|Acquisition Program: || Objective: ||There is a need to investigate reactive self-decontaminating surfaces and surface treatments with the maximum potential to kill biological organisms in order to minimize hazard to human health. Self sanitizing surfaces have relevant applications to both porous and non-porous surfaces including bandages, clothing, CB-Agent resistant coatings for vehicles, equipment, and structures. The biological effects of combining a discrete germinant / toxicant array on a thin film surface have only been initially investigated.
|| Description: ||One approach to creating such a propoerty is to modify the chemistry of the free surface to include small length scale germinant and toxicant features which come into contact with a target organism at the same time. The goal is to force the organism into a more vulnerable mode (i.e., change of metabolic state from endospore to vegetative). This change in metabolism changes the behavior of the cell wall, making it more succeptible to uptake of toxicant agents, thus increasing the chances of killing the agent.
It is very important for a successful proposal to demonstrate PI qualifications in both surface physics and microbiology. This is a highly interdisciplinary topic area and diverse teams are encouraged to apply.
|| ||PHASE I: There are a great many potential materials and feature length scales and geometries that could be used for such an approach. In Phase I the contractor should test a number of surfaces looking at the effects of geometry, spacing, and different concentrations and types of toxicants and germinants in order to gain a better understanding of the underlying mechanisms. The surfaces should be tested against live agent simulants.
|| ||PHASE II: The best performing sample surfaces should be selcted for a larger scale performance trial. The physical and chemical interaction between biological agents and the surface should be observed and characterized in order to tailor the surface to optimize the effective log kill while maintaining mechanical durability. The surfaces have the potential to be used in combat, and therefore must be sufficiently robust to maintain effectiveness under harsh conditions (abrasion, etc.). Civilian commercial sector applications may not require this additional hardening constraint, but it is a genuine requirement for a truly successful Phase II project.
|| ||PHASE III|| ||DUAL USE COMMERCIALIZATION: Self sanitizing surfaces have potential industrial and architectural applications including heating and ventillation duct linings, furniture, kitchen surfaces, medical equipment, operating room floors and walls, and many others. Military applications include forward facilities, CONUS facilities, vehicles, equipment which may be exposed to biological agents or simply need to be kept free of biological agents.
|| References: ||. M. A. Gelman, B. Weisblum, D. M. Lynn, and S. H. Gellman, “Biocidal Activity of Polystyrenes that are Cationic by Virtue of Protonation.” Organic Letters 2004, 6, 557-560.
2. P. Gilbert, J.R. Das, M.V. Jones & D.G. Allison. (2001) "Assessment of resistance towards biocides following the attachment of micro-organisms to, and growth on, surfaces" Journal of Applied Microbiology 91:2, 248-254
3. Wood, CaldweII, Evans, Jones, Korber, Wolfhaardt, Wilson & Gilbert
"Surface-catalysed disinfection of thick Pseudomonas aeruginosa biofilms" Journal of Applied Microbiology, Volume 84 Page 1092 - June 1998
doi:10.1046/j.1365-2672.1998.00446.x Volume 84 Issue 6
4. R. Kügler, O. Bouloussa and F. Rondelez "Evidence of a charge-density threshold for optimum efficiency of biocidal cationic surfaces" Laboratoire de Physico Chimie Curie, Institut Curie, Section de Recherche, 11 rue Pierre et Marie Curie, 75005 Paris, France. 2005 Microbiology
5. A. M. Demchenko1, K. G. Nazarenko1, A. P. Makei1, S. V. Prikhod'ko1, I. N. Kurmakova1 and A. P. Tretyak, "Synthesis and Anticorrosion and Biocidal Activity of Triazoloazepine Derivatives" Russian Journal of Applied Chemistry
Volume 77, Number 5, May 2004, Pages: 790 - 793
|Keywords: ||self-sanitizing, thin film, discrete component, surface physics, bio agent|