Journal of Materials Science and Nanomaterials
Open Access

Nanozymes; Antioxidants; Oxidative stress; Reactive oxygen species; Therapeutic potential; Enzyme mimetics

Introduction

Oxidative stress, defined as the imbalance between reactive oxygen species (ROS) production and the body’s antioxidant defense mechanisms, plays a pivotal role in the pathogenesis of numerous diseases, including neurodegenerative disorders, cancer, cardiovascular diseases, and diabetes. Excessive ROS levels damage cellular components such as lipids, proteins, and DNA, leading to disrupted cellular homeostasis and triggering pathological processes. As such, effective antioxidant strategies are imperative for mitigating oxidative stress and its detrimental effects [1]. Natural antioxidant enzymes, such as superoxide dismutase (SOD), catalase, and glutathione peroxidase, provide the first line of defense against ROS. However, their clinical applications are limited by instability, susceptibility to degradation, and challenges in large-scale production. The advent of nanozymes, nanomaterials exhibiting enzyme-like catalytic activities, offers a novel approach to mimic the activity of these natural enzymes. Since their discovery in 2007, nanozymes have garnered immense interest in the scientific community due to their robust catalytic properties, structural tunability, and cost-effectiveness [2]. Nanozymes exhibit diverse enzymatic activities, including oxidase, peroxidase, SOD-like, and catalase-like activities, depending on their composition, size, and surface modifications. For example, cerium oxide nanoparticles (CeO2) demonstrate reversible redox cycling between Ce3+ and Ce4+, enabling them to scavenge ROS effectively. Similarly, iron oxide nanoparticles and carbon-based nanozymes have shown promise as ROS neutralizers. These properties position nanozymes as versatile tools for combating oxidative stress [3]. The application of nanozymes extends beyond ROS neutralization. Their inherent stability and ease of surface functionalization allow for targeted delivery and enhanced biocompatibility, making them suitable for therapeutic interventions in diseases where oxidative stress plays a central role. Despite these advantages, challenges such as potential long-term toxicity, clearance mechanisms, and optimization of catalytic activity in physiological conditions remain to be addressed [4]. This review aims to delve into the mechanisms underlying nanozyme antioxidant activities, their therapeutic potential, and the challenges that need to be overcome to translate these nanomaterials into clinical settings. By exploring the latest advancements and highlighting future research directions, this paper seeks to provide a comprehensive understanding of nanozymes as promising antioxidant agents [5].

Results

Recent studies have significantly advanced our understanding of the mechanisms by which nanozymes exert their antioxidant effects. A key mechanism involves the catalytic decomposition of ROS through surface-mediated redox reactions. For instance, cerium oxide nanoparticles (CeO2) exhibit dynamic valence switching between Ce3+ and Ce4+, effectively neutralizing superoxide anions and hydrogen peroxide. Similarly, manganese oxide nanoparticles mimic superoxide dismutase by catalyzing the dismutation of superoxide radicals into oxygen and hydrogen peroxide. These activities are highly dependent on the structural and compositional properties of the nanozymes, which can be tuned through surface modifications and doping with other elements. In addition to direct ROS scavenging, nanozymes have demonstrated indirect antioxidant effects by modulating cellular signaling pathways. For example, platinum nanoparticles have been shown to upregulate the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, a key regulator of cellular antioxidant defenses. This dual mechanism of action-direct ROS neutralization and enhancement of endogenous antioxidant systems-positions nanozymes as highly effective agents for mitigating oxidative stress. Therapeutic applications of nanozymes have been explored in various disease models. In neurodegenerative diseases such as Alzheimer’s and Parkinson’s, nanozymes have shown promise in protecting neurons from oxidative damage and improving cognitive functions in animal models. Similarly, in cardiovascular diseases, nanozymes have been utilized to reduce oxidative damage in myocardial tissues and improve cardiac function. Despite these promising results, variability in therapeutic outcomes due to differences in nanozyme formulations and delivery methods underscores the need for standardization and optimization in future studies.

Discussion

The promising antioxidant properties of nanozymes offer exciting possibilities for their therapeutic applications. However, translating these nanomaterials into clinical practice requires addressing several challenges. One primary concern is biocompatibility and potential toxicity. While many studies report favorable safety profiles, long-term studies assessing bioaccumulation and off-target effects are limited. Additionally, optimizing the catalytic activity of nanozymes under physiological conditions is critical. Factors such as pH, ionic strength, and interaction with biomolecules can influence their efficacy. Surface modifications, such as PEGylation or functionalization with targeting ligands, have shown promise in enhancing biocompatibility and specificity [6]. Another challenge lies in achieving efficient delivery to target tissues. Nanoparticle size, surface charge, and circulation time are critical parameters influencing biodistribution and cellular uptake. Advances in nanocarrier technologies, including liposomes and polymeric nanoparticles, could improve the therapeutic efficacy of nanozymes by ensuring targeted and sustained delivery. Furthermore, understanding the interplay between nanozymes and cellular antioxidant pathways is essential for maximizing their therapeutic benefits while minimizing potential interference with physiological processes [7]. Future research should focus on developing high-throughput screening methods to identify nanozyme formulations with optimal antioxidant activity and safety profiles. Additionally, investigating the synergistic effects of combining nanozymes with conventional therapies could open new avenues for treatment strategies. By addressing these challenges, nanozymes have the potential to revolutionize antioxidant therapy and improve outcomes in oxidative stress-related diseases [8].

Conclusion

Nanozymes represent a groundbreaking advancement in the field of antioxidant therapy, offering robust catalytic activities, tunable properties, and versatile therapeutic applications. Their ability to neutralize ROS directly and modulate endogenous antioxidant pathways positions them as powerful tools against oxidative stress-related diseases. Despite significant progress in understanding their mechanisms and therapeutic potential, challenges such as biocompatibility, delivery efficiency, and long-term safety must be addressed to enable clinical translation. By leveraging advances in nanotechnology and interdisciplinary research, nanozymes could pave the way for novel and effective treatments for conditions driven by oxidative stress. Future efforts should focus on overcoming current limitations and exploring synergistic approaches to fully realize the potential of nanozymes as next-generation antioxidants.

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