Nanostructural Organization of Naturally Occurring Composites—Part II: Silica‐Chitin‐Based Biocomposites

Abstract

Investigations of the micro- and nanostructures and chemical composition of the sponge skeletons as examples for natural structural biocomposites are of fundamental scientific relevance. Recently, we show that some demosponges (Verongula gigantea, Aplysinasp.) and glass sponges (Farrea occa, Euplectella aspergillum) possess chitin as a component of their skeletons. The main practical approach we used for chitin isolation was based on alkali treatment of corresponding external layers of spicules sponge material with the aim of obtaining alkali-resistant compounds for detailed analysis. Here, we present a detailed study of the structural and physicochemical properties of spicules of the glass spongeRossella fibulata. The structural similarity of chitin derived from this sponge to invertebrate alpha chitin has been confirmed by us unambiguously using physicochemical and biochemical methods. This is the first report of a silica-chitin composite biomaterial found inRossella species. Finally, the present work includes a discussion related to strategies for the practical application of silica-chitin-based composites as biomaterials.

Nanomaterials: A Review of Their Action and Application in Pest Management and Evaluation of DNA-Tagged Particles

“…DNA-tagged gold nanoparticles can affect phosphorylation in relation to kinase activity that helps to inhibit the indirect effect of DNA functions and thus lysis of the insect-pest tissue leads to death of the S. litura. DNA-conjugatedgold nanoparticles have an effect on kinase activity (Brennan et al 2006;Wang et al 2006;Ehrlich et al 2008). In this context, DNA-tagged nanopolymer has a tremendous potential to locate the specific damaged part of the tissues in relation to its application in different physiological processes (Stadler et al 2007;Liedl et al 2010).…”

Silicatein expression in the hexactinellid Crateromorpha meyeri: the lead marker gene restricted to siliceous sponges

“…In a previous study, the silicatein protein has been demonstrated to exist within the silica layers of Monorhaphis chuni spicules (Müller et al 2008c). Subsequently, collagen has been proposed to be located on the surfaces of those lamellae (Ehrlich et al 2008). However, this conclusion must be substantiated in the future by protein analysis data from NaDodSO 4 -PAGE and also by direct chemical/molecular biological analyses or by immunochemical approaches (Ehrlich et al 2008).…”

Bioinspired control of colloidal silica in vitro by dual polymeric assemblies of zwitterionic phosphomethylated chitosan and polycations or polyanions

“…The link that may exist between polysaccharides and the formation of biosilica seems to be an interesting area to explore. We are aware of evidence that some diatoms produce extracellular chitin (a PCH precursor), and that there is no proof that chitin-like biomolecules are present inside diatom cells [9][10][11][12][13][14]. Therefore, the approach followed herein is an attempt to "model" silicic acid "pre-concentration" in vitro, just prior to its condensation yielding colloidal silica, or essentially to delay silicic acid condensation.…”

“…The presence of chitin within the framework skeleton of Farrea occa [9] and Euplectella aspergillum [10] as well as separate spicules Rossella fibulata [11] could also be revealed by gentle NaOH-based desilicification technique established by Ehrlich et al [12,13]. It was suggested that silicate ions and silica oligomers preferentially interact with glycopyranose rings exposed at the chitin surface, presumably by polar and H-bonding interactions [14].…”