Phototriggered Release of Tumor-Imaging and Therapy Agents from Lyophilized Multifunctional Polyacrylamide Nanoparticles.

The success of polyacrylamide nanoparticles in drug delivery spurred the creation of variations in surface functional groups. We report herein a simple, reproducible, and efficient approach for the creation of modifiable nanoparticles that are characterized by their long-term stability and high loading efficiency. In our experiments, a hydrophobic photosensitizer, such as 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide- a (HPPH), was able to be postloaded at more than 90% efficiency across all types of nanoparticles (NPs). Moreover, the NPs have tunable release kinetics, ranging from 9% to 23%, released by 96 h in 1% serum albumin, depending on the surface modification used. Additionally, it was observed that the NPs had a photorelease mechanism where >60% of the payload was released when exposed to at least 2 J of light. This held true with the photosensitizer and hydrophobic chemotherapeutics like curcumin. To test the impact these modifications have in vitro , two different bladder cancer cell lines were chosen (UMUC3 and T24). These nanoparticles increase the efficacy of the photosensitizer by 4-fold in UMUC3, with the cationic and amino-functionalized particles having the highest efficacy. This increase in efficacy, high uptake, and favorable subcellular localization makes the cationic modification of the nanoparticle extremely attractive for future studies.