Bacterial contamination affects industrial processes, food processing equipment, biomaterials, and other biomedical contamination. The ability to control bacterial adhesion on surfaces and to kill harmful bacteria requires that new methodologies are developed. Over the last decades, the resistance of pathogenic bacteria to antimicrobial agents has become a major challenge. A novel approach would be to use a new class of nano-antibiotics, which can kill bacteria without promoting antimicrobial resistance. The goal of this project is to study how silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) can be exploited as antibacterial agents. Among different metals, silver is known for its antibacterial and growth inhibitory effects. Gold does not show any bactericidal effect in bulk amount. However at the nanoscale, gold NPs in a certain size range have some unique properties that make them good candidates for killing bacteria through pore formation in bacterial membranes. A great benefit of this research is that since AgNPs and AuNPs kill bacteria through membrane-associated processes, there is a low likelihood of bacteria being able to develop a resistance to their actions. This project will be conducted under supervision of Dr. Jonghoon Choi, a noted expert on nano-biotechnology, at Hanyang University in Korea.
In this project the antimicrobial effect of gold and silver nanoparticles (NPs) on Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli) will be characterized. NP solutions of varying sizes and concentrations will be prepared. Morphology and size of NPs will be characterized by transmission electron microscopy (TEM) and light scattering. Electrostatic charge of NPs will be characterized via zeta potential measurements. Minimum Inhibitory Concentration (MIC) of NPs on E. coli and S. aureus will be determined by using plate counting and growth rate experiments. This NSF EAPSI award is funded in collaboration with the National Research Foundation of Korea.
With increasing resistance of bacteria to conventional antibiotics, there is an urgent need to develop new effective antimicrobial reagents free of resistance and cost. Silver and copper nanoparticles are known as antimicrobial agents against bacterial pathogens. Despite of their high antibacterial effects, metal nanoparticles have high tendency to aggregate which leads to loss of their bactericidal activities. In order to prevent aggregation, it is suggested to combine silver and copper nanoparticles with carbon nanotubes. Carbon nanotubes (CNTs) are important forms of carbon that have several unique properties such as high strength and biocompatibility. These special properties make them good candidates for different bioengineering applications. In this research, silver and copper nanoparticles were combined with carbon nanotubes to be used as antibacterial agents. It was characterized that these hybrid materials show synergistically increased antibacterial activity. Development of nanoantibiotic agents helps society because our ability to control infectious diseases relies on how fast we can design and apply bactericidal agents to overcome the bacterial resistance problem. This research was conducted under supervision of Dr. Jonghoon Choi a noted expert on nano-biotechnology at Hanyang University in Korea. Fulfilling this project enhanced the infrastructure for research and education in this field, since it developed collaboration between a U.S. university and the host facility. A significant impact of this was developing networks and partnerships between the two institutions. The result of the project was disseminated in form of journal publication. In addition, the PI gave an informative presentation for other graduate students on campus. The presentation was about her experience of applying for EAPSI award and conducting research in a foreign country. Consequently, it motivated and enhanced participation of other graduate students in international collaborations. These kinds of activities would help them to gain professional experience beyond this nation’s borders early in their careers and strength the nation’s science and engineering capabilities.
