Synthesis and comparative study on the antimicrobial activity of hybrid materials based on silver nanoparticles (AgNps) stabilized by polyvinylpyrrolidone (PVP)

Abstract

Hybrid materials based on polyvinylpyrrolidone (PVP) with silver nanoparticles (AgNps) were synthesized applying two different strategies based on thermal or chemical reduction of silver ions to silver nanoparticles using PVP as a stabilizer. The formation of spherical silver nanoparticles with diameter ranging from 9 to 16 nm was confirmed by TEM analysis. UV-vis and FTIR spectroscopy were also applied to confirm the successful formation of AgNps. The antibacterial activity of the synthesized AgNPs/PVP against etalon strains of three different groups of bacteria-Staphylococcus aureus (S. aureus; grampositive bacteria), Escherichia coli (E. coli; gram-negative bacteria), Pseudomonas aeruginosa (P. aeruginosa; nonferment gram-negative bacteria), as well as against spores of Bacillus subtilis (B. subtilis) was studied. AgNps/PVP were tested for the presence of fungicidal activity against different yeasts and mold such as Candida albicans, Candida krusei, Candida tropicalis, Candida glabrata, and Aspergillus brasiliensis. The hybrid materials showed a strong antimicrobial effect against the tested bacterial and fungal strains and therefore have potential applications in biotechnology and biomedical science.

Silver Nanoparticles as Potential Antibacterial Agents

“…An important feature to evaluate the real efficiency of the nanoparticles is derived from the chosen stabilization method employed. To this regard several coatings and chemicals have been reported: (i) starch was successfully employed to prepare AgNPs which had a disrupting effect on biofilms produced by P. aeruginosa and S. aureus [82]; (ii) citrate-capped AgNPs of various sizes were shown to inhibit P. aeruginosa PAO1 biofilms [83]; (iii) polyvinylpyrrolidone (PVP) showed good antibacterial activity towards S. aureus, E. coli, P. aeruginosa, Bacillus subtilis, and good fungicidal activity against various yeasts and molds [84]; (iv) β-cyclodextrin is also an effective capping and stabilizing agent that reduces the toxicity of AgNPs against the mammalian cell while enhancing their antibiofilm activity [85]. Mohanty et al [82] used a simple and environment friendly approach to form stable colloids of nontoxic AgNPs using starch to reduce silver nitrate to silver metal and simultaneously stabilize the nanoparticles in starch solution.…”

Assessment of in situ-Prepared Polyvinylpyrrolidone-Silver Nanocomposite for Antimicrobial Applications

“…For long period of time, different chemical forms of silver have been accepted as effective antimicrobial agents which are highly active against bacteria, viruses and fungi [4][5][6]. However, a decline in silver medical applications as antimicrobial occurred due to the progress of antibiotics [3,7,8].…”

“…Polymers with certain affinity toward metals such as chitin, chitosan [32] polyvinyl alcohol, polyacrylamide, acrylonitrile, and PVP, are the most used substance for metal nanoparticles stabilization [12]. Considerable attention is drawn to PVP owing to its special chemical and physical properties recommending it as a coating or as additive to different materials [6]. PVP can perform a dual role: first is stability and second is controlling the rate of silver ions reduction and aggregation process of silver atoms [6,33].…”

“…Considerable attention is drawn to PVP owing to its special chemical and physical properties recommending it as a coating or as additive to different materials [6]. PVP can perform a dual role: first is stability and second is controlling the rate of silver ions reduction and aggregation process of silver atoms [6,33]. Moreover, low toxicity and acceptable biocompatibility make PVP suitable and promising for medical applications [31].…”

Influence of Precursor Concentration and Temperature on the Formation of Nanosilver in Chemical Reduction Method

“…Both of these peaks were slightly shifted from the PVP peaks. Bryaskova et al (2011) mentioned in their paper that the peak shifting was related to the formation of coordination bonds between silver atoms and oxygen or nitrogen atoms from PVP units. Basically, the characteristic peaks of PVP were detected in the S1T8 spectrum, indicating that the PVP molecules were adsorbed on the NSPs surface (Liu et al 2008).…”