Environmental Pathogen Control with Innovative Engineering Tools
Many pathogens, including bacteria and viruses, are environmental persistent and difficult to control. They can lead to gastroenteritis, respiratory tract infection, hospital acquired infection, etc. They are everywhere: on your hand, on the contact surfaces, in the air, in the water, on food and food processing surfaces. Conventional strategies may not be able to effectively capture or inactive theses pathogens, and we are thus inspired to develop new engineering tools to control pathogen transmission and minimize the spread of infectious diseases.
Ongoing Projects
Development of a Visible-Light-Responsive Antimicrobial Packaging System for Improving Food Quality and Safety (Funded by USDA-NIFA Novel Foods and Innovative Manufacturing Technologies Program, 2021-2023)
Microbial contamination causes food spoilage and increases the risk of foodborne illnesses. Food packaging materials are crucial for safe food storage, handling, and transportation, and play an essential role in extending the shelf-life of foods. Antimicrobial embedded packaging materials, a type of smart packaging, hold promise for reducing food spoilage and preventing foodborne diseases; however, current antimicrobial packaging solutions face challenges, including rapid exhaustion of antimicrobial agents, potential toxicity by some of the antimicrobial agents, and the inability to inactivate a broad spectrum of bacteria. Thus, there is a pressing need to develop effective and sustainable antimicrobial packaging systems to ensure food quality and safety.
We are collaborating with Profs. Haibo Huang, Young-Tek Kim, Yun Yin, and Monica Ponder (all at Virginia Tech), and we aim to develop a photo-responsive, antimicrobial packaging film using dye-sensitized TiO2 bio-composites to improve food quality and safety. This research will be the first attempt to design and fabricate a dye-sensitized packaging film that can harvest visible light photons to produce a blast of reactive oxygen species (ROS) to inactivate spoilage bacteria and foodborne pathogens attached to film or contained on foods. Upon completion of the project, we will be able to characterize the effectiveness of dye-sensitized photocatalytic materials to inactive bacteria on packaging film and contained food and develop photocatalytic packaging films to reduce food spoilage and prevent foodborne illnesses.
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Completed Projects
Development of Graphitic-Carbon-Nitride-Based Antimicrobial Nanomaterials for
Safe Food Processing and Packaging (Funded by USDA-NIFA Nanotechnology for Agricultural and Food Systems Program, 2017-2021)
Safe Food Processing and Packaging (Funded by USDA-NIFA Nanotechnology for Agricultural and Food Systems Program, 2017-2021)
Foodborne pathogens raise significant concerns in public health and economic losses. In the food processing industry microbial cross-contamination compromises the safety of processed food. Defective and dead zones on processing surfaces not only provide a favorable environment for the accumulation of food residuals, harbor biofilms, and stimulate pathogen growth, but their cleaning and sanitation are generally difficult and ineffective. Food packaging is critical for food storage, handling, and transport, but defected or soiled food packages and packaged food spoilage may promote further pathogen propagation. Antimicrobial packaging materials exist, but the antimicrobial agents eventually become exhausted in long-term food storage, and the use of one agent may not be effective to inactivate a sufficiently broad range of pathogens. Therefore, there is a need for an effective, broad-spectrum, sustainable antimicrobial material to address the above challenges in food processing and packaging.
We are collaborating with Profs. Santiago Solares (GW MAE) and Hanning Chen (American University) to design, synthesize, characterize, and apply g-C3N4-based antimicrobial nanomaterials and composites for safe food processing and packaging. We will use molecular simulations to rationally design the nanomaterials and their polymer composites with enhanced surface area, charge separation, and light absorption, guiding the fabrication of g-C3N4 with an optimum performance for pathogen inactivation. Next the material will be evaluated for planktonic pathogen inactivation and biofilm control in complex food matrices, for understanding long-term performance and nanomaterial safety. Finally, a quantitative reactive-transport model will be developed to predict the pathogenic biofilm’s life cycle, including growth, death, attachment, dispersal, and trafficking. This work will not only provide fundamental insights in nanotechnology, but will also lay out a systematic design-fabrication-application-evaluation strategy of nanomaterials for food science and engineering.
Electrospun Nanofibrous Air Filters for Coronavirus Control (Funded by NSF-Nanoscale Interactions Program, 2020-2021)
The spread of COVID-19 is difficult to control, because SARS-CoV-2 is environmentally persistent and it can be suspended in aerosols for long-range, airborne transmission and infection. Air filtration is crucial to control SARS-CoV-2 transmission, however most air filters used in residential, commercial, and industrial buildings are not effective for retaining viruses. As a personal protective equipment for healthcare personnel or even the general public, respirators that can effectively capture the virus are also urgently needed for this pandemic. Electrospinning has emerged as a novel technology to synthesize non-woven nanofibrous mats, and it is both industrially viable for large-scale manufacturing and deployable onsite for small-scale applications by a portable device. The nanofibrous mats are ideal for air filtration, because they have a reduced pore size to efficiently capture the virus, a large porosity to reduce air pressure drop in filtration, well-controlled properties, and mechanical robustness and flexibility.
We are collaborating with Prof. Yun Shen (University of California, Riverside), and we aim to rationally design and fabricate electrospun nanofibrous air filters that are effective, low-cost, scalable, and easy for implementation for coronavirus control, including SARS-CoV-2, and to understand the mechanism of coronavirus removal in filtration. Specifically, we will use electrospinning to develop nanofibrous air filters with diverse morphologies, retained charges, and selective binding sites to enhance the capture of bioaerosols containing coronaviruses. We will also identify key virus-nanomaterial interactions with both simulation and experimental tools, which can guide future air filter design and optimization. The research will advance our understanding of the interplay between viral pathogens and nanomaterials in complex environmental matrices, and initiate a fast response for controlling pathogen transmission and protecting the public health with engineering tools.
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A microscopic (left) and true-to-size view of the nanofibers
This project has been reported by GW Today and GW Hatchet. |