Jiang Yuehan, Chen Yiyi, Tian Dong, Shen Feiyue, Wan Xue, Xu Lu, Chen Yichu, Zhang Haozhe, Hu Jinguang, Shen Fei
Institute of Ecological and Environmental Sciences, Sichuan Agricultural University, Chengdu, Sichuan 611130, P. R. China.
Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Dr NW, Calgary, AB T2N 1N4, Canada.
Soft Matter. 2020 Sep 10. doi: 10.1039/d0sm01402h.
Lignin nanospheres (LNPs) are an emerging high-value material platform to realize lignin valorization. The modification or introduction of new functions to LNPs is of great significance to expand its downstream applications. This work evaluated the technical feasibility of preparing lignin-xylan hybrid nanospheres (LXNPs) through a simple solution-based self-assembly process, with the goal of achieving the application as pesticide carriers for enzyme-mediated controlled release. Hybrid LXNPs with various weigh ratios (lignin to xylan, 3 : 1, 1 : 1, 1 : 3) were obtained using deep eutectic solvent-extracted condensed lignin and water-insoluble xylan fragments, which exhibited a nanosphere size of about 166-210 nm with considerable stability in the pH range of 4-10. LXNPs with lignin to xylan ratios of 3 : 1 and 1 : 1 showed well-defined core-shell structures with enriched hydroxyl groups on the surface. It was proposed that lignin could anchor xylan fragments through van der Waals force and hydrophobic interactions between lignin phenylpropanes and xylan molecular backbones, thus facilitating the self-assembly process for the formation of this specific spherical structure. The resulting hydrophobic LXNPs core enabled the facile encapsulation of the biological pesticide avermectin (AVM) with 57.9-67.0% efficiency using one-pot synthesis. When these AVM-encapsulated LXNPs were subjected to enzymatic hydrolysis using xylanase, considerable AVM release of 44.8-55.1% was achieved after 16 h, in comparison to the 4.1% release only for those without xylanase. This work showed the high promise of fabricating hybrid LXNPs through the self-assembly process and also provided a universal nanosphere carrier for drug encapsulation and subsequent enzyme-mediated controlled release.
木质素纳米球（LNPs）是一种新兴的高价值材料平台，可实现木质素的增值利用。对LNPs进行改性或引入新功能对于拓展其下游应用具有重要意义。本研究通过简单的基于溶液的自组装过程，评估了制备木质素-木聚糖杂化纳米球（LXNPs）的技术可行性，目标是将其应用于酶介导控释的农药载体。使用深度共熔溶剂提取的缩合木质素和水不溶性木聚糖片段，获得了不同重量比（木质素与木聚糖，3∶1、1∶1、1∶3）的杂化LXNPs，其纳米球尺寸约为166 - 210 nm，在pH值4 - 10范围内具有相当的稳定性。木质素与木聚糖比例为3∶1和1∶1的LXNPs呈现出明确的核壳结构，表面富含羟基。研究表明，木质素可通过范德华力以及木质素苯丙烷与木聚糖分子主链之间的疏水相互作用锚定木聚糖片段，从而促进形成这种特定球形结构的自组装过程。所得的疏水性LXNPs核心能够通过一锅法合成以57.9 - 67.0%的效率轻松包封生物农药阿维菌素（AVM）。当这些包封AVM的LXNPs用木聚糖酶进行酶解时，16小时后实现了44.8 - 55.1%的可观AVM释放，相比之下，未使用木聚糖酶的对照组仅释放4.1%。本研究表明通过自组装过程制备杂化LXNPs具有很高的潜力，并且还为药物包封及后续酶介导控释提供了一种通用的纳米球载体。
