Evaluation of platinum nanoparticles on human platelets

Patel, Pushpa (2024). Evaluation of platinum nanoparticles on human platelets. University of Birmingham. Ph.D.

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Abstract

Platinum nanoparticles (PtNPs) are the key catalyst of proton exchange membrane fuel cells (PEMFC); however, their degradation may pose a potential health risk if they are inhaled and translocate across the lungs gaining access to the bloodstream, where they will encounter platelets. Platelets are critical to the cardiovascular system where they maintain haemostasis (leading to cessation of bleeding). On the other hand, excessive activation of platelets underlies a variety of thrombotic diseases including ischaemic stroke and heart attack. Activation of platelets has been observed by nanoparticles including diesel exhaust particles in vitro, nonetheless, not much is known on how the physicochemical properties of the nanoparticles influence platelet activation. This thesis aims to create an array of PtNPs exhibiting negative, positive, and neutral charges, and to investigate their ability to induce activation of human platelets including aggregation. Citrate capped PtNPs were synthesised and characterised by TEM, DLS, zeta potential and XPS for size, surface charge and surface composition. Alkane and polyethylene glycol (PEG) thiols and other surface modifying compounds were used to functionalise these PtNPs to exhibit negative, positive, and neutral charges via ligand exchange and synthesis methods. Following characterisation, functionalisation of PtNPs was met with varying degrees of success. It was revealed the negatively and neutrally charged PtNPs were only partially functionalised by the alkane and PEGylated thiols. Positively charged PtNPs were found to be unstable. Albeit these partially functionalised PtNPs were assessed in platelet activation and aggregation. Negatively charged and neutrally charged PtNPs were unable to induce platelet aggregation, while platelet aggregation was observed by citrate capped PtNP. Platelet aggregation was found to be influenced by the zeta potential of PtNPs.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):