Dying and Dead bacteria
With the growing menace of drug-resistant bacterial strains, it is vital to develop novel strategies for preventing hospital acquired infections. Inspired by antibacterial surfaces found in nature, a research team in the Department of Materials Engineering has developed a simple etching technique that renders aluminum and its alloys with micro- and nanoscale features. Such multi-scale surface topography was found to exhibit enhanced antibacterial activities against wide ranging microorganisms including drug-resistant bacteria isolated from the hospitals. Multi-scale topography on Al 5052 alloy surface was shown to kill up to 82 % of E. coli, 25 % of K. pneumoniae and 86 % of P. aeruginosa drug-resistant cells. In addition, the etched Al 5052 surface reduced the cell number of S. aureus cells to one-tenth of the attached cells on the control alloy surface. The microscale topography was only able to resist the bacterial attachment whereas the multi-scale roughness, especially the nanostructures, resulted in bactericidal activity. The fabrication method is simple and can be easily scaled for industrial production. Through detailed study of a wide variety of feature sizes on various surfaces, specific ranges for a combination of several parameters were identified that can yield a highly bactericidal surface. These findings could provide design rules for engineering bactericidal surfaces irrespective of the method of fabrication. When tested in hospital-like settings these etched surfaces significantly reduced the bacterial load. Such engineered surfaces with multi-scale topography can help to minimize the spread of bacterial infections, especially in the hospital environment.
Research publication: J. Hasan, S. Jain, R. Padmarajan, S. Purighalla, V.K. Sambandamurthy, K. Chatterjee: “Multi-scale surface topography to minimize adherence and viability of nosocomial drug-resistant bacteria” Materials & Design 2017: in press (http://www.sciencedirect.com/science/article/pii/S026412751731105X)
The research team: https://sites.google.com/site/iiscbiomaterials/