The intersection of biomedical science and materials engineering is an exciting one, and largely falls in the province of biomaterials and tissue engineering. Many of the advances being made at the interface of these two disciplines are central to new medical and health-based technologies and are changing the way we live and treat illness.
Biomaterials are materials that are used in medical devices or are in contact with biological systems and do not adversely affect the living organism. The field of biomaterials is highly multidisciplinary and involves principles from medicine, materials science and engineering, chemistry and biology. It involves the engineering and testing of materials for use in devices for therapies. Its multidisciplinary nature often means that materials engineers work closely with surgeons, biologists, chemists, surface scientists and other engineers among others.
Implants eg. titanium hip joints, artificial lenses
Tissue engineering for the regeneration of damaged or diseased tissues eg. nerve regeneration for spinal cord injuries
Surfaces for the culture of stem cells
Using peptides and DNA molecules as building blocks to build new nano-structures
Engineering approaches to manipulate cell function
Site-specific drug delivery using nano-structured materials
Improved dressings for chronic wounds
Current research projects in the group are in the fields of neural regeneration, electrode materials for neural interfaces and photo-responsive polymers, amongst others.
Engineering smart materials to repair damaged neural pathways in the central nervous system
Neural tissue engineering (NTE) attempts to regenerate damaged neurons by providing artificial cellular niches, which promote attachment, growth, proliferation and migration. This is particularly of interest in the central nervous system (brain and spinal cord), where neural regeneration is typically very limited. Various different materials are under investigation for this purpose, including electrospun polymer fibres and various types of injectable hydrogels. The physical and chemical properties of these materials can be tuned which is vital as neural stem cell development is dependant on the properties of the scaffold. The longer-term goal of this research is to utilise cell-scaffold constructs that will assist in functional recovery of the damaged brain and spinal cord.
Migration of endogenous neural stem cells (green) into a nanofibrous scaffold implanted in the brain.
New scaffolds for cardiac repair
Heart disease is the leading cause of death and disability worldwide, accounting for 30–40 per cent of all human mortality. Currently two strategies, (embryonic) stem cell-based therapy and left ventricle restraint are under intensive investigation for the treatment of the devastating disease. A combinatorial approach of stem cell therapy and mechanical passive restraint represents a novel approach. A heart patch serves two purposes: to deliver functional cardiomyocytes to the infarct heart muscle and provide mechanical restrain to the weak left ventricle. The essential requirements on a heart patch material include long-term elasticity, cell-delivery ability and degradability. The most important challenge that materials scientist currently encounter in the field of cardiac tissue engineering is to make a nonlinear elastic polymer that is similar to that of the myocardium. Such nonlinear elasticity would ensure that the heart patch can ‘beat’ together with the recipient heart, thus providing appropriate restraints to the left ventricle throughout the beating process.
New biocompatible rubbers, including crosslinked and thermoplastic elastomers, are under development in our research. Other work involves the development of materials, which would be suitable for temporary implants. The need for such materials is particularly great in vascular surgery where a temporary, bioresorbable stent could provide support to the walls of a blood vessel when it is required and dissolve when its mission is fulfilled –without a further invasion of the surgeon. Tough requirements on such materials with regard to their strength, fatigue resistance and biocorrosion properties are being addressed by developing processing techniques that help in establishing the desired combinations of properties. Work in this area requires cross-disciplinary collaboration between materials engineers, biologists and clinical doctors and offers exciting research opportunities for undergraduate and graduate students.