Grantee Research Project Results
Final Report: Determine and Confirm the Field Use Protocol for NanoProtect™ Nontoxic Decontaminate for Facilities and Equipment Following a Bioincident
EPA Contract Number: EPD05048Title: Determine and Confirm the Field Use Protocol for NanoProtect™ Nontoxic Decontaminate for Facilities and Equipment Following a Bioincident
Investigators: Hamouda, Tarek
Small Business: NanoBio Corporation
EPA Contact: Richards, April
Phase: II
Project Period: April 1, 2005 through June 30, 2006
Project Amount: $224,666
RFA: Small Business Innovation Research (SBIR) - Phase II (2005) Recipients Lists
Research Category: Hazardous Waste/Remediation , SBIR - Homeland Security , Small Business Innovation Research (SBIR)
Description:
The objective of this research project conducted by NanoBio Corporation was to develop a non-toxic nanoemulsion for decontamination of facilities and equipment contaminated with anthrax. The nanoemulsion is an oil-in-water emulsion with broad-spectrum antimicrobial activity optimized for decontamination of Bacillus anthracis. NanoProtect™ is made of ingredients on the Generally Recognized as Safe (GRAS) list and an active ingredient commonly used in household cleaning products. NanoProtect™ has been optimized to achieve maximum sporicidal activity with shelf life adequate for prolonged storage. This has been achieved by fine tuning the emulsion ingredients to target the lethal spores without detrimental effect on the emulsion stability.
In this project, the decontamination protocol has been optimized using panels made of five different materials commonly found in building environments. These include vinyl floor tiles, carpet, painted dry wall, metal office furniture, and ceiling tiles.
Initial experiments were performed to optimize spore recovery from the test panels. Improving spore recovery was important to verify that spore reduction is because of actual reduction of spore count and not because of the inability to recover spores from the panels. Low recovery would result in false increase in emulsion log reduction. In other instances, it was essential to confirm that the reduction of spore count is not because of clinging of the spores to the cling wrap, which was used to cover the panels during overnight incubation.
Initial experiments were performed on small 3-by-3 inch panels. Floor tiles were used initially to define all the criteria required to enhance the emulsion sporicidal activity. Preliminary experiments included defining the optimum emulsion concentration, number of emulsion applications, volume used for treatment, length of treatment, temperature of incubation, and wetness of the panels throughout the treatment. After optimization of these initial treatment criteria using the floor tiles, the other surfaces were tested to confirm these findings, or if necessary, to adapt the protocol for different surfaces.
Confirmatory tests were performed using 1-by-1 foot panels made of the same material tested in the pilot experiments. The use of a bigger surface was important to confirm that the proposed protocol could be scaled up for decontamination of anthrax.
Additional tests were performed to establish that the emulsion has a broad spectrum antimicrobial activity and that it can be used to eliminate other biological hazards. The minimal inhibitory concentration (MIC) was determined against bacteria and fungi and the anti-viral activity determined using a virucidal suspension assay. Finally, emulsion stability was evaluated to ensure adequate shelf life throughout the course of the project.
Summary/Accomplishments (Outputs/Outcomes):
In this project, nanoemulsion formulation was developed for the decontamination of surfaces contaminated with anthrax. NanoProtect™ was developed with a goal of balancing between sporicidal activity, stability, and safety. Emulsion tested on five different surfaces was effective for decontamination of anthrax spores. Initial experiments were performed to define the criteria for decontamination. Increasing the temperature to 35ºC has improved the emulsion sporicidal activity. It was found that the maximum sporicidal activity was achieved when the emulsion was applied on the contaminated surfaces in quantities large enough to remain wet for an overnight treatment (22 hours). Porous surfaces, such as carpets, required more emulsion because they tended to absorb large quantities. Non-porous surface (floor tiles) need less emulsion for decontamination, but spore killing was enhanced if covered with a cloth to distribute the emulsion evenly and to keep enough emulsion for an extended time to allow for maximum spore killing.
After defining the treatment criteria, NanoProtect™ was tested on four different panels using these criteria. It was found that one treatment of application was sufficient as long as the surfaces were kept saturated with emulsion for the length of the treatment. This also demonstrated the prolonged activity of the emulsion. Emulsion applications resulted in 5.4 log reduction of spores on floor panels, 4.5-5.0 log reduction on drywall, and 3.5-3.9 log reduction on carpet. Spore reduction on metal office furniture depended on the brand tested. Tests performed on Marvel desks showed 5 log reduction, whereas tests performed on older steel case cabinets showed only 2.2 log reduction. This last difference in spore killing illustrates that the emulsion sporicidal activity is affected by the type of the paint used for the office furniture. It is possible that some of these paints might have components that reduce the sporicidal activity of the emulsion.
As a result of the nature of the emulsion, cleaning following decontamination will not be an issue. The use of a wet-dry vacuum followed by wiping with mild detergent in the case of hard surface (or carpet shampoo in the case of carpet) will result in complete elimination of the emulsion and any remaining spores. It also was determined that the cost of decontamination of ceiling tiles using nanoemulsion will exceed the cost of replacement of the tiles.
MIC assay performed against other microorganisms showed that the emulsions were highly effective against Legionella pneumophila (625 ppm1 ), Aspergillus niger (625 ppm), Stachybotrys chartarum (1250 ppm), Staphylococcus aureus (313 ppm), Salmonella choleraesuis (625 ppm), Pseudomonas aeruginosa (2500 ppm), and Yersinia enterocolitica (313 ppm). The virucidal suspension assay showed that the nanoemulsion also was highly effective against Vaccinia (96.8% in 10 minutes and 99.8% in 30 minutes) and Human Coronavirus (≥ 99.97% in 10 minutes). The emulsion is stable when stored at room temperature for 1 year.
This program has been effective in defining additional capabilities of the nanoemulsions. Nanoemulsion was effective in decontamination of bone and tendon transplant extracted from cadavers and used for human allograft tissues. The emulsion effectively improved the process and reduced the microbial load in the graft tissue including bacterial spores and fungi, which were identified as difficult and persistent pathogens in human allograft processing.
1 All the numbers between the parentheses represent the MIC for the nanoemulsion against each of these organisms in relation to the neat emulsion formulation.
Conclusions:
NanoProtect™ would be an effective product for decontamination of buildings in case of contamination from biowarfare organisms including B. anthracis spores. It is effective, safe, easy-to-use, and has a prolonged shelf life.
Supplemental Keywords:
anthrax, nanoemulsion, sporicidal, allograft processing, NanoProtect™, non-toxic decontaminate, bioincident, bioterrorism, biodefense, antimicrobial, Bacillus globigii, Bacillus anthracis, anthrax, spores, pathogen, decontamination, ecosystem protection, environmental exposure, bioattack, biocides, biodefense technology, biomonitoring, biosensing, biotechnology, Homeland Security, nanoengineering, SBIR, small business,, RFA, Scientific Discipline, TREATMENT/CONTROL, Ecosystem Protection/Environmental Exposure & Risk, RESEARCH, Sustainable Industry/Business, Environmental Chemistry, Sustainable Environment, Technology, Monitoring/Modeling, Monitoring, Technology for Sustainable Environment, Environmental Monitoring, New/Innovative technologies, Ecological Risk Assessment, Environmental Engineering, homeland security, decontamination, biosensing, antimicrobial nanoemulsion technology, anthrax decontamination, bioterrorism, nanotechnology, field portable, anthrax, biotechnology, biodefense technology, biomonitoring, biocides, nano engineeringSBIR Phase I:
Reformulated NanoBio Nontoxic Hard Surface Sanitizer/Disinfectant Formulation To Inactivate and Kill B. Anthracis and Other Bioattack Pathogens | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.