title: Catechol-functionalized chitosan/iron oxide nanoparticle composite inspired by mussel thread coating and squid beak interfacial chemistry.
abstract: Biological materials offer a wide range of multifunctional and structural properties that are currently not achieved in synthetic materials. Herein we report on the synthesis and preparation of bioinspired organic/inorganic composites that mimic the key physicochemical features associated with the mechanical strengthening of both squid beaks and mussel thread coatings using chitosan as an initial template. While chitosan is a well-known biocompatible material, it suffers from key drawbacks that have limited its usage in a wider range of structural biomedical applications. First, its load-bearing capability in hydrated conditions remains poor, and second it completely dissolves at pH < 6, preventing its use in mild acidic microenvironments. In order to overcome these intrinsic limitations, a chitosan-based organic/inorganic biocomposite is prepared that mimics the interfacial chemistry of squid beaks and mussel thread coating. Chitosan was functionalized with catechol moieties in a highly controlled fashion and combined with superparamagnetic iron oxide (γ-Fe2O3) nanoparticles to give composites that represent a significant improvement in functionality of chitosan-based biomaterials. The inorganic/organic (γ-Fe2O3/catechol) interfaces are stabilized and strengthened by coordination bonding, resulting in hybrid composites with improved stability at high temperatures, physiological pH conditions, and acid/base conditions. The inclusion of superparamagnetic particles also makes the composites stimuli-responsive.
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Zvarec
authors.forename: Sreekanth
authors.initials: S
authors.lastname: Purushotham
authors.forename: Admir
authors.initials: A
authors.lastname: Masic
authors.forename: Raju V
authors.initials: RV
authors.lastname: Ramanujan
authors.forename: Ali
authors.initials: A
authors.lastname: Miserez
mesh_terms: D000818:Animals; D032701:Biomimetics / Q000379:methods; D049872:Bivalvia; D002396:Catechols / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D049832:Decapodiformes; D005290:Ferric Compounds / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*
chemical_list: D002396:Catechols; D005290:Ferric Compounds; C000499:ferric oxide; D048271:Chitosan; C034221:catechol