Physicochemical characteristics of liposomes are decisive for their antirestenosis efficacy following local delivery

To develop an ameliorated sirolimus (SIR) liposome for intramural delivery, the effects of various carrier physicochemical parameters on the antirestenosis efficacy were evaluated. Different liposomes were prepared, characterized and administered to balloon injured rats (12 animal groups). Their efficacies were investigated using morphometric, immunohistochemical and computed tomography imaging analyses. The antirestenosis efficacy of SIR liposomes decreased in the following order: cationic 100 nm vesicles ≥ cationic 60 nm vesicles > neutral 100 nm vesicles ≥ stealth 100 nm vesicles > anionic 100 nm vesicles. The 100 µg SIR loaded in cationic liposomes showed almost no artery stenosis. Appropriate modulation of physicochemical characteristics makes it possible to optimize the liposomes for local delivery.