ABSTRACT
In order to overcome the limitation of systemic administration of methylene blue, this study investigated the encapsulation of methylene blue in polymeric liposomes and drug release following sonication. We encapsulated methylene blue into nanoliposomes. The dynamic light scattering [DLS] method was used to measure the size distribution of the liposomes. After loading methylene blue into these liposomes, both drug encapsulation efficiency and stability were fluorometrically determined. Biodistribution of drug was studied in vivo in a mouse model of adenocarcinoma tumor cells. The amount of drug released upon 1 MHz sonication at an intensity of 2 W/cm2 was fluorometrically verified in vitro. DLS studies showed that the synthesized liposomes had an average size of 66.19 +/- 4.49 nm. Methylene blue was efficiently encapsulated in nanoparticles at an average of 65.21 +/- 3.47%. Stability of the generated liposomes decreased with time. Biodistribution study revealed that the drug content in the group that received liposomal drugs in their tumor tissue was significantly higher than in the group that received methylene blue in its free form and in the heart was inverse [P<0.05]. The results indicated that a 5 min application of 1 MHz ultrasound caused a methylene blue release of approximately 51.8 +/- 8.3% from the nanoparticles. This study has shown that fabricated liposomes are suitable for the encapsulation and delivery of hydrophilic photosensitizers such as methylene blue. Ultrasound-triggered release was achieved by the use of a 1 MHz ultrasound