Nano-pesticide Research in CAAS Dr. Haixin Cui Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences cuihaixin@caas.cn 2014.11.18
Pesticides are an essential substances for the security of agricultural production Global input over 4.5 million tons per year Involving thousands of toxic compounds Saving about 30% loss of the total production 2
Conventional formulations of pesticide with low efficiency and safety Techinial (TC) Formulation Water-dilution Using Insoluble compounds Emulsifiable concentrate (EC) Water power (WP) Pesticide solution Spraying More than 70% pesticides flow into the environment, and residue in plant products in process of application. 3
Inefficient use of pesticides causing a series of food safety and environmental problems Residues in food, environmental pollution, loss of biodiversity, ecological degradation, etc. 4
Nanotechnologies offering a tool for novel formulation of environmentally friendly pesticide A new way for developing novel formulation of pesticide with high efficacy and safety, such as insecticides, fungicides, herbicides, antibiotics, growth regulator, and bio-active compounds; An excellent means for establishing environmentally friendly and sustainable agriculture system by reduced overall chemical usage, decreased toxic residues and improved management of fertilization and crop protection; An important approach for controlling pesticide residues and pollution by reducing cropland input and environmental emissions. 5
Fundamental study on nanotechnology to improve the efficacy and safety of pesticides 6
Size-down of pesticide particles increasing bioavailability and efficiency 7
Four key scientific issues to be clear 8
1. Formulation of smart nano-delivery systems Dispersion approaches Delivery systems Properties Construction dispersion, stability, adhesion, permeability and release loading model, assembly process and preparation process 9
2. Mechanism on leaf deposition and dose transfer Improving leaf adhesion, deposition rate and duration 10
3. Bioavailability increase of pesticide nano-delivery system Increase of toxicity and effectiveness through improving interaction mode and targeting delivery. 11
4. Catalytic degradation of pesticide residues and improvement of environmental behaviors Increase on food safety and decrease on environmental risks. 12
Research Objectives of Nano-pesticides Desirable Properties Examples of Nanopesticieds-Enabled Technologies Targeted delivery Controlled release Water dispersion Chemical stability Bioavailability Efficacy duration Increasing targetable transmission efficiency of pesticide into action targets, such as plants, insects, pathogen. Controlling release speed of pesticide to maintain least effective concentration for killing pests and pathogens. Increasing solubility and dispersion for fat-soluble drugs in aqueous solution. Improving chemical stability for light-sensitive compounds by restricting photo-degradation. Increasing bioavailability for saving pesticides. Reducing pesticides application and treatment frequency by extended efficacy duration. Lower toxicity Protecting biodiversity in ecosystem. Environmental friendliness Reducing food residues and non-point source pollution due to the minimum pesticide loss. 13
R&D Strategies for Nano-pesticides Technical Obstacles Safe carrier systems Nano-encapsulation Nano-emulsion Target mediated modification Nanosized process Inclusion Nano-coated granulation Aqueous colloid dispersion system Priority Issues of Nano-pesticieds-Enabled Technologies To formulate smart delivery systems in mesoporous, nano-structured material, molecular sieve or nano-particles, etc. To improve release rate and chemical stability by encapsulated pesticide in nano-capsules, micelles, liposomes, etc. To increase solubility and dispersion for fat-soluble drugs in aqueous solution by self-emulsifying delivery system. To improve affinity of pesticide to leaf surface using target-mediated molecules. To render higher solubility and dispersion for insoluble or fatdispersible compounds nanosized in aqueous solution. To control release and protect pesticide molecules by absorbed pesticide in nano-polymer or mesoporous materials. To create slow/controlled release formulation of insecticides or fungicides to control soil infection diseases and soil pests. To develop EC alternative products with less toxic solvents for fatsoluble compounds. 14
Advantages of Nano-pesticides Increase on use efficiency by improvement of drug release and delivery properties; Substantial residue reduction in food and environmental pollution; Decrease of toxicity to non-target wildlife and ecological system; Improvement on crop protection and production management; Cost savings by reduction on pesticide dosage and frequency. 15
Prospective Application of Nanopesticides Slow/controlled release formulation may be preferable choices in controlling soil diseases, pests and weeds for reduced toxic residues in soil and food; Aqueous dispersion formulation may gradually substitute EC products to avoid the pollution of organic solvents ; Nano-capsule formulation may be used in larger scale for improved stability, bioavailability and efficacy duration of biopesticides; Leaf-affinity formulation might be more suitable in crop spraying for increased utilization of biological targets. 16
Some Strategies to Avoid the Risks Risks and safety of nanopesticides Some toxic nano-particles from pesticides may flow into the environment and food systems threaten human health and ecosystem balance. safety and risk assessments of nanopesticides Research must be conducted according to established method of nano-toxicology and nano-medicine. Avoiding usage of high toxic nano-particles More safe and biodegradable carriers nanomaterials developed for the production of nano-pesticides. should be 17
Research projects (as a national leader) Project Research plan Duration Novel nano-carriers for agricultural bio-drugs Photocatalystic ethyline degradation unit for fruit fresh storage Nano-carriers delivery systems for gene transfer Novel Formulation of Biological pesticides Application of nanomaterials in agriculture Basic Research on Improving the Effectiveness and Safety of Pesticides by nanotechnology 863 Program 2006-2010 863 Program 2007-2010 National Priority R&D Program 2009-2010 863 Program 2011-2015 CAAS Program 2014-2018 973 Program 2014-2018 18
Application of nano-tio2 sol in crop diseases control Photochem. Photobiol. 2010, 1135 39 Eur. Cells Mater. 2010, 293-293 NSTI-Nanotech. 2009, 286-89 19
Sustained-release of nanocapsule pesticide Nanocapsule pesticides were prepared using biocompatible polymers, which can reduce spray drift through improved behaviors of adhesion on leaves, and prevent them from environmental degradation. Micropor. Mesopor. Mat. 2013, 169, 1-6 Microchim. Acta 2011, 73, 51-7 IET Nanobiotechnol. 2009, 4, 103 08 Pest Manag. Sci. 2011, 67, 831 36 20
21 21
Nano agricultural innovation team Thanks!