Green synthesis of Cu/zirconium silicate nanocomposite by using Rubia tinctorum leaf extract and its application in the preparation of N ‐benzyl‐ N ‐arylcyanamides

Development of Biologically Active Phytosynthesized Silver Nanoparticles Using Marrubium vulgare L. Extracts: Applications and Cytotoxicity Studies

Metal nanoparticle phytosynthesis has become, in recent decades, one of the most promising alternatives for the development of nanomaterials using "green chemistry" methods. The present work describes, for the first time in the literature, the phytosynthesis of silver nanoparticles (AgNPs) using extracts obtained by two methods using the aerial parts of Marrubium vulgare L. The extracts (obtained by classical temperature extraction and microwave-assisted extraction) were characterized in terms of total phenolics content and by HPLC analysis, while the phytosynthesis process was confirmed using X-ray diffraction and transmission electron microscopy, the results suggesting that the classical method led to the obtaining of smaller-dimension AgNPs (average diameter under 15 nm by TEM). In terms of biological properties, the study confirmed that AgNPs as well as the M. vulgare crude extracts reduced the viability of human gingival fibroblasts in a concentration- and time-dependent manner, with microwave-assisted extracts having the more pronounced effects. Additionally, the study unveiled that AgNPs transiently increased nitric oxide levels which then decreased over time, thus offering valuable insights into their potential therapeutic use and safety profile.

Plant Extract-Based Synthesis of Metallic Nanomaterials, Their Applications, and Safety Concerns

Nanotechnology has attracted the attention of researchers from different scientific fields because of the escalated properties of nanomaterials compared with the properties of macromolecules. Nanomaterials can be prepared through different approaches involving physical and chemical methods. The development of nanomaterials through plant-based green chemistry approaches is more advantageous than other methods from the perspectives of environmental safety, animal, and human health. The biomolecules and metabolites of plants act as reducing and capping agents for the synthesis of metallic green nanomaterials. Plant-based synthesis is a preferred approach as it is not only cost-effective, easy, safe, clean, and eco-friendly but also provides pure nanomaterials in high yield. Since nanomaterials have antimicrobial and antioxidant potential, green nanomaterials synthesized from plants can be used for a variety of biomedical and environmental remediation applications. Past studies have focused mainly on the overall biogenic synthesis of individual or combinations of metallic nanomaterials and their oxides from different biological sources, including microorganisms and biomolecules. Moreover, from the viewpoint of biomedical applications, the literature is mainly focusing on synthetic nanomaterials. Herein, we discuss the extraction of green molecules and recent developments in the synthesis of different plant-based metallic nanomaterials, including silver, gold, platinum, palladium, copper, zinc, iron, and carbon. Apart from the biomedical applications of metallic nanomaterials, including antimicrobial, anticancer, diagnostic, drug delivery, tissue engineering, and regenerative medicine applications, their environmental remediation potential is also discussed. Furthermore, safety concerns and safety regulations pertaining to green nanomaterials are also discussed. This article is protected by copyright. All rights reserved.