Nanomaterial Registry: Minimal Information Standards for Well-Characterized Nanomaterials in Environmental and Biological Studies

Michele L. OstraatApril 19, 2012

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Authoritative Web-Based Registry– Biological and environmental interactions of well-

characterized nanomaterials Broad stakeholder involvement from industry,

regulatory, government, and academia Significant Long-Term Impact

– Develop new models, assays, standards, and manufacturing methods

– Accelerate the translation of new nanomaterials for biomedical and environmental applications

– Promote standards and support science-based regulatory decision-making

Biological and Environmental Applications for Nanotechnology

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Priorities and Features Active program focus to

• Develop a minimal information standard for nanomaterials

• Deploy consistent vocabulary and nomenclature

• Develop an ontology and matching systems

• Address interoperability with existing and future data sets

• Develop evaluation criteria for consistent and validated curation

• Facilitate collaborations across the nanomaterial research community

Features include– Search – basic and advanced– Browse– Comparison– Matching

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Leveraging & Developing Minimal Information Standards

Minimum information that must be known in order to report biological and/or environmental interactions

Challenges for Registry– Minimal information is not simply a

list of physico-chemical characteristics

– Sufficient information on instrumentation and methodologies used to measure characteristics must also be reported

Promote standard protocols

Characteristic ISO, 2009 OECD, 2008 NIST, 2008 Warheit, 2008 Ray, 2007 MINChar, 2009 Agglomeration State/Aggregation x x x x x x Particle Size/Size Distribution x x x x x x Purity x x x x x Surface Area x x x x x Surface Chemistry x x x x x Composition x x x x x Shape x x x x Solubility x x x Stability x x x x Surface Charge x x x x Surface Reactivity x x Synthesis/Preparation x x Concentration x x Zeta Potential x x Crystal Structure/Crystallinity x x Surface/Interfacial Energy x Catalytic Properties x Dustiness x Fat Solubility/Oleophilicity x Grain Size x Water Solubility/Hydrophilicity x TEM Picture(s) x Photocatalytic Activity x Pour Density x Porosity x Octanol-Water Partition Coefficiency x Redox Potential x Radical Formation Potential x

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Example: Minimal Information and Protocols

Particle characteristics can change depending upon protocol

Report information related to characteristics and protocols

5

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Example: Nanomaterial Morphologies

Zhang, J Coll Int Sci, 2(15) 2009

www.nano-lab.com

www.nano-lab.com

Tomalia, J Nanopart Res (2009) 11

Wang, Materials Today 2004

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Example: Size and Size Distribution

Many nanomaterials are characterized by their ensemble properties

Can change over time and in different environments

10 1000

1x106

2x106

3x106

4x106

5x106

6x106

7x106

8x106

9x106

Qpr = 1 cm3/min

Qpr = 3 cm3/min

Qpr = 6 cm3/min

Qpr = 10 cm3/min

Qpr = 25 cm3/min

Qpr = 35 cm3/min

Qpr = 45 cm3/min

Qpr = 75 cm3/min

dN

/d lo

g (

D p)

(cm

-3)

Dp (nm)

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Example: Purity and Composition As synthesized, MWCNTs

contain various species– Soot– Single-walled tubes– Multi-walled tubes– Metal catalysts

Common Challenges:– How to describe and quantify– How to correlate any observed

response to characteristic– Disclosure of proprietary

coatings and processes

Multi-walled carbon nanotubes (MWCNTs)

Si nanoparticles w/ surface structure

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Minimal Information Standards for Nanomaterials

Minimal Information = PCC + Measurement Details + Protocol Details

Particle size

Size distribution

Agglomeration state

Aggregation state

Surface area

Shape

Composition

Purity

Surface chemistry

Surface charge

Surface reactivity

Solubility

Stability

Material TypeMolecular IdentityDensityCrystallinityCrystal StructureMean Crystallite SizeLattice ParametersSurface Coverage LevelThicknessShell ContinuityMeasurement Sub-TypeProportion of NanomaterialProportion of CoreProportion of ShellProportion of CoatingProportion of Ligand

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Minimal Information About Nanomaterials

Particle size

Size distribution

Agglomeration state

Aggregation state

Surface area

Shape

Composition

Purity

Surface chemistry

Surface charge

Surface reactivity

Solubility

Stability

SizeDiameterMean diameterMean primary particle sizeMean hydrodynamic diameterMean aerodynamic diameterMolecular weight (MW)Number Average Molecular Weight (Mn)Weight Average Molecular Weight (Mw)Volume Average Molecular Weight (Mv)Nanomaterial StateMeasurement Sub-Type

Number Average Volume WeightedIntensity Weighted

DLSViscositypH of SuspensionTemperature of SuspensionDispersing Agent TypePurity of Dispersing AgentConcentration of Dispersing AgentSample ConcentrationMedium TypeRefractive Index of MediumIonic StrengthSonication/Milling PowerSonication/Milling TimeAlgorithm used

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Analytical Instrumentation NeedsPCCs: Particle Size, Particle Size Distribution and Agglomeration / Aggregation State

Dynamic Light Scattering Transmission Electron Microscopy Scanning Electron Microscopy Atomic Force Microscopy Dynamic Mechanical Analysis Differential Mobility Analysis – aerosol

Example DLS protocols and parameters: Algorithm used Viscosity pH of Suspension Temperature of Suspension Dispersing Agent Purity of Dispersing Agent Concentration of Dispersing Agent Sample Concentration Solvent/Medium Type Ionic Strength Sonication/Milling Power Sonication/Milling Time

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Establishing Compliance Levels

…functioning behind the scene

• Minimal Information• Instrumentation• Methods• Parameters

Sta

ge 1 Curate Data

Elements Sta

ge 2 Apply Weighting

Factors Sta

ge 3 Calculate

Compliance Levels

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Technique Details

Best Practice Questions

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Minimal Information Standards – Bio & Env Biological Interactions Minimal

Information includes Categories:

– In vivo– In vitro– In silico

Content:– General study details– Exposure summary– Endpoints for

Toxicity Pharmacodynamics Biodistribution Biotransformation

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Minimal Information Standards – Bio & Env Environmental Interactions

Minimal Information includes Environmental Compartments:

– Air– Water– Soil

Content:– General study details– Exposure summary– Endpoints for

Fate and Transport Transformation

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Thank You

Contact Information:

Michele Ostraat 919-541-5830

mostraat@rti.org

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