Document Type

Thesis

Degree Name

Master of Science (MSc)

Department

Health Science

Faculty/School

Faculty of Science

First Advisor

Dr. Sarah Poynter

Advisor Role

Thesis Supervisor

Second Advisor

Dr. Stephanie DeWitte-Orr

Advisor Role

Thesis Committee Member

Third Advisor

Dr. Nirosha Murugan

Advisor Role

Thesis Committee Member

Abstract

Cancer is a group of diseases characterized by abnormal and uncontrolled cell division, which typically results in the formation of tumours. Even with advances in treatments, cancer remains one of the leading causes of death globally. Melanoma is an aggressive form of skin cancer which is highly malignant, develops in the pigment-producing cells of the skin, melanocytes, and in the late stages of the disease poses a significant challenge for therapeutic intervention due to its multidrug resistance. The innate immune system is the first line of defence against invading pathogens, including viruses, bacteria, and fungi, and can recognize and destroy aberrant cells, including cancerous ones. Because cancer, including melanoma, is immune evasive, it becomes difficult for the immune system to detect and clear cancerous cells. Existing therapeutic options include surgical removal of tumours and conventional chemotherapy, but these approaches have been characteristically marked by cases of recurrence and severe cellular damage to healthy cells, which can lead to long-term side effects. Additionally, melanomas on sensitive body parts, for example, the eyelid, are more challenging to treat with surgery. There is a need for more diversity in melanoma therapies and innovative treatments with fewer side effects and decreased risks for resistance.

Immunotherapy has emerged as a ground-breaking approach that holds promise for melanoma therapy. By helping enhance or assist the immune system, it can better perform its role in clearing tumour cells. Double-stranded (ds) RNA is a potent immunostimulant, activating innate immune pathways, including type I interferon and proinflammatory cytokines. Nucleic acid-based therapies benefit from a carrier, which provides protection from host nucleases and enhances uptake. As nucleic acids are anionic, cationic nanoparticles can be employed as a delivery system. Chitosan nanoparticles (ChNPs) have been extensively studied as a drug delivery biopolymer for properties including biocompatibility, biodegradability, anti-microbial activity, and non-toxicity. ChNPs offer a versatile platform for delivery of dsRNA to a tumour and surrounding environment, as well as protection of dsRNA from degradation by serum nucleases. This research explored the potential of ChNPs as a delivery system for dsRNA for immunotherapy in B16F10, murine melanoma cells. This study will investigate the following objectives: (a) characterization of dsRNA-chitosan nanoparticle complex physical properties, (b) elucidating immune responsiveness and cytotoxic effects, and (c) determining uptake and the role of class A scavenger receptor for dsRNA-chitosan in mouse melanoma cells. ChNPs were synthesized and demonstrated to have a positive zeta value of +25mV, thus forming stable electrostatic complexes with dsRNA exhibiting sizes around 200nm. Gene expression studies revealed that ChNP-dsRNA complexes significantly upregulated key interferon-stimulated genes (ISGs; CXCL10, ISG15 and ISG20) in B16F10 melanoma cells, with enhanced upregulation seen when treatments were performed in DMEM culture media compared to F10/HAMs media. Cell viability assays demonstrated a time- and dose-dependent decline in viability over 72 hours, and competitive receptor binding assays confirmed that class A scavenger receptors facilitate the uptake of these complexes. The findings of this study position ChNP as a promising delivery system for dsRNA and ChNP-dsRNA as an ideal candidate for immunotherapy.

Convocation Year

2025

Convocation Season

Fall

Download

Available for download on Wednesday, August 26, 2026

Share

COinS