Recent Advances on Nanomaterials for Diagnostic, Treatment, and Prevention of COVID-19

Introduction

The emergence of the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) virus, also known as COVID-19 (Coronavirus disease 2019), toward the end of 2019, was one of the events that redefined our medical safety globally (Khan, 2021). It is an infectious illness (Choi, 2020). Since its discovery, researchers have undertaken countless activities dedicated to the prevention, treatment, and diagnosis of this virus. Several scientific publishing houses joined forces to disseminate the latest developments related to COVID-19. Immediately, pharmaceutical laboratories and research centers looked for solutions to offer alternatives that would allow the world population to return to normality before the appearance of the virus. One of the most important tasks was the development of vaccines that would allow the virus’s transmission to be halted, at least for the known variants (Chauhan, 2020; Chung, 2020; Shin, 2020). Fortunately, several pharmaceutical companies are offering vaccine alternatives that seek to immunize the world's population. Unfortunately, the security problem has not been completely solved, since not all countries have the same economic and health possibilities. In addition, multiple variants of the virus have emerged in different countries and it is not yet possible to establish whether the vaccines will eliminate the current risk. Some experts comment on the possibility that this event is the beginning of a novel health strategy that will force a permanent change in the way things have been done so far (Kostarelos, 2020; Pathak, 2021).

Coronaviruses are a type of virus that causes illness in the upper respiratory system and can cause more serious problems than a regular cold (Antiochia, 2021). Hundreds of coronaviruses have been found so far, with camels, pigs, cats, dogs, and bats being the most common carriers. However, through a mechanism known as spillover, these coronaviruses can sometimes reach humans (HCoV) and cause sickness. A total of seven HCoVs have been discovered and classified into two groups. The common flu is caused by the first group of viruses, which includes HCoV-HKU1, HCoV-OC43, HCoV-NL63, and HCoV-229E, which is considered a mild illness. The MERS coronavirus (MERS-CoV), the SARS coronavirus (SARS-CoV), and the new SARS coronavirus (SARS-CoV-2) are all members of the second category, and they all have catastrophic consequences that can even lead to death.

As a complement to the pharmaceutical strategy of vaccines, researchers are using nanotechnology and specifically nanomaterials to develop solutions that allow the prevention, treatment, and diagnosis of COVID-19 (Rai, M. 2020; Rai, P.K. 2020; Tang, 2021). Until now, the first test for COVID-19 has been based on a real-time reverse-transcription polymerase chain reaction (RT-PCR). This detection takes about 3 to 8 hours, and its reagent kits as well as the infrastructure to install and measure many samples, and its low effectiveness in detecting asymptomatic patients make it impractical (Adhikari, 2020). Other quick tests based on the detection of human stool, blood serum, antibodies, or nasal swabs to identify COVID-19 in about 30 minutes have been proposed, however, they rely on certain test patterns and stages of infection to make a sure diagnosis. COVID-19 is diagnosed at the point of care using protein and nucleic acid-based test kits. As of April 2020, 29 therapeutic drugs had been proposed to treat COVID-19. Only Favipiravir, Chloroquine, Hydroxychloroquine, and Remdersivir have been examined for antiviral cases, and the results were promising. The use of these drugs depends on person to person, due to the pre-existing medical conditions of the patient.