DYNAMIC INTERACTIONS OF GRAPHENE-BASED MATERIALS WITH MAMMALIAN CELLS: FROM CELLULAR MECHANISMS TO POTENTIAL DRUG DELIVERY APPLICATIONS

Abstract

Graphene-based materials (GBMs), due to their large surface area, surface versatility, and excellent biocompatibility, hold great potential for biomedical applications. However, a general understanding of how GBMs interact with cells is still lacking, even though this is a prerequisite for their safe and efficient biomedical use. In this thesis, we addressed existing methodological weaknesses and developed a robust protocol to accurately assess the uptake of GBMs in healthy (BEAS-2B, NIH/3T3, HaCaT, 293T, PNT2 and HPF) and diseased (HeLa, A549, PC3, DU 145, LNCaP, SW 480, SH-SY5Y, U87 MG, MPS VI and Pompe) cells. We offer previously unreported findings of temporal dynamics in the cellular uptake of GBMs. We showed that GBMs were taken up via multiple endocytic pathways, but the main uptake mechanism was both size and time-dependent. Furthermore, we established that GBMs terminate in the lysosomes, regardless of their size and without inducing cellular damage. Subsequently, we assessed the uptake of GBMs by a panel of commercially available non-cancer and cancer cell lines, and we revealed striking differences in the pattern of internalisation between the two. We identified key properties of GBMs as well as differential biological effects these materials had on migratory behaviour and structural properties of the cells, revealing the cellular mechanism that accounted for the uptake differences. Finally, we tailored the therapeutic application of GBMs based on established cellular interactions. We systematically compared the cytotoxicity and uptake profile of Graphene Oxide (GO) and defect-free Graphene Flakes (Gr) in healthy and lysosomal storage diseased (LSD) human fibroblasts. Despite their excellent biocompatibility, we offer previously unreported evidence for the uptake differences between GO and Gr. Furthermore, we demonstrated for the first time that positively charged Gr have the potential to enhance the clearance of the non-degradable substrates in LSD patients-derived cells. In summary, we provided comprehensive insight into cellular interactions of GBMs in a large panel of commercially available and human-derived cell lines, emphasizing the need to use the non-labelled materials and a set of complementary techniques, as well as to tailor the therapeutic applications based on revealed interactions.

Date of Award	1 Aug 2023
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Kostas Kostarelos (Supervisor) & Sandra Vranic (Supervisor)