Abstract:

Clay minerals have been widely utilized for industrial materials manufacturing and environmental remediation of heavy metals and organic contaminants, largely due to their layered structures and outstanding physio-chemical properties. In the medical field, antibiotic overuse has led to increased antimicrobial resistance, causing global concerns over antibiotic effectiveness. Thus it has become imperative to develop new bactericidal materials. The biomedical application of clay for treating wound abscesses, dyspepsia and joint inflammation has long been known, yet in-depth analysis of its antibacterial mechanisms has only been possible with the advancement of modern analytical methods. In the last decade, clays collected worldwide are shown to have broad-spectrum bactericidal activity, and such activity is closely associated with metal toxicity, structural Fe(II), surface charge and reactive oxygen species (ROS, generated by oxygen exposure) in clays. Besides, clay materials can be used as effective drug carrier for preparing antibacterial nanocomposite to enhance the physical property and activity of bactericidal agents. This article summarizes the recent studies on antibacterial activities and bactericidal processes and mechanisms of naturally reduced iron-containing clays, discusses the shared characteristics among clays with distinct antibacterial capabilities, and briefly describes the bactericidal activities of nanocomposites based on clays as carriers, aiming to address the current challenges and future development of antibacterial clays.

Key words: clay minerals, antibacterial activities, bactericidal mechanisms, medical development