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

  • To hold, or expect to achieve by 15 August, an Upper Second Class Honours (2:1) Degree or equivalent from a UK institution (or overseas award deemed to be equivalent via UK NARIC) in a related or cognate field.
  • Experience using research methods or other approaches relevant to the subject domain

Funding

    The University offers the following awards to support PhD study and applications are invited from UK, EU and overseas for 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 £15,285 per annum for three years. EU applicants will only be eligible for the fee’s component of the studentship (no maintenance award is provided). For Non-EU nationals the candidate must be "settled" in the UK. 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.

    Due consideration should be given to financing your studies; for further information on cost of living etc. please refer to: www.ulster.ac.uk/doctoralcollege/postgraduate-research/fees-and-funding/financing-your-studies


Other information


The Doctoral College at Ulster University