Source: GEORGIA SOUTHERN UNIVERSITY submitted to
SUPER-REPELLENT ANTIMICROBIAL COATINGS TO ENSURE FOOD SAFETY
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
0227263
Grant No.
2011-67022-30229
Cumulative Award Amt.
$271,462.78
Proposal No.
2011-06299
Multistate No.
(N/A)
Project Start Date
Sep 1, 2011
Project End Date
Nov 30, 2014
Grant Year
2012
Program Code
[A1511]- Agriculture Systems and Technology: Nanotechnology for Agricultural and Food Systems
Project Director
Ming, W.
Recipient Organization
GEORGIA SOUTHERN UNIVERSITY
PO BOX 8015, HOLLIS, SUITE 1101D
STATESBORO,GA 30460
Performing Department
Department of Chemistry
Non Technical Summary
Unsafe food and food poisoning due to insufficient protection from pathogenic bacteria results in human suffering from illness and tremendous financial repercussions. Numerous outbreaks in the U.S. were due to contaminated food processing facility. Therefore, it is of extreme importance to prevent the accumulation of pathogenic bacteria inside food processing facilities. Our objective is to develop super-repellent antimicrobial nanostructured coatings for food processing facilities (both food contact and non-contact surfaces) to eliminate a major external source of bacterial infection for food. The super-repellent antimicrobial coatings, which are topographically structured to mimic the lotus leaf surface (i.e., dual-scale structure), will combine two mechanisms of eliminating bacteria into one system: repelling (due to super-repellency against both water and oil) and killing (due to covalently bonded quaternary ammonium groups at the coating surface). The innovative antimicrobial coatings can be applied to food processing facilities and peripheral surfaces (drains, floors, storage tanks, apparel, etc.), and have the potential to greatly reduce bacterial attachment and biofilm formation, thus reducing foodborne pathogens. Moreover, the technology to be developed may also find applications in healthcare settings, personal hygiene industry, biomedical industry, and other high-touch, high risk environments, making significant contributions to a better and safer society.
Animal Health Component
40%
Research Effort Categories
Basic
60%
Applied
40%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
7124010200050%
7125399200050%
Knowledge Area
712 - Protect Food from Contamination by Pathogenic Microorganisms, Parasites, and Naturally Occurring Toxins;

Subject Of Investigation
5399 - Structures, facilities, and equipment, general/other; 4010 - Bacteria;

Field Of Science
2000 - Chemistry;
Goals / Objectives
Our objectives are to eliminate bacteria common in processing/packaging facilities by applying a super-repellent antimicrobial coating on various surfaces (including equipment, interior wall, ceiling, drain, storage tank, etc.) in the facility. The nanostructured coating can effectively repel most of the bacteria, and kill the rest that manage to adhere to the surfaces in the facility to ensure food safety. Our goals are two-fold: (1) to synthesize and characterize super-repellent antimicrobial polymeric coatings; (2) to examine the antimicrobial properties and establish structure/property relationships for these coatings. In our targeted super-repellent antimicrobial coatings, the antimicrobial moieties (quaternary ammonium groups) will be covalently bonded to the polymer matrix, preventing them from leaching out into food. The outputs of this project include: (A) Activities: (1) Preparation and characterization of smooth antimicrobial coatings; (2) Preparation and characterization of nanostructured, super-repellent antimicrobial coatings; (3) Preparation and characterization of mechanically robust, super-repellent antimicrobial coatings; (4) Antimicrobial tests, with the aim at understanding the mechanism of antimicrobial actions (killing and/or repelling of bacteria); (5) Mentoring a postdoctoral researcher and several undergraduate students. (B) Events: Reporting project findings, when appropriate, in relevant conferences and symposia; (C) Products: Potential patent applications; peer-reviewed journal publications.
Project Methods
Our planned research will be divided into the following main tasks: (1) Smooth antimicrobial coatings We will prepare smooth antimicrobial polymer coatings by using a surface segregation strategy to examine whether covalently bonded antimicrobial species still have antimicrobial properties. Via this approach, the antimicrobial moieties such as quaternary ammonium compounds (QAC), will be segregated at the coating surface (it is unnecessary to have antimicrobial groups in the bulk of a coating) and, in the meantime, chemically bonded to the cross-linked polymer network. The key in our approach is that the QAC groups will be connected to a fluorinated or silicone (PDMS) chain (low surface-energy species), which provides the driving force for the QAC-containing moiety to segregate at the coating surface. (2) Super-repellent antimicrobial nanostructured coatings To eliminate bacteria in a more effective way, i.e. combining repelling bacteria with killing bacteria, we aim at preparing super-repellent antimicrobial nanostructured coatings with a raspberry-like surface topography. The raspberry-like nanosized structure is expected to reduce significantly the anchoring area for microbes, making it very difficult for them to attach. In addition, the presence of perfluorinated QAC groups will make sure that those tenacious bacteria, which manage to adhere to the surface, are killed upon contact with the super-repellent surface. Therefore, the super-repellent antimicrobial coatings will allow both contact-killing and maximum repelling of bacteria. (3) Antimicrobial tests Initial events in microbial adhesion will likely play a role in the final biofilm structure. Our goal is to stop the biofilm process before it can take anchor with our super-repellent coatings. For tenacious bacteria, which overcome the super-repellent barrier, we further aim to demonstrate bactericidal properties against two common foodborne sources of infection, E. coli and Salmonella. Exposure of coated surfaces to these bacterial solutions will allow us to determine the minimum inhibitory content (MIC) of the antimicrobial on the surface. The following samples will be primarily used for antimicrobial tests: -Smooth antimicrobial coatings (biocidal assessment) -Super-repellent coatings with no QAC, compared to smooth fluorinated coatings (biostatic assessment: inhibit ability to attach) -Super-repellent antimicrobial coatings (biocidal assessment: kill tenacious bacteria) To verify whether the antimicrobial action is due to the combination of a bactericidal effect and a repellent effect, live/dead cell analysis using flow cytometry will be performed after bringing the test strains in contact with the active coating. We will run antimicrobial leaching tests to confirm that the covalently attached antimicrobial groups remain bound to the nanostructured coatings. We will also examine the durability of these coatings.

Progress 09/01/11 to 11/30/14

Outputs
Target Audience: The super-repellent antimicrobial coatings we have prepared in this NIFA-supported project, which can significantly reduce bacterial adhesion (>99% reduction) while capable of killing those tenacious bacteria that managed to adhere to the surface, thus remain long-term antimicrobial, may find widespread applications in food processing facility, healthcare settings, personal hygiene industry, and other high-touch, high risk environments. On the basis of the results we have obtained from this project, we have so far published 5 peer-reviewed papers, 1 book chapter is now in press, and another 5 manuscripts are currently being finalized. Over the project period, the PI gave 8 invited talks in national/international conferences and 8 invited seminars in academia/industry; the postdoc supported by this project also gave two oral talks in an international conference. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? One postdoc and 7 undergraduate students (6 chemistry major and 1 biology major) performed well and gained ample research experience in this project. In particular, the postdoc has grown significantly professionally, as evidenced by numerous peer-reviewed journal publications and conference talks. How have the results been disseminated to communities of interest? Based on the results from this project, we have so far published 5 peer-reviewed journal papers, 1 book chapter is now in press with Wiley, and 5 manuscripts are currently being finalized. In disseminating our results, the PI also gave 8 invited talks at national/international conferences and another 8 invited seminars in academia/industry; the postdoc also gave two contributed talks in an international conference. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? We have successfully designed and prepared super-repellent antimicrobial surfaces on the basis of hierarchically structured coatings bearing quaternary ammonium compounds (QACs); these antimicrobial coatings hold great promise to be long-term effective and thus find widespread applications in food processing facility, healthcare settings, personal hygiene industry, and other high-touch, high risk environments. Our detailed accomplishments are as follows. (1) We designed and prepared new perfluorinated, reactive QACs (one with hydroxyl and the other with acrylic double bonds) and incorporated them to polyurethane and acrylic coatings via thermal and UV curing, respectively, leading to excellent smooth antimicrobial coatings against both gram-negative and gram-positive bacteria (zone-of-inhibition test confirmed there was no leaching); (2) We designed, prepared, and thoroughly characterized hierarchically structured, super-repellent surfaces, made via a layer-by-layer particle deposition approach, which demonstrated excellent antibioadhesion property; (3) When a perfluorinated reactive QAC (RfQAC) was introduced to the hierarchically structured surface, the coating was not only super-repellent against bacteria but aslo able to totally kill the very few bacteria that managed to adhere to the surface; (4) We demonstracted that on our super-repellent antimicrobial coatings, the bacterial adhesion was reduced by 99% without RfQAC, and when RfQAC was incorporated, the remaining 1% bacteria were further completely killed, clearly indicating that the antimicrobial action was due to the combinaiton of two mechanisms: repelling and killing; (5) 1 postdoc and 7 undergraduate students have gained research experience in this project; and (6) As a side project, we also designed and prepared very effective antifogging/frost-resisting polymer coatings, as well as dual-functional antifogging/antimicrobial polymer coatings on the basis of conventional materials.

Publications

  • Type: Book Chapters Status: Awaiting Publication Year Published: 2015 Citation: Zhao, J.; Ming, W. Superhydrophobic and superoleophobic polymeric surfaces, in Functional Polymer Coatings (Wu, L.; Baghdachi, J.; Ed.), John Wiley & Sons, 2015, in press.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Zhao, J.; Ming, W. Super-repellent antimicrobial surfaces, 248th ACS National Meeting, San Francisco, August 2014.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Ming, W. Smart coatings from polymer hybrids, 248th ACS National Meeting, San Francisco, August 2014.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Zhao, J.; Meyer, A.; Ma, L.; Ming, W. Smart antifogging/frost-resisting polymer coatings, XXIII International Materials Congress, Cancun, Mexico, August 2014.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Zhao, J.; Ming, W. Super-repellent surfaces reduce bioadhesion, 88th ACS 2014 Colloid & Surface Science Symposium, Philadelphia, PA, June 2014.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Zhao, J.; Ming, W. Acrylic copolymer coatings with excellent antifogging and frost-resisting properties, 88th ACS 2014 Colloid & Surface Science Symposium, Philadelphia, PA, June 2014.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Ming, W. Super-repellent functional textiles, TechTextil 2014, Atlanta, GA, May 2014.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Zhao, J.; Meyer, A.; Ma, L.; Ming, W. Acrylic coatings with surprising antifogging and frost-resisting properties, American Coatings Conference, Atlanta, GA, April 2014.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Zhao, J.; Ming, W. Super-repellent antimicrobial coatings, Smart Coatings 2014, Orlando, FL, Feb. 2014
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Zhao, J.; Ming, W. Anti-bioadhesion on hierarchically structured, superhydrophobic surfaces, 245th American Chemical Society (ACS) National Meeting, New Orleans, LA, Apr. 2013.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Ming, W. Super-repellent functional cotton textiles, Fiber Society Fall 2013 Conference, Clemson, SC, Oct. 2013.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Zhao, J.; Song, L.; Yin, J.; Ming, W. Anti-bioadhesion on hierarchically structured, superhydrophobic surfaces. Chemical Communications 2013, 49, 9191-9193.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Zhao, J.; Leng, B.; Shao, Z.; de With, G.; Ming, W. Triple-scale structured, superhydrophobic and highly oleophobic surfaces. RSC Advances 2013, 3, 22332-22339.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Zhao, J.; Meyer, A.; Ma, L.; Ming, W. Acrylic coatings with surprising antifogging and frost-resisting properties, Chemical Communications 2013, 49, 11764-11766.
  • Type: Journal Articles Status: Published Year Published: 2011 Citation: Yagci, M. B.; Bolca, S.; Heuts, J. P. A.; Ming, W., de With, G. Self-Stratifying Antimicrobial Polyurethane Coatings, Progress in Organic Coatings 2011, 72, 305-314.
  • Type: Journal Articles Status: Published Year Published: 2011 Citation: Yagci, M. B.; Bolca, S.; Heuts, J. P. A.; Ming, W., de With, G. Antimicrobial Polyurethane Coatings Based on Ionic Liquid Quaternary Ammonium Compounds, Progress in Organic Coatings 2011, 72, 343-347.


Progress 09/01/12 to 08/31/13

Outputs
Target Audience: The super-repellent, hierarchically structured coatings we have made via layer-by-layer particle deposition, which can reduce protein adsorption and suppress completely platelet adhesion (bacterial adhesion will be tested soon) may find applications in food processing facility, healthcare settings, personal hygiene industry, and other high-touch, high risk environments. We published three peer-reviewed papers during the report period, and I gave an invited talk during ACS spring meeting (2013) on the results from this NIFA-sponsored research. Changes/Problems: The project was no-cost extended to 11/30/2014. What opportunities for training and professional development has the project provided? One postdoc scholar has been performing well in this project and has grown significantly professionally, as evidenced by three peer-reviewed journal publications. In addition, four undergraduate students gained research experience over the report period; one of them is a coauthor of a paper and will be a coauthor of a forthcoming paper. How have the results been disseminated to communities of interest? Yes, we published three peer-reviewed papers during this report period, and I also gave an invited talk on antibioadhesion during ACS National Meeting in Spring 2013. What do you plan to do during the next reporting period to accomplish the goals? We'll continue the current research directions of the project. In particular, we will focus on antimicriobial tests to demonstrate that the antimicrobial mechanism of our coatings is the combined action of bacteria-repelling and bacteria-killing, which will make the antimicrobial effect long lasting. We will apply the super-repellent antimicrobial coatings on various surfaces.

Impacts
What was accomplished under these goals? During this report period, our major accomplishments are as follows: (1) We prepared super-repellent surfaces via layer-by-layer particle deposition that demonstrated excellent anti-bioadhesion property (significantly reduced protein adsorption and no platelet adhesion at all); (2) We prepared a series of reactive perfluoroalkyl-containing quaternary ammonium compounds (RfQACs), which can be covalently incorporated into various coatings for the purpose of killing bacteria; (3) As a spin of the above research, we developed very effective antifogging/frost-resisting coating on the basis of simple acrylic copolymers. The coating has demonstrated excellent antifogging performance even against boiling water steam, and showed exceptional capability in resisting frost formation.

Publications

  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Zhao, J.; Song, L.; Yin, J.; Ming, W. Anti-bioadhesion on hierarchically structured, superhydrophobic surfaces. Chemical Communications 2013, 49, 9191-9193.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Zhao, J.; Leng, B.; Shao, Z.; de With, G.; Ming, W. Triple-scale structured, superhydrophobic and highly oleophobic surfaces. RSC Advances 2013, 3, 22332-22339.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Zhao, J.; Meyer, A.; Ma, L.; Ming, W. Acrylic coatings with surprising antifogging and frost-resisting properties, Chemical Communications 2013, 49, 11764-11766.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2013 Citation: Anti-bioadhesion on hierarchically structured, superhydrophobic surfaces, American Chemical Society (ACS) National Meeting, New Orleans, LA, Apr. 2013. (Invited talk)


Progress 09/01/11 to 08/31/12

Outputs
OUTPUTS: The following outputs have been achieved during the reporting period: 1. We have successfully prepared hierarchically structured, superhydrophobic surfaces, with single-, dual-, and triple-scale roughness via a layer-by-layer (LbL) particle deposition approach. 2. These superhydrophobic surfaces, especially the triple-scale structured surface, exhibited significantly reduced protein adsorption, and could completely suppress platelet adhesion. 3. We have synthesized reactive, perfluoroalkyl quaternary ammonium compounds (RfQAC); the reactive groups include acrylic double bond, hydroxyl and siloxane, which will allow us to covalently bond the RfQACs to structured coatings. 4. We also started preparing super-repellent, antimicrobial fabric. PARTICIPANTS: A post-doc, Dr. Jie Zhao, joined the project in Dec. 2011. TARGET AUDIENCES: The super-repellent, hierarchically structured coatings we have made via layer-by-layer particle deposition, which can reduce protein adsorption and suppress completely platelet adhesion (bacterial adhesion will be tested soon) may find applications in food processing facility, healthcare settings, personal hygiene industry, and other high-touch, high risk environments. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Following our successful synthesis of reactive perfluoroalkyl quaternary ammonium compounds (RfQAC), which were covalently incorporated into polyurethane coatings, leading to very effective smooth, antimicrobial coatings, we turned our attention to prepare hierarchically structured coatings aiming at obtaining super-repellent coatings that would resist bacterial adhesion. The hierarchically structured coatings we have made via layer-by-layer particle deposition have demonstrated excellent anti-bioadhesion property (significantly reduced protein adsorption and no platelet adhesion at all). So, even without grafting RfQAC compounds onto the structured coatings, these coatings may become an attractive platform for a range of biomedical applications through synergistically tuning surface chemistry and topography. We also made RfQAC compounds with other reactive groups such as acrylic double bond and siloxane, which will allow us to covalently bond the RfQACs to various substrates, such as coatings, fabric, and even paper. This will certainly broaden the application areas of our strategy that are pertinent to food safety.

Publications

  • Zhao, J., Ming, W. Anti-bioadhesion on Hierarchically Structured, Superhydrophobic Surfaces, Abstract submitted to ACS Spring Meeting 2013 (New Orleans).