1. Antimicrobial Coatings Center for Particulate & Surfactant Systems (CPaSS) IAB Meeting Columbia University August 20, 2009 Vijay Krishna 1, Wei Bai 1, 2, Gayathri Rammohan 1, Hideya Nakamura 1, Paul Indeglia 1, 2, Ben Koopman 1, 2 and Brij Moudgil 1, 3 1 Particle Engineering Research Center, 2 Department of Environmental Engineering Sciences, 3 Department of Materials Science and Engineering, University of Florida

2. Background  2 million infections and 90,000 deaths due to disease transmission in hospitals 1 - fungal infections are the 3 rd most common life-threatening systemic infection 2  Allergy and respiratory problems account for 25% of emergency room visits in the U.S. annually, and is the #1 chronic cause of school absenteeism 3  $20 billion/yr lost in U.S. due to asthma 4 1.Klein, E., et al. (2007) Hospitalizations and deaths caused by methicillin- resistant Staphylococcus aureus, United States, 1999–2005. Emerging Infectious Diseases 2.http://www.globalhealth.org/news/article/735 3.http://www.aafa.org/display.cfm?id=7&sub=100&cont=652 4.http://www.nhlbi.nih.gov/resources/docs/07-chtbk.pdf. 5.http://www.sciencedaily.com/releases/1999/09/990903070829.htm 6.http://alligator.org/articles/2009/01/30/news/local/090130_avocado.txt Pharmaceutical Industry Household Disinfectants Food and Agriculture Industry  $9 billion/yr lost in U.S. due to fungal diseases in plants 5.  A recent threat by laurel wilt fungus, which kills avocado plants, could cost the Florida avocado industry up to $54 million within a year 6

3. Approach Conventional Photocatalysis  Sunlight or solar UV (black) lights serve as the excitation source  Eliminates need for chemical disinfectants and their associated toxic byproducts  Microbes are completely mineralized Novel TiO 2 -PHF nanocomposite for enhanced photocatalysis  Photocatalytic nanocomposites synthesized through self-assembly  PHF concentration 10-100 times lower than other enhancers (e.g., metals, dye) Advantages of PHF  PHF is non-toxic and presently used for therapeutics and cosmetics Barrier  Recombination reduces the efficiency of photocatalysis to 10% of theoretical value

4. Specific Objective To develop and test TiO 2 -PHF or PHF based coatings for household use, food, agriculture & pharmaceutical industry Presented at March 2009 CPaSS Meeting (Gainesville, FL) 5 wt% 0.1 wt% TiO 2 PHF 0 0 0.001 wt% % Dye degradation 2 x faster Enhancement observed with 50 times lower TiO 2 conc.

5. Specific Objective To develop and test TiO 2 -PHF or PHF based coatings for household use, food, agriculture & pharmaceutical industry Presented at March 2009 CPaSS Meeting (Gainesville, FL) 5 wt% 0.1 wt% TiO 2 PHF 0 0 0.001 wt% % Dye degradation 2 x faster Enhancement observed with 50 times lower TiO 2 conc. Questions  Environmental implications of PHF  Economics of PHF usage  Stability of PHF coating

6. Environmental Implications of PHF Biodegradable  PHF can be degraded by common white-rot fungi, which infects plants. [Schreiner, et al. 2009] Polyhydroxy Fullerenes Water-soluble Biocompatible Biodegradable Non-toxic at low dosages  PHF dosage for most applications much lower (2 orders of magnitude) than LC50 [Isakovic, et al. 2006, Sayes, et al. 2004, Sayes, et al. 2007, Trajkovic, et al. 2007, Usenko, et al. 2007, Yin, et al. 2009]

7. Cost Analysis for TiO 2 -PHF Nanocomposite Coating DosageCost ($/sqft)* Estimated cost reduction Conventional coating 5 wt% TiO 2 $0.00246 — Proposed TiO 2 -PHF coating 0.1 wt% TiO 2 $0.00185 0.001 wt% PHF Comparison between conventional TiO 2 and TiO 2 -PHF coatings Small-scale price ($/gram) Scale-up cost reduction factor Bulk Price ($/gram) TiO 2 $0.16*61.5 (calculated)$0.0026** PHF$75060 (assumed)$12.50 TiO 2 and PHF costs used in developing economic estimates 25 % *Fisher Scientific; **http://www.radian-group.ru/eng/him.html TiO 2 -PHF coatings are cost competitive

8. Only Nutrient Aspergillus niger growth on a ceramic tile after 3 days in dark and 90% humid environment Wait a minute!!! PHF by itself is Antifungal Nutrient & 0.1 wt% TiO 2 Nutrient & 0.1 wt% TiO 2 + 0.001 wt% PHF TiO 2 + PHF is fungistatic Patent Pending Comparison with conventional antifungal MIC (ppm) Cost ($/Liter) PHF0.002$0.0015 Thiabendazole5*$0.0018** **http://www.sciencelab.com/page /S/PVAR/10427/SLT3937 *Kourai et al., European J Med Chem, 41, 2006;

9. Preliminary testing of PHF for Food & Agriculture Applications Control PHF Control PHF After 3 days After 8 days PHF: A new class of Fungicide!!!

10. Summary  TiO 2 -PHF coatings perform better than conventional coatings  PHF is non-toxic, biocompatible and biodegradable  Polyhydroxy fullerenes are fungistatic  Provisional patent filed Next Steps…  Extend PHF application to food and agriculture industry (e.g., food additives & washable coatings on fruits for improving shelf-life)  Determine mechanism of fungal inhibition pathway for optimizing PHF molecular structure  Optimize PHF coating for stability under different environmental conditions including temperature, humidity, and exposure to water. Acknowledgments  Industrial partners of PERC  State of Florida – CNBS