Designing of thermosensitive liposomes from natural lipids for multimodality cancer therapy

Abstract

Thermosensitive liposomes prepared from synthetic lipids such as dipalmitoyl phosphatidylcholine, distearoyl phosphatidyl choline and cholesterol (Ch) have been tried for local drug release in response to hyperthermia for achieving tumour drug targeting. Herein we report a novel method of preparation of temperature-sensitive liposomes using natural lipids egg phosphatidylcholine (PC):Ch (7:1 molar ratio) and ethanol 6% (v/v) having a transition temperature of 43°C, temperature attainable by local hyperthermic treatment of tumours. The anticancer drug dacarbazine [5-(3,3′-dimethyl-1-triazino) imidazole-4-carboxamide] was entrapped in these liposomes. The in vivo efficacy of temperature-sensitive unilamellar vesicles encapsulated dacarbazine in combination with hyperthermia was determined in murine fibrosarcomas. These PC:Ch liposomes are biodegradable, non-toxic and more cost effective in comparison with liposomes prepared from synthetic lipids for use in multimodality cancer therapy.

Key Words:

• Temperature-sensitive liposome
• phase transition
• hyperthermia
• targeting chemotherapy
• ethanol