Electroactive Biomaterials for Drug Delivery, Neuromodulation, and Tissue Engineering

Hardy, John (2016) Electroactive Biomaterials for Drug Delivery, Neuromodulation, and Tissue Engineering. In: Bioprocessing of Advanced Cellular Therapies Congress, 2016-06-02 - 2016-06-03, London Heathrow Marriot Hotel.

Abstract

Electrical fields affect a variety of tissues (e.g. bone, cardiac, muscle, nerve and skin) and play important roles in a multitude of biological processes (e.g. angiogenesis, cell division, cell signalling, nerve sprouting, prenatal development and wound healing), which has inspired the development of electroactive biomaterials, some of which (e.g. non-biodegradable cardiac pacemakers, cochlear implants, electrodes for deep brain stimulation) have been clinically translated. The tuneable properties of conducting/electroactive polymers (CPs or EAPs, respectively) such as derivatives of polyaniline, polypyrrole or polythiophene make them attractive components of electroactive biomaterials for drug delivery devices, electrodes or tissue scaffolds. The highly conjugated backbone of EAPs is responsible for their high conductivity, yet it also renders them non-biodegradable. Clearly, non-biodegradable EAPs are best suited for devices that will be implanted for long periods such as electrode-based biointerfaces, whereas, biodegradable EAPs are ideal for devices implanted for comparatively short durations such as drug delivery devices or tissue scaffolds. With a view towards the generation of EAP-based materials for long-term applications, we have 3D-printed EAP-based materials and shown them to be capable of both drug delivery and acting as a neural interface. With a view towards the generation of electroactive tissue scaffolds, we have developed EAP-based materials capable of electrically stimulating the cells that reside therein (e.g., cardiac myocytes, fibroblasts, Schwann cells, stem cells) and demonstrated that electrical stimulation of the scaffold elicits a response from the cells. Furthermore, we have developed the first examples of degradable EAP-based drug delivery devices, that deliver drugs upon the application of an electrical stimulus, which conceptually allows the release profile of the drug to be tailored to treat the condition in the most therapeutically effective way (i.e. controlling the chronopharmacology of the drug in line with the chronobiology of the condition to be treated). An overview of these developments will be presented.