Film-Forming Capability and Antibacterial Activity of Surface-Deacetylated Chitin Nanocrystals: Role of Degree of Deacetylation

作者：Jing Liao, Ruizhi Wen, Yijin Wang, Yuhang Zhou, Jiamin Zhang · 发表于：Biomacromolecules · 年份：2024 · DOI：10.1021/acs.biomac.4c00528 · 被引用次数：20 · 研究领域：Nanocomposite Films for Food Packaging、Advanced Drug Delivery Systems、Polydiacetylene-based materials and applications

Developing sustainable food-active packaging materials is a major issue in food preservation applications. Chitin nanocrystals (ChNCs) are regarded as unique bioderived nanomaterials due to their inherent nitrogen moiety. By tuning the chemical functionality of this nanomaterial, it is possible to affect its properties, such as film-forming capability and antibacterial activity. In this work, surface-deacetylated chitin nanocrystals (D-ChNCs) with different degrees of deacetylation (DDs) were prepared by partial deacetylation of native chitin and subsequent acid hydrolysis, and their film-forming capability and antibacterial activity were studied systematically. The D-ChNCs showed favorable film-forming ability and antibacterial activity, which are closely related to their DD. With the increase in DD (from 5.7% to 45.4%), the formed transparent films based on ChNCs showed gradually increased elongation at break (from 0.5% to 2.5%) and water contact angle (from 25.5° to 87.0°), but decreased break strength (from 3.13 to 0.89 MPa), Young’s modulus (from 0.84 to 0.24 MPa), and water vapor permeability (from 4.7 × 10 –10 to 4.1 × 10 –10 g/m s Pa). Moreover, the antibacterial activity of the D-ChNCs against E. coli and S. aureus also increased with the increase of DD. This study also found that the depolarization and potential dissipation of the bacterial cell membrane induced by the contact between amino-rich D-ChNCs and bacteria through electrostatic attraction are the possible ...