Izon Science

Izon Science Ltd.

Type	Limited
Industry	Nanotechnology
Founded	2005
Headquarters	Christchurch, New Zealand
Area served	Worldwide
Key people	Hans van der Voorn (Chairman and CEO)
Products	qNano, qViro-X
Website	www.izon.com

Izon Science Ltd. is a nanotechnology company that has developed instrumentation for nano- and micro- scale particle analysis. The company’s main products, qViro-X and qNano are in use in a wide range of research institutes and universities around the world.^[1][2] The company was incorporated as Australo Ltd. on January 10, 2005, and renamed Izon Science Ltd. on November 17, 2008. Its headquarters are located in Burnside, Christchurch, New Zealand.^[3]

The measurement methodology used by Izon instruments is known as Tunable Resistive Pulse Sensing (TRPS), and utilizes dynamically resizable nanopores for real-time particle detection, quantitation and characterisation.^[4][5]

Capabilities include high resolution particle sizing, size distribution measurement, concentration analysis, real-time particle-particle interaction monitoring, and particle-by-particle charge and mobility analysis.

Measurement Methodology

Tunable Resistive Pulse Sensing

Tunable Resistive Pulse Sensing (TRPS) allows high-throughput single particle measurements as colloids and/or biomolecular analytes are driven through pores, one at a time. Particles crossing the nanopore are detected as a transient change in the ionic current flow, which is denoted as a blockade event with its amplitude denoted as the blockade magnitude.^[6][7] As blockade magnitude is proportional to particle size, accurate particle sizing can be achieved after calibration with a known standard. Analysis of individual particle translocation through the pore allows determination of particle electrophoretic mobility and calculation of individual particle charge, simultaneous with size, a unique feature of TRPS.^[8]

Nanopore-based Measurement

Fixed geometry micro-scale apertures for particle detection have been used in a wide range of industrial applications since the invention by W.H. Coulter in the 1950s.^[9] Quantitative resistive pulse sensing of nanoparticles using Coulter-type counters has been shown to hold promise as a fast and accurate alternative to established sizing methods.^[10][11] Fixed pore size enables sensitive size measurements, but also limits analysis size range, which has implications for the measurable sample polydispersity.

Izon’s instrumentation overcomes this limitation by using size-tunable pores that allow for the optimisation of the resistance pulse magnitude relative to the background current by matching the pore-size closely to the particle-size. As detection occurs on a particle by particle basis, the true average and polydispersity distribution can be determined, without the averaging effects inherent in other size analysis technologies, such as dynamic light scattering.^[12]

Products

qViro and qNano were released as the world’s first commercial nanopore platform on 22 June 2009, representing the culmination of an extensive four-year R&D programme.^[13][14] The qViro-X superseded the qViro in March 2012 as a specialized virus analysis system for rapid determination of viral titre and aggregation, featuring improved decontamination-proof design.

qNano

The qNano, shown above with the Variable Pressure Module (VPM), is a bench-top instrument for the practical implementation of TRPS for fluid-borne analysis of nanometre-scale particles.

qNano is a bench-top instrument for the practical implementation of TRPS for fluid-borne analysis of nano- and micro -scale particles. This instrument incorporates a sensitive manual control system for Izon’s dynamically adjustable nanopores, enabling tunable, resistive pulse sensing over a wide particle size range (typically 50 nm – 20μm).^[15] Data acquisition software allows raw or filtered data to be viewed in real-time. TRPS using qNano enables particle-by-particle determination of the size, charge and concentration of a wide range of particle types.

Applications include:

• Particle-based drug delivery systems (e.g. liposomes, nano- and micro- bubbles, polymers, "Smart" drug delivery particles, etc)
• Analysis of extracellular vesicles (e.g. exosomes & microvesicles)
• Virus, VLP and bacterial analysis
• Biomedical diagnostics research (e.g. dye-doped nanoparticles, functionalized nanoparticles for immunodetection)
• Industrial research applications (e.g. paint pigments, food & beverage, magnetic & metallic particles, etc.)

The qNano is sold as a full system ready for use including the base instrument, variable pressure module (VPM), fluid cell and a starter kit of nanopores, buffer solution and standard particle sets.

qViro-X

The qViro-X was launched in March 2012, as Izon's next generation virus analysis system, specifically designed for use in quality control environments such as viral vaccine manufacturing. Measurement involves pipetting 40 μL of sample into the upper fluid cell of qViro-X. Detection occurs in real-time, allowing measurement of thousands of viral particles, with total analysis time per sample of 10 – 15 minutes.

Accurate viral particle size distribution output, determined on a particle-by-particle basis is useful for assessment of viral aggregation and stability during vaccine production. The number of viral aggregates can be reliably measured and displayed in relation to the total number of pure virus particles in the sample. As qViro-X is capable of rapid counting the total number of virus particles present in a sample (vp / mL), when used in conjunction with infectivity assays this allows users to determine the relative concentrations of infective virus particles vs. total viral particles present.

Disposable elements of the instrument ensure that issues of contamination are handled easily. The stainless steel body of the instrument allows wash-down with harsh chemicals to meet stringent decontamination requirements. 21 CFR Part 11 compliant software provides a full data audit trail that meets FDA requirements.

Applications include:

• Vaccinology & Vaccine Production
• Virus Quantitation & Stability Assessment
• Gene Therapy Research - Quantitation and Analysis of Viral Vectors
• Microbiology & Virology Research (e.g. Virus-Cell Interactions)

qViro

qViro is the first tunable nanopore-based virus counting instrument that was launched in June 2009, and provided the ability to rapidly count and characterise individual virus particles in real-time.

The qViro shared advantages of Izon's other TRPS systems including dynamically adjustable nanopores that could be tuned for coverage of a range of viral particle sizes, giving researchers the capacity for precision counting of viruses; data acquisition software allowing virus count to be viewed in real-time; and disposable elements that enabled issues of contamination to be handled according to researchers’ needs.

qViro was designed to enable modularised upgrades such as full, software controlled automation of nanopore aperture adjustment, feedback control capability, pressurised control of flow and automated fluid control systems. The Instrument has a small footprint and fits easily into fume-hoods and biological containment facilities.

Capabilities

Particle Sizing

qNano and qViro allow single particle measurement, and size distribution analysis of particle populations.

A discrete electrical signal is registered by the system each time a particle passes through the nanopore. Each individual particle signal is analysed and the make-up of the constituent populations is built up for the sample.

The magnitude of the electrical signal shows the volume of the particle (i.e. particle diameter). This allows rapid quantification of:

• Absolute size
• Size distribution and volume fraction analysis
• Resolving distinct populations within a sample mixture
• Assessment of polydispersity
• Aggregation and/or fragmentation levels
• Number and concentration of differently sized particles

Concentration

Evaluating the concentration of samples containing nano-sized particles is a key parameter for researchers in many fields. qNano and qViro can determine the concentration of a wide range of particle types including mono and polydispersed populations. It provides rapid and accurate determination of:

• Bacteria count
• Virus count
• Amount of drug
• Drug delivery dosage
• Amount of viral aggregates
• Amount of bacteria and cellular fragments

Reaction Dynamics

Reaction dynamics include – identification and analysis of particle-particle, particle-biomolecule, functionalization and aggregation interactions.

The beginning, middle and end of interactions can be effectively mapped by analysing subtle changes in particle size, surface charge and concentration simultaneously and on a particle-by-particle basis, allowing interaction dynamics and yields to be determined.

This can be applied to many different situations:

• Confirmation of binding interactions and functionalization
• Comparison of sample properties prior to and post interaction
• Small molecule detection and diagnostics – binding reactions between small molecules and the surface of particles allows detection of molecules that may otherwise be below the detection limit of the instrument
• Comparison of properties after exposure to different experimental conditions, such as pH, ionic strength, amount of added reagents and temperature
• Real time monitoring of binding interaction events, particle-by-particle, by combining reactants in the top fluid cell

The latest version of Izon’s Control Suite Software v2.1, allows improved analysis of reactions as they occur over time.

Applications & Research Fields

Research fields which are currently using the qNano and qViro platforms include drug delivery research, virology, vaccinology, gene therapy, microvesicle analysis, nanoscience and industrial research applications, e.g. microfluidics research.^[16] The qViro and qNano instruments can be used in a wide range of research environments including laboratories, clinics and in the field.^[17]

Parts & Consumables

Nanopores

Izon's thermoplastic polyurethane nanopores are consumable items which fit to qNano and qViro instruments.

The nanopores are manufactured in a thermoplastic polyurethane cruciform using a proprietary technique. When fitted to the qNano or qViro instruments, the cruciform can be stretched evenly along the x and y axes to effect nanometre scale adjustments to the nanopore.

Fluid Cells

Each fluid cell is divided into two sections, the top and bottom sections of the fluid cell being connected together after the nanopore cruciform has been positioned between the two halves. The minimum volume of sample fluid required is 40μL.

Direct access points to the fluid in the upper and lower fluid cell compartments allows for easy and safe handling of samples.

An electrical connection is made to the bottom of the fluid cell via a shielded SMA connector. Silver chloride electrodes are fitted into the fluid cell. The fluid cell is designed with shielding to minimize electrical noise.

Variable Pressure Module

The variable pressure module (VPM) provides pressure and vacuum control of sample flow, complementing the electrophoretic operation of the qNano and qViro instruments. The application of pressure as a dominant force allows charged and uncharged particles to be detected by the system, as electrophoresis is no longer required for driving sample flow.

VPM also allows accurate concentration determination.

The additional sample flow generated by the VPM adds two orders of magnitude to the lower detection limit of the qNano and qViro instruments. Sample concentrations down to around 10^5 particles per mL may be measured.

By finely controlling and balancing electrophoretic and pressure forces exerted on the particle, detailed mobility and charge information can be extracted in a wide range of electrolyte environments.

The VPM was initially sold as an add-on module but now comes standard with qNano or qViro instruments.

References

External links

• Official Website