I. Introduction
The healthcare-associated infections (HAIs) represents a high problem in the hospital environments, due to viruses and bacteria adhere to the surfaces of hospital textiles, these microorganisms are derived from bodily substances, such as skin, feces, blood, urine and vomiting1-5. Current autoclave laundry and disinfection processes remove dirt but are far from sterile so they are not sufficient to interrupt the transmission of (HAIs)6.
The nanotechnology is a science, that represents an opportunity to improve properties of materials, by means of the use of particles of sizes of 10-9m incorporated in them7. Nano-particles can be applied in textile material to provide properties such as (self-cleaning surfaces, stain resistance, water repellency, electrical conductivity, antimicrobial resistance, hydrophilicity or controlled hydrophobicity, wrinkle resistance, anti-static, antiodor, fire resistance, UV radiation protection, abrasion resistance, shrink resistance, etc.)7. Nanoparticles have a high surface area ratio and a high energy surface, have a better affinity for the fabric, due to of their nanometric size penetrate deeper into the fibers8.
Metal and metal oxide antibacterial nanoparticles immersed in textiles provide protection properties against microorganisms9. A type of metal antibacterial nanoparticle is those silver (Ag), its microbicide mechanism acts suppressing respiration and microbial basal metabolism, inhibiting its multiplication and growth10. The application of silver nanoparticles in textiles makes them resistant to odors, so they are applied in socks in order to inhibit the growth of bacteria8.
The oxide metal antibacterial nanoparticles are Titanium dioxide (TiO2) and Zinc oxide (ZnO) these have photocatalytic activity, being irradiated by ultraviolet light with greater energy than their band separations, electrons and holes interact with the oxygen and H2O molecules that are adsorbed on the surface of the nanoparticles to produce reactive oxygen species (ROS), hydroxyl radical, etc., which interfere with the organic material by decomposing the bacteria7,11-17.
Non-woven textiles are widely used in hospital environments due to their random fiber conformation, filtration capacity, permeability and porosity18-20. The properties of the nonwoven textiles with antibacterial nanoparticles incorporated in their fibers are the reason of the present study, in which a technological surveillance was developed around the subject.
II. Methodology
A technological surveillance was developed using the search equation with the terms "antibacterial" and "nanoparticles" through the use of the Scopus database, these contains the largest bibliographical references of scientific literature, with over 18,000 titles from 5,000 international publishers21. The term “Antibacterial”, and the term “nanoparticles” produces 4,099 results. In order to limit the results, the term "electrospun" was added to the search equation, which produced a total of 93 results.
A. Analysis of documents by author. Between 2007 and 2017, 10 authors have published about the properties that antibacterial nanoparticles offer to nonwoven. Among the most relevant authors are Kim, H.Y. with 4 publications, Pant, H.R with 4 publications also, Bai, J; Cui, W; Fan, C; Heo, D.N; Kim, C.S; Kwon, I.K; Lee, S.J; Li, C; with 3 publications each one of them (Table 1)22:
Author | Number of documents |
---|---|
Kim, H.Y | 4 |
Pant, H.R | 4 |
Bai, J | 3 |
Cui, W | 3 |
Fan, C | 3 |
Heo, D.N | 3 |
Kim, C.S | 3 |
Kwon, I.K | 3 |
Lee, S.J | 3 |
Li, C | 3 |
The Fig. 1, shows the relationship between the authors and the total number of articles associated with each of them22:
B. Properties analyzed by authors. Technological surveillance will be approached from the 10 authors mentioned above, due to it is pertinent to consider the properties antimicrobial of nonwoven fabric for hospital environments, these authors recognize the characterization of this type of material as their main objective.
1. Weight: Mass per unit area (g/m2), it was measured by dividing the mass and area of this material23-25.
2. Thickness: Sample thicknesses were measured using a digital micrometer with an accuracy of 1μm. 10 parallel measurements were taken for each sample and mean values were used as the film thickness26-31.
3. Air Permeability: This procedure allows the measurement of the amount of air sucked laterally between the ring and the sample. Air permeability is expressed in units of millimeters over seconds (mm/s)23,30,32-35.
4. Contact angle measurement (WCA): Is a procedure to calculate the surface properties (surface tension and dispersion) of a polar or non-polar liquid on a substrate27,36,37.
5. Water Absorption: This method determines the relative water absorption rate of the plastics when they are submerged23,37,38.
6. Stability of nanoparticles: Accelerated washing tests evaluate color fastness and staining of all types of textiles. This test is used to investigate the stability of the nanoparticles in the samples. The samples are tested under suitable conditions of temperature, detergent solution, bleaching and abrasive action in such a way that the color change is similar to that which occurs in five handwashing with or without chlorine39,40.
7. Water vapor permeability (WVT): This method allows to determine the passage of water vapor through plastic films, which are not more than 32mm of thick23,30,31,33,34,41.
8. Flammability test: This procedure makes it possible to determine the response of the polymer materials to the flame under controlled laboratory conditions, thereby indicating their acceptability with regard to flammability for a particular application42.
9. Tensile Strength: This procedure allows the determination of the maximum tensile stress that the nonwoven material can withstand before breaking27-29,43-45.
10. Abrasion resistance: This procedure quantitatively determines the duration of the nonwoven in its normal use, subjecting it under laboratory conditions to an Martindale abrasion tester23.
C. Relationship of properties with international Standards. The properties mentioned by the authors are related to international standards (Table 2), in order to provide a higher quality applicable to non-woven textiles containing antibacterial nanoparticles, improving the healthiness in the hospital environment.
Properties | International Standards |
---|---|
Weight | NTC 2598-EN29073-1 |
Thickness | NTC2599-EN29073-2 |
Air Permeability | ASTM D737 |
Contact angle measurement (WCA) | ASTM D7490 |
Water Absorption | ASTM D570 |
Stability of nanoparticles | AATCC 61 2(A) |
Water vapor permeability (WVT) | ASTM E96 |
Flammability test | UL94 |
Tensile Strength | NTC 2600-ISO9073 |
Abrasion resistance | ASTM D3884 |
III. Results and Discussion
In this study, a technological surveillance was developed around the subject of the properties of non-woven textiles with antibacterial nanoparticles incorporated, for use in covers and curtains of hospital environments. Among the most notable results are the materials used to develop nonwoven textiles, the sizes used for the evaluation of the properties and the equipment used for their morphological and mechanical characterization.
A. Materials used to develop nonwoven textiles
The authors in their respective studies developed nonwoven textiles from different materials according to their properties and the application of these (Table 3).
Materials | Properties of materials | Application of nonwoven |
---|---|---|
Nylon (PA6) 6-Polyamide 6 | It is a biodegradable, biocompatible and synthetic polymeric material that has good mechanical properties, such as its hardness, elasticity, toughness and resistance to abrasion, wear, oils, heat and chemical and the capacity of easy processing. | It is used in automobile parts, wipes, battery separators, synthetic suede, brush bristles and protective garments. Nanofibers of nylon-6 have been reported as effective means of water filtration. |
Gelatin type A | It is a polymer with compositions and biological properties almost identical to those of collagen, it is soluble in water and economical. | Gelatin nanofibers are used for tissue scaffolds, wound healing, health care devices and other biomedical applications. |
Polyimide (PI) | PI are a class of high performance polymers that combine high thermal stability with good mechanical properties, heat resistance and chemical resistance to solvents. | It features various applications, including protective clothing for firefighters and filtration membranes. |
Polyurethane (PU) | It has properties such as low temperature flexibility, abrasion resistance, controllable hardness, transparency, and excellent hydrolytic stability. | Polyurethanes have been used in garments and textile coatings for garments, such as raincoats and industrial safety clothing. |
Polylactide (PLA) | It has excellent mechanical properties, is compostable, biocompatible with respect to cells, tissues and organs and is biodegradable. | PLA can be used to prepare foams, films, fibers and nonwoven. |
Polyester (PET) | It is semi-crystalline, transparent and thermoplastic with high strength. | It is widely used to produce fibers, films and packaging materials with high barrier properties, clothing, and industrial fabrics. |
Agar, k-carrageenan and carboxymethyl cellulose (CMC) | They are biodegradable, biocompatible, renewable annually and abundantly available. | With good property of formation of antimicrobial films. |
Poly (lactic-coglycolic acid) (PLGA) | PLGA formed by polyglycolic acid (PGA) and polylactic acid (PLA) is biocompatible and biodegradable material. | It is used as a platform for the release of TiO2 nanoparticles into the environment. |
Polypropylene (PP) | The fibers are economical, lightweight, have high chemical resistance and high absorbency. | It is used for sanitary applications such as surgical masks, diapers, filters, bands, etc., that need to show antibacterial effects. |
This table indicates that both synthetic and natural polymers are being used for use in hospital environments due to their biocompatibility and biodegradability as well as good mechanical properties. Nylon-6 is the most widely used polymer for the creation of non-woven antibacterial textiles as indicated by multiple authors, so further research is recommended around this material to better understand their properties with embedded nanoparticles.
B. Properties, sizes and equipment
In various articles analyzed in the present investigation, about the properties of nonwoven textile with antibacterial nanoparticles immersed in it. The authors reported sample sizes used for their characterization and equipment to develop these assessments (Table 4).
Properties | Sample sizes | Equipment |
---|---|---|
Weight | Three test pieces, each of a minimum area of 50,000 mm2. | Scales |
Thickness | Three test pieces, each of a minimum area of 2500 mm2. | Micrometer |
Air Permeability | Ten circular test pieces, each of a minimum area of 5 cm2. | Frazier Air Permeability Tester |
Contact angle measurement (WCA) | Three test pieces, each of a minimum area of 3x10 cm. | Contact angle analyzer |
Water Absorption | Three samples of diameter 1,5 cm and a thickness of 1 mm | Dryer oven Scales Watch crystal |
Stability of nanoparticles | Three sample sizes 50x150 mm | Atomic absorption spectroscopy |
Water vapor permeability (WVT) | Three circular sample sizes (7.5x7.5 cm) | Vaporometer - permeameter |
Flammability test | Three samples of length 125 mm x Width 13 mm x Thickness 1.5 mm | Test equipment for flammability of 45 degrees, or vertical. |
Tensile Strength | Five test pieces of 50 mm + -0.5 mm wide. With a length sufficient to allow separation of jaws of 200 mm. | Universal machine |
Abrasion resistance | Ten square samples of approximately 15 cm | Martindale abrasión tester |
This information allows to clarify for each one of the properties of the non-woven, the required sample sizes, and the necessary equipment to develop their respective characterization, in order to provide tools that allow to speed up their analysis.
V. Conclusion
The objective of this research was to construct a technological surveillance as a basis for studying the nonwoven textiles with antibacterial nanoparticles immersed in their fibers, in order to better understand the properties that improve in these to be reinforced, different authors have addressed the topic of non-woven textiles for various applications including tissue regeneration membranes, water filters, and protective clothing.
Between 2007 and 2017, the number of publications in this field increased significantly, especially in specialized journals with materials, chemistry and biomedical sciences. The countries with the highest number of papers between these years are China with 28 papers and Korea South with 24 papers, but in Scopus there are no reports yet of Colombia, which makes it necessary to increase the R & D processes in our country to provide healthy improvements in hospital settings. At present, only 6 articles produced in Colombia are reported in Scopus in relation to the subject of non-woven mainly in applications of water filters in engineering applications, coatings for Stents in health applications and Geotextiles in applications of earth sciences. Therefore, it is necessary to explore in greater depth the properties of non-woven to be used other multiple applications among them in a hospital environment.
The properties analyzed by the different authors for non-woven textiles are associated with the standard NTC 5366 "Textiles for hospital and institutional use", which describes the minimum requirements that a textile for hospital use must meet. By associating properties with international standards, higher quality can be provided to non-woven textiles through characterization tests.
Various types of natural and synthetic polymers have been used to develop non-woven textiles, according to their properties they present a variety of applications in the biomedical field. International standards for non-woven fabrics specify the appropriate sample sizes and equipment for the characterization protocols. In future studies, the durability of the nonwoven fabric and the time of effect of the antibacterial nanoparticles could be considered, in order to provide more information regarding the useful life of this type of reinforcement.