PhD Study : Fabrication of PEEK bioactive composites with substituted hydroxyapatite for orthopaedic and dental applications via 3D printing

Summary

Polyetherether ketone (PEEK) is widely explored as a polymer for biomedical applications due to its excellent mechanical properties. However, it exhibits poor adhesion to surrounding soft tissues because of its inert nature. The inert behaviour of PEEK can be modified by creating composites with bioactive ceramic fillers such as hydroxyapatite.

Hydroxyapatite is a bioceramic material that chemically resembles the mineral component of bone and can be synthetically produced. This mineral, a type of calcium phosphate, contributes to the hardness and rigidity of bones and teeth. It is commonly employed in bone grafts, bone implants, dental cements, and coatings for orthopaedic implants to enhance the integration and strength of these devices within the body. Similarity in composition to natural bone makes it an ideal material for promoting bone tissue growth and integration. Additionally, hydroxyapatite can be modified with various elements, such as silver, strontium, fluoride, or zinc, to impart specific properties like antibacterial capabilities or enhanced bone integration [1, 2]. This makes it a versatile material in the field of biomedical engineering and regenerative medicine.

Additive manufacturing, also known as 3D printing, is a relatively recent technology capable of producing customized parts in a short timeframe. It enables the creation of complex shapes that are beyond the scope of conventional technologies such as extrusion and injection moulding [3]. In the realm of regenerative medicine, it has demonstrated the ability to create patient-specific medical implants. Its main advantages lie in minimal material waste, reduced manufacturing costs, and a lower environmental impact.

In this project, PEEK composites will be processed using fused deposition modelling (FDM) after creating composite filaments through extrusion technology. PEEK will be loaded with varying percentages of bioceramic particles. Additionally, synthesized bioceramic particles will undergo characterization through techniques such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), Differential Scanning Calorimetry (DSC), and Thermogravimetric Analysis (TGA). 3D-printed PEEK composite samples will be subjected to mechanical testing (tensile, compression, impact), micro-Computed Tomography (micro-CT), bioactivity testing, cell adhesion, and antibacterial studies.

The researcher will have an opportunity to work on state-of-the art 3D printers and high end characterisation equipment based at our new Belfast campus and NIACE. This project would suit candidates with a background in Biomedical, Materials, Mechanical, and Mechatronics Engineering. Experience in 3D printing or polymer processing would be advantageous.

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

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
• Masters at 65%
• Work experience relevant to the proposed project
• Publications - peer-reviewed

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

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 £19,237 (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