Molecularly imprinted polymer-based nanodiagnostics for clinically pertinent bacteria and virus detection for future pandemics

There seems to be a growing curiosity for utilizing MIPs to recognize molecules that can be applied in numerous fields, such as biomimetic antibodies, detection of viruses and bacteria, the broad range of sensing devices, etc., owing to its scalability and economic viability. MIPs have higher thermal and chemical stability, delivering a promising potential for recognizing bacteria and viruses. The bacteria and virus imprinted polymer exhibit elongated product life-time, reproducible fabrication, robustness, reusability, sensitivity, and high target selectivity. Moreover, the MIPs could give consistent screening along with negligible false positive/negative outcomes, which is vital for the control and prevention of viral and bacterial infections. In the viral and bacterial imprinting process, critical aspects, such as compositional complexity, fragility, solubility, and target size, should be systematically evaluated and analytically considered. Although, the application of MIPs has a number of drawbacks and challenges that require solving to develop sensing platforms with high specificity and sensitivity for clinical application. In the present review, current progress and advancement regarding the reasoning and applications of MIPs as recognition molecules in various biosensors for detecting bacteria and viruses and its existing noteworthy challenges along with future perspectives are also reflected.

Identification of potent inhibitors of SARS-CoV-2 exoribonuclease by fluorescence polarization assay

The emergence of SARS-CoV-2 has triggered a pandemic with devastating consequences to the world. One of the proteins essential to the virus life cycle is nsp14, which is a bifunctional protein that encodes a 3'to 5' exoribonuclease activity in its N-terminus, and a methyl transferase activity in its C-terminus. Nsp14 in complex with the accessory protein nsp10 is involved in a proofreading mechanism that ensures the genetic stability of its massive viral genome, and is associated to the resistance against nucleotide analogs targeting the polymerase nsp12. Because of its key role, nsp14-nsp10 complex constitutes an attractive target for antiviral development. Here we present a fluorescence polarization (FP) assay development to measure the exoribonuclease activity and its inhibition in vitro. The FP method is sensitive, robust, amenable to miniaturization and offers confirmation by visualizing the degradation of the fluorescent RNA in acrylamide gels. We performed a screening of a focused library of 113 metal chelators at 20 and 5 μM compound concentration and IC50 measurement of 9 hits showing efficiency at micromolar level. We also tested the focused library in SARS-CoV-2 infected Vero cells and we confirmed 3 hits previously detected in the in vitro screening out of 6 promising inhibitors. In conclusion the FP method proposed is a reliable tool to discover inhibitors of the SARS-CoV-2 exoribonuclease activity and will help to find new antivirals to be used in combination with nucleoside analogs.

A Review of Dietary Intake of Acrylamide in Humans.

The dietary intake of acrylamide (AA) is a health concern, and food is being monitored worldwide, but the extent of AA exposure from the diet is uncertain. The aim of this review was to provide an overview of estimated dietary intake. We performed a PubMed search identifying studies that used dietary questionnaires and recalls to estimate total dietary AA intake. A total of 101 studies were included, corresponding to 68 original study populations from 26 countries. Questionnaires were used in 57 studies, dietary recalls were used in 33 studies, and 11 studies used both methods. The estimated median AA intake ranged from 0.02 to 1.53 µg/kg body weight/day between studies. Children were represented in 25 studies, and the body-weight-adjusted estimated AA intake was up to three times higher for children than adults. The majority of studies were from Europe (n = 65), Asia (n = 17), and the USA (n = 12). Studies from Asia generally estimated lower intakes than studies from Europe and the USA. Differences in methods undermine direct comparison across studies. The assessment of AA intake through dietary questionnaires and recalls has limitations. The integration of these methods with the analysis of validated biomarkers of exposure/internal dose would improve the accuracy of dietary AA intake exposure estimation. This overview shows that AA exposure is widespread and the large variation across and within populations shows a potential for reduced intake among those with the highest exposure.