Marine hydroid perisarc: a chitin- and melanin-reinforced composite with DOPA-iron(III) complexes.

Dong Soo Hwang, Admir Masic, Ekavianty Prajatelistia, Mihaela Iordachescu, J Herbert Waite

Index: Acta Biomater. 9(9) , 8110-7, (2013)

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Abstract

Many marine invertebrates utilize biomacromolecules as building blocks to form their load-bearing tissues. These polymeric tissues are appealing for their unusual physical and mechanical properties, including high hardness and stiffness, toughness and low density. Here, a marine hydroid perisarc of Aglaophenia latirostris was investigated to understand how nature designs a stiff, tough and lightweight sheathing structure. Chitin, protein and a melanin-like pigment, were found to represent 10, 17 and 60 wt.% of the perisarc, respectively. Interestingly, similar to the adhesive and coating of marine mussel byssus, a DOPA (3,4-dihydroxyphenylalanine) containing protein and iron were detected in the perisarc. Resonance Raman microprobe analysis of perisarc indicates the presence of catechol-iron(III) complexes in situ, but it remains to be determined whether the DOPA-iron(III) interaction plays a cohesive role in holding the protein, chitin and melanin networks together.Copyright © 2013 Acta Materialia Inc. All rights reserved.