Optimization of Gold Nanoparticle Biosynthesis by <i>Es</i><i>cherichia</i> <i>co</i><i>li</i> DH5α and its Conjugation with Gentamicin

Abstract

Metal nanoparticles are one option for targeted drug delivery. In order to increase antibiotic efficiency and decrease its side effects, antibiotic conjugated nanoparticles have been known as a suitable approach. The aim of this study was optimization of gold nanoparticle biosynthesis byEscherichia coliDH5α and its conjugation with gentamicin. For this purpose gold nanoparticles were biosynthesized from HAuCl4and confirmed by Uv/ Vis, XRD, DLS and SEM. Then the effects of different parameters on optimum conditions for gold nanoparticles production were investigated. The MIC and MBC of gentamicin and its conjugate were investigated againstE. coli,Clostridium perfringensandClostridium botulinum. The results revealed that among different treatments, centrifuge (10000 rpm, 10 min) and sonication are the optimum conditions for gold nanoparticle production with less than 10 nm sizes. Filtration was also the best method for purifying nanoparticles. The conjugated nanoparticles significantly reduced the MIC of gentamicin againstE. coliand also overcame the natural resistance of tested anaerobic bacteria. In conclusion, the optimized method is an effective, inexpensive and environmental friendly method for biosynthesis of gold nanoparticles. Overcoming natural resistance of anaerobic bacteria using antibiotic conjugates with nanoparticles provides hopes for further experiments and in vivo studies.

Prolonged Antimicrobial Activity of PMMA Bone Cement with Embedded Gentamicin-Releasing Silica Nanocarriers

“…Hence, the ideal bone cement should provide antimicrobial activity for an extended period of time in order to exhibit a prophylactic action against late infection offset; this could be achieved through the application of drug delivery systems . For this purpose, antibiotic delivery systems have been prepared through various techniques, for example, tethering the drug to a surface − or to a particle, − encapsulating the active molecule in nanoparticles or liposomes or depositing the drug using layer-by-layer (LbL) assembly. , Such multitude of approaches demonstrates the clear clinical need of an antimicrobial delivery system for bone cement; however, it also reveals the still unsatisfactory performance of the available approaches. For example, the entrapment of an antibiotic in mesoporous silica coated with hydrolyzable polymers suffers the trade-off between an extended efficacy and immediate release; in order to extend the release, thicker coatings are required, but this, in turn, prevents release in the first hours/days of contact with fluids .…”

Bactericidal effect of gentamicin conjugated gold nanoparticles

“…Motamedi et al . showed that conjugation of GTM with GNPs can facilitate antibiotic penetration towards bacterial cells [14], as GTM alone does not cross cell membranes efficiently [13]. Depending on the antibiotic used, an increase in the activity of the antibiotic–colloidal‐gold mixture ranged from 12 to 40%, as compared with the activities of the native drugs [13].…”