Biodegradable Polyacrylamide-Based Theranostic Platforms for Tumor-Imaging and Photodynamic Therapy

The goal of my thesis work was to create theranostic nanoparticles for tumor imaging and therapy based on biodegradable polyacrylamide (PAA) nanoparticles. In order to achieve this goal; my thesis is divided into six parts. The first chapter is an overview of the current research in the area of theranostics, synthetic and nanotechnology based. The second chapter details the various loading methodologies present, their loading efficiency, and photophysical characterization. The post-loading method showed the highest loading efficiency. The third chapter investigates the in vitro and in vivo Phototherapeutic efficacy of these nanoparticles. Chapters 2 and 3 showed that the post-loading methodology produced the highest phototherapeutic activity. The fourth chapter utilizes biodegradable polyacrylamide nanoparticle for the formation of a theranostic nanoconstruct for near-infrared fluorescence imaging and photodynamic therapy (PDT). By varying the ratio of photosensitizer to cyanine dye a single nanoconstruct was afforded for near-infrared fluorescence and PDT. The sixth and final chapter highlights the use of PAA nanoparticles for PET/near-infrared fluorescence with an option of PDT. The post-loading methodology showed a remarkable enhancement in the uptake of the radiolabeled PS to the tumor while minimizing the PS accumulation in residual organs. The fifth chapter describes the utility of porphyrin based PS and PAA nanoparticles for photoacoustic imaging. A conjugation of the porphyrin based PS to the surface of the PAA nanoparticles caused the enhanced aggregation of the PS, which was found to result in the increased photoacoustic signal. Overall, it was shown that polyacrylamide nanoparticles provided a platform to reach our goal.