School of Energy & Chemical Engineering, UNIST (Ulsan National Institute of Science and Technology), Ulsan, 44919, Republic of Korea.
School of Interdisciplinary Science and Engineering, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea; Division of Environmental Science and Engineering, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea.
Carbohydr Polym. 2021 May 1;259:117782. doi: 10.1016/j.carbpol.2021.117782. Epub 2021 Feb 9.
The degree of acetylation (DA), which determines as the molar proportion of N-acetyl-D-glucosamine units on chitosan, characterizes the physical, chemical, and biological properties of chitosan. Thus, DA can be a critical factor in the utilization of chitosan. Nevertheless, quantitative studies on the molecular interactions of chitosan as a function of DA are lacking. Here, we directly measured the molecular interaction (adhesion and cohesion) of molecularly thin chitosan films, dependent on the molecular weight and DA, using a surface forces apparatus. Using low molecular weight (LMW, ∼5 kDa) and high molecular weight (HMW, ∼135 kDa) chitosan, we obtained several DA ranges through a reacetylation method. The interactions of LMW chitosan were greatly influenced by the intrinsic charge of the chitosan units, whereas for HMW chitosan, chain flexibility was found to be the major factor affecting molecular interaction Taken together, our comprehensive data provides a holistic understanding of the interaction mechanism of chitosan.
乙酰化程度（DA）决定了壳聚糖上 N-乙酰-D-葡萄糖胺单元的摩尔比例，其特征在于壳聚糖的物理、化学和生物学性质。因此，DA 可能是壳聚糖利用的关键因素。然而，缺乏关于 DA 作为功能的壳聚糖分子相互作用的定量研究。在这里，我们使用表面力仪直接测量了分子薄的壳聚糖薄膜的分子相互作用（粘附和内聚），这取决于分子量和 DA。我们使用低分子量（LMW，约 5 kDa）和高分子量（HMW，约 135 kDa）壳聚糖，通过再乙酰化方法获得了几个 DA 范围。LMW 壳聚糖的相互作用受壳聚糖单元固有电荷的极大影响，而对于 HMW 壳聚糖，链柔韧性被发现是影响分子相互作用的主要因素。总的来说，我们全面的数据提供了对壳聚糖相互作用机制的整体理解。
