Nanozymes to fight the COVID-19 and future pandemics

International audienceIn 2019, the pandemic induced by the rapid spread of the severe acute respiratory syndrome coronavirus-2 'SARS-CoV-2', also named coronavirus disease 'COVID-19', has rapidly caused serious health, economic, social, and political issues worldwide. This has been accentuated by asymptomatic carriers, fast viral mutations, incoherent lockdown policies, and limited methods of detection and treatment. Nucleic acid tests for COVID-19 are lengthy and complicated, and the rapid antibody tests produce false-negative diagnoses, particularly in the early stage of infection. Moreover, there are no specific and effective medicines available for treatment. Therefore, rapid diagnostics and therapeutics are urgently required. Here, we argue that nanozymesenzyme-mimicking nanoparticles-could be used for faster, more sensitive, and accurate detection and treatment of the COVID-19. Indeed, nanozymes have high surface areas allowing easier bioconjugation for detection, and nanozymes possess integrated drug-functionalization for treatment. Moreover, the size, composition, and surface chemistry of nanozymes can be rationally designed for improved theranostic applications

Smart nanomaterials for cancer diagnosis and treatment

AbstractInnovations in nanomedicine has guided the improved outcomes for cancer diagnosis and therapy. However, frequent use of nanomaterials remains challenging due to specific limitations like non-targeted distribution causing low signal-to-noise ratio for diagnostics, complex fabrication, reduced-biocompatibility, decreased photostability, and systemic toxicity of nanomaterials within the body. Thus, better nanomaterial-systems with controlled physicochemical and biological properties, form the need of the hour. In this context, smart nanomaterials serve as promising solution, as they can be activated under specific exogenous or endogenous stimuli such as pH, temperature, enzymes, or a particular biological molecule. The properties of smart nanomaterials make them ideal candidates for various applications like biosensors, controlled drug release, and treatment of various diseases. Recently, smart nanomaterial-based cancer theranostic approaches have been developed, and they are displaying better selectivity and sensitivity with reduced side-effects in comparison to conventional methods. In cancer therapy, the smart nanomaterials-system only activates in response to tumor microenvironment (TME) and remains in deactivated state in normal cells, which further reduces the side-effects and systemic toxicities. Thus, the present review aims to describe the stimulus-based classification of smart nanomaterials, tumor microenvironment-responsive behaviour, and their up-to-date applications in cancer theranostics. Besides, present review addresses the development of various smart nanomaterials and their advantages for diagnosing and treating cancer. Here, we also discuss about the drug targeting and sustained drug release from nanocarriers, and different types of nanomaterials which have been engineered for this intent. Additionally, the present challenges and prospects of nanomaterials in effective cancer diagnosis and therapeutics have been discussed.</jats:p

Surface Engineered Peroxidase-Mimicking Gold Nanoparticles to Subside Cell Inflammation

The smart design of nanoparticles with varying surfaces may open a new avenue for potential biomedical applications. Consequently, several approaches have been established for controlled synthesis to develop the unique physicochemical properties of nanoparticles. However, many of the synthesis and functionalization methods are chemical-based and might be toxic to limit the full potential of nanoparticles. Here, curcumin (a plant-derived material) based synthesis of gold (Au) nanoparticles, followed by the development of a suitable exterior corona using isoniazid (INH, antibiotic), tyrosine (Tyr, amino acid), and quercetin (Qrc, antioxidant), is reported. All these nanoparticles (Cur-Au, Cur-AuINH, Cur-AuTyr, and Cur-AuQrc) possess inherent peroxidase-mimicking natures depending on the surface corona of respective nanoparticles, and they are found to be excellent candidates for free radical scavenging action. The peroxidase-mimicking nanoparticle interactions with red blood cells and mouse macrophages confirmed their hemo- and biocompatible nature. Moreover, these surface-engineered Au nanoparticles were found to be suitable in subsiding key pro-inflammatory cytokines such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β). The inherent peroxidase-mimicking behavior and anti-inflammatory potential without any significant toxicity of these nanoparticles may open new prospects for nanomedicine