Nano-Self Assembled Photosensitizer Composed of Methoxy Poly(ethylene glycol)-Conjugated Chlorin e6 for Enhanced Photosensing of HCT116 Cells

We synthesized methoxy poly(ethylene glycol) (MPEG)-chlorin e6 (Ce6) conjugates to increase aqueous solubility of Ce6, to fabricate nanoparticles, and to improve tumor targetability of Ce6. MPEG-Ce6 conjugates (abbreviated as Pe6) associated in the aqueous solution as a nanoparticle. Pe6 nanoparticles have small diameter less than 100 nm, spherical shape, and core-shell structure in the aqueous environment. They have improved photophysical properties compared to Ce6 itself. Photosensitivity of Pe6 nanoparticles were studied using HCT116 human colon carcinoma cells. Pe6 nanoparticles practically have no dark-toxicity against HCT116 human colon carcinoma cells while they showed enhanced cellular uptake, phototoxicity, and ROS generation at in vitro cell culture experiment. Furthermore, they showed improved tumor tissue penetration and accumulation in vivo animal studies. We suggested Pe6 nanoparticles as an ideal candidate for PDT of colon cancer.