Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy.
Centre for Colloid and Surface Science (CSGI), University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy.
Molecules. 2024 Aug 21;29(16):3935. doi: 10.3390/molecules29163935.
Biofumigation was proposed as an alternative to synthetic pesticides for the disinfection of agricultural soils, in view of the biocidal effect of isothiocyanates (ITCs) released by some vegetal species, like . However, biofumigation also presents limitations; thus, a novel and viable alternative could be the direct introduction of ITCs into agricultural soils as components loaded into biodegradable hydrogels. Thus, in this work, ITCs-based microemulsions were developed, which can be loaded into porous polymer-based hydrogel beads based on sodium alginate (ALG) or sodium carboxymethyl cellulose (CMC). Three ITCs (ethyl, phenyl, and allyl isothiocyanate) and three different surfactants (sodium dodecylsulfate, Brij 35, and Tween 80) were considered. The optimal system was characterized with attenuated ATR-FTIR spectroscopy and differential scanning calorimetry to study how the microemulsion/gels interaction affects the gel properties, such as the equilibrium water content or free water index. Finally, loading and release profiles were studied by means of UV-Vis spectrophotometry. It was found that CMC hydrogel beads showed a slightly more efficient profile of micelles' release in water with respect to ALG beads. For this reason, and due to the enhanced contribution of Fe(III) to their biocidal properties, CMC-based hydrogels are the most promising in view of the application on real agricultural soils.
生物熏蒸被提议作为一种替代合成农药的方法，用于农业土壤的消毒，因为某些植物物种释放的异硫氰酸酯（ITCs）具有杀菌作用，例如。然而，生物熏蒸也存在局限性；因此，一种新的可行替代方法可能是将 ITCs 直接作为负载到可生物降解水凝胶中的成分引入农业土壤中。因此，在这项工作中，开发了基于 ITCs 的微乳液，这些微乳液可以负载到基于海藻酸钠（ALG）或羧甲基纤维素钠（CMC）的多孔聚合物水凝胶珠中。考虑了三种 ITCs（乙基、苯基和烯丙基异硫氰酸酯）和三种不同的表面活性剂（十二烷基硫酸钠、Brij 35 和吐温 80）。通过衰减全反射傅里叶变换红外光谱和差示扫描量热法对最佳体系进行了表征，以研究微乳液/凝胶相互作用如何影响凝胶性质，例如平衡水含量或游离水指数。最后，通过紫外可见分光光度法研究了负载和释放曲线。结果发现，CMC 水凝胶珠在水中释放胶束的效率略高于 ALG 水凝胶珠。出于这个原因，并且由于 Fe(III) 对其杀菌性能的增强贡献，CMC 基水凝胶在实际农业土壤中的应用方面最有前途。
