John Hardy is a 50th Anniversary Lecturer in the Department of Chemistry and Materials Science Institute at Lancaster University. He obtained his first degree from the University of Bristol, and his PhD from the University of York working with Professor David Smith on supramolecular materials. He moved to Strasbourg in France to work on supramolecular materials with Professors Jean-Marie Lehn and Jack Harrowfield, to Bayreuth in Germany to work on silk protein-based biomaterials with Professor Thomas Scheibel, to the United States to work on organic bioelectronics for neuromodulation, drug delivery and tissue engineering with Professors Christine Schmidt (Austin, TX; Gainesville, FL) and David Kaplan (Boston, MA), and to Northern Ireland to work on light-responsive drug delivery systems with Professor Colin McCoy. He has published multiple papers and patents, serves on the Editorial Board for the International Journal of Molecular Sciences and Future Science OA, and kicked off his independent career developing materials that respond to electricity, light and magnetism for biomedical applications in Lancaster in August 2015.
Multiphoton fabrication of bioelectronic biomaterials for neuromodulation (MFBBN)
Electromagnetic fields affect a variety of tissues (e.g. bone, muscle, nerve and skin) and play important roles in a multitude of biological processes (e.g. nerve sprouting, prenatal development and wound healing), mediated by subcellular level changes, including alterations in protein distribution, gene expression, metal ion content, and action potentials. This has inspired the development of electrically conducting devices for biomedical applications, including: biosensors, drug delivery devices, cardiac/neural electrodes, and tissue scaffolds. It is noteworthy that there are a number of FDA approved devices capable of electrical stimulation in the body, including cardiac pacemakers, bionic eyes, bionic ears and electrodes for deep brain stimulation; all of which are designed for long term implantation. Polymers are ubiquitous in daily life, and conducting polymers (e.g. polyaniline, polypyrrole, poly(3,4-ethylenedioxythiophene)) have shown themselves to be capable of electrically stimulating cells. Furthermore, when implanted in mammals their immunogenicities are similar to FDA-approved polymers such as poly(lactic-co-glycolic acid) (PLGA), supporting their safety in vivo. These preclinical studies suggest that conducting polymer-based biomaterials are promising for clinical translation.
The aim of this proposal is to use multiphoton fabrication to print conducting biomaterials for use as neural electrodes, characterize their physicochemical and electrical properties, and to validate the efficacy of the bioelectronic devices to interact with brain tissue ex vivo in collaboration with Frances Edwards at UCL Neuroscience. Clinically approved electrodes are manufactured from inorganic materials (e.g. titanium nitride, platinum, and iridium oxide), however, their mechanical properties are far from those of soft tissues in the central and peripheral nervous system, and such mechanical mismatch leads to local tissue inflammation and their encapsulation in fibrous scar tissue that impedes the successful function of the neural electrode (in some cases this necessitates the application of up to 7V to stimulate the nerve tissue which leads to tissue damage). The development of neural electrodes with biomimetic chemical and mechanical properties is highly attractive as it may facilitate the widespread use of such electronic devices. We present our progress so far in this endeavour facilitated by a Pathfinder Award.