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Lecture

WEB One more Step in the Fight against Pathogenic Bacteria - The Oligodynamic Effect of Ag and Cu Nanoparticle loaded Hollow Mesoporous Silica Capsules

Tuesday (22.09.2020)
12:05 - 12:20 B: Biomaterials
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Due to an increase of antibiotic resistant bacteria there is an indisputable necessity for alternative antimicrobial drugs and their treatment options. The biocidal impact of positively charged metal ions is known as oligodynamic effect and has been taken advantage of for millennia to keep prevention strategies on the long run against their biological antagonists. In combination with modern nanotechnology this concept leads to new solutions against bacterial infections within biodegradable drug delivery systems.

In this work, hollow mesoporous silica capsules (HMSC) were synthesized via a hard iron oxide template. After silica-shell formation, the iron oxide template was removed through acidic leaching, leading to the desired hollow mesoporous silica capsules, a suitable drug delivery material. Ag (Ag@HMSC) and Cu (Cu@HMSC) nanoparticle loading was performed using the green reducing agents citric or ascorbic acid, respectively. The distribution and morphology of rattle-type Ag and Cu nanoparticles on HMSC was analyzed with transmission electron microscopy (TEM) while the different oxidation states were analyzed with X-ray photoelectron spectroscopy (XPS). The sustained release of oligodynamic ions was achieved under physiological conditions at 37°C and was quantified through UV-vis analysis of the metal dithionates. The antimicrobial activity of Ag@HMSC and Cu@HMSC was determined by INT assay using gram-positive (B. subtilis) and gram-negative bacteria cultures (E. coli) which revealed a significant antibacterial effect through sustained metal ion release.

 

Speaker:
Sven Saniternik
University of Cologne
Additional Authors:
  • Dr. Isabel Gessner
    University of Cologne
  • Eva Krakor
    University of Cologne
  • Prof. Dr. Sanjay Mathur
    University of Cologne