Chennai: Ultrasmall sponge-like particles covered by human lung and immune cell membranes can attract, soak up, and neutralise the novel coronavirus, according to a lab study. This may lead to new therapies for Covid-19.
The research, published in the journal Nano Letters, says that these nanosponges, which are thousand times smaller than the width of a single human hair, are named so as they soak up harmful pathogens and toxins.
These particles were developed by engineers, including those from the University of California (UC) San Diego in the US, for their ability to prevent the novel coronavirus, SARS-CoV-2, from hijacking host cells.
Following incubation with the nanosponges, the researchers said, “SARS-CoV-2 is neutralized and unable to infect cells.”
In experiments performed on lab-grown cells, they said nanosponges built with lung and immune cell membranes caused SARS-CoV-2 to lose nearly 90 per cent of its ‘viral infectivity” in a dose-dependent manner.
The researches explained that viral infectivity is a measure of the ability of a virus to enter the host cell and exploit its resources to replicate and produce additional infectious copies of itself.
According to study co-author Liangfang Zhang, a nanoengineering professor at the UC San Diego, “Traditionally, drug developers for infectious diseases dive deep on the details of the pathogen in order to find druggable targets. Our approach is different.”
He added: “We only need to know what the target cells are. And then we aim to protect the targets by creating biomimetic decoys.”
The scientists explained that instead of targeting the virus itself, the nanosponges are designed to protect the healthy cells which the virus invades.
They said the nanosponges when engineered with fragments of the outer membranes of the human immune system’s macrophage cells can also soak up inflammatory cell-cell signalling proteins called cytokines.
The scientists said that the cytokines, which are sometimes overdriven by immune response to the infection, are implicated in some of the most dangerous, and sometimes deadly, aspects of Covid-19.
Explaining the structure of the nanosponges, the researchers said they consist of a polymer core coated in membranes extracted from either the cells lining the lung’s outer layer, or the immune system’s macrophages.
They said these membranes cover the sponges with all the same protein receptors as the cells they impersonate, adding that this includes whatever receptors the novel coronavirus uses to enter cells in the human body.