Creation of 3D chitin/chitosan composite scaffold from naturally pre-structured verongiid sponge skeleton

Abstract

This study represents the first creation and characterization of a 3D chitin/chitosan composite scaffold derived from the naturally pre-structured skeleton of the cultivated marine demosponge Aplysina aerophoba, aiming to preserve the intricate architecture of the unique tube-like chitin while incorporating chitosan layers. Advanced staining methods, including the use of iodine and Cibacron Brilliant Red (CBR), were employed to distinguish these polysaccharides. ATR-FTIR spectroscopy confirmed the system’s structural integrity and identified the optimal chitin/chitosan balance, achieved after 60-minute treatment in 38 % NaOH at 95◦ C. Fluorescent microscopy using fluorescein isothiocyanate (FITC) effectively confirmed the presence of chitosan layers in the created chitin/chitosan scaffolds. Scanning electron microscopy analysis further elucidated significant morphological distinctions, where chitin fibers displayed a smooth, uniform surface, contrasting with the ragged and irregular texture of chitosan-containing fibers, indicating significant surface modifications. Zeta potential measurements confirmed the partial transformation of chitin into chitosan. The dual-layer configuration, consisting of a resilient chitin core and a versatile chitosan exterior, not only provides structural support, but also enhances the scaffold ’ s functionality for potential technological and biomedical applications. The preferential metallization of the chitosan phase by copper nanoparticles in the created 3D chitin/chitosan composite opens the way to the potential use of such scaffolds in catalysis.