Extreme biomimetics: Preservation of molecular detail in centimeter-scale samples of biological meshes laid down by sponges.

Fabrication of biomimetic materials and scaffolds is usually a micro- or even nanoscale process; however, most testing and all manufacturing require larger-scale synthesis of nanoscale features. Here, we propose the utilization of naturally prefabricated three-dimensional (3D) spongin scaffolds that preserve molecular detail across centimeter-scale samples. The fine-scale structure of this collagenous resource is stable at temperatures of up to 1200°C and can produce up to 4 × 10-cm-large 3D microfibrous and nanoporous turbostratic graphite. Our findings highlight the fact that this turbostratic graphite is exceptional at preserving the nanostructural features typical for triple-helix collagen. The resulting carbon sponge resembles the shape and unique microarchitecture of the original spongin scaffold. Copper electroplating of the obtained composite leads to a hybrid material with excellent catalytic performance with respect to the reduction of p-nitrophenol in both freshwater and marine environments.

Chitin of poriferan origin and the bioelectrometallurgy of copper/copper oxide.

Chitinous scaffolds isolated from marine demosponge Ianthella basta represent novel templates for deposition of metals such as copper and copper oxides. In contrast to traditional Extreme Biomimetics methods which are based on high temperature reactions, here, we propose an alternative way based on a well-known process - electrochemical deposition or plating. This method allows production of 3D composite materials with metallic and metal oxide structures within their surfaces. For the first time chitinous scaffolds of poriferan origin, which possess a 3D network structure, were used for the copper plating. The nanocrystallites of metallic phase obtained on chitinous fibres represents replicas of the original nanofibrous substrate.

Isolation and identification of chitin in three-dimensional skeleton of Aplysina fistularis marine sponge.

The recent discovery of chitin within skeletons of numerous marine and freshwater sponges (Porifera) stimulates further experiments to identify this structural aminopolysaccharide in new species of these aquatical animals. Aplysina fistularis (Verongida: Demospongiae: Porifera) is well known to produce biologically active bromotyrosines. Here, we present a detailed study of the structural and physico-chemical properties of the three-dimensional skeletal scaffolds of this sponge. Calcofluor white staining, Raman and IR spectroscopy, ESI-MS as well as chitinase digestion test were applied in order to unequivocally prove the first discovery of α-chitin in skeleton of A. fistularis.