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Nanoparticle Tracking Analysis is a method that allows for the visualization and analysis of nanoparticles within a liquid which depends on the rate of Brownian motion related to particle size.
This is important within the field of medicine due to requiring characterization of nanosized particles that can be used to carry drugs, such as polymer-based or virus-like particles or lipid-based carriers.
Most macromolecular drugs which include proteins, peptides, DNA or RNA are administered in a drug delivery system such as through injections; this is due to the susceptibility oral administration has to enzymatic degradation and low absorption levels.
This illustrates the significance of this method as nano-sized colloidal particle characterization ensures the quality and stability of these integral drug carriers. This article will provide an overview of this technique and its applications in the field of medicine.
The Nanoparticle Tracking Analysis (NTA) technique utilizes a combination of laser light scattering microscopy and a charge-coupled device camera, allowing the visualization and recording of the nanoparticles in a liquid. This technique was first commercialized in 2006 as an innovative sizing system for particles that range from 30 to 1000 nm in size.
How does it work?
The particles held within a solution are loaded into a sample chamber which is directly accessible by a laser diode that causes laser light to scatter when the particles move into the path of the beam. The scattering of light is known as the Tyndall effect and this fluctuation of the light signal is collected by the microscope and viewed with the digital camera which records the movement of these particles.
The NTA utilizes software to identify and track each particle moving under Brownian motion which is then related to the particle size in accordance with a formula derived from the Stokes-Einstein equation that calculates their hydrodynamic diameters.
This technique provides high-resolution nanoparticle size as well as aggregation measurements, with a fluorescent mode that can assist labeled particles with specific results. The subtle changes in characteristics of particles can also be analyzed through real-time monitoring.
Benefits of NTA
The advantages of this nanoparticle tracking analysis technique consist of low sample volumes and little sample preparation along with low volumes of consumables required which also reduces daily costs. The non-destructive advantage of this method also allows the sample to be recovered and used if required for any reason.
The Significance of NTA
This nanoparticle tracking analysis is integral to the advancement of the field of medicine as it enables the characterization of nano-sized particles which hold such significant roles.
A study conducted in Austria by Peneder et al used NTA to create and determine silver and gold nanoparticles through a combination of sodium citrate solution and silver nitrate and gold salt, respectively. The use of NTA, as well as spectrophotometry, enabled the stability of the nanoparticles to be monitored over time as well as their size, determined.
The importance of both size and stability of nanoparticles lies within their applications, with size determining the roles these particles play in medicine, while the stability ensures their reliability. Both these properties are integral to the advancement of medicine, as creating these nanoparticles with differing sizes allows them to be used for various purposes.
While nano-sized particles are used for injection-based drug delivery, there is also more research into using nanoparticles for a more targeted drug delivery approach. A benefit of using nano-sized particles is the natural interaction these particles have with other cells which are of similar size, this can enable more targeted cell therapies. This high precision advantage of nanoparticles has in turn driven research into nanoparticle encapsulation of chemotherapy drugs which would impact the overall experience of chemotherapy as a treatment, decreasing systemic toxicity and improving quality of life.
Crossing of the Blood-Brain Barrier
The NTA method can determine the size of these particles which is integral for this purpose as the smaller the particle, the easier it is for it to travel to different areas in the body, such as the brain, through crossing the blood-brain barrier.
This would be beneficial when providing drugs to the brain due to the nanosize of these particles as it would enable drugs that would normally be too large to travel to the brain in their current state to be able to surpass this challenge. This would be a significant application for various different conditions, from cancers to mental health treatments.
The crossing of this previously near-impossible barrier can also enable more targeted brain tumor identification.
The high atomic number of nanoparticles boosts imaging signals and this can cause more X-ray interactions and along with their high surface area, can help to target tumor tissue more readily, thus aiding a more targeted radiotherapy delivery treatment. This targeted approach to specific areas would enable less harm to healthy tissue as well as assist with adjuvant chemotherapy.
The stability of these particles is also important as it determines how long they can stay in the body, and this can be determined through NTA. This analysis can allow the nanoparticle stability to be manipulated for drug delivery purposes through predicting the breakdown of these particles once it has reached its target area.
The NTA technique can be seen as being beneficial for the advancement of nanomedicine with the characterization of these particles being accurately sized and monitored for various purposes, ensuring the reliability of these particles when used within medicine.
References and Further Reading
Chen, Y., Yang, J., Fu, S. and Wu, J., 2020. Gold Nanoparticles as Radiosensitizers in Cancer Radiotherapy. International Journal of Nanomedicine, Volume 15, pp.9407-9430. https://dx.doi.org/10.2147%2FIJN.S272902
Filipe, V., Hawe, A. and Jiskoot, W., 2010. Critical Evaluation of Nanoparticle Tracking Analysis (NTA) by NanoSight for the Measurement of Nanoparticles and Protein Aggregates. Pharmaceutical Research, 27(5), pp.796-810. https://doi.org/10.1007/s11095-010-0073-2
Peneder, H., Punz, E., Joubert, I.A., Geppert, M., & Himly, M. (2020). Nanoparticle tracking analysis. Open Schools Journal for Open Science, 3(2). https://doi.org/10.12681/osj.22598