PhD Study : Autonomous Smart Patches: New Approaches to Controlled Drug Delivery

Summary

Background:

Transdermal drug patches have often been heralded as a pain free approach to the delivery of therapeutic agents and there has been considerable commercial interest with the availability of over the counter (nicotine) and prescription (fentanyl) products. Drug delivery is typically achieved through passive diffusion across the stratum corneum into the underlying microcirculation but the hydrophobicity of the skin barrier restricts the drug candidates to small molecular weight lipophilic species. Once applied, the dosage cannot be modulated other than simply removing the patch. Microneedles can offer a means of painlessly breaching the skin and allow the transport of polar/large molecular material (i.e. insulin).

While there have been extensive developments within this field, the majority remain limited by a lack of control over the release dynamics. The evolution of systems offering smarter, stimuli reactive, release has gathered pace with mechanical, electrical and light actuation systems coming to the fore.

Aim:

The proposed project will build on existing microneedle expertise within the group but incorporate the innovative element of electronic control over the timing, extent and frequency of reagent release. This would eventually set the foundations for an autonomous patch capable of administering personalised drug therapies.

Methodology:

The strategy exploits a composite microneedle structure comprising cellulose acetate phthalate (CAP) and a phase change material based on poly(ethylene glycol) methyl ether-block-poly(lactide-co-glycolide) (PEG-PLGA). The outer CAP material provides structural integrity and piercing capability while the inner PEG-PLGA composite is key to the delivery control. The latter is solid at physiological temperatures but transitions to a liquid state at 40oC. Thus, integration of the microneedle composite with a small resistive heater which can be controlled via Bluetooth from a phone (Figure 1) could thereby enable more precise control over the release profile.

Proposed Plan:

Year 1. Production/characterisation of the composite microneedles and their thermal release properties using model drugs in simulated conditions. Optimisation of yield through investigating transfer from the MN baseplate through the needles.

Year 2. Establish appropriate models through which to evaluate MN delivery and transdermal yield through and within skin. Validation of device operation.

Year 3. Optimisation of patch constituents and technology demonstration through the controlled autonomous delivery (single/repetitive dosing) of micronutrients, analgesics and hormones. A key advantage of the proposed strategy is the ability to have a multi-needle patch enabling repetitive dosing over a prolonged period and which would eventually offer closed loop combination therapy dosing. Autonomous control through a smart phone app directly addresses issues of therapy compliance and would be particularly useful in contexts such as:  nutrition, chronic pain, cancer and dementia where regularity of dosing is critical for improving outcomes.

Upper Second Class Honours (2:1) Degree from a UK institution (overseas award deemed equivalent via UK NARIC) in Biochemistry, Biomolecular Sciences, Biomedical Engineering.

Essential criteria

Applicants should hold, or expect to obtain, a First or Upper Second Class Honours Degree in a subject relevant to the proposed area of study.

We may also consider applications from those who hold equivalent qualifications, for example, a Lower Second Class Honours Degree plus a Master’s Degree with Distinction.

In exceptional circumstances, the University may consider a portfolio of evidence from applicants who have appropriate professional experience which is equivalent to the learning outcomes of an Honours degree in lieu of academic qualifications.

• Experience using research methods or other approaches relevant to the subject domain

Funding and eligibility

The University offers the following levels of support:

Department for the Economy (DFE)

The scholarship will cover tuition fees at the Home rate and a maintenance allowance of £19,000 (tbc) per annum for three years (subject to satisfactory academic performance).

This scholarship also comes with £900 per annum for three years as a research training support grant (RTSG) allocation to help support the PhD researcher.

• Candidates with pre-settled or settled status under the EU Settlement Scheme, who also satisfy a three year residency requirement in the UK prior to the start of the course for which a Studentship is held MAY receive a Studentship covering fees and maintenance.
• Republic of Ireland (ROI) nationals who satisfy three years’ residency in the UK prior to the start of the course MAY receive a Studentship covering fees and maintenance (ROI nationals don’t need to have pre-settled or settled status under the EU Settlement Scheme to qualify).
• Other non-ROI EU applicants are ‘International’ are not eligible for this source of funding.
• Applicants who already hold a doctoral degree or who have been registered on a programme of research leading to the award of a doctoral degree on a full-time basis for more than one year (or part-time equivalent) are NOT eligible to apply for an award.

Due consideration should be given to financing your studies. Further information on cost of living