ROLE OF NANOTECHNOLOGY IN INSECTICIDE FORMULATION

Presenter:GIRI NAGAHARISH,Ph. D Entomology.

There’s Plenty of Room at the Bottom”

Seminar outline:

1. Introduction

2. Nanotechnology Applications

3. Nanotechnology in Insecticide Formulation

4. Case studies

5. Nano formulated products in market

6. Environmental Impact of Nano based Insecticides

INTRODUCTION

Loss of insecticides into environment

What are nanomaterials ??

Kah et al, 2013

Nanomaterials used unknowingly for thousands of years Eg. Gold nanoparticles that were used to stain drinking glasses

Nanoscale is defined as particle size having an upper limit of about 100 nm

The term nanomaterial refers to materials with external dimensions, or internal structures, that are on a nanoscale (OECD, ISO)

CLASSIFICATION Nanomaterials are classified according to the length scale of

each of its dimension 0 D : all three dimensions in the nanoscale (nanoparticles)

1 D : one dimension in nanoscale and other two in macroscale ( nanofibers, nanowires)

2 D : two dimensions in nanoscale and the other in the macroscale ( nano sheets, thin films)

3 D : no dimensions at the nanoscale, all are in the macroscale (nanostructures with nanomaterials)

20-300 nm 7-100 nm 2 nm

Learning from Mother Nature

Psaltoda claripennis

Look deep into nature, and then you will understand everything better. Albert Einstein

Blue morpho butterfly

~ 2000 Years Ago

Sulfide nanocrystals used by Greeks and Romans to dye hairs

~ 1000 Years Ago

Gold nanoparticles of different sizes used to produce different colors in stained glass windows

1959 “There is plenty of room at the bottom” by R. Feynman1974 Taniguchi uses the term nanotechnology for the first time

1981 IBM develops Scanning Tunneling Microscope1985 “Buckyball” - Scientists at Rice University and University of Sussex

discover C60

1986 • “Engines of Creation” - First book on nanotechnology by K. Eric Drexler.

• Atomic Force Microscope invented by Binnig, Quate and Gerbe

1989 IBM logo made with individual atoms (A boy and His Atom )1991 Carbon nanotube discovered by S. Iijima 1999 “Nanomedicine” – 1st nanomedicine book by R. Freitas 2000 “National Nanotechnology Initiative” launched

(British Standards Institution, 2005)

Time line of Nanotechnology

8

What is specific about Nano ?Below about 100 nm the rules that govern the behavior of the elements of our known world start to give way to the rules of quantum mechanics, and everything changes Quantum effects

9

Things behave differently in nano-world

CHARACTERIZATION OF NANOPARTICLES

DLS

SEM TEM

AFMSTM

METHODS OF NANOPARTICLE PRODUCTION

(Royal Society and Royal Academy of Engineering, 2004)

Application of nanotechnology in agriculture and allied sciences

• Food technology• Crop improvement• Seed technology• Precision farming• Nano-fertilizer for

balance crop nutrition• Plant disease diagnose• Weed management

• Water management• Biosensors (Electronic

nose)• Agricultural engineering

issue• Animal science• Fishery and aquaculture• Pest management

NANOTECHNOLOGY IN

INSECTICIDE FORMULATION

Scope and present status

Kah, et al, 2013

The development of new formulations is a very active field of research

Nanopesticides are any formulation that intentionally includes elements in the nanometre size range and/or claims novel properties

3,000 patent applications 60 peer-reviewed papers 25 reports and reviews

Nanopesticide formulations

Different formulations of a pesticide

Nanoemulsion or ultrafine emulsions or submicron emulsions

Nanosuspension or Nanodispersion

Nanoencapsulation

Nanoparticles

16

NANOEMULSION VS NANOSUSPENSION

Suspension is a a non soluble solid suspended in a liquid medium (solid in liquid

mixture of solid( dispersed phase) in liquid(dispersion medium)

Emulsion is mixture of oil and water (Two liquids). An emulsion has two phases, a continues phase ( large quantity) and a discontinues phase particle size 0.1nm 100nm ( present in small quantity)

1. Oil in water (o/w)

2. Water in oil (w/o)

In nanosuspension particles size 200±50 nm

In nanoemulsion particles size ≤ 100 nm

Kahi et al, 2013

Nanoemulsions are oil-in-water (o/w) type

Size of droplet sometimes overlap with microemulsion

Possess stability against sedimentation or Ostwald ripening

Microemulsion Nanoemulsion•Thermodynamically stable. •Kinetically stable

. 20% surfactant • 5-10 % surfactant

Nanoemulsions

Nano

Em

ulsio

n

High energy emulsion

High pressure homogeniser

Ultra-sonification

Low energy emulsion

Self emulsion

Phase transition

Phase inversion

Klang et al., 2012; Kah et al., 2013

Nano

disp

ersio

n or

susp

ensio

n

Dry/wet milling

Extract precipitation

Solvent evaporation

Novaluron nanoparticles: Formation and potential use in controlling agricultural insect pests

Elek et al, 2010

• Nanoparticles of novaluron prepared by direct conversion of O/W microemulsions containing pesticide and volatile solvents, into powders

• This was achieved by rapid evaporation of all the liquids in the microemulsion by spray drying .

• Finally in nanoformulations the droplet size was approximately 6 nm

• which is free of organic solvents and is environmentally preferable, in addition to the minimal low energy requirement in the production process

Stability and Biological Activity Evaluation of Chlorantraniliprole Solid Nanodispersions Prepared by High Pressure Homogenization

Cui et al., 2016

Nanoencapsulation is the coating of various substances within another material at various sizes in the nano-range

The encapsulated material is internal phase or core material E.g. pesticides

The encapsulation material is external phase or shell or coating E.g. nanocapsules

NANOENCAPSULATION

Specific Advantages

Slower releasing Not prematurely degradable due to thermal stability Biodegradability

NANOENCAPSULATION

Polymer-Based Nanoencapsulat

ion Materials

Lipid-Based Nanoencapsulat

ion Materials

Porous inorganic Nanoencapsulation

Materials

Clay-Based Nanoencapsulat

ion Materials

Nanocapsules

Nanospheres

Micelles

Nanogels

Liposomes

Solid lipid nanoparticle

s

Mesoporous hollow silica

nanoparticles

Porous hollow silica

nanoparticles

Clay materials

Layer double hydroxides

Nuruzzaman et al, 2016

SYNTHESIS BY DIFFERENT METHODS

Polymer-Based Nanoencapsulat

ion Materials

Lipid-Based Nanoencapsulation Materials

Nanoprecipitation

Solvent evaporation

Emulsion concervation

Non mechanicalMechanical

Nuruzzaman et al, 2016

Emulsion diffusion

Double emulsification

Nanocapsules

Emulsion evaporation

Layer by layerEmulsion polymerizationInterfacial polymerization

Solvent displacement

Sonication/Ultra sonication

Extrusion method

Micro fluidization

Heating method

Colloidal mill method

High pressure homogenizationReverse phase

evaporation

Deletion of mixed detergent lipid

micelles

Porous hollow silica

nanoparticles Clay materials

Layer double hydroxides

SYNTHESIS BY DIFFERENT METHODS

Solvent evaporation process

Template method

Clay-Based Nanoencapsulation Materials

CovulconizationPolymerization &Solution method

Solid state intercalation

Sol gel emulsion

Supercritical Co2Fluid methods

Deamination or Top down Controlled nucleation or bottom up

Release mechanism of Nanoencapsulated materials

Diffusion

Dissolution

Osmotic

Thermal

Mechanical

Chemical

Enzymatic

Polymer-Based Nanoencapsulation Materials

Employing it for pesticide delivery is a recently developed approach

produced by natural sources, environmentally friendly and biodegradable materials

comparatively low cost

When two or more different monomers unite together to polymerize, their result is called a copolymer

Block copolymers comprise two or more homopolymer subunits linked by covalent bonds.

E.g. synthetic and natural polymers, such as polyethylene glycol, poly-ε-caprolactone, chitosan, and sodium alginate

Entomotoxicity and biosafety assessment of PEGylated acephate nanoparticles: A biologically safe alternative to neurotoxic pesticides

Pradhan et al., 2014Mortality of Spodoptera litura treated with nano- and conventional acephate at different concentrations

Nanocapsules

o Nanocapsules are vesicular systems that are made up of a polymeric membrane encapsulating the active compounds as an inner liquid core at the nanoscale level

o The active substances are dissolved in the inner liquid core.

o Widely utilised method

Using a melt dispersion method, synthesized round-shaped Nanocapsules of PEG loaded with garlic essential oil

The oil-loading efficiency reach 80% at the optimal ratio of essential oil to PEG (10%)

<240 nm in the average diameter

The control efficacy against adult T. castaneum remained over 80% after five months due to the slow and persistent release of the active components from the nanoparticles

The control efficacy of free garlic essential oil at the similar concentration (640 mg/kg) was only 11%.

Structural Characterization of Nanoparticles Loaded with Garlic Essential Oil and Their Insecticidal Activity against Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

Yang et al., 2009

TEM image

A novel photodegradable insecticide: Preparation, characterization and properties evaluation of nano-Imidacloprid

Guan et. al 2008

Imidacloprid (IMI) microcrystals were encapsulated with chitosan (CHI) and sodium alginate (ALG) through layer-by-layer (LbL) self-assembly

Among the different photocatalysts, SDS/Ag/TiO2 had the highest photocatalytic activity

Toxicity of the novel nano-SDS/Ag/TiO2-IMI was higher in the adult stage compared to the 95% IMI as indicated by the lower LC50 value

one hand, to increase the toxicity and synthesize the controlled release formulations; on the other hand, to find the optimum photocatalysis to break up the pesticides.

SEM images of IMI microcrystals (a) uncoated, (b) coated with 5 layers ofCHI/ALG, (c) coated with 10 layers of CHI-ALG.

The degradation of nano-IMI on photocatalysts (a): catalyst powders underUV light; (b): catalyst powders under natural light

Synthesis, characterization and on field evaluation of pesticide loaded sodium alginate nanoparticles

Kumar et. al, 2014

Nanoparticles were formulated by emulsion cross linking technology in the range of 50–100 nm

Four different formulations i.e. control, dummy, plain and encapsulated (loaded) were evaluated on four different plots which were of same dimensions

In vitro cytotoxicity results of imidacloprid loaded sodium alginate nanoparticles

Preparation, characterization and efficiency of nanoencapsulated imidacloprid under laboratory conditions

Memarizadeh et. al, 2014

Nano-imidacloprid was prepared by direct encapsulation with ABA triblock linear dendritic copolymers composed of poly(citric acid) (PCA) as A block an poly(ethylene glycol) (PEG) as B block

Higher loading capacity and slower release rate of imidacloprid from nano-imidacloprid at optimum pH of Glyphodes pyloalis's gut (pH=10) compared to neutral pH confirmed the selective and controllable action of nano-imidacloprid

Nanospheres

Nanospheres constitute the active nanocarrier system where the active compounds are uniformly distributed and embedded into the polymeric matrix

This nanoparticle can be synthesized by implementing the same methods of nanocapsule synthesis

The polymerization technique plays the key role in the synthesis of this nanomaterial

E.g. emulsion or interfacial polymerization

Micelles:

Micelles are ideal bioactive nanocarriers for encapsulating pesticides, especially for water-insoluble agents

amphiphilic block copolymers, polymers, surfactants, etc. play vital role in formation

Hydrophobic pesticides can be trapped inside the core

Nanogels

Nanogels are aqueous dispersions of hydrogel particles formed by physically or chemically cross-linked polymer networks.

Water-soluble or hydrophilic polymers are modified to create hydrophobic properties, which allow them to interact with each other electrostatically and/or form hydrogen bonds among themselves

This is considered for common pharmaceutical nanocarriers because of their high loading capacity, high stability, and responsiveness to environmental factors such as ionic strength, pH, and temperature

Efficient Management of Fruit Pests by Pheromone Nanogels

Bhagat et. al, 2012

Slow release of ME from the nanogels

Handling and transportation without refrigeration, and reduction in the frequency of pheromone recharging in the orchard

Nanogel was found chemically, thermally and mechanically stable

2. Lipid-Based Nanomaterials

Better encapsulating efficiency and low toxicity

Great potential to encapsulate the hydrophilic, hydrophobic, and lipophilic active ingredients

They regularly facilitate the dispersion of hydrophobic AIs in aqueous solutions

Absorption of the bioactive compounds through the cuticle of the insect body is high

Nanoliposomes

Flexible in nature and able to encapsulate all kinds of molecules

Both the water-soluble and -insoluble active ingredients can be delivered simultaneously

Facilitate the application of multi pesticide application (both contact and systemic)

High costs, low payload, and comparatively faster release of active ingredients are the disadvantages of this carrier material

Solid Lipid Nanoparticles (SLN)

Superior carrier material relative to other nanocarrier materials in controlled releasing nature

No disadvantages in terms of physical and chemical storage stability, toxicity, loading capacity, production scale, target-oriented releasing properties, feasibility

With general ingredients synthesis can be made i.e. by Lipids solid at room and physiological temperature, surfactants/ emulsifiers and water

3. Porous Inorganic Nanomaterials

In recent years the synthesis of inorganic porous nanomaterials with interesting hierarchical morphologies has attracted much attention

High thermal and chemical stability, non toxic and resistance to rapid elimination by plant enzyme system

Porous Silica Nanoparticles

In terms of pesticide delivery, porous silica nanoparticles are the most prominent as encapsulating materials among the porous nanomaterials

Depending on the surface structure and interior design grouped as MSNs, PHSNs

The pesticides are encapsulated by non covalent bonding between active compounds and SiO2 nanoparticles

Adsorption and release of biocides with mesoporous silica nanoparticles

Popat et al., 2012

Imidacloprid) was effectively loaded into the mesoporous silica nanoparticles (MSNs)

with different pore sizes, morphologies and mesoporous structures for termite control

Found that the adsorption amount and release profile of imidacloprid were dependent on the type of mesoporous structure and surface area of particles

Specifically, MCM-48 type mesoporous silica nanoparticles with a three dimensional (3D) open network structure and high surface area displayed the highest adsorption capacity compared to other types of silica nanoparticles.

Up to 16% adsorption capacity

Controversy about Nano based formulations

Many pesticide formulations described as “nano” in the literature exceed the limit of 100 nm

Companies developing formulations in the nano range may choose not refer to their new products as nanoformulations as the “nano” may associated with a large public uncertainty

E. g: Microemulsions

WHAT PRODUCTS ARE ALREADY ON MARKET…??

Bouwmeester et al., 2007

An overview of Nano-formulations of insecticide under development

Formulation Product name Manufacture/Company

Advantage/ Purpose

Nano emulsion Citronella oil   NC & National Science & Tech Dvpt., Agency, Thailand.

Prolong mosquito protection time.

Triazophos Clge. of Chemistry & Environ.Science, China

Relatively stable in acidic and neutral solutions and easily hydrolyzed in basic solution

Nanosuspension Novaluran 

Makhteshim chemical works Ltd., Israel

Increased penetration through the cuticle.

 Beta Cypermethrin

 College of chemistry & Mol. Sci., Wuhan University, China

Faster dissolution rate

NANO PESTICIDES AND THEIR ENVIRONMENTAL IMPACT

Wiesner et al., 2006

THANK YOU