Uptake, toxicity, and photo-release studies of pulsed laser responsive nano-polymersomes.

Polymersomes have potential for drug delivery applications due to their ability to efficiently encapsulate both hydrophobic and hydrophilic molecules. The ability to control cargo release from these vesicles with high spatiotemporal control would be transformative in biological systems. One such way to accomplish this is with a light-responsive polymersome system, whereby pulsed laser irradiation can be utilized to bring about membrane disruption and subsequent cargo release. Gold nanoparticles are optimal photosensitizers due to their strong interaction with light stemming from their surface plasmon resonance. Nano-scale polymersomes self-assembled with dodecanethiol-functionalized gold nanoparticles have been shown to undergo membrane disruption and subsequent cargo release in response to pulsed laser irradiations. The work herein investigates the uptake and toxicity of this system in mouse NIH-3T3 cells as well as the ability to deliver cargo upon irradiation. Nano-polymersome uptake was studied via confocal microscopy, whereby cells were incubated with polymersomes and subsequently stained with NucBlue and Cellmask to confirm endocytosis. Cell viability was confirmed via LDH assay. To demonstrate cargo release, cells containing doxorubicin loaded polymersomes were irradiated with a 532 nm picosecond laser and doxorubicin associated cytotoxicity was demonstrated upon increasing irradiation time.