title: The effect of the encapsulation of bacteria in redox phospholipid polymer hydrogels on electron transfer efficiency in living cell-based devices.
abstract: Development of living cell-based devices holds great promise in many biomedical and industrial applications. To increase our understanding of the process, we investigated the biological and electrochemical properties of a redox phospholipid polymer hydrogel containing an electron-generating bacteria (Shewanella oneidensis MR-1). A water-soluble and amphiphilic phospholipid polymer, poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate-co-p-vinylphenylboronic acid-co-vinylferrocene) (PMBVF), was our choice for incorporation into a hydrogel matrix that promotes encapsulation of bacteria and acts as an electron transfer mediator. This hydrogel formed spontaneously and encapsulated Shewanella in three-dimensional structures. Visual analysis showed that the encapsulated Shewanella maintained viability and metabolic activity even after long-term storage. Cyclic voltammetry measurement indicated that the PMBVF/poly(vinyl alcohol) (PMBVF/PVA) hydrogel had stable and high electron transfer efficiency. Amperometric measurement showed that the hydrogel could maintain the electron transfer efficiency even when Shewanella was encapsulated. Thus, the PMBVF/PVA hydrogel not only provides a mild environment for long-term bacterial survival but also maintains electron transfer efficiency from the bacteria to the electrode. We conclude that hydrogel/bacteria hybrid biomaterials, such as PMBVF/PVA/Shewanella, may find application in the fabrication of living cell-based devices.
authors.affiliation: Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Lin
authors.forename: Koichi
authors.initials: K
authors.lastname: Nishio
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Konno
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ishihara
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D001674:Bioelectric Energy Sources; D020100:Hydrogels / Q000737:chemistry*; D010084:Oxidation-Reduction; D010743:Phospholipids / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D020592:Shewanella / Q000378:metabolism
chemical_list: D020100:Hydrogels; D010743:Phospholipids; D011108:Polymers