Recent Advancements in the Formulation of Nanomaterials-Based Nanozymes, Their Catalytic Activity, and Biomedical Applications

Iridium nanoparticles supported on polyaniline nanotubes for peroxidase mimicking towards total antioxidant capacity assay of fruits and vegetables

In this study, a straightforward approach is presented for the first time to anchor Ir nanoparticles on the surface of uniform polyaniline (PANi) nanotubes (NTs), which can be used as an efficient peroxidase (POD)-like catalyst. The morphology and chemical structure of the PANi-Ir nanocomposite are characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffractometer (XRD), Raman and X-ray photoelectron spectroscopy (XPS) measurements. Owing to the strong interaction between Ir nanoparticles and PANi, a remarkable catalytic enhancement is achieved compared to the bare Ir black catalyst and individual PANi NTs, dominating withan electron transfer mechanism. Furthermore, an efficient colorimetric sensor for ascorbic acid (AA) is developed with a low detection limit of 1.0 μM (S/N = 3), and a total antioxidant capacity (TAC) sensing platform is also constructed for the rigorous detection and analysis of fruits and vegetables.

Advances in metal-organic framework-based nanozymes in ROS scavenging medicine

Reactive oxygen species (ROS) play important roles in regulating various physiological functions in the human body, however, excessive ROS can cause serious damage to the human body, considering the various limitations of natural enzymes as scavengers of ROS in the body, the development of better materials for the scavenging of ROS is of great significance to the biomedical field, and nanozymes, as a kind of nanomaterials which can show the activity of natural enzymes. Have a good potential for the development in the area of ROS scavenging. Metal-organic frameworks (MOFs), which are porous crystalline materials with a periodic network structure composed of metal nodes and organic ligands, have been developed with a variety of active nanozymes including catalase-like, superoxide dismutase-like, and glutathione peroxidase-like enzymes due to the adjustability of active sites, structural diversity, excellent biocompatibility, and they have shown a wide range of applications and prospects. In the present review, we first introduce three representative natural enzymes for ROS scavenging in the human body, methods for the detection of relevant enzyme-like activities and mechanisms of enzyme-like clearance are discussed, meanwhile, we systematically summarize the progress of the research on MOF-based nanozymes, including the design strategy, mechanism of action, and medical application, etc. Finally, the current challenges of MOF-based nanozymes are summarized, and the future development direction is anticipated. We hope that this review can contribute to the research of MOF-based nanozymes in the medical field related to the scavenging of ROS.

Sustainable Synthesis of Novel Green-Based Nanoparticles for Therapeutic Interventions and Environmental Remediation

The advancement in nanotechnology has completely revolutionized various fields, including pharmaceutical sciences, and streamlined the potential therapeutic of many diseases that endanger human life. The synthesis of green nanoparticles by biological processes is an aspect of the newly emerging scientific field known as "green nanotechnology". Due to their safe, eco-friendly, nontoxic nature, green synthesis tools are better suited to produce nanoparticles between 1 and 100 nm. Nanoformulation of different types of nanoparticles has been made possible by using green production techniques and commercially feasible novel precursors, such as seed extracts, algae, and fungi, that act as potent reducing, capping, and stabilizing agents. In addition to this, the biofunctionalization of nanoparticles has also broadened its horizon in the field of environmental remediation and various novel therapeutic innovations including wound healing, antimicrobial, anticancer, and nano biosensing. However, the major challenge pertaining to green nanotechnology is the agglomeration of nanoparticles that may alter the surface topology, which can affect biological physiology, thereby contributing to system toxicity. Therefore, a thorough grasp of nanoparticle toxicity and biocompatibility is required to harness the applications of nanotechnology in therapeutics.

Ultrasensitive cortisol electrochemical immunosensor amplifying by Au single-atom nanozymes and HRP enzymes

Cortisol, a corticosteroid hormone as a primary stress hormone response to internal and external stress, has been regarded as a gold standard reliable biomarker to evaluate human mental stress. The double enzymes strategy, using nanozyme and enzyme amplifying the electrochemical signal, has been widely used to improve the performance of electrochemical biosensors. An ultra-sensitive electrochemical cortisol sensor based on Au single-atom nanozymes had been fabricated through HRP labeled anti-cortisol antibody binding with Au by Au-S bond. Based on the high catalytic activity of Au single-atom nanozymes and the high selectivity of HRP-labeled anti-cortisol antibodies, the cortisol electrochemical sensor-based Au single-atom nanozymes had an excellent response to cortisol, such as high electrochemical activity, high sensitivity, high selectivity, and wide linear range (0.15-300 ng mL-1) and low detection (0.48 pg mL-1) through the four-parameter logistic model with 95% confidence. The electrochemical cortisol sensor was used to determine the cortisol concentration of human saliva at different times.

Insights of biopolymeric blended formulations for diabetic wound healing

Diabetic wounds (DWs) pose a significant health burden worldwide, with their management presenting numerous challenges. Biopolymeric formulations have recently gained attention as promising therapeutic approaches for diabetic wound healing. These formulations, composed of biocompatible and biodegradable polymers, offer unique properties such as controlled drug release, enhanced wound closure, and reduced scarring. In this review, we aim to provide a comprehensive overview of the current state of research and future prospects regarding the application of biopolymeric formulations for diabetic wound healing. The review begins by highlighting the underlying pathophysiology of DWs, including impaired angiogenesis, chronic inflammation, and compromised extracellular matrix (ECM) formation. It further explores the key characteristics of biopolymeric materials, such as their biocompatibility, biodegradability, and tunable physicochemical properties, which make them suitable for diabetic wound healing applications. The discussion further delves into the types of biopolymeric formulations utilized in the treatment of DWs. These include hydrogels, nanoparticles (NP), scaffolds, films, and dressings. Furthermore, the review addresses the challenges associated with biopolymeric formulations for diabetic wound healing. In conclusion, biopolymeric formulations present a promising avenue for diabetic wound healing. Their unique properties and versatility allow for tailored approaches to address the specific challenges associated with DWs. However, further research and developments are required to optimize their therapeutic efficacy, stability, manufacturing processes, and regulatory considerations. With continued advancements in biopolymeric formulations, the future holds great promise for improving the management and outcomes of DWs.

Nanozyme-assisted amplification-free CRISPR/Cas system realizes visual detection

The CRISPR (clustered regularly interspaced short palindromic repeats)/Cas (CRISPR associated) system has proven to be a powerful tool for nucleic acid detection due to its inherent advantages of effective nucleic acid identification and editing capabilities, and is therefore known as the next-generation of molecular diagnostic technology. However, the detection technologies based on CRISPR/Cas systems require preamplification of target analytes; that is, target gene amplification steps through isothermal amplification or PCR before detection to increase target analyte concentrations. This creates a number of testing limitations, such as extended testing time and the need for more sophisticated testing instruments. To overcome the above limitations, various amplification-free assay strategies based on CRISPR/Cas systems have been explored as alternatives, which omit the preamplification step to increase the concentrations of the target analytes. Nanozymes play a pivotal role in enhancing the sensitivity of CRISPR-based detection, enabling visual and rapid CRISPR assays. The utilization of nanozyme exceptional enzyme-like catalytic activity holds great promise for signal amplification in both electrochemical and optical domains, encompassing strategies for electrochemical signal sensors and colorimetric signal sensors. Rather than relying on converting a single detection target analyte into multiple analytes, these methods focus on signal amplification, the main mechanism of which involves the ability to form a large number of reporter molecules or to improve the performance of the sensor. This exploitation of nanozymes for signal amplification results in the heightened sensitivity and accuracy of detection outcomes. In addition to the strategies that improve sensor performance through the application of nanozymes, additional methods are needed to achieve visual signal amplification strategies without preamplification processes. Herein, we review the strategies for improving CRISPR/Cas systems that do not require preamplification, providing a simple, intuitive and preamplification-free CRISPR/Cas system detection platform by improving in-system one-step amplification programs, or enhancing nanozyme-mediated signal amplification strategies.