<p>Simple Approaches for the Synthesis of AgNPs in Solution and Solid Phase Using Modified Methoxypolyethylene Glycol and Evaluation of Their Antimicrobial Activity</p>

Abstract

Purpose: Simple methodology for preparation of metal nanoparticles such as AgNPs uses an methanolic aqueous medium at room temperature or a solvent-free procedure under microwave irradiation. The prepared AgNPs showed a significant antimicrobial effect against Gram-positive bacteria, Gram-negative bacteria, and fungi. Methods: The modified methoxypolyethylene glycol bishydrazino-s-triazine (mPEGTH2) showed remarkable activity for reducing Ag + to Ag 0 in an aqueous methanolic solution and using a solvent-free method (solid phase) under microwave irradiation. In the solid phase synthesis, the size and shape of the AgNPs can be controlled by varying the weight ratio of mPEGTH2 to AgNO 3 used. In addition, the antimicrobial activity depends on the ratio of mPEGTH2 to AgNO 3. The mPEGTH2-AgNPs (2:1) demonstrated higher antimicrobial activity compared to mPEGTH2-AgNPs (1:1) against Gram-positive bacteria, Gram-negative bacteria, and C.albicans. Results: This work presents simple methods for the synthesis of AgNPs using modified methoxypolyethylene glycol with bishydrazino-s-triazine (mPEGTH2); a solution method, using methanol-water medium at room temperature, and a solvent-free (solid phase) method, employing microwave irradiation or direct heating which could be used for the preparation of AgNPs on large scale. In the solid phase, ratios of mPEGTH2 to AgNO 3 (1:1 or 2:1, respectively) are very important to control the size and shape of AgNPs. While in solution phase is not necessary where the molar ratio used is 10:1. Most of the experimental methods resulted in AgNPs ranging in size from 7 to 10 nm as observed from XRD and TEM characterization. The antimicrobial activity of the AgNPs was also dependent on the weight ratio of mPEGTH2 to AgNO 3 , with a large effect as observed when using the solvent-free method. The mPEGTH2-AgNPs (2:1) demonstrated higher antimicrobial activities compared to mPEGTH2-AgNPs (1:1) against S. aureus, S. epidermidis, E. faecalis, E. coli, P. aeruginosa, S. typhimurium, and C. albicans. In all cases, the MICs and MBCs of mPEGTH2-AgNPs (1:1) were lower than those of mPEGTH2-AgNPs (2:1). Conclusion: In summary, mPEGTH2-AgNPs (2:1) is a promising candidate to kill pathogenic microbes. In particular, the method used for the preparation of AgNPs by using polyethylene glycol polymer modified with bishydrazino-s-triazine has the most potential and would be the most cost-effective method. This method of the synthesis of nanoparticles may be suitable for the preparation of other metal nanoparticles, which would allow for numerous applications in medicinal and industrial.

Electrochemistry as a Complementary Technique for Revealing the Influence of Reducing Agent Concentration on AgNPs

“…Nanomaterials appear to have a vital role in materials science, chemistry, physics, and medicine, already finding applications in several fields, including therapeutic, diagnostic, and sensors. − According to research, the preparation of nanoparticles depends on many experimental conditions, including the choice of a reducing agent. Understanding the reasons for the aggregation, shape, surface, and change of size of nanoparticles after integration into a target application is critical for optimizing performance.…”

Green synthesis of silver nanoparticles through oil: Promoting full-thickness cutaneous wound healing in methicillin-resistant Staphylococcus aureus infections

“…The SEM result discovered Lceo-AgNPs damaged bacteria form and the dead bacteria residue huddled together. The interaction and adhesion of AgNPs with bacterial surface could modify cell wall structure, induce intracellular production of reactive oxygen species (ROS), disrupt plasma membrane, alter protein interactions, obstruct DNA replication, and damage the macromolecules (lipids, proteins, DNA, and RNA) ( Patra and Baek, 2017 ; El-Faham et al, 2020 ). Up to now, AgNPs have been unable to induce resistance in any bacterial strains tested, which have been approved by the US Food and Drug Administration (FDA) as a fungicide for burn wound dressings ( Mao et al, 2016 ).…”