Multifunctional Nanoplateforms for Biomedical Imaging and Photodynamic Therapy.

Abstract

Nanoplatforms have considerable potential for delivery of biomedical agents, so as to overcome inherent limitations of small molecule drugs or contrast agents, such as fast degradation, aggregation and lack of targeting ability. In this dissertation, we demonstrate improved imaging and therapy techniques using polyacrylamide (PAA) based nanoparticles (NPs) and star-shaped polyethylene glycol (PEG) platforms for cancer and cardiac arrhythmia treatment. The proposed albumin conjugated PAA NPs provided strong fluorescence and photoacoustic intensities for the Indocyanine Green (ICG) contrast agent for use in cancer imaging. These protein hybrid NPs not only enhanced the chemical stability of ICG but also showed in vitro cancer cell specificity, with the help of targeting moieties. We also developed methylene blue (MB) conjugated PAA NPs for photodynamic therapy (PDT). Its reactive oxygen species (ROS) productivity was enhanced by utilizing longer cross-linker than in previous PAA NPs and a newly designed microfluidic device contributes to faster tests on the cell killing efficacy of photo-drug NPs. Lastly, Chlorin e6 (Ce6) and cardiac targeting peptide (CTP) were conjugated to 8-arm PEG for extremely small sized nanoplatforms (CTP‒Ce6‒PEG); it showed great potential for treating cardiac arrhythmia by PDT, demonstrating selective ablation of arrhythmia causing myocyte cells. Overall, this dissertation, reporting on biomedical imaging and therapy based on nanotechnology, shows their potentialities towards further modifications for clinical usage and commercialization, not only for cancer but also for heart disease.