Size and Zeta Potential Clicked Germination Attenuation and Anti-Sporangiospores Activity of PEI-Functionalized Silver Nanoparticles against COVID-19 Associated Mucorales (Rhizopus arrhizus).

The SARS-CoV-2 infections in Indian people have been associated with a mucormycotic fungal infection caused by the filamentous fungi Rhizopus arrhizus. The sporangiospores of R. arrhizus are omnipresent in the environment and cause infection through inhalation or ingestion of contaminated air and foods. Therefore, the anti-sporangiospore activity of polyethyleneimine functionalized silver nanoparticles (PEI-f-Ag-NPs) with variable size and surface charge as a function of the molecular weight of PEI was explored. The results showed that both PEI-f-AgNP-1 and PEI-f-AgNP-2, potentially, attenuated the germination and reduced the viability of sporangiospores. Furthermore, the results showed that the minimum inhibitory concentration (MIC) values of both PEI-f-AgNP-1 and PEI-f-AgNP-2 (1.65 and 6.50 µg/mL, respectively) were dependent on the nanoparticle size and surface ζ potentials. Similarly, the sporangiospore germination inhibition at MIC values was recorded, showing 97.33% and 94% germination inhibition, respectively, by PEI-f-AgNP-1 and 2 within 24 h, respectively. The confocal laser scanning microscopy, SEM-EDS, and confocal Raman spectroscopy investigation of PEI-f-Ag-NPs treated sporangiospores confirmed size and surface charge-dependent killing dynamics in sporangiospores. To the best of our knowledge, this is the first investigation of the polyethyleneimine functionalized silver nanoparticle-mediated size and surface charge-dependent anti-sporangiospore activity against R. arrhizus, along with a possible antifungal mechanism.

Novel photonic methods for diagnosis of SARS-CoV-2 infection.

The COVID-19 pandemic that began in March 2020 continues in many countries. The ongoing pandemic makes early diagnosis a crucial part of efforts to prevent the spread of SARS-CoV-2 infections. As such, the development of a rapid, reliable, and low-cost technique with increased sensitivity for detection of SARS-CoV-2 is an important priority of the scientific community. At present, nucleic acid-based techniques are primarily used as the reference approach for the detection of SARS-CoV-2 infection. However, in several cases, false positive results have been observed with these techniques. Due to the drawbacks associated with existing techniques, the development of new techniques for the diagnosis of COVID-19 is an important research activity. We provide an overview of novel diagnostic methods for SARS-CoV-2 diagnosis that integrate photonic technology with artificial intelligence. Recent developments in emerging diagnostic techniques based on the principles of advanced molecular spectroscopy and microscopy are considered.

Isoflavonoid-Antibiotic Thin Films Fabricated by MAPLE with Improved Resistance to Microbial Colonization.

Staphylococcus aureus (Gram-positive) and Pseudomonas aeruginosa (Gram-negative) bacteria represent major infectious threats in the hospital environment due to their wide distribution, opportunistic behavior, and increasing antibiotic resistance. This study reports on the deposition of polyvinylpyrrolidone/antibiotic/isoflavonoid thin films by the matrix-assisted pulsed laser evaporation (MAPLE) method as anti-adhesion barrier coatings, on biomedical surfaces for improved resistance to microbial colonization. The thin films were characterized by Fourier transform infrared spectroscopy, infrared microscopy, and scanning electron microscopy. In vitro biological assay tests were performed to evaluate the influence of the thin films on the development of biofilms formed by Gram-positive and Gram-negative bacterial strains. In vitro biocompatibility tests were assessed on human endothelial cells examined for up to five days of incubation, via qualitative and quantitative methods. The results of this study revealed that the laser-fabricated coatings are biocompatible and resistant to microbial colonization and biofilm formation, making them successful candidates for biomedical devices and contact surfaces that would otherwise be amenable to contact transmission.

Recent advances in carbon nanomaterials for biomedical applications: A review.

With the emergence of new pathogens like coronavirus disease 2019 and the prevalence of cancer as one of the leading causes of mortality globally, the effort to develop appropriate materials to address these challenges is a critical research area. Researchers around the world are investigating new types of materials and biological systems to fight against various diseases that affect humans and animals. Carbon nanostructures with their properties of straightforward functionalization, capability for drug loading, biocompatibility, and antiviral properties have become a major focus of biomedical researchers. However, reducing toxicity, enhancing biocompatibility, improving dispersibility, and enhancing water solubility have been challenging for carbon-based biomedical systems. The goal of this article is to provide a review on the latest progress involving the use of carbon nanostructures, namely fullerenes, graphene, and carbon nanotubes, for drug delivery, cancer therapy, and antiviral applications.

Novel Antimicrobial Surfaces to Defeat COVID-19 Transmission.

Antimicrobial surface coatings function as a contact biocide and are extensively used to prevent the growth and transmission of pathogens on environmental surfaces. Currently, scientists and researchers are intensively working to develop antimicrobial, antiviral coating solutions that would efficiently impede/stop the contagion of COVID-19 via surface contamination. Herein we present a flavonoid-based antimicrobial surface coating fabricated by laser processing that has the potential to eradicate COVID-19 contact transmission. Quercetin-containing coatings showed better resistance to microbial colonization than antibiotic-containing ones.

Rapid and label-free detection of COVID-19 using coherent anti-Stokes Raman scattering microscopy.

From the 1918 influenza pandemic (H1N1) until the recent 2019 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, no efficient diagnostic tools have been developed for sensitive identification of viral pathogens. Rigorous, early, and accurate detection of viral pathogens is not only linked to preventing transmission but also to timely treatment and monitoring of drug resistance. Reverse transcription-polymerase chain reaction (RT-PCR), the gold standard method for microbiology and virology testing, suffers from both false-negative and false-positive results arising from the detection limit, contamination of samples/templates, exponential DNA amplification, and variation of viral ribonucleic acid sequences within a single individual during the course of the infection. Rapid, sensitive, and label-free detection of SARS-CoV-2 can provide a first line of defense against the current pandemic. A promising technique is non-linear coherent anti-Stokes Raman scattering (CARS) microscopy, which has the ability to capture rich spatiotemporal structural and functional information at a high acquisition speed in a label-free manner from a biological system. Raman scattering is a process in which the distinctive spectral signatures associated with light-sample interaction provide information on the chemical composition of the sample. In this prospective, we briefly discuss the development and future prospects of CARS for real-time multiplexed label-free detection of SARS-CoV-2 pathogens.