Nanoparticles are of interest in medicine for the targeted delivery of drugs or vaccines deep into the body. For such purposes, the concentration of the tiny particles must be known as precisely as possible. An analytical measurement system has now been developed in a collaboration between the Physikalisch-Technische Bundesanstalt (PTB) and the company LUM GmbH in Berlin. It measures the light that is scattered by each individual nanoparticle in various directions. The system can be used for nanoparticles with a size of around 40 nm up to microparticles of approx. 10 µm.
In the single particle counter, the suspension is injected into the conical area of the flow-through cuvette using a cannula and then accelerated by the taper and the surrounding sheath flow. This separates the particles along the direction of flow and most of them pass the laser focus individually. The scattered light is measured for each particle in the direction of the laser beam (forward scattering) and perpendicular to it (sideways scattering).
Medicine has high hopes for nanoparticles: for example, they could be used as vehicles to help drugs overcome biological barriers such as the air-blood or blood-brain barrier.
Conversely, nanoparticles place great demands on measurement technology, which is needed for product development, production quality control and, last but not least, for product risk assessment.
The first devices are already in use at a global pharmaceutical company in the EU for the development of a coronavirus vaccine and at a renowned German research institute.
Source: es/ptb / Dr. Martin Hussels
