A Glucose BioFuel Cell Implanted in Rats

Abstract

Powering future generations of implanted medical devices will require cumbersome transcutaneous energy transfer or harvesting energy from the human body. No functional solution that harvests power from the body is currently available, despite attempts to use the Seebeck thermoelectric effect, vibrations or body movements. Glucose fuel cells appear more promising, since they produce electrical energy from glucose and dioxygen, two substrates present in physiological fluids. The most powerful ones, Glucose BioFuel Cells (GBFCs), are based on enzymes electrically wired by redox mediators. However, GBFCs cannot be implanted in animals, mainly because the enzymes they rely on either require low pH or are inhibited by chloride or urate anions, present in the Extra Cellular Fluid (ECF). Here we present the first functional implantable GBFC, working in the retroperitoneal space of freely moving rats. The breakthrough relies on the design of a new family of GBFCs, characterized by an innovative and simple mechanical confinement of various enzymes and redox mediators: enzymes are no longer covalently bound to the surface of the electron collectors, which enables use of a wide variety of enzymes and redox mediators, augments the quantity of active enzymes, and simplifies GBFC construction. Our most efficient GBFC was based on composite graphite discs containing glucose oxidase and ubiquinone at the anode, polyphenol oxidase (PPO) and quinone at the cathode. PPO reduces dioxygen into water, at pH 7 and in the presence of chloride ions and urates at physiological concentrations. This GBFC, with electrodes of 0.133 mL, produced a peak specific power of 24.4 µW mL−1, which is better than pacemakers' requirements and paves the way for the development of a new generation of implantable artificial organs, covering a wide range of medical applications.

An enzymatic biofuel cell based on electrically wired polyphenol oxidase and glucose oxidase operating under physiological conditions

“…Composite graphite discs containing enzyme and redox mediator were designed by mechanical compression with graphite particles [17]. Electrical contact was made through a platinum wire stuck by carbon paste glue.…”

“…Glucose-O 2 biofuel cells are interesting devices because of their in vivo availability, allowing their implantation in living organisms [17]. Since the first example reported about glucose-O 2 biofuel implanted in the abdomen of a rat [17], different strategies regarding the method of implantation have been reported [18][19][20][21].…”

“…Since the first example reported about glucose-O 2 biofuel implanted in the abdomen of a rat [17], different strategies regarding the method of implantation have been reported [18][19][20][21]. New implantable systems have been tested in cockroaches [20] and molluscs, in snails [18] and clams [19].…”

Mediated electron transfer of cellobiose dehydrogenase and glucose oxidase at osmium polymer-modified nanoporous gold electrodes

“…The cell was comprised of two composite graphite discs modified with GOx and polyphenol oxidase to form the anode and cathode, respectively. Using ubiquinone as mediator the cell had a power output of 24.4 µW/mL [28].…”

Vertically Aligned Pd Nanowires for Glucose Oxidase Bioanode

“…The biofuel cell circuit is completed with an external load to allow the conduction of electrons from the bioanode to the biocathode ( Figure 1). Therefore, the choice of the anodic and cathodic material depends on several factors including but not limited to the biocatalyst to catalyze the electrode reactions; the integration of the biocatalyst with the appropriate physicochemical transduction element for harvesting energy from the various concentration of glucose in blood or interstitial fluid; effective transduction element surface area in order to increase the number of binding sites for the biocatalyst; ease of fabrication; and enhanced durability to ensure extended functional lifetimes of biofuel cell devices for implantation [9][10][11][12][13][14]. Furthermore, a biocompatible encapsulating layer for the biofuel cell is required in order to enhance the biocompatibility and durability of the entire device in vivo.…”