Sustainable Biomaterial Formulations for 3D Bioprinting of Gradient Structures

Description

Global populations are ageing. By 2030, 1 in 6 people will be 60 years or older. The number of octogenarians is expected to triple between 2020 and 2050.  Ageing presents with a decline in tissue and cell functions, increasing the risk of age-related diseases and ultimately death. This irreversible pathophysiological process and risk of disease is amplified by the effects of unhealthy lifestyle choices and socioeconomic health inequalities. For example, oral health is significantly affected by age; chronic inflammation such as periodontal disease is the primary cause of tooth loss in elderly patients and often impacts malnutrition. Older patients have greatly increased complication rates related to systemic conditions such as cardiovascular, disease and osteoporosis. Whilst lifestyle, nutritional and pharmacological interventions can help prevent and address a number of age-related conditions, a step-change in the design of effective and minimally invasive oral health treatment modalities, and biomaterials to deliver them, is required for this medically compromised patient group.

A particularly challenging area is creating materials which mimic gradient structures at interfaces between hard and soft tissues with distinct mechanical properties and morphologies e.g. between tooth, implant or bone and surrounding soft tissue in the jaw. For such tissue regenerative biomaterials we require both: a scalable method of production and precise spatial control over physico-chemical and mechanical properties, resulting morphologies and cellular responses. Extrusion-based 3D printing, also known as Direct Ink Writing (DIW), is the most viable additive manufacturing technique for producing high-resolution, complex and 3D structures with spatially varying compositions and properties to address this challenge. DIW can deposit and generate structures from any material which behaves as a yield stress fluid and can be formulated into a viscoplastic “ink” or paste.  By judicious choice of inks and post-processing steps, it is anticipated that this approach can help develop the next generation of biomaterials for an ageing population.

This project aims to (i) further develop our understanding of the fundamental DIW requirements for bioprinting applications, (ii) understand and formulate new sustainable biomaterials for DIW and (iii) develop novel printing and post-processing strategies to impart gradient structures into the resulting scaffolds. Utilising a library of model biopolymers (alginates, polysaccharides, cellulose-derivatives), biocompatible polymers (e.g. PEG, PVMEMA) and cytocompatible derivatives, the student will explore the underpinning relationships between the formulation microstructure (and component interactions), rheology and the ability to successfully print bio-compatible scaffold. Printing or post-processing strategies to impart gradients in mechanical properties will be investigated, e.g. double crosslinked and interpenetrating network formation through frontal photopolymerisation or diffusion-limited specific ion binding. The osteogenic properties of printed scaffolds will be evaluated in-vitro for potential pre-clinical testing with Dr Gurzawska-Comis. Further biological testing will be explored with Dr Gurzawska-Comis and network of European collaborators.

This project will utilise the Complex Fluids Laboratory in the School of Engineering (part of Dr García-Tuñón’s UKRI Future Research Leaders Fellowship), interdisciplinary expertise and clinical links with Dr Gurzawska-Comis and her network,  state of the art characterisation equipment in the Materials Innovation Factory. 

Applicant Eligibility

Candidates will have, or be due to obtain, a Master’s Degree or equivalent from a reputable University in an appropriate field of Physical Sciences or Engineering. Exceptional candidates with a First Class Bachelor’s Degree in an appropriate field will also be considered.

Application Process

Candidates wishing to apply should complete University of Liverpool application form [How to apply for a PhD - University of Liverpool] applying for a PhD in Materials Engineering. Uploading: Degree Certificates & Transcripts, CV, personal statement and academic references.

We want all of our staff and Students to feel that Liverpool is an inclusive and welcoming environment that actively celebrates and encourages diversity. We are committed to working with students to make all reasonable project adaptations including supporting those with caring responsibilities, disabilities or other personal circumstances. For example, If you have a disability you may be entitled to a Disabled Students Allowance on top of your studentship to help cover the costs of any additional support that a person studying for a doctorate might need as a result. 

We believe everyone deserves an excellent education and encourage students from all backgrounds and personal circumstances to apply. 

Enquiries

Candidates wishing to discuss the research project should contact the primary supervisor [w.sharratt@liverpool.ac.uk], those wishing to discuss the application process should discuss this with the School PGR Office [soepgr@liverpool.ac.uk].

Availability

Open to UK applicants

Funding information

Funded studentship

The EPSRC funded Studentship will cover full tuition fees of £4,786 per year and pay a maintenance grant for 4 years, starting at the UKRI minimum of £19,237 pa. for 2024-2025. The Studentship also comes with access to additional funding in the form of a research training support grant which is available to fund conference attendance, fieldwork, internships etc.

Supervisors

References

  1. Rau, D.A., et al., Progress in Materials Science, 2023: 101188
  2. Pattnaik, A. et al., Biomaterials, 296, 2023, 122078
  3. Li, C. et al., Trends in Biotechnology, 39, 2, 2021, 150-164
  4. Huang et al., Bioactive Materials, 33, 2024, 129-156
  5. García-Tuñón, E., et al., Physics of Fluids, 2023: 35(1)