Physicochemical delivery of amphiphilic copolymers to specific organelles

In this study, a novel polymer material was introduced into cells and was delivered to specific organelles. Various fluorescently labeled copolymers of 2-methacryloyloxyethylphosphorylcholine (MPC) and alkyl methacrylates, such as n-hexyl methacrylate (HMA), n-dodecyl methacrylate (DMA) and stearyl methacrylate (SMA), were synthesized. HeLa cells were treated with the copolymers and subsequently observed by confocal fluorescence microscopy. The results indicated that the localization behavior of the copolymers was dependent on their structure. For instance, poly(HMA-co-MPC) was non-cytotoxic and was localized in specific cellular organelles such as the endoplasmic reticulum. In contrast, poly(DMA-co-MPC) was cytotoxic and was partially transported to specific organelles. Poly(SMA-co-MPC) hardly entered the cells. The mechanism of delivery and structure-function relationships of the copolymers are also discussed. Polymer Journal (2011) 43, 718-722; doi:10.1038/pj.2011.49; published online 15 June 2011