Interfacing biological tissues in the brain with electronic systems seems like science fiction, but developing effective strategies can aid in the treatment of neurodegenerative disorders, open opportunities for neurologically controlled prosthetics, or aid in modulating cardiovascular disease management, among other applications. Creating devices with the ability to interface with biological systems is a unique challenge. Utilizing conductive polymers can improve biocompatibility over alternatives including metals and inorganic semiconductors. Pre-formed polymers implanted into organisms are not always well tolerated, so alternative techniques for polymer assembly in situ may offer a more effective and robust alternative. Researchers at Purdue University, led by Jianguo Mei, PhD, are exploring how to form these conducting polymers from monomers applied directly to tissues. Their goal is to develop a system that is efficient and specifically integrated into the biological system, while limiting adverse effects, like inflammation or behavioral changes. The team focused on a system to assemble n-doped poly(benzodifurandione) (n-PBDF) in vivo from injected monomers, using an organism’s native catalysts, specifically, the hemoproteins, which are abundant in the blood, to build the polymers. Their research is published in a paper entitled, “Blood-catalyzed n-doped polymers for reversible optical neural control,” in Science. “The development of n-type conducting polymers that assemble directly in vivo offers transformative, substrate-free strategy for stable electrical interfaces,” wrote the authors. Using zebrafish and mice, the researchers tested both the safety and efficacy of injecting monomers that would polymerize into functional molecules. Zebrafish embryos injected in the yolk showed formation of the polymer, which…
