Bioinspired calcium carbonate coatings to control magnesium implant bioabsorption

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Synthetic Chemistry Chemical Sciences
Summary
The chosen PhD candidate will investigate a novel calcium carbonate coating inspired by the way a crab grows a new shell. In theory the coating will slow the bioabsorption of a magnesium implant - the purpose of this project is to find out if it can.

Background
Almost 1000 children are born with damaged vessels in their heart in England and Wales each year. Collapsed vessels are normally treated with a metallic cage (stent) which holds the vessel open, but such surgery cannot be performed in young children because as the child grows the stent does not. However, stenting is less invasive than other options, has the lowest complication risk, and the shortest hospital stay.

One potential solution to this problem is a bioabsorbable stent made of magnesium which is gradually absorbed by the body, so is not permanent. This means the stent could be used in a younger patient, and there is evidence that the slow reduction of support can help long-term healing. However, magnesium on its own is absorbed too quickly.
This project aims to create a novel amorphous calcium carbonate coating for stents which is biologically inspired. Similar to a crab’s shell, the amorphous calcium carbonate coating will protect the underlying magnesium and slow its absorption. The coatings will be created using electrodeposition which allows for fine control of composition, crystallinity and absorption rate. Once the coatings have been optimised and characterised, their safety and biocompatibility will be assessed for platelet activation and coating delamination.

Why apply?
We are looking for a highly motivated candidate with a strong background in materials, engineering, chemical engineering, or related area to research these exciting new coatings. The project will involve a combination of laboratory testing and numerical simulation work.

By the end of the doctorate the candidate will:
• have extensive knowledge of calcium carbonate coating chemistry and electrochemical deposition methods
• be an expert in magnesium stent safety and design
• have been trained in a wide range of materials characterisation techniques
• be able to develop numerical models to represent and predict electrodeposition behaviour
• have presented their work at, at least, one international conference and built up a network of contacts
The candidate will have the opportunity to be involved in teaching laboratories and undergraduate student project supervision. Furthermore, the University of Bath provides a wide range of training courses and career support for PhD students.

Research centre
Materials and Structures Centre within the Department of Mechanical Engineering at the University of Bath.

Industrial collaboration
Opportunities to collaborate with the medical devices industry and form international academic links.

Research questions/methods
This research project aims to achieve the following:
1. Create a novel amorphous calcium carbonate coating on a magnesium substrate using electrodeposition
2. Determine whether coatings slow the bioabsorption rate of magnesium
3. Use data from biologically sourced magnesium-calcium carbonate materials to optimise the coatings
4. Assess basic biocompatibility and safety