School of Life and Environmental Sciences, Deakin University, Waurn Ponds Campus, Geelong, VIC, 3217, Australia.
Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville Campus, 381 Royal Parade, Parkville, VIC, 3052, Australia.
J Nanobiotechnology. 2018 Nov 21;16(1):94. doi: 10.1186/s12951-018-0423-5.
Modern agricultural practises rely on surfactant-based spray applications to eliminate weeds in crops. The wide spread and indiscriminate use of surfactants may result in a number of deleterious effects that are not limited to impacts on the crop and surrounding farm eco-system but include effects on human health. To provide a safer alternative to the use of surfactant-based formulations, we have synthesised a novel, self-assembling herbicide conjugate for the delivery of a broad leaf herbicide, picloram.
The synthesized self-assembling amphiphile-picloram (SAP) conjugate has three extending arms: a lipophilic lauryl chain, a hydrophilic polyethylene glycol chain and the amphiphobic agrochemical active picloram. We propose that the SAP conjugate maintains its colloidal stability by quickly transitioning between micellar and inverse micellar phases in hydrophilic and lipophilic environments respectively. The SAP conjugate provides the advantage of a phase structure that enables enhanced interaction with the hydrophobic epicuticular wax surface of the leaf. We have investigated the herbicidal efficiency of the SAP conjugate compared against that of commercial picloram formulations using the model plant Arabidopsis thaliana and found that when tested at agriculturally relevant doses between 0.58 and 11.70 mM a dose-dependent herbicidal effect with comparable kill rates was evident.
Though self-assembling drug carriers are not new to the pharmaceutical industry their use for the delivery of agrochemicals shows great promise but is largely unexplored. We have shown that SAP may be used as an alternative to current surfactant-based agrochemical formulations and has the potential to shift present practises towards a more sustainable approach.
现代农业实践依赖基于表面活性剂的喷雾应用来消除作物中的杂草。表面活性剂的广泛和无差别使用可能导致许多有害影响，不仅限于对作物和周围农田生态系统的影响，还包括对人类健康的影响。为了提供一种更安全的替代基于表面活性剂的制剂的方法，我们合成了一种新型的自组装除草剂缀合物，用于输送广谱除草剂草甘膦。
合成的自组装两亲体-草甘膦（SAP）缀合物有三个伸展臂：亲脂性月桂基链、亲水性聚乙二醇链和疏水性农用化学品活性草甘膦。我们提出，SAP 缀合物通过在亲水和疏水环境中分别快速在胶束和反胶束相之间转换，保持其胶体稳定性。SAP 缀合物提供了一种相结构的优势，使它能够增强与叶的疏水性表皮蜡表面的相互作用。我们已经研究了 SAP 缀合物与商业草甘膦制剂相比的除草效率，使用模式植物拟南芥，并发现当在农业相关剂量（0.58 至 11.70mM 之间）下进行测试时，明显存在剂量依赖性除草效果和可比的杀伤率。
尽管自组装药物载体在制药行业并不新鲜，但它们在输送农用化学品方面显示出巨大的潜力，但在很大程度上尚未得到探索。我们已经表明，SAP 可以用作当前基于表面活性剂的农用化学品制剂的替代品，并且有可能将目前的实践转向更可持续的方法。
