Layer-by-layer quantum dots-based nanotheranostics: combined drug delivery and breast cancer imaging

Lead Research Organisation: Newcastle University
Department Name: Sch of Engineering

Abstract

The project will use a layer by layer technique to incorporate anti-cancer drugs to the surface of carbon quantum dots for both imaging and treatment purposes.
This project will start with a review of literature to determine the best way to synthesise carbon dots. The carbon dots will originate from biomass that will be obtained from renewable sources such as food or agricultural wastes (nut shells, coffee/tea waste). Careful consideration will have to be taken in choosing the initial biomass material; different biomass can change the properties of the resulting carbon dots. Biomass with high heteroatom content can dope the CD with the respective heteroatom. An example of this is feathers, they produce carbon dots doped with sulphur and nitrogen, this results in higher quantum yield. The biomass will be converted to carbon dots by thermo chemical means (pyrolysis, hydrothermal, cold plasma technology or a combination). The synthesis will be a two-step reaction that produces carbon dots that do not need any further passivation; initially, coffee grounds will be used as the carbon source. The carbon dots will be characterised by; SEM-EDX (size and elemental analysis), TEM (size analysis), FTIR (surface analysis), XRD (crystal structure), UV-Vis (wavelength emission analysis), photoluminescence, XPS (elemental analysis) and Raman Spectroscopy (stokes shift analysis) methods. The properties we are looking for in the carbon dots to make good imaging agents are water solubility, broad stokes shifts, high quantum yield, narrow and tuneable emission wavelength, resistance to photobleaching and tuneable size.
Single carbon quantum dots will then be functionalised by a layer by layer assembly. Recently developed equipment by the school of engineering will be used (Fig 4). The equipment is hybrid of dipping and spray layer by layer strategies. The nanocoated created will be embedded with standard anticancer drugs (celecoxib or rapamycin, starting with celecoxib). The LbL assemblies will be assessed morphologically using FE-SEM and chemically by FTIR and XPS. The functionality that is needed from the layer by layer functionalisation to make an effective treatment for cancer are: no effect or an enhancing effect on the quantum dot photoluminescence, targeting for cancer cells, release of the drug inside the cancer cell and no detrimental effect, or, an enhancing effect on drug treatment capabilities. The anti-cancer drugs will be monitored in physiological conditions at the BIOLAB and BIOFAB laboratories by using spectroscopy analyses (UV-Vis). Preliminary in vitro cell tests on testing the effects of the nano-functionalised quantum dots will be performed in collaboration with the Cancer Institute.

The questions that I wish to answer in this project are:
1. Can the carbon quantum dot synthesised be functionalised via a layer by layer process?
2. Was is the best layer by layer agent and process to use?
3. Can the functionalised carbon dots be used as a nanotheranostic agent?
4. What is the best anti-cancer drug to use?

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