Nanoparticle-Based Strategies to Combat COVID-19.

Coronavirus disease 2019 (COVID-19) is the worst pandemic disease of the current millennium. This disease is caused by the highly contagious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which first exhibited human-to-human transmission in December 2019 and has infected millions of people within months across 213 different countries. Its ability to be transmitted by asymptomatic carriers has put a massive strain on the currently available testing resources. Currently, there are no clinically proven therapeutic methods that clearly inhibit the effects of this virus, and COVID-19 vaccines are still in the development phase. Strategies need to be explored to expand testing capacities, to develop effective therapeutics, and to develop safe vaccines that provide lasting immunity. Nanoparticles (NPs) have been widely used in many medical applications, such as biosensing, drug delivery, imaging, and antimicrobial treatment. SARS-CoV-2 is an enveloped virus with particle-like characteristics and a diameter of 60-140 nm. Synthetic NPs can closely mimic the virus and interact strongly with its proteins due to their morphological similarities. Hence, NP-based strategies for tackling this virus have immense potential. NPs have been previously found to be effective tools against many viruses, especially against those from the Coronaviridae family. This Review outlines the role of NPs in diagnostics, therapeutics, and vaccination for the other two epidemic coronaviruses, the 2003 severe acute respiratory syndrome (SARS) virus and the 2012 Middle East respiratory syndrome (MERS) virus. We also highlight nanomaterial-based approaches to address other coronaviruses, such as human coronaviruses (HCoVs); feline coronavirus (FCoV); avian coronavirus infectious bronchitis virus (IBV); coronavirus models, such as porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome virus (PRRSV), and transmissible gastroenteritis virus (TGEV); and other viruses that share similarities with SARS-CoV-2. This Review combines the salient principles from previous antiviral studies with recent research conducted on SARS-CoV-2 to outline NP-based strategies that can be used to combat COVID-19 and similar pandemics in the future.