Remote loading of Aloe Emodin in gemini based cationic liposomes.

The anthraquinone compound Aloe-Emodin (AE) has shown antineoplastic, antibacterial, antiviral, anti-inflammatory properties and scavenging activity on free radicals. Due to these therapeutic features, AE has been attracting increasing interest and could be applied in the cure of many diseases. However, up to now the physicochemical features of this compound have not been fully investigated; further, its wide application might be hindered by its scarce solubility in aqueous medium (?19 ?M). The inclusion of AE in nanocarriers, such as cationic liposomes, could allow delivering it effectively and selectively to target sites reducing side effects in the remaining tissues. In this work, the weak acid nature of AE, due to its two phenolic functions, was exploited to remotely load it in the internal aqueous phase of liposomes in response to a difference in pH between the inside and the outside of the liposomes, pHin>pHout. The inclusion of AE in gemini based cationic liposomes by the acetate gradient method was obtained at high AE/lipid ratio (up to 1:30).