Masks and PPE that repel bodily fluids and viruses for better protection. Performance is durable under repeated washing for reuse.
Healthcare professionals are exposed to high doses of human coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes COVID-19. There is a need for new textile coatings with biohazard repellency that may be applied to textiles to better protect healthcare professionals from various droplets and viruses. Furthermore, due to equipment shortages and better environmental impact, there is a need to create masks and PPE that are reusable as opposed to disposable or single-use.
Silver nanoparticle technology as well as the other existing coatings used in medical textiles are unsuitable for addressing the virus protection and equipment shortage needs of the current COVID-19 pandemic. Silver nanoparticles and other coatings are easily removed in the wash, rendering the surface ineffective, and are thus limited to single-use disposable textiles. Many of these coatings also have poor mechanical durability as simple scratching or handling may remove the coatings and its associated protection. Silver nanoparticles also have major challenges with high cost that are further amplified with their application to disposable textiles.
Body fluid repellency is important for improving the protection and hygiene of PPE since body fluids are common vectors for disease transmission. Similarly, PPE pose a risk of transmission during doffing. Strategies for creating body fluid-repellent substrates consist of designing a surface that can fully repel body fluids. Virus particles that are spread in droplets of human body fluids will not be absorbed into the fabric, but instead be repelled.
The technology consists of a durable and wash-stable anti-virofouling coating that may be applied to reusable textiles. The treatment repels various droplets due to its low surface energy, multi-length scale roughness. The treated surface area reduces the surface area in contact with the liquids by an estimated 350 times compared to untreated surfaces. The treatment is mechanically robust due to its multi-layer, multi-length scale roughness and wash-stable because it has very high pressure stability.
The treatment consists of a non-woven polypropylene microfiber treated with polytetrafluoroethylene nanoparticles. Conventional respiratory masks like the N95 consist of multiple layers of non-woven polypropylene(PP) microfibers. We propose treating the microfiber layer with nanoparticles. The combination of microfiber/ nanoparticle roughness and the selection of low surface energy polymers creates trapped air that prevents liquids from being absorbed into the fabric.
The value proposition of the proposed coating is that it offers (1) > 90% reduction in virus adhesion, (2) low cost, (3) mechanical durability, and (4) wash stability. This is in contrast to state-of-the-art bactericide agent loading approaches which have (1) high-cost, (2) poor durability, (3) environmental toxicity, and (4) evolved resistance. This value proposition has been demonstrated in our recently published paper, “Superhemophobic and Anti-Virofouling Coating for Mechanically Durable and Wash-Stable Medical Textiles,” in ACS Applied Materials & Interfaces. Our results demonstrate that coated textiles reduce the attachment of adenovirus type 4 and 7a virions by 99.2 ± 0.2% and 97.6 ± 0.1% (2.10 and 1.62 log), respectively, compared to non coated controls. The treated textiles provide for these repellencies by reducing the surface area in contact with liquids by an estimated 350 times less (2.54 log) compared to control textiles.
Moreover, the treated textiles exhibit unprecedented durability, maintaining their droplet and viral repellency after extensive and harsh abrasion (Ford Laboratory Test Method BN 108-02) and washing (ASTMG131-96). Droplet and viral repellency were maintained after 5000 abrasion cycles with a Scotch-Brite scrub applied under 30kPa of pressure at a constant speed of 60 cycles per minute. Droplet and viral repellency were also maintained after 12 ultrasonic wash cycles where each wash cycle consisted of ultrasonication for 40 minutes at 80 W and 49 °C in a solution of 200 mL of H2O and 0.5 g of Extran MN 01 powdered detergent. The multi-layer nature of the surface provides for mechanical robustness as any rough abrasion to the surface results in the exposure of a similar underlying low surface energy surface. The multi-length scale of the surface also aids in this robustness as the PP microfibers act as protuberances that protect PTFE nanoparticle roughness from being abraded off. Anti-virorepellency is maintained after a variety of harsh abrasion or razor blade scratching or slicing conditions. The treated surfaces also have a high breakthrough pressure of at least 255 kPa; therefore, the water repellency is stable up to 15 meters underwater.
Who will take these actions?
Fabrication, characterization and durability testing will be conducted at the University of Pittsburgh in the LAMP (Lab of Advanced Materials in Pittsburgh) by a PhD student, Anthony Galante, under the advisement of professor, Dr. Paul Leu. Virus testing with beta-coronavirus will be conducted under the advice of Dr. Robert Shanks and Dr. Eric Romanowski in the Campbell Laboratory for Infectious Eye Diseases at the UPMC (University of Pittsburgh Medical Center) Ear & Eye Institute. Virus filtration experiments will be performed in collaboration with MIT Fabric Hub. We are collaborating with textile manufacturer, Leonisa, and talking to Children’s Hospital of Pittsburgh with regard to bringing the technology to the real world.
What are the projected costs?
Total funds anticipated is $50,000 in order to facilitate fabrication, research, collaboration and publication. Funds ($20,000) are requested to help support research efforts for one (1) graduate student, and three (3) professors. Funds ($15,000) are requested for laboratory maintenance & user fees. Furthermore, maintenance contracts for certain equipment in the lab and publication fees are included in the budget. Funds ($10,000) are requested for laboratory supplies and materials for sample preparation and experiments. Funds ($5,000) are requested towards publication fees and traveling to conferences to share the findings.
This project is a single year effort. Initial phase of the project (3 months) consists of sample fabrication, characterization and optimization. The second phase (3 months) consists of testing the durability of the treatment. Phase 3 (5 months) consists of testing the biohazard repellency and inactivation with beta-coronavirus. The final phase (1 month) of the project consists of reporting the results.
About the author(s)
Anthony J. Galante is a 4th year PhD student in Industrial Engineering at the University of Pittsburgh. His research focuses on medical coating technology. His work has been showcased in Pittsburgh NPR, Pittsburgh Magazine and the Student Spotlight of the International Fiber Journal.
Dr. Paul Leu is an Associate Professor in the Industrial Engineering Department at the University of Pittsburgh. His research group the Laboratory for Advanced Materials at Pittsburgh (LAMP) focuses on functional materials which have included functionalities such as antibacterial, antifogging, self-cleaning, and antireflection. He has been recipient of the Oak Ridge Associated University Powe Junior Faculty Enhancement Award, UPS Minority Advancement Award, and the NSF CAREER Award. His research has been showcased in Scientific American Frontiers, Pittsburgh NPR, and Pittsburgh Magazine.
Dr. Robert M. Q. Shanks is an Associate professor in Opthalmology, Microbiology and Molecular Genetics. He is also the science director of the Campbell Laboratory for Infectious Eye Diseases at University of Pittsburgh School of Medicine (UPMC). Dr. Eric G. Romanowski is a research director in the Charles T. Campbell Ophthalmic Microbiology Laboratory at UPMC.