COVID-19, neurovascular thrombotic problem and short summary on blood coagulation disorder: a brief review

Neuroinvasion of severe acute respiratory syndrome corona virus-2 (SARS-CoV-2): future risk of epilepsy

Central nervous system (CNS) infection is one of the important risk factors for epilepsy. COVID-19 pandemic, which is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has primarily been considered to involve respiratory system only, but it can also affect the CNS. A wide range of neurological manifestations have been reported in SARS-CoV-2 infected patients including seizures, status epilepticus, stroke, which are considered as important risk factors for the development of epilepsy. In post-mortem, brain tissue samples of COVID-19 patients have shown neuropathological changes and presence of SARS-CoV-2 RNA and viral proteins. In this review, mechanisms of SARS-CoV-2 neuroinvasion like neuronal retrograde trans-synaptic route and vascular route are described along with important neurological manifestations in COVID-19 patients such as seizures and cerebrovascular diseases, which have been found to be associated with the development of epilepsy. Hence, an increased risk of future burden of epilepsy in susceptible COVID-19 survivors has been proposed and preventive measures are suggested. The present review highlights about the possible association between neurological manifestations and future risk of epilepsy in COVID-19 patients.

Gold single atom-based aptananozyme as an ultrasensitive and selective colorimetric probe for detection of thrombin and C-reactive protein

An ultra-efficient biocatalytic peroxidase-like Au-based single-atom nanozyme (Au-SAzymes) has been synthesized from isolated Au atoms on black nitrogen doped carbon (Au-N-C) using a simple complexation-adsorption-pyrolysis method. The atomic structure of AuN4 centers in black carbon was revealed by combined high-resolution transmission electron microscopy/high-angle annular dark-field scanning transmission electron microscopy. The Au-SAzymes showed a remarkable peroxidase activity with 1.7 nM as Michaelis-Menten constant, higher than most previously reported SAzyme activity. Density functional theory and Monte Carlo calculations revealed the adsorption of H2O2 on AuN4 with formation of OH* and O*. Molecular recognition was greatly enhanced via label-free integration of thiol-terminal aptamers on the surface of single Au atoms (Aptamer/Au-SAzyme) to design off-on ultrasensitive aptananozyme-based sensor for detecting thrombin and CRP with 550 pM and 500 pg mL-1 limits of detection, respectively. The Aptamer/Au-SAzyme showed satisfactory accuracy and precision when applied to the serum and plasma of COVID-19 patients. Due to the maximum Au atom utilization, approximately 3636 samples can be run per 1 mg of gold, highlighting the commercialization potential of the developed Aptamer/Au-SAzyme approach.

Safety of COVID-19 Vaccines: Spotlight on Neurological Complications

The COVID-19 pandemic has led to unprecedented demand on the global healthcare system. Remarkably, at the end of 2021, COVID-19 vaccines received approvals for human use in several countries worldwide. Since then, a solid base for response in the fight against the virus has been placed. COVID-19 vaccines have been shown to be safe and effective drugs. Nevertheless, all kinds of vaccines may be associated with the possible appearance of neurological complications, and COVID-19 vaccines are not free from neurological side effects. Neurological complications of COVID-19 vaccination are usually mild, short-duration, and self-limiting. However, severe and unexpected post-vaccination complications are rare but possible events. They include the Guillain-Barré syndrome, facial palsy, other neuropathies, encephalitis, meningitis, myelitis, autoimmune disorders, and cerebrovascular events. The fear of severe or fatal neurological complications fed the “vaccine hesitancy” phenomenon, posing a vital communication challenge between the scientific community and public opinion. This review aims to collect and discuss the frequency, management, and outcome of reported neurological complications of COVID-19 vaccines after eighteen months of the World Health Organization’s approval of COVID-19 vaccination, providing an overview of safety and concerns related to the most potent weapon against the SARS-CoV-2.