A team of researchers at the United States Naval Research Laboratory and National Center for Advancing Translational Sciences (NCATS) developed SARS-CoV-2 nanoparticle probes to delve deeper into the behavior of the virus.

These probes will be used to study fundamental interactions between SARS-CoV-2 spike proteins and human cells, as per the study published in the peer-reviewed science journal ACS Nano .

The study was titled ‘Quantum Dot-Conjugated SARS-CoV-2 Spike Pseudo-Virions Enable Tracking of Host Cell Surface Angiotensin-Converting Enzyme 2 Binding and Endocytosis’.

Eunkeu Oh, Ph.D., an NRL biophysicist and one of the authors, stated in the study: “We developed nanoparticle-based pseudo-virions that bind to the host cell and track themselves inside of cells without being contagious. This opens an opportunity to expand the same strategy to various other infectious diseases.”

Coronavirus proliferates in the human body by targeting ACE2 receptor cells and clings itself with ACE-2 via its external spike protein in order to multiply.

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The researchers worked to develop non-infectious probes to study SARS-CoV-2, the virus that has caused the ongoing pandemic.

Another author Mason Wolak, Ph.D., acting head of NRL’s Optical Nanomaterials Section, said in a statement: “Simply put, keeping the virus out of cells prevents it from replicating, propagating, and exacerbating infection.”

He added: “The ultimate goals of the collaboration are to clarify the fundamental mechanisms by which SARS-CoV-2 causes infection and to screen and identify potential drugs to inhibit these mechanisms.”

Scientists stressed on the importance of the quantum dot nanoparticles that are fluorescent in colour. The nanoparticles can be used to track and examine ACE2 receptor cells and their translocation.

Researchers mentioned in their study that the nanoparticle probes developed at NRL are comprised of multiple spike protein subunits attached to the surface of a light-emitting quantum dot core.

‘Pseudo-virions’

“We refer to these probes as ‘Pseudo-virions’ because they approximate the shape of the SARS-CoV-2 virus while also mimicking their physiological interactions with human cells,” said Wolak.

NRL and NCATS are currently designing and examining the feasibility of high-throughput cellular imaging tests to screen therapeutic agents for inhibition of Spike/ACE2 binding and internalisation.

Researchers noted that these tests would allow for screening of up to 1,536 drug targets per experiment.

Researchers are planning to investigate further the mechanism that makes the virus highly infectious with mutated spike proteins, authors mentioned in their research.