Liaoning Key Laboratory of Lignocellulose Chemistry and Biomaterials, Dalian Polytechnic University, Dalian, Liaoning 116034, China.
Department of Cardiology, Shaanxi Province People's Hospital and The Third Affiliated Hospital Medical College of Xi'an Jiaotong University, Xi'an, Shaanxi Province 710018, China.
Int J Biol Macromol. 2023 Jun 1;239:124268. doi: 10.1016/j.ijbiomac.2023.124268. Epub 2023 Mar 31.
Recently, the application of lignin activation by demethylation to improve reactivity and enrich multiple functions has intensively attracted attention. However, it is still challenge up to now due to the low reactivity and complexity of lignin structure. Here, an effective demethylation way was explored by microwave-assisted method for substantially enhancing the hydroxyl (-OH) content and retaining the structure of lignin. Then, the optimum demethylated lignin was used to removal heavy metal ions and promote wound healing, respectively. In detail, for microwave-assisted demethylated poplar lignin (M-DPOL), the contents of phenolic (Ar-OH) and total hydroxyl (Tot-OH) groups reached the maximum for 60 min at 90 °C in DMF with 7.38 and 9.13 mmol/g, respectively. After demethylation, with this M-DPOL as lignin-based adsorbent, the maximum adsorption capacity (Q) for Pb ions reached 104.16 mg/g. Based on the isotherm, kinetic and thermodynamic models analyses, the chemisorption occurred in monolayer on the surface of M-DPOL, and all adsorption processes were endothermic and spontaneous. Meanwhile, M-DPOL as a wound dressing had excellent antioxidant property, outstanding bactericidal activity and remarkable biocompatibility, suggesting that it did not interfere with cell proliferation. Besides, the wounded rats treated with M-DPOL significantly promoted its formation of re-epithelialization and wound healing of full-thickness skin defects. Overall, microwave-assisted method of demethylated lignin can offer great advantages for heavy metal ions removal and wound care dressing, which facilitates high value application of lignin.
最近，通过脱甲基化来激活木质素以提高反应性和丰富多种功能的应用引起了人们的广泛关注。然而，由于木质素结构的低反应性和复杂性，这仍然是一个挑战。在这里，我们探索了一种有效的微波辅助脱甲基化方法，可显著提高羟基（-OH）含量并保留木质素的结构。然后，分别使用最佳脱甲基化木质素去除重金属离子和促进伤口愈合。具体来说，对于微波辅助脱甲基杨木木质素（M-DPOL），在 DMF 中于 90°C 下处理 60 分钟时，酚（Ar-OH）和总羟基（Tot-OH）基团的含量达到最大值，分别为 7.38mmol/g 和 9.13mmol/g。脱甲基化后，以 M-DPOL 作为木质素基吸附剂，Pb 离子的最大吸附量（Q）达到 104.16mg/g。基于等温线、动力学和热力学模型分析，化学吸附在 M-DPOL 表面单层发生，所有吸附过程均为吸热和自发的。同时，M-DPOL 作为一种伤口敷料具有出色的抗氧化性能、优异的杀菌活性和显著的生物相容性，表明它不会干扰细胞增殖。此外，用 M-DPOL 处理的创伤大鼠显著促进了其上皮化形成和全层皮肤缺损的伤口愈合。总体而言，脱甲基化木质素的微波辅助方法可为去除重金属离子和伤口护理敷料提供巨大优势，促进木质素的高值应用。
