Neurological disorders are one of the world’s leading medical and societal challenges, affecting approximately 2.6 billion people worldwide. In Europe, the economic burden of neurodegenerative diseases is rapidly growing, with estimated costs to exceed €350 billion/year by 2050. The European Commission has strongly invested in novel strategies to prevent and treat neurological disorders, which constitutes a major challenge towards the United Nations’ Sustainable Development Goal for 2030 on Good Health and Well Being. Because of the lack of efficiency of pharmacological options, alternatives such as electrical stimulation using implanted electrodes are becoming increasingly popular. However, this strategy lacks spatiotemporal control over the stimulation of specific neural circuits. Although light has been employed in the modulation of the electrical activity of single cells with unprecedented resolution, this strategy required genetic modification to express membrane proteins sensitive to visible light. Another caveat of clinically approved devices consists of their adverse effects, which are commonly associated with the rigidity and redox reactions associated with Faradaic charge conduction in metal electrodes.
Non-genetic, light-mediated stimulation could offer a promising alternative to transform the treatment of neurological disorders and promote brain tissue regeneration. In order to realise that, biointerfaces need to be designed with flexible materials with low electrochemical impedance, in order to minimise electrode degradation and tissue damage. Graphene is an ideal candidate for this application because not only fits these requirements but also electrically responds to light. However, in order to develop minimally invasive devices, the use of tissue-penetrating near-infrared (NIR) radiation may be limited by graphene’s capability of converting it to heat.
This project aims to incorporate lanthanide-doped upconversion nanoparticles (UCNPs) capable of absorbing NIR radiation and emitting visible light. Graphene was therefore conjugated with UCNPs in order to generate electrodes capable of enhancing electrical conductivity upon NIR activation.
