Conjugated polymer composites for the prevention of implant- and device-related infections

Summary

Healthcare-associated infections (HAIs) pose a significant global burden, responsible for over 90,000 deaths annually in Europe alone. Implants and biomedical devices are often implicated in HAI development, with catheter-related bloodstream infections, surgical site infections and ventilator-associated events representing prevalent HAIs linked with high mortality rates. Treating these implant- or device-related HAIs with antibiotics is challenging due to the formation of resilient biofilms on their surfaces, facilitating proliferation of antimicrobial resistant bacteria within. While antibiotic eluting biomaterials have been investigated as a solution, maintaining sustained antimicrobial release is difficult. This can lead to exposure of microorganisms to sub-therapeutic concentrations and further promote antimicrobial resistance (AMR). Alternative antimicrobial strategies are urgently needed to prevent bacterial colonisation of these materials, without contributing to AMR.

In response, this proposed research aims to leverage the unique properties of conjugated polymers (CPs) to prevent microbial colonisation of biomaterial surfaces. CPs, or conductive polymers, are biocompatible macromolecules consisting of alternating single and double bonds, with delocalised π-electrons along their backbone. This structure affords them with distinctive electrical and optical properties, which can be enhanced by the addition of dopants. CPs have been recently explored for various biomedical applications: tissue engineering, biosensing, bioelectronics, anticancer, antimicrobial and drug delivery systems.

Specifically, this project aims to develop CP-incorporated materials that produce a broad-spectrum antimicrobial effect upon exposure to low intensity electrical microcurrents and near infrared (NIR) light. Development of microbial resistance to this multitargeted, combinational approach is unlikely. Furthermore, the electronic and ionic conductivity of the CP-incorporated composites will also be investigated and explored for microbial sensing applications.

The specific objectives of this interdisciplinary project are to develop a range of CP-incorporated composites produced using scalable methods e.g. polymer blending and electrochemical polymerisation techniques; to thoroughly characterise the composites, with the addition of dopants to optimise the resultant materials’ properties; to investigate the electricidal and photothermal antimicrobial effect produced upon exposure to clinically appropriate, non-invasive microampere electrical stimuli and NIR irradiation; to assess the composites’ biocompatibility using cell culture techniques; and to exploit CP’s electronic and ionic conductivity for detection of bacteria.

Optimised CP composites have the potential to be integrated into a wide range of biomedical devices and implants, such as central venous catheters, pacemakers, implantable access ports (e.g. vascular, intrathecal, intraventricular), and orthopaedic implants. These devices are often relied upon by vulnerable individuals, including the elderly, immunocompromised or critically ill. By preventing microbial colonisation on these surfaces, this research could significantly reduce the incidence of implant- and device-related infections, thereby improving patient outcomes and reducing healthcare-associated morbidity and mortality.

Important Information: Applications for more than one PhD studentship are welcome, however if you apply for more than one PhD project within Biomedical Sciences, your first application on the system will be deemed your first-choice preference and further applications will be ordered based on the sequential time of submission. If you are successfully shortlisted, you will be interviewed only on your first-choice application and ranked accordingly. Those ranked highest will be offered a PhD studentship. In the situation where you are ranked highly and your first-choice project is already allocated to someone who was ranked higher than you, you may be offered your 2nd or 3rd choice project depending on the availability of this project.

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.

• Sound understanding of subject area as evidenced by a comprehensive research proposal
• A comprehensive and articulate personal statement

Desirable Criteria

If the University receives a large number of applicants for the project, the following desirable criteria may be applied to shortlist applicants for interview.

• First Class Honours (1st) Degree
• Completion of Masters at a level equivalent to commendation or distinction at Ulster
• Practice-based research experience and/or dissemination
• Experience using research methods or other approaches relevant to the subject domain
• Work experience relevant to the proposed project
• Publications record appropriate to career stage
• Experience of presentation of research findings

Equal Opportunities

The University is an equal opportunities employer and welcomes applicants from all sections of the community, particularly from those with disabilities.

Appointment will be made on merit.

Funding and eligibility

This project is funded by:

• Department for the Economy (DfE)
• Vice Chancellor's Research Scholarship (VCRS)

Our fully funded PhD scholarships will cover tuition fees and provide a maintenance allowance of £19,237 (tbc) per annum for three years (subject to satisfactory academic performance).  A Research Training Support Grant (RTSG) of £900 per annum is also available.

These scholarships, funded via the Department for the Economy (DfE) and the Vice Chancellor’s Research Scholarships (VCRS), are open to applicants worldwide, regardless of residency or domicile.

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.