Medical Textiles

Holly Morris, Richard Murray

• Publisher: CRC Press
• Year: 2021
• ISBN:
  9781000514315
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Biomedical Science
• Index: Technology & Engineering

This textbook aims to ensure that advances in medical textiles are addressed and that recent developments are able to be appreciated and understood not only by medical practitioners and healthcare personnel but also by textile scientists and technologists. The idea is to stimulate collaborative research and development in the field of medical textiles and to equip researchers with an understanding of the steps they need to take to ensure that their efforts, be they to develop new devices for implantation or items for external application, are carried out in such a way as to improve their effectiveness and enhance the prospects for their implementation. Attention is drawn to the need to improve outcomes in the practical setting and to guidance on the detailed planning required prior to engaging in experimental work. Standard tests can help researchers to monitor performance, but for some important applications such as those required to demonstrate antimicrobial and fluid-repellent performance in most items of protective wear, standard tests consistently fall seriously short in terms of predicting how well they might work in the practical setting. Guidance is therefore given for their further development.

Chapters within the textbook cover:

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• The history of innovation within medical textiles with particular attention given to key concepts of the latter part of the 19th Century and subsequent associated developments.

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• Textile and polymer science underpinning fibres, fabrics, nano-fibre technology and the functional finishes that can be applied to enhance the performance of medical textile products.

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• Woven, knitted, nonwoven and braided fabrics and the key performance characteristics of each fabric type which make them particularly suited to specific medical textile roles such as mesh, grafts, filtration and scaffolds for tissue engineering.

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• Implantable medical textiles, non-implantable medical textiles, health and hygiene products and extracorporeal devices that use textile products.

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• Legislative requirements for medical devices.

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• The design of experiments and suitability for purpose of textile test methods.

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• Case studies to illustrate how medical textiles are applied in practice.

The book provides essential reading for textile professionals, biomedical engineers, and others involved in the research, design and engineering of medical and healthcare appliances, and for those employed in the medical profession wishing to gain new insights into the wealth of materials at their disposal.

1 Introduction

DOI: 10.1201/9781003170570-1

As defined by The Textile Institute, a medical textile is “a textile structure which has been designed and produced for use in any of a variety of medical applications, including implantable applications” (The Textile Institute, 2021). The field of medical textiles is one of the fastest growing parts of the technical textiles sector of the textile industry, with products ranging from personal protective equipment (PPE) through to bandage materials, and replacement parts for the human body to bioscaffolds for tissue engineering. This book provides details about the roles for which textiles can be employed in the healthcare sector as well as reviewing current developments within the field. Due to advances in technology, and mainly, but not only, in nanotechnology, the technical medical textile sector is undergoing rapid progression and expansion particularly in fields such as wound healing, pressure and bandaging garments, and implantable textiles. In addition, there is growth in medical devices aided by the incorporation of a growing range of durable and effective antimicrobial agents and in the development of smart garments intended to provide remote monitoring of patient’s vital functions. Population growth, an ageing population, and rising standards of living will all continue to fuel the growth of this sector.

A total of 3,238 papers about medical textiles were published between 2000 and 2021 according to a search of the record provided by PubMed®/Medline® (PubMed.gov 2021), of which over half of the total (2,075) emerged in the last 5 years. The largest category in the past 20 years, antimicrobial textiles, accounted for 2,077 papers in total. The papers reported research on both the development and incorporation of the antimicrobial agents to bring about the desired antimicrobial effects and on the efficacy of the resultant textiles/garments. The intended applications of the antimicrobial textiles ranged from barrier fabrics in uniforms for healthcare personnel and in their personal protective equipment, through sutures and implantable items, to wipes, dressings for wound care, and hospital textiles in general. The surge in published research on antimicrobial topics over the past 5 years can be attributed, at least in part, to advances in nanotechnology (Mishra et al. 2014, 133–226), enabling the incorporation of the active antimicrobial agent in nanoparticle form into the textile either during spinning of the fibre-forming polymer or through finishing treatments. Helpfully, the nanoparticles can be applied to fabrics intended for medical use without detrimental effects on their textile properties. Regarding effectiveness, such treatments with antimicrobial agents in the form of nanoparticles can demonstrate high levels of antimicrobial activity coupled with excellent durability (both in use and through repeated cycles of laundering), much better than metal salts or adsorbed quaternary ammonium compounds for example, which work by leaching from the treated fabric and therefore become diminished by laundering. The fully developed versions of antimicrobial nano-finishes can therefore find widespread application. In this regard, nanosilver (nano-Ag) treatments can be thought of as leading the way. Despite concerns (even in this case) over possible leaching of the nanosilver from the garment onto the skin of the wearer (which it would be wise to keep under review), skin contact has been shown to be not so great a problem (Liao, Li, and Tjong 2019, 449; Mahltig and Haase 2012, 1262–1266). As for loss into the environment at the end of the textile’s useful life, given consideration of the complete lifetime assessment, concerns are reduced, and overall, nanosilver treatments can be judged to have made a positive contribution to health and to establish a secure and substantial niche in the market for antimicrobial textiles (Pourzahedi, Vance, and Eckelman 2017, 7148–7158). That may be so, but there are now several other nano-particulate agents and combinations of agents demonstrating similarly high levels of effectiveness, and pre-treatments with chitosan or carbon nanotubes, for example, are being shown to enhance not only uptake of the active agents, but also their effectiveness and durability. For protective clothing for healthcare workers, however, rather than any single agent, the antibacterial treatments that are expected to show the most benefit in practice are multifunctional finishes which combine antimicrobial action with surface modification to enable the fabric to repel/shed hazardous liquids such as bodily fluids (Mitchell, Spencer, and Edmiston 2015, 285–292). Unfortunately, however, up to the present time, despite great enthusiasm being expressed in research papers about the high level of antibacterial activity as shown by standard test methods for several treatments for medical textiles, antimicrobial effectiveness is not exhibited by those antimicrobial-treated materials when they are used in the PPE garments worn by healthcare personnel during surgery or patient care.

Finishing treatments including antimicrobial treatments on textiles are addressed in Chapter 5, but will also be discussed elsewhere in the context of each particular application. What is interesting to note is that while there might have been a substantial surge in the development of antibacterial treatments for textiles, the same level of activity does not explicitly apply to viruses. Although there was a single reference to virus removal (in water treatment) by liquid filters (Schabikowski 2019, 4373–4382) and a small number to surgical respirators, there was only one reference to work engaged specifically in the development of an antiviral textile barrier material aimed at forming part of the healthcare workers’ PPE. Parthasarathi and Thilagavathi engaged with trying to more fully address improved protection from potential infection by viruses, using a bacteriophage as a surrogate virus, and unlike the test methods for antibacterial activity, this test does appear to more closely represent the range of conditions experienced by PPE during surgery and patient care and the authors were confident that they had developed an effective barrier material for this kind of use (Parthasarathi and Thilagavathi 2015, 1095–1105).

Electro-spun nanofibres are relatively slow to produce compared to outputs from traditional wet, dry, or melt-spinning processes. Nevertheless, they are worth the effort because of the very particular properties they possess on account of their fine diameter which allows for the production of structures that possess extremely high surface areas combined with great flexibility. The electrospinning process is well-established and can be applied to a wide range of polymers given suitable solvents and sufficient polymer-chain entanglement. Although they can readily be collected and used in the form of a web, such webs are very weak and tricky to handle, so most interest lies in collection in the form of continuous bundles or yarns of nanofibres, bundles which can be of very neat construction and may be twisted together to yield twofold nanofibre yarns for example. Also, yarns can be created by coating a conventional filament yarn with nanofibres to bring together in that core-spun yarn characteristics not achievable alone; such core-spun yarns have the strength of the conventional yarn combined with the surface characteristics of the nanofibres. If, however, the core is made from a soluble polymer, dissolving that core can yield hollow yarns (of interest as reservoirs for drug delivery). Electro-spun yarns made from synthetic absorbable polymers (SA polymers) now play a significant role in medical textiles both as scaffolds for tissue engineering and in drug delivery. That achievement is due in great part to the way the massive surface areas and the porosities of electro-spun fibrous assemblies/fabrics provide such excellent scaffolds for cell proliferation and growth during the period that the steadily degrading electro-spun-polymer yarn bundle is needed to continue to offer support (Mokhtari et al. 2016, 191–207). The sought-after performance from these particular materials arises, therefore, not only from the nano-fibrous nature of the textile support but also from the properties conveyed into the structure by the SA polymer. Accordingly, there has been a significant amount of work carried out on candidate SA polymers and the best ways of preparing the fibrous materials to achieve repair without the need to engage in further surgical procedures to remove the support once it has achieved the desired effect.

References

1. Liao, Chengzhu, Yuchao Li, and Sie Chin Tjong. “Bactericidal and cytotoxic properties of silver nanoparticles.” International Journal of Molecular Sciences 20, no. 2 (2019): 449.
2. Mahltig, Boris, and Hajo Haase. “Comparison of the effectiveness of different silver-containing textile products on bacteria and human cells.” Journal of The Textile Institute 103, no. 11 (2012): 1262–1266.
3. Mishra, Rajesh, J. Militky, Vijaykumar Baheti, Juan Huang, B. Kale, Mohanapriya Venkataraman, V. Bele, V. Arumugam, Guocheng Zhu, and Yan Wang. “The production, characterization and applications of nanoparticles in the textile industry.” Textile Progress 46, no. 2 (2014): 133–226.
4. Mitchell, A., M. Spencer, and C. Edmiston Jr. “Role of healthcare apparel and other healthcare textiles in the transmission of pathogens: A review of the literature.” Journal of Hospital Infection 90, no. 4 (2015): 285–292.
5. Mokhtari, F., M. Salehi, F. Zamani, F. Hajiani, F. Zeighami, and M. Latifi. “Advances in electrospinning: The production and application of nanofibres and nanofibrous structures.” Textile Progress 48, no. 3 (2016): 119–219.
6. Parthasarathi, V., and G. Thilagavathi. “Development of tri-laminate antiviral surgical gown for liquid barrier protection.” Journal of The Textile Institute 106, no. 10 (2015): 1095–1105.
7. Pourzahedi, Leila, Marina Vance, and Matthew J. Eckelman. “Life cycle assessment and release studies for 15 nanosilver-enabled consumer products: Investigating hotspots and patterns of contribution.” Environmental Science & Technology 51, no. 12 (2017): 7148–7158.
8. PubMed. “PubMed.gov.” 2021. Accessed May 22, 2021. https://pubmed.ncbi.nlm.nih.gov
9. Schabikowski, Mateusz, Alicja Cichoń, Zoltán Németh, Władysław Kubiak, Dariusz Kata, and Thomas Graule. “Electrospun iron and copper oxide fibers for virus retention applications.” Textile Research Journal 89, no. 21–22 (2019): 4373–4382.
10. The Textile Institute. “Textile terms and definitions.” 2021. Accessed January 7, 2021. https://www.ttandd.org/content/textile-terms-and-definitions.

2 The Development of Textiles in Medicine and the Healthcare Environment over Time

DOI: 10.1201/9781003170570-2

2.1 Introduction

It is thought that in ancient times, leaves, grasses, and flax may have been used as wound dressings, and it has also been hypothesised that bandages may have been made from wool or linen, but evidence has long since degraded. However, archaeological evidence does show that the Egyptians used linen bandages to splint broken bones and to wrap around bodies in the mummification process (Forrest 1982, 198–205), whilst in China, where historically clothing has been an indicator of societal rank, silk was a material worn only by the privileged, and undyed hemp ramie were the poor person’s clothing materials. Later, the poor wore cotton, and although flax was used in sutures, cotton was the fabric for staunching bleeding and for bandages. Lower socio-economic classes in Japan also tended to use coarse fabrics made from hemp or flax.

The first written references to the use of textiles in medicine and healthcare in the West date back to the ancient Greeks; over 130 wounds sustained during the Trojan War, and the management of them, are discussed by Homer in his poem, the Iliad. However, it is considered that the attribution of development of medical textiles to the Greeks may be based more on their excellence in record-keeping rather than their own innovation, and that it was in India that much of the initial work was thought to have been carried out, particularly in the case of sutures in India, as indicated by many of the items being listed by the Indian, Susruta (Mackenzie 1973). By the time of Hippocrates (460–375 BCE), a philosophical as well as a practical approach to medicine had developed (Fox 2020).

Whilst these early developments must be regarded as significant, many major innovations are much more recent hence main focus of attention in this chapter is on more-recent key developments, particularly those which have taken place since the mid-1800s.

2.2 Protecting the Patients and the Healthcare Staff

2.2.1 Patient and Practitioner Safety

Whilst the Hippocratic Oath, once sworn as entrance into the medical profession, has now been replaced by the Declaration of Geneva, the fundamental principle in medicine that the health of the patient will be the first consideration remains in place to the present day (World Medical Association 2017). Certainly, patient safety is of paramount importance and due consideration needs to be granted, as there can often be a very fine line between causing serious harm and achieving considerable good. For example, before the introduction of anaesthetics, the emphasis was on the operating surgeon to be swift and accurate, with little emphasis on hygiene due to the poor knowledge of the nature of pathogens. Armed, however, with the new knowledge from ‘germ theory’ comes the recognition that apart from being properly trained and equipped with the means to help the patient with their surgical techniques, medical practitioners and healthcare workers also need to be provided with adequate personal protection to help themselves to keep working effectively. There was also a recognition that they needed to be trained to systematically apply all necessary steps, not only in terms of immediate surgical-treatment techniques but also in patient aftercare and personal safety. This was not always appreciated or applied; sometimes because the fundamental scientific principles had yet to be established or had been misunderstood, in others, principles were understood but testing and/or training in equipment was insufficient, neglected, or needed to be developed.

Following the French Revolution an...

Table of contents

• Cover
• Half-Title
• Series
• Title
• Copyright
• Dedication
• Contents
• Preface
• Acknowledgements
• Authors
• Chapter 1 Introduction
• Chapter 2 The Development of Textiles in Medicine and the Healthcare Environment over Time
• Chapter 3 Textile Materials for Healthcare and Medical Applications
• Chapter 4 Fibre Types and the Polymers Used in Medical Textiles
• Chapter 5 Medical Textiles: Finishing
• Chapter 6 Ensuring Regulatory Compliance
• Chapter 7 Implantable Medical Textiles
• Chapter 8 Non-implantable Medical Textiles
• Chapter 9 Healthcare, Hygiene, and Personal Protective Equipment (PPE)
• Chapter 10 Extracorporeal Devices
• Chapter 11 Intelligent (SMART) Medical and Healthcare Textiles
• Chapter 12 Case Studies
• Chapter 13 Medical Textiles: The State of the Art
• Index