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Abstract: Double-stranded DNA is one of functional polymers, but the large amounts of DNA sources, such as salmon milt and shellfish gonads, have been discarded as industrial wastes. Therefore, conversion of this discarded DNA to be a useful material would be beneficial to utilize the unique property of DNA. These materials including DNA have been prepared by mixing with the organic polymers, such as alginic acid, collagen, and chitosan. However, since these materials have consisted from entirely organic components, these do not have the mechanical strength for a material. So, we prepared the organic–inorganic hybrid materials by mixing DNA with silane coupling reagents bis(trimethoxysilylpropyl)amine or bis[(3-trimethoxysilyl)propyl]ethylenediamine. These hybrid materials with the flexibility were water-insoluble and resistant to hydrolysis by nuclease. In addition, the mechanical strength of this hybrid material was approximately twice as high as that of DNA without mixing with silane coupling reagents. Furthermore, the double-stranded DNA in the hybrid materials has been maintained in a B-form structure in aqueous solution. Thus, we demonstrated the utilization of DNA as a functional material. As a result, this material could selectively accumulate harmful DNA-intercalating compounds with the planar structure, such as dibenzo-p-dioxin, dibenzofuran, and ethidium bromide. Organic–inorganic hybrid material including double-stranded DNA has potential to serve as a useful biomaterial for medical, engineering, and environmental applications. [Copyright &y& Elsevier]

Abstract: Recently, membranes with high anhydrous proton conducting have been attracted remarkable interest for the application to the polymer electrolyte membrane fuel cell (PEFC). In this paper, we have investigated the anhydrous proton conductor consisting of alginic acid (AA), one of the acidic biopolymers, and imidazole (Im). This AA–Im composite material showed the proton conductivity of 2×10-3Scm-1 at 130°C under anhydrous conditions. Additionally, these AA–Im composite materials have the highly mechanical property and thermal stability. Furthermore, the biological products, such as biopolymer, are cheap, non-hazardous, and environmentally benign. The proton conductive biopolymer composite material may have the potential for its superior ion conducting properties, in particular, under anhydrous (water-free) or extremely low humidity conditions. [Copyright &y& Elsevier]