Stability Phenomena Associated with the Development of Polymer-Based Nanopesticides

Abstract

Pesticides have been used in agricultural activity for decades because they represent the first defense against pathogens, harmful insects, and parasitic weeds. Conventional pesticides are commonly employed at high dosages to prevent their loss and degradation, guaranteeing effectiveness; however, this results in a large waste of resources and significant environmental pollution. In this regard, the search for biocompatible, biodegradable, and responsive materials has received greater attention in the last years to achieve the obtention of an efficient and green pesticide formulation. Nanotechnology is a useful tool to design and develop “nanopesticides” that limit pest degradation and ensure a controlled release using a lower concentration than the conventional methods. Besides different types of nanoparticles, polymeric nanocarriers represent the most promising group of nanomaterials to improve the agrochemicals’ sustainability due to polymers’ intrinsic properties. Polymeric nanoparticles are biocompatible, biodegradable, and suitable for chemical surface modification, making them attractive for pesticide delivery. This review summarizes the current use of synthetic and natural polymer-based nanopesticides, discussing their characteristics and their most common design shapes. Furthermore, we approached the instability phenomena in polymer-based nanopesticides and strategies to avoid it. Finally, we discussed the environmental risks and future challenges of polymeric nanopesticides to present a comprehensive analysis of this type of nanosystem.

Effects of three tebuconazole nanopesticides on the survival of Daphnia magna

“…11 Moreover, as stabilization agents play a role in the release of the a.s, it is needed to state that stabilization agents are critical in the formulation and stability of NFs, commonly used to prevent the agglomeration of nanoparticles and to maintain their stability in solution. 66 They can improve the stability, particle size, mobility, and efficacy of nanoparticles, which is essential for their use in various applications such as drug delivery, environmental remediation, and agriculture. 67 Surfactants due to their amphiphilic nature are exploited to stabilize hydrophobic nanomaterials in aqueous media.…”

“…Surfactants like PVA and polysorbate (e.g., Tween-80) are highly effective as colloidal stabilizers of suspensions used for decades in the synthesis of different nanomaterials, especially in polymeric nanocarriers, benefited from their high biodegradability in the environment. 12,31,66,68,69 Tween-80 as a non-ionic surfactant consisting of polyethoxylated sorbitan and oleic acid is often used also in food products due to its lower toxicity and high emulsifying ability, 70 while the simultaneous use of Tween-80 with high hydrophilic surfactants, for instance span surfactants, in the fabrication of nanomaterials can significantly improve the hydrophobicity of nanomaterials. 71 Similar to our result in PCL-TBZ in a study by Grillo et al (2012), 12 the release of three encapsulated herbicides from PCL (in one concentration) was investigated in water.…”

Nanopesticides: A Review on Current Research and Future Perspective

“…One such example is the essential oil of Lippa origanoides which, on encapsulation with nanogel chitosan modified with ferulic acid, showed stable release of AI with greater efficiency. [68] Figure 3. Schematic representation of different nano-based formulations.…”

“…Pesticides with oil show less solubility, due to which there has been an increase in the use of polymers that can form nanogels and thus encapsulate these pesticides. One such example is the essential oil of Lippa origanoides which, on encapsulation with nanogel chitosan modified with ferulic acid, showed stable release of AI with greater efficiency [68] …”