Thymol as Starting Material for the Development of a Biobased Material with Enhanced Antimicrobial Activity: Synthesis, Characterization, and Potential Application.

A biobased material, polythymol (PTF), was prepared using thymol, a monoterpene obtained from the essential oil of Thymus vulgaris (Lamiaceae), as a starting material with the aim of enhancing the antimicrobial properties of this natural product. Initially, different processes were performed in order to optimize the reaction conditions to obtain a macromolecule with a high purity and yield. PTF was characterized using different techniques, such as NMR, infrared, UV-Vis, and thermogravimetric analyses. The antimicrobial activity of both PTF and thymol was evaluated against different microorganisms, including S. aureus, E. coli, P. aeruginosa, and C. albicans. The obtained MIC values showed a higher potential for PTF than the monomer thymol-for example, against S. aureus (500 and 31.5 µg·mL-1 for thymol and PTF, respectively). Therefore, the obtained results show that the polymerization of thymol afforded more active biomaterial than the starting monomeric antimicrobial compound (thymol), suggesting that PTF is an important biomaterial.

Micro-Addition of Silver to Copper: One Small Step in Composition, a Change for a Giant Leap in Biocidal Activity.

The use of copper as an antimicrobial agent has a long history and has gained renewed interest in the context of the COVID-19 pandemic. In this study, the authors investigated the antimicrobial properties of an alloy composed of copper with a small percentage of silver (Cu-0.03% wt.Ag). The alloy was tested against various pathogens, including Escherichia coli, Staphylococcus aureus, Candida albicans, Pseudomonas aeruginosa, and the H1N1 virus, using contact exposure tests. Results showed that the alloy was capable of inactivating these pathogens in two hours or less, indicating its strong antimicrobial activity. Electrochemical measurements were also performed, revealing that the small addition of silver to copper promoted a higher resistance to corrosion and shifted the formation of copper ions to higher potentials. This shift led to a slow but continuous release of Cu2+ ions, which have high biocidal activity. These findings show that the addition of small amounts of silver to copper can enhance its biocidal properties and improve its effectiveness as an antimicrobial material.