Inclusion of a photosensitizer in liposomes formed by DMPC/gemini surfactant: correlation between physicochemical and biological features of the complexes.

Mixed cationic liposomes composed by different ratios of dimyristoyl-sn-glycero-phosphatidylcoline (DMPC) and a cationic gemini surfactant have been studied by various physicochemical tools as vehicles for m-tetrahydroxyphenylchlorin (m-THPC), a photosensitizer used in photodynamic therapy. Entrapment and location of m-THPC within the lipid double layer have been evaluated by different techniques and the new formulations have been tested on a stabilized cell line from a human colon tumor, COLO206. A correlation between the physicochemical features of formulations and their efficiency as photosensitizers vector was found.