, liposomes