3D printed biopolymers with shape memory behaviour

In our aging population, the need for smart solutions to repair or regenerate diseased and injured tissues is ever-increasing. As each individual is unique, mass-produced implants and generic treatments do not suffice. 3D printing provides a tool to create personalised solutions, taking into account the patient's specific anatomy. In recent years, surgeons have started to use this technology to print models for pre-operative planning, personalised saw and drill guides to enhance surgical precision, and even implant prosthetics tailored to the patient such as hips, knees and skullcaps. The range of materials that is suitable for both 3D printing and use inside the body is quite limited, and needs to be expanded to fully pick the fruits of this fascinating technology. This project aims at developing 3D printable biomaterials with a specific added functionality, which is shape memory behaviour. Shape memory materials can spontaneously change shape over time, in a controlled manner. They show great potential for medical applications, for example as self-tightening sutures, stents that unfold inside the body, or paediatric implants that grow with the growing patient. In this project, we will combine the strengths of shape memory and 3D printing, by developing novel shape memory plastics that can be 3D printed into virtually any shape. A thorough study will reveal how the newly developed materials will change shape over time, and how we can influence this behaviour by changing both the material itself and the 3D printed shape. This understanding will then facilitate the generation of personalised biomedical devices with unprecedented functionalities.

The successful completion of this project will add a completely new dimension to the evolving field of 3D printing, and can bring unforeseen solutions to a large number of applications within medicine and beyond. The impact on society of the project is evident as in our aging population, the need for repairing and regenerating diseased or injured tissues is ever-increasing. The availability of donor tissues is exceeded by far by the demand, reflected in long waiting lists. This accounts for an enormous economic burden in terms of healthcare costs and loss of productivity, in addition to the poor quality of life for the patients. Furthermore, current medical treatments including urethral dilation, scoliosis correction and tissue expansion require regular medical intervention to implement incremental shape or dimensional changes. This forms a practical and economical burden which can be heavily reduced by the development of shape memory devices, in which 'the material is the machine'. This project will deliver new enabling technology that will aid in developing more effective therapies.
Furthermore, the impact of this research will considerably enrich the methodology used previously by the scientific community. The following areas will be impacted:
* Materials science: we will better understand how design can be used to control shape memory behaviour
* Biomedical engineering: the project will enable the 3D printing of personalised medical devices and growing implants for growing children
* Biology and Bioengineering: 3D structures that grow spontaneously can be used to influence (stem) cells, which could not be studied so well before

Collaborations have been initiated researchers in abovementioned areas, medical device companies and clinicians to ensure the outcomes of this project will directly feed into larger follow-up grants that will explore the utility of the developed 3D printable shape memory polymers in different ways.
Both topics of 3D printing and shape memory materials are visually attractive and appealing to many people. This will be utilised in public engagement activities, particularly for enthusing children for Science & Technology.
Finally, this proposal will bring a valuable and versatile piece of equipment, the Dynamic Mechanical Thermal Analyser, to Edinburgh to the benefit of many researchers who are looking out for access to this technique.