International Journal of Nanomedicine (Mar 2020)
Correlative ex situ and Liquid-Cell TEM Observation of Bacterial Cell Membrane Damage Induced by Rough Surface Topology
Abstract
David J Banner,1 Emre Firlar,1,2 Justas Jakubonis,1 Yusuf Baggia,1 Jodi K Osborn,1 Reza Shahbazian-Yassar,2 Constantine M Megaridis,2 Tolou Shokuhfar1,2 1Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA; 2Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, IL 60607, USACorrespondence: Tolou ShokuhfarDepartment of Bioengineering (MC 063), University of Illinois at Chicago, 851 S. Morgan St, SEO 218, Chicago, IL 60607, USATel +1 312 996-2335Fax +1 312 996-5291Email [email protected]: Nanoscale surface roughness has been suggested to have antibacterial and antifouling properties. Several existing models have attempted to explain the antibacterial mechanism of nanoscale rough surfaces without direct observation. Here, conventional and liquid-cell TEM are implemented to observe nanoscale bacteria/surface roughness interaction. The visualization of such interactions enables the inference of possible antibacterial mechanisms.Methods and Results: Nanotextures are synthesized on biocompatible polymer microparticles (MPs) via plasma etching. Both conventional and liquid-phase transmission electron microscopy observations suggest that these MPs may cause cell lysis via bacterial binding to a single protrusion of the nanotexture. The bacterium/protrusion interaction locally compromises the cell wall, thus causing bacterial death. This study suggests that local mechanical damage and leakage of the cytosol kill the bacteria first, with subsequent degradation of the cell envelope.Conclusion: Nanoscale surface roughness may act via a penetrative bactericidal mechanism. This insight suggests that future research may focus on optimizing bacterial binding to individual nanoscale projections in addition to stretching bacteria between nanopillars. Further, antibacterial nanotextures may find use in novel applications employing particles in addition to nanotextures on fibers or films.Keywords: liquid TEM, graphene liquid cell, antibacterial nanopatterns, antibacterial surface topology, antibacterial microparticles