Evaluation of mesoporous silica nanoparticles-based nanoantibiotics and capsaicin on E. coli and S. aureus biofilms
- 1Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi, Turku, Finland(aslita@abo.fi)
- 2The Arctic University of Norway, Tromsø, Norway
- 3İzmir KatipCelebiUniversity, Faculty of Engineering and Architecture, Department of Biomedical Engineering, İzmir, Turkey
Introduction
Since antibiotics were discovered, bacteria have demonstrated the ability to develop resistance by many different mechanisms. According to WHO reports from 2014, there has been an alarming increase in the antibiotic resistant bacterial strains in most parts of the world1. Our previous results showed that a nanoantibiotic (NAB) design created in our laboratory2, composed of a cerium oxide core, mesoporous silica shell loaded with capsaicin, and a chitosan coating, are effective against planktonic E. coli. However, most of the pathogenic bacteria form biofilms during infections. That is why the next stage of studying NAB is to determine whether they are effective against biofilms of different species. Moreover, the results of NAB efficiency against planktonic E. coli did not clearly show the contribution of the antibiotic drug component of NAB – capsaicin. Hence, the first step of the current study is to determine whether and to what degree, mesoporous silica nanoparticles (MSN) – serving as NAB model in this case - penetrate biofilms as a function of particle shape and surface coating; as well as finding the efficient concentration of capsaicin against E. coli and S. aureus to optimize the NAB dosing against biofilms.
Aim
To check in vitro penetration of MSN on S. aureus biofilm and antibacterial activity of NAB and pure capsaicin on E. coli and S. aureus biofilms.
Methods
To investigate NAB efficiency on biofilms MBEC-high-throughput assay3 was performed. Equal biofilms formed on peg-lids were incubated with different concentrations of NAB and capsaicin. After different time point biofilms were sonicated and plated on agar plated to perform CFU counting. To determine the efficient concentration of capsaicin, biofilms were formed in 12 well plates and then incubated with different concentrations of capsaicin. To visualize inhibitory effect, plating for CFU counting and Resazurin assay were applied. To evaluate the penetration of particles, labeled and non-labeled particles were added to fully grown St. aureus biofilms, incubated and visualized with confocal microscopy and structured illumination microscopy.
Results
Conclusion
References
How to cite: Slita, A., Govardhanam, P., Opstad, I., Sen Karaman, D., and Rosenholm, J.: Evaluation of mesoporous silica nanoparticles-based nanoantibiotics and capsaicin on E. coli and S. aureus biofilms, biofilms 9 conference, Karlsruhe, Germany, 29 September–1 Oct 2020, biofilms9-133, https://doi.org/10.5194/biofilms9-133, 2020
