Antimicrobial Metal Nanomaterials: From Passive to Stimuli‐Activated Applications

Abstract

The development of antimicrobial drug resistance among pathogenic bacteria and fungi is one of the most significant health issues of the 21st century. Recently, advances in nanotechnology have led to the development of nanomaterials, particularly metals that exhibit antimicrobial properties. These metal nanomaterials have emerged as promising alternatives to traditional antimicrobial therapies. In this review, a broad overview of metal nanomaterials, their synthesis, properties, and interactions with pathogenic micro‐organisms is first provided. Secondly, the range of nanomaterials that demonstrate passive antimicrobial properties are outlined and in‐depth analysis and comparison of stimuli‐responsive antimicrobial nanomaterials are provided, which represent the next generation of microbiocidal nanomaterials. The stimulus applied to activate such nanomaterials includes light (including photocatalytic and photothermal) and magnetic fields, which can induce magnetic hyperthermia and kinetically driven magnetic activation. Broadly, this review aims to summarize the currently available research and provide future scope for the development of metal nanomaterial‐based antimicrobial technologies, particularly those that can be activated through externally applied stimuli.

Antibacterial and Antiviral Functional Materials: Chemistry and Biological Activity toward Tackling COVID-19-like Pandemics

“…Ensuring low or zero toxicity of NPs or polymeric composites when employing them as antimicrobial coatings or materials is one of the major challenging tasks. 27 Many reports comprehensively have presented the nanotoxicological evaluation data of antimicrobial nanomaterials and polymers and support the same. 420 , 425 , 426 In addition to the development of newer and more effective materials, future work in this area is also expected to focus on the control and evaluation of the toxicity of nanomaterials and polymers.…”

“…In the biomedical era, polymeric (synthetic and biopolymers) and nanomaterials including metal and metal oxide are gaining significant attention and dramatic progress due to their small size, large surface area, flexible surface modifications, unique biocidal delivery properties, loading capability, biodegradability, enhanced surface charge, self-assembly, smart release, and inherent antimicrobial properties. 27 , 388 , 411 − 418 In order to enhance their potential in specific biomedical field, their physicochemical properties and structural as well as biological characteristics need to be enhanced through doping, size control, and surface modifications. 27 , 60 , 419 Recently, few reports have analyzed the toxicity profile of antimicrobial polymers and nanomaterials.…”

“… 27 , 388 , 411 − 418 In order to enhance their potential in specific biomedical field, their physicochemical properties and structural as well as biological characteristics need to be enhanced through doping, size control, and surface modifications. 27 , 60 , 419 Recently, few reports have analyzed the toxicity profile of antimicrobial polymers and nanomaterials. 413 , 420 − 423 Hence, during the design of experiments, while preserving the biomedical functions of these polymeric or nanomaterials, toxicological evaluation should also be taken into consideration through preclinical and clinical tests of both in vivo and in vitro .…”

“…For example, one of the most common pathogen species called Candida causes hospital-acquired bloodstream infections in the United States, with around 400 000 cases a year worldwide, which are often associated with implanted medical devices. 27 , 30 , 31 Globally, the reported deaths due to antimicrobial-resistant infections is nearly 700 000 per year. 22 If new antibiotics are not developed to mitigate the rise of antimicrobial resistance, then by 2050, the world economy has to spend US$100 trillion on such infections and related issues which are predicted to affect the lives of more than 10 million people per year.…”

Synthesis, Properties, and Biological Applications of Metallic Alloy Nanoparticles

“…Au nanoparticles show antibacterial properties at 2 nm size and Ag nanoparticles offer higher antibacterial properties with triangle-shaped nanoplates compared to other shapes. The underlying mechanisms of bactericidal effects of nanoparticles are diverse; metal nanoparticles are proposed to hinder bacterial growth by affecting the bacterial cell surface, entering into bacterial cells and inducing reactive oxygen species (ROS), damaging DNA, proteins, or inhibiting enzyme activities [ 273 , 274 , 275 ].…”