Nanosponges could provide a broad acting countermeasure to Covid-19
There development of therapeutics and preventative measures for addressing Covid-19 is a pressing issue. However, according to a group of researchers in the US, the rapid rate of mutation will pose a major challenge to the development of treatments.
Inspired by the fact that the infectivity of SARS-CoV-2 relies on its binding with protein receptors on the target cells, US scientists from University of California San Diego, La Jolla and Boston University School of Medicine, Boston, Massachusetts, have created cellular nanosponges as a medical counter measure to the coronavirus. The work has been published in Nano Letters.
The nanosponges are comprised of human-cell-derived membranes, sourced from cells that are naturally targeted by SARS-CoV-2. These cells are wrapped around polymeric nanoparticle cores. The resulting nanosponges inherit the surface antigen profiles of the source cells and serve as decoys to bind with SARS-CoV-2. Such binding interaction blocks viral entry and inhibits viral infectivity. The nanosponges display the same receptors that the viruses depend on for cellular entry. The theory, say the researchers, is that upon binding with the nanosponges, the corona viruses are unable to infect their usual cellular targets.
To evaluate the toxicity of the nanosponges through testing in mice, the researchers investigated the intratracheal route of administration using the highest feasible nanosponge dose. The investigations confirmed the short-term safety of cellular nanosponges.
The researchers said that the nanosponge platform offers a unique benefit over other therapies currently in development for covid-19; in that the nanosponges are mutation and potentially virus agnostic. In principle, as long as the target of the virus remains the identified host cell, the nanosponges will be able to neutralise the infection, providing a broad acting countermeasure resistant to mutations. The researchers are conducting further validation using appropriate animal models; this will pave the way for human clinical trials in the future.