Microscopic Evaluation of Novel Light Activated Molecular Nanomachines

Project Background

An important need for future bio-medical research and fundamental cell biology is the targeted in vivo destruction of selected cells and cell types. Our key innovation is the development of a fundamentally new single-cell precision biological research tool using cell type and metabolic/morphological state specific molecular nanomachines and biologically safe near infra-red activation. Once fully developed and validated it could open new horizons toward wound healing, tumour/cancer progression, such as chemotherapeutic agent and drug resistant cancer studies and improve and extend the molecular toolbox of bioscientists and biomedical researchers world-wide.

Using precisely designed molecular nanomachines (MNMs) and complementary experimental protocols, molecular mechanical action can irreversibly disrupt external or internal cellular membranes and expedite cell death in a controlled manner. By chemical modifications, the MNMs can be used to target specific cell types through unique cell-surface recognition elements. The efficacy of this method, using single photon activation in the UV domain to introduce necrotic cell death was published by us in Nature (2017, 548, 567-572).

Project Description

Our overarching future aim is to extend our study beyond in vitro applications. However, using UV light to activate these molecular machines in vivo has significant limitations associated with non-uniform activation, shallow tissue penetration and unwanted UV damage. In order to overcome these limitations, we have recently extended our research into the biologically safe multi-(two)-photon (2PE) activation domain.

Preliminary studies show that our MNMs can be successfully activated using 2PE. To take our research to the next level and continue the path of developing a single-cell-precision biophysical research tool our aims and objectives are:

1) Extend the family of cell-type specific MNMs to target skin, colorectal, breast and prostate cancer cell lines, by incorporating short peptide sequences allowing MNM membrane anchoring and targeted single-cell precision necrotic cell destruction.

2) Develop MNMs with excitation/activation wavelengths extending into the visible range (above 405 nm) by redesigning our core MNM structure. This approach will circumvent harmful UV activation (single photon), and will shift the 2PE activation further into the NIR region and may enhance the multi-photon cross-section.

3) Establish whether a more biologically favoured apoptotic cell death pathway could be promoted. This will be facilitated by incorporating hydrophilic pendant side chains in order to facilitate membrane transport, uptake and promote subsequent light activated ‘drilling’ from within the cell.

These aspirations will pave the way towards the development of MNMs with hybrid substitution where one pendant arm will aid cellular uptake and the second arm will consist of a short peptide sequence for intra-cellular ‘targeting’.

This work is in collaboration with Prof. James M. Tour (Rice University, USA) and his group, who will supply vital MNM intermediates, core structures and providing synthetic guidance. This support is extended by a potential up to 3-month placement for the PhD student at the Tour lab.

Desired research skills/Studentship profile:

Sound written communication skills are required.

Experience in some areas relevant to the post is required. This may include, for example, experience of the synthesis and characterization of new materials, experience of using optical microscopy techniques.

Excellent team-working and interpersonal skills.

A motivated, enthusiastic and organised person.

Good time management skills and an ability to focus on the objectives of the project.

Ability to carry out a range of basic tasks in chemical laboratories and operate standard laboratory spectroscopy equipment.
Good IT skills – e.g. competent in use of MS Office software Labview and Matlab programming skills are particularly welcomed.

Health and Safety awareness.

Expertise in or a scholarly knowledge in live-cell imaging, multiphoton and optical microscopy.