Date of Award

2024

Degree Type

Thesis

Degree Name

Master of Science in Pharmaceutical Sciences

Department

Biomedical and Pharmaceutical Sciences

First Advisor

Jyothi U. Menon

Abstract

Hepatocellular carcinoma (HCC) poses a significant global health challenge, being the sixth most common cancer and the third leading cause of cancer death, with over 906,000 new cases and 830,000 fatalities globally in 2020. Conventional HCC treatments like surgery, transarterial chemoembolization (TACE), and chemotherapy are limited by high recurrence rates, limited patient eligibility - particularly applicable only to a subset with early-stage disease and optimal liver function - and chemoresistance, complicating effective disease management. Existing targeted drug therapies are often hampered by limited efficacy, with many patients experiencing rapid disease progression or significant adverse effects. This situation is further exacerbated by the complex interplay of molecular pathways involved in HCC development and progression, such as the MAPK and PI3K/Akt pathways, which not only drive tumor growth but also contribute to the resistance mechanisms against standard treatments. To address these limitations, this study employs nanoparticle-mediated delivery systems, specifically pH-responsive poly(lactic-co-glycolic acid) (PLGA) polymer nanoparticles coated with Carboxymethyl Chitosan (CMC), to encapsulate Lenvatinib in the PLGA core and conjugate Crizotinib on the outer surface of the coated PLGA nanoparticles. Lenvatinib, an inhibitor of multiple receptor tyrosine kinases, and Crizotinib, a c-MET receptor inhibitor, were chosen for their potential to synergistically inhibit the MAPK and PI3K/Akt pathways, which are crucial in HCC progression and drug resistance. Thus, this study seeks to overcome the intrinsic challenges of current drug therapies by harnessing pH-responsive nanoparticle-based drug delivery for precise targeting and controlled release, alongside a novel combination drug therapy approach within this system, promising improved efficacy against HCC. We employed Dynamic Light Scattering (DLS) to confirm the stability of our nanoparticles, ensuring a consistent size distribution and zeta potential, indicative of a stable colloidal system suitable for drug delivery. Fourier Transform Infrared Spectroscopy (FTIR) verified the presence of CMC coating on the nanoparticles, essential for the pH-responsive drug release mechanism we aimed to exploit. In vitro drug release studies highlighted the pH responsiveness of 1% (w/v) CMC-coated nanoparticles, with significantly higher drug release observed in the acidic pH of 5.5, mirroring the HCC tumor microenvironment. This emphasizes the nanoparticles' potential for targeted therapy, ensuring efficient drug delivery to the tumor site. Cytotoxicity assays revealed the safety of our empty formulations, with cell viability remaining high across nanoparticle concentrations ranging from 0 to 2000 µg/ml. Notably, cellular uptake studies highlighted the enhanced internalization of nanoparticles conjugated with the c-Met-inhibitor Crizotinib, suggesting a strategic advantage in drug delivery. The culmination of our research was evidenced by the significant reduction in cell viability from day 3 onwards in dual drug-loaded nanoparticles (Lenvatinib encapsulated and Crizotinib-conjugated), showcasing the synergistic effect of Lenvatinib and Crizotinib in inhibiting crucial pathways involved in HCC. These findings advocate for the potential of our nanoparticle platform in offering a more precise, targeted, and effective approach to HCC treatment, warranting further in vivo investigations to translate these promising in vitro results into clinical applications.

Available for download on Thursday, May 21, 2026

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