Cancer Nanomedicine: Quantitative Visualisation and Efficacy of Nanoparticle Delivery

Abstract

Cancer persists as a major public health concern with poor survival rates for aggressive tumours. Nanotechnology offers opportunities to develop delivery vehicles (nanoparticles) which can improve drug efficacy in cancer cells while reducing collateral toxicity caused by many current therapies. A key challenge in the clinical translation of therapeutic nanoparticles stems from the complexities of drug delivery; namely a need for greater understanding of how the biophysical characteristics of nanoparticles affects their tumour penetration and cell uptake. This thesis sought to address this challenge, developing advanced imaging and analysis methodologies to evaluate nanoparticle uptake and efficacy in quantitative cell models. We initially investigated the capability of rapid fluorescence lifetime imaging microscopy to measure nanoparticle cellular uptake. Results showcased the ability of this emerging quantitative imaging approach to track and quantify changes in nanoparticle dynamics on a second time scale, localising significant changes in nanoparticle lifetime with uptake across extracellular and nuclear boundaries in live cells. Broadening our study into tumour models which recapitulate key elements of the tumour microenvironment, glioblastoma, neuroblastoma and non-small cell lung cancer cells were grown as 3D spheroids and used to study the penetration kinetics of nanoparticles with confocal microscopy. The development of rigorous analysis methods enabled direct evaluation of nanoparticle kinetics. Subsequent study by lightsheet microscopy and real-time force imaging cytometry identified that nanoparticle uptake was influenced not only by nanoparticle size but also the stiffness and density of the cell model. Applying these analyses to functionalised nanoparticles for brain cancer delivery, we identified that lactoferrin coated nanoparticles (Lf-NP) had enhanced penetration kinetics. Low-density lipoprotein receptor (LRP1), for which lactoferrin is a key ligand, was shown to be highly expressed on the blood-brain barrier (BBB) and in glioblastoma. Following, in vitro models identified that Lf-NP could cross the BBB, and drug-loaded iterations of these nanoparticles were revealed to have elevated efficacy against glioblastoma cells. Collectively, these findings showcase methods to systematically visualise and quantify nanoparticle tumour cell uptake and highlight functionalised drug-loaded nanoparticles for further investigation in brain cancer.