A Polyphenol Decorated <i>Triplex</i> Hybrid\nBiomaterial: Structure–Function, Release Profiles, Sorption,\nand Antipathogenic Effects

Herein, nonwoven alkali modified flax substrates were\ncoated with\nincremental levels of chitosan, followed by immobilization of tannic\nacid, via a facile “dip-coating” strategy to yield a\nunique hierarchal “triplex” hybrid biomaterial, denoted\nas “THB”. The characterization of the physicochemical\nproperties of THB employed complementary spectroscopic (IR, Raman,\nand NMR) techniques, which support the role of hydrogen bonding and\nelectrostatic interactions between the components: chitosan as the\nsecondary biopolymer coating and the tertiary adsorbed polyphenols.\nXRD and SEM techniques provide further structural insight that confirms\nthe unique semicrystalline nature and porous hierarchal structure\nof the biocomposite. The THBs present a polyphenol kinetic release\nprofile that follows the Korsmeyer-Peppas model that concurs with\nFickian diffusion for heterogeneous polymer systems. Furthermore,\nthese systems demonstrate a tailored solvent uptake capacity (up to\n4 g/g) in aqueous PBS media. Antipathogenic activity tests revealed\n95% elimination of pathogens (<i>E. coli</i>, <i>S.\naureus</i>, and <i>C. albicans</i>) at a dose of 50\nmg for the THB system. The trend in the structure–property\nrelationships for the THB systems indicates synergistic effects of\nelectrostatic multiform interactions between protonated chitosan and\nthe polyphenol units. Herein, we report <i>the first example</i> of a unique hierarchal biomaterial via a facile design strategy\nfor diversiform roles as responsive adsorbents for environmental remediation\nto biomedical applications (e.g., controlled release, topical administration,\nor antimicrobial surface coatings).