To apply for this programme, please visit www.advanced-biomedical-materials-cdt.manchester.ac.uk. Informal enquiries are welcome, to [Email Address Removed].
ABM CDT PHAs are FDA approved polymers produced by bacteria under nutrient limiting conditions using renewable carbon sources. There are two types of PHAs, short chain length PHAs, scl-PHAs, (C3-C5 units) such as P(3HB) and medium chain length PHAs, mcl-PHAs, (C6-C16 units) such as P(3HO-co-3HD). The degradation products of PHAs are much less acidic than those of PLA and PLGA, and are natural metabolites, hence PHAs are less inflammatory and immunogenic in nature. Also, PHAs degrade by surface erosion and therefore PHA-based scaffolds degrade in a controlled predictable manner, a great advantage as compared to PLA and PLGA that degrade by bulk erosion. Another advantage of using PHAs is the tuneability of their properties. By varying the bacterial strain/carbon source/media composition/fermentation conditions during production, the PHA monomer content and consequently their material properties and degradability can be tailored.
A relatively novel technology for polymer fibre technology is the development of core-sheath fibres using pressurised gyration (PG). This technology allows the production of core–sheath bicomponent polymer fibres in a single-step with scale-up possibilities (~4 kg h−1). Layered fibres are formed where the thin sheath can contain a functional polymer and the core can be a more traditional strength-bearing biopolymer.
There are many biomedical applications that require non-woven fibre-based sheets/scaffolds such as wound healing patches, cardiac patches, periosteum replacements, heart valves, hernia meshes, meshes for urinary incontinence, maxillofacial replacements.
In this project the production of a range of PHA-based core-sheath fibre sheets will be optimised in collaboration with Professor Mohan Edirisinghe, University College London, External Academic Partner for this project. Further, their use in a variety of applications, including bone, skin and cardiac Tissue Engineering (TE) will be established.
Main questions to be answered:
The main questions to be addressed are:
- Optimisation of the conditions to produce a range of PHAs (scl-PHAs and mcl-PHAs) and their characterisation
- Optimisation of the conditions to produce core-sheath bicomponent polymer fibres using the scl and mcl PHAs, PHA blends, and other synthetic polymers established for medical applications such as PLLA, PLGA and PCL (in collaboration with Prof. Edirisinghe, UCL)
- Characterisation of the core-sheath fibre sheets produced with respect to their fibre dimensions, their size distribution, and apparent mechanical properties
- Functional assessment of the fibre sheets for application in bone, skin, and cardiac TE in vitro using mesenchymal stem cells, human dermal fibroblasts and cardiomyocytes respectively
University of Manchester, Department of Materials - 19 PhD Projects Available
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