Location: Cotton Quality and Innovation Research
2022 Annual Report
Objectives
Enhanced Cotton (EC) for Value Added Applications research proposed here is performed within the Cotton Chemistry Utilization Unit (CCU) and intends to enable cotton’s use in expanded high value applications. The objectives cover a broad range of potential product types and thus are divergent to some extent. However, we strive to overlap in shared collaborative direction as illustrated below. The objectives of the EC Project are:
1. Resolve modifications in cotton-based textiles to enable new commercial applications of skin and wound contacting materials.
2. Enable, through chemical technologies, commercial production of conventional cotton-based (barrier protective) materials.
3. Derive novel cotton value-added products through nanocellulosic materials and conventional processes.
The research objectives proposed above, in conjunction with the Cotton Nonwovens research project, are targeted to improving U.S. cotton production by increasing the demand for domestic cotton. Increasing domestic consumption will come from identifying key consumer unmet needs specific for cotton, and areas where domestic cotton is required for end use products. Historically, solutions to downturns in U.S. cotton consumption have come from infusing cotton with new technologies that impart a competitive edge to cotton (e.g. permanent press) over synthetic fibers, or creating a customer-expedited supply of high quality cotton products that compete well with overseas production. However, in the current global market, development of proprietary technologies specific to the domestic consumption of cotton, are needed. Each of the research areas listed above is critically important at this time because each, if successful, will contribute greatly to increasing the domestic demands of cotton.
Approach
For Objective 1, a broad set of characteristics requires a varied approach to de novo design and preparation of cotton-based prototypes as body-contacting material. The target products of the approach are hemostatic, antimicrobial, chronic wound dressings and incontinence topsheet absorbents. Although each of these product areas share similar fabric characteristics they differ in functionality. Experiments for these four fabric groups will vary based on the functional target use. Evaluation of the influence of fiber structure on fabric surface polarity is important to hemostatic and incontinence fabrics, and design features at the cellulose crystallite level and molecular modifications are important to the chronic wound dressing. These will be assessed for activity through in vitro assessment models based on current leads, and prototypes developed from structure/function relations. Structure-activity relations of the fiber/fabric derivatizations will be examined at the fiber, microfibrillar and molecular level using fiber surface chemistry, electrokinetic, fluorescence, colorimetry, infrared spectroscopy, x-ray crystallography, and computational chemistry. The derivatized cotton materials will utilize chemical and physical cotton fabric modifications as are required to optimize activity and may employ some synthetic modifications i.e. protease sensor constructs are outlined in Obj. 3.
For Objective 2, discovery and development are outlined in three phases. In Phase 1, principle focus will be on the Layer-by-Layer (LbL) technology which will be applied to cotton nonwovens and compared on both bleached and greige cotton. Multifunctional activities will be explored i.e. antimicrobial, UV protection, and flame retardant activity. Phase 2 will predominantly be devoted to optimizing LbL functional properties to correspond with environmentally friendly, non-toxic approaches to conferring functionality i.e. antimicrobial, UV protection, and flame retardant activity while exploring ways to improve fabric hand. Phase 3 focus will be on working with stakeholders to identify LbL fabric technology with interest in applications i.e. military, sporting, wilderness medicine, fire barriers etc., and identifying key functionalities for cotton-based marketing and price point economy.
For Objective 3, mechanical milling of feedstock materials will yield a uniform-sized intermediate raw material, which will be subjected to alkaline and oxidative chemical treatments to remove pectin, hemicellulose and lignin. The ensuing suspension of nanocellulose will be hydrolyzed with dilute sulfuric acid and then subjected to high-pressure homogenization, leading to a sulfated cellulose nanofiber (sCNF). The sCNF products obtained by this process will be characterized by an array of analytical methods as detailed in the Methods section of (Jordan, Easson et al. 2019). From these isolated and characterized products, hydrogels, thin films and aerogels will be prepared and nanomaterial-treated cotton analogs will be prepared to obtain an initial nanomaterial-treated composites. Several lead compounds will be prepared to explore different chemistries.
Progress Report
Progress was made on all three objectives, all of which fall under National Program 306, Component 2, Quality and Utilization of Agricultural Products, Non-Food. Progress on this project focuses on Problem 2A to increase or protect the market demand for (or increase the value of) existing U.S.-produced non-food bio-based products derived from agricultural products and byproducts. Agricultural Research Service (ARS) researchers in New Orleans, Louisiana, have developed new products, applications, and processes for expansion of domestic cotton in the areas of: (1) moisture control properties and hygienic and cotton fabric hand applications; (2) conversion of biomass to nanocrystals; (3) flame retardant cotton; (4) utilization of enabling technologies for improved flame retardant cotton; (5) sensors that utilize a form of high surface are cellulose to detect disease biomarkers; (6) cotton-based blood antibacterial and antiviral fabrics for wound dressings and face masks; (7) and, hemorrhage control dressings with improved clotting properties.
Hemorrhage Control Dressing in Support of Objective 1: Preventing battlefield injury and hemorrhage is the highest priority of U.S. military trauma surgeons and researchers. In a collaborative effort with a stakeholder, we developed cotton-based nonwoven materials designed to accelerate blood clotting. We determined blood clotting activity of the materials. We developed blood clotting analysis methods for fiber-based materials. Zeolite is a high surface area aluminosilicate that enhances blood clotting. Zeolite was applied to cotton dressings, and pectin, and calcium formulations were designed to promote adherence of the compound to cotton fibers. We found that sodium and ammonium forms of zeolite on cotton dressings promote rapid clotting the best. Based on these results a lead candidate for commercialization will be selected to evaluate in hemorrhage studies.
Intelligent Cotton Dressings with Protease Sensors in Support of Objective 1 and 3: The ability to monitor, predict and improve wound healing is an important tool for the healthcare industry. Proteins play a significant role in the way wounds heal. Proteases are specialized proteins that break down other proteins. Thus, increased levels of proteases in a wound can prevent other proteins from functioning in wound healing. Sensors that detect dangerous levels of proteases improve healthcare. We designed sensor with a cellulose gel isolated from cotton. This improved sensor detection and performance. However, current sensor technology needs improvement. Thus, ARS researchers at New Orleans, Louisiana, prepared a special form of the cellulose gel to sensitively detect destructive levels of proteases in wounds. The special gel has increased surface area and can swell when hydrated. These properties make it more sensitive to detect elevated levels of proteases in wounds. The development of this special material provides the basis for improving point of care devices used at the bedside. We used a method to visualize the sensitivity of the sensor. We found that the new sensor design detects much lower amounts of proteases than current sensors. The new material has a small unit size so that more protease sensors can be placed in the same volume. Therefore, the specialized gel can detect more protease, with a better signal, than comparable materials. Progress from this research has shown that these materials can improve sensor performance. The special cellulose gel is also being studied as a scaffold for important wound healing factors. This research provides a starting point to develop different sensors for point of care monitoring and treatment in the future.
Increasing the Strength Properties of Paper with Nanocellulose and Cottonseed Protein in Support of Objective 3: The paper and packaging industry is interested in improving paper strength. There are many methods to do this, but most harm the environment. It is important to develop ways to improve paper properties that are natural and will not harm the Earth. Proteins obtained from cotton seed have a broad range of uses. They can be used in films, adhesives and paper products. ARS researchers have combined protein and cellulose fibers from cotton to create a paper-like material. We demonstrated that the paper performance was improved. The strength of dry paper was increased by as much as 97%. This work shows that using natural cotton products to improve paper offers consumers a renewable product choice that could be useful in the paper and packaging industry.
Cotton fabrics use vitamin C to promote disinfectant activity in Support of Objective 1 & 2: There is a worldwide demand for effective, safe, and economical textile fabrics that prevent the spread of infectious diseases. Agricultural Research Service (ARS) researchers developed a low-cost treatment of cotton fabrics by attaching small amounts of vitamin C to the fabric. We attached Vitamin C to the cellulose present in the cotton fabric. The treated fabric prevents growth of bacteria and viruses at the 99.99 percent level. We found that the mechanism of antimicrobial activity is generation of hydrogen peroxide. The hydrogen peroxide levels are produced upon contact with microbes and viruses and are safe for human use. We found that the duration of hydrogen peroxide generation was up to two to three days. The preparation of the modified cotton fabric is also ideal for manufacturing lines and streamlines the production process. We are working with the cotton and textile manufacturing industry to transfer the process. The modified cotton fabric will be applicable to a wide range of textile uses including facemasks, wound dressings, hygienic wipes, and fabrics used as barriers to the spread of microbes and viruses in hospitals.
Microencapsulation and Spray Drying in Support of Objective 2: Microencapsulation has become an alternative approach to improving the sustained release of compounds of commercial interest to confer properties suitable for protection against microbes, mosquitoes, and flame retardant activity. The technology is adaptable for cotton textile treatment. Recently, ARS researchers at New Orleans, Louisiana, have developed microcapsules using flame retardant, mosquito repellant, and antimicrobial compounds such as phosphorus–nitrogen small molecules, tea tree oil, essential and naturally occurring oils. We prepared microcapsules by depositing a thin coating on small solid particles or liquid droplets. Cotton fabrics treated with microcapsules will be studied for their slow time-release properties. The results that validate the design of the microcapsule-treated fabrics using standard test methods for sustained release of small molecules and oils.
Flame Retardant Cotton In support of Objective 2: Original approaches to prepare flame retardant cotton fabrics are required to advance the industrial development of low-cost and effective flame retardant cotton. Innovative approaches to incorporating flame retardant properties to cotton include combining microencapsulation and microwave technologies. Microencapsulation is a process in which flame retardant compounds can be coated onto the fabric with extremely small capsules that allow slow release of the compounds onto the textile fiber. Microwave technology is a household name for cooking, but it is also used by industry to rapidly cure textiles. ARS researchers used microencapsulation and/or microwave technologies to modify cotton fabrics. The small amount of solvent used is an advance over current industrial processes to make flame retardant cotton. Thus, we showed that microwave-assisted technology is a rapid chemical treatment for cotton fabrics. The cotton fabrics designed contained environmentally friendly molecules including urea, diammonium phosphate, and phosphorous nitrogen rich containing compounds. We developed an efficient method for the chemical treatments of fabrics. The modified fabrics tested positive for flame retardant activity. The treatment gives higher yields and the addition of more of the chemical to the fabric (100 percent add-on). The compounds are also low-cost and commercially amenable to large-scale production of cotton fabrics.
Accomplishments
1. Cotton-Based Sensor Assembly and Design to Detect and Trap COVID-19 associated virus. Potential for a cotton-based sensor to trap and detect the virus that causes COVID-19. Combating the virus that has caused the COVID-19 pandemic has been a challenge for healthcare professionals and the public at large. ARS researchers in New Orleans, Louisiana have investigated how cotton can be made applicable to both the detection and prevention of virus infection. Their work on detecting and preventing the spread of the virus first focused on how the virus enters human cells. The virus enters human cells by binding to the virus surface. Thus, the design of virus sensors employs information about how it adheres to human cells. The ARS researchers at New Orleans, Louisiana, used this concept to help design special chemical agents (peptides). The peptides were prepared and studied for their ability to adhere to the surface of the virus. Using a special technique to study the peptides’ structure, they showed that the shape of the peptides influences their ability to adhere to the virus. In addition, it was found that as the peptides increased in negative charge their binding to the virus increases. This finding prompted the ARS researchers to survey reported viral variants for charge differences. Subsequently, they and others found and reported a common property of the variants of concern in the COVID-19 pandemic. This property is the tendency of the virus mutations to form increasing net positive charge on their surface to promote infection. Thus, there is a correlation of increased positive charge with increased virulence. This finding will help in designing protective cotton textiles of the future. These textiles may be tailored to detect, trap, and neutralize viruses. This could also help in the design of personal protective equipment and influence how we approach the current and future pandemics by improving on their efficacy .
Review Publications
Mackin, R.T., Fontenot, K.R., Edwards, J.V., Prevost, N.T., Jordan, J.H., Easson, M.W., Condon, B.D., French, A.D. 2022. Detection of human neutrophil elastase by fluorescent peptide sensors conjugated to TEMPO-oxidized nanofibrillated cellulose. International Journal of Molecular Sciences. 23(6):3101. https://doi.org/10.3390/ijms23063101.
Mackin, R.T., Edwards, J.V., Atuk, E.B., Beltrami, N., Condon, B.D., Jayawickramarajah, J., French, A.D. 2022. Structure/function analysis of truncated amino-terminal ACE2 peptide analogs that bind SARS-CoV-2 spike glycoprotein. Molecules. 27:2070. https://doi.org/10.3390/molecules27072070.
Jordan, J.H., Cheng, H.N., Easson, M.W., Yao, W., Condon, B.D., Gibb, B.C. 2021. Effect of nanocellulose on the properties of cottonseed protein isolate as a paper strength agent. Materials. 14:4128. https://doi.org/10.3390/ma14154128.
Easson, M.W., Jordan, J.H. 2021. Preparation of cellulose nanocrystals from cotton gin motes and cotton gin trash. In: Sarker, M.I., Liu, L.S., Yadav, M.P., Yosief, H.O., Hussain, S.A., editors. Conversion of Renewable Biomass into Bioproducts. ACS Symposium Series, Vol. 1392. Washington, DC:American Chemical Society. 1392:15-33. https://doi.org/10.1021/bk-2021-1392.ch003.
Hillyer, M.B., Jordan, J.H., Nam, S., Easson, M.W., Condon, B.D. 2022. Silver nanoparticle-intercalated cotton fiber for catalytic degradation of aqueous organic dyes for water pollution mitigation. Nanomaterials. 12(10):1621. https://doi.org/10.3390/nano12101621.
