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

Aim: To develop an ameliorated sirolimus (SIR) liposome for intramural delivery, the effects of various carrier physicochemical parameters on the antirestenosis efficacy were evaluated.
Materials & Methods: Different liposomes were prepared, characterized and administered to balloon injured rats (12 animal groups). Their efficacies were investigated using morphometric, immunohistochemical and in vivo computed tomography imaging analyses.
Results: 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.
Conclusion: Appropriate modulation of physicochemical characteristics makes it possible to optimize the liposomes for local delivery.