Optimization of purification techniques for lumen-loaded magnetoliposomes.

Liposomes encapsulating magnetic nanoparticles, known as magnetoliposomes, have become a hot topic in biomedical research for applications in remote-triggered drug delivery and diagnostic imaging. One of the most crucial steps in the preparation of magnetoliposomes is the purification of non-encapsulated magnetic nanoparticles, as a non-efficient purification can lead to misleading results. Purification is challenging especially when magnetic nanoparticles are loaded in the liposome lumen due to the small size differences between the magnetoliposomes and the non-encapsulated magnetic nanoparticles. This work presents a comparison of three well known purification techniques, namely size exclusion chromatography, centrifugation and salt-induced aggregation, using five commercial magnetic nanoparticles with different configurations. The optimal purification techniques for two magnetic nanoparticles were studied further in the synthesis of magnetoliposomes. In conclusion, we show that an efficient magnetoliposomes purification requires the performance of a detailed study to select a valid method that is strongly dependent upon magnetic nanoparticles choices.