Medical Textiles in Healthcare and Hygiene Products

In the previous article, we got an overview of technical textiles, among which medical textiles is one of the rapidly escalating segments. The medical textile industry is globally competitive, with the U.S. ranking fourth in global export value after China, India, and Germany. The increasing awareness among consumers in the society and demand for enhancing the quality of life has led to increased consumption and constant growth of medical textiles over the last decade. Not only is their consumption increasing, but also these textiles are becoming more sophisticated and smart to address the diverse needs of healthcare industries. 

This advancement is owing to the growing world population, improved hygiene and healthcare standards, higher life expectancy and a greater population of aged people with growing expectations for enhanced healthcare. This article outlines the application of medical textiles in healthcare and hygiene products.



1. Applications of medical textile in healthcare

Based on the end-use, medical textile is broadly divided into healthcare & hygiene, surgical (implantable and non-implantable) and extra-corporeal devices.



Figure-1: Classification of Medical Textiles

Healthcare and hygiene products:

Healthcare and hygiene products are vastly in use making up a large portion of the medical textiles market. The products under this category include those that are in regular use by hospitals, healthcare facilities, and individuals for hygiene and safety purposes. These products should exhibit a number of key characteristics such as cleanness, contamination-free and infection control. Surgical covers, bedding, incontinence products, clothing and wipes, come under healthcare and hygiene products. These products may be either washable or discarded after a single use.

Examples - Surgical gowns, Caps, Masks, Surgical Drapes, Hospital Beddings, Personal protective clothing (PPE), Incontinence products, wipes, etc. 



Figure-2: Examples of Healthcare & Hygiene Medical Textiles

Surgical:

Surgical medical textiles are implantable or non-implantable materials.

Implantable medical textiles are those which are designed for functioning within the body. The rise in the number of chronic diseases including coronary heart diseases, cholesterol, and hypertension is expected to positively influence the demand for medical textiles in the implantable goods segment. Implantable materials have a wide range of restorative uses—for example, they may be used to replace damaged blood vessels, suture wounds, stand in as artificial skin, or replace damaged heart valves. 

Biocompatibility of the material is of utmost importance for these textile materials. Medical textiles are suitable for implantable devices due to the suitability of making textile material into two- or three-dimensional structures, with the desired macroscopic structure and surface design.

Examples - Sutures, Artificial skins, Eye contact lens, Artificial ligament, orthopaedic Implants, Cardiovascular implants, etc.



Figure-3: Examples of Implantable Medical Textiles

Textile materials have been made into meshes for hernia repair and vascular prostheses for implantation, as well as cartilage, nerve, and liver regeneration.

Non-implantable medical textiles are used on the skin (may or may not be in contact with it) and are not meant to be used within the body. The materials need to be essentially sterile, lint-free, and non-toxic. Surgical dressings for wound care forms the majorly used non-implantable medical textile. Post-surgery garments for optimum support and compression - promote the healing process.

Examples - Absorbent pad, Bandage, Adhesive tape, Plaster, Gauze, elasticated bandage, etc.



Figure-4: Examples of Non-Implantable Medical Textiles

Extra-corporeal devices:

Extra-corporeal medical devices are a mechanical imitation of an organ that supports the function of vital organ systems. These devices act as a filtration unit, replicating the role as artificial kidneys, artificial livers, and mechanical lungs. The role of medical textiles in extra-corporeal devices is the use of hollow fibre membranes for filtration.

Examples - Artificial kidney, Artificial liver, Mechanical lung, etc.

Figure-5: Examples of Medical Textiles in Extra-Corporeal Medical Devices

2. Properties of the medical textiles

The major requirements from a medical textile are its biocompatibility, no allergenic response, absorbency, non-toxicity, strength, elasticity, durability, anti-static nature, and to a certain extent biodegradability and biostability. Depending on the end-usage, the set of properties required differ.

Healthcare and hygiene medical textiles require properties like:

  • Stable, spatial structure
  • Purity and nontoxicity
  • Sterility
  • Ability to manage exudates and fluid without causing irritation or maceration
  • Comfort
  • Provision of thermal insulation
  • Breathability
  • Mechanical protection
  • Moisture and liquid absorption
  • Low adherence
  • Nonsensitizing, nonallergic
  • Not contaminating a wound with loose fibers or other particles
  • Providing an effective barrier against microorganisms, dirt, liquid, and other foreign bodies

Surgical gown and protective clothing required barrier properties. Fibres with irregular surfaces/ cross-sections and shorter in length are more effective in preventing the transmission of particles. In incontinence products, the absorbency and the tactile properties are particularly important.

Implantable medical textiles

For implantable medical textiles, biocompatibility is of prime importance. Biocompatibility requires the following properties:
  • Porosity - determines the rate at which human tissue will grow and encapsulate the implant
  • Small circular fibres are better encapsulated within human tissue than larger fibres with irregular cross-sections
  • The fibre and its constituent polymer must not release toxic substances
  • The fibre should be free from surface contaminants such as lubricants and sizing agents
  • The fibre should be biodegradable.

Sutures need sufficient tensile strength, good knotting strength, complete biodegradability, sterile, and non-allergenic. For other implants, the structure of textile material should mimic different biological tissues like muscles, tendons, or ligaments. The requirements of artificial ligaments are extensive and it must have at least three important properties such as high tensile strength, high elongation, and right stiffness. An ideal vascular graft, similarly to other implantable, should be non-cytotoxic, should not trigger a negative immunogenic response, and present similar mechanical characteristics as the native vessel. 
The most important mechanical properties of the mesh for whatever the use (hernia repair or pelvic organ prolapse) is the necessity to have a mechanical behaviour close to or slightly higher than the local human tissue behaviour, i.e. the elasticity of natural tissue has to be maintained. Among the required mechanical properties of the stents, the most important is to maintain around the open lumen, ensuring healthy blood flow. The textile structure used as scaffolds for tissue engineering, it is desirable to produce textile materials that do not alter their mechanical properties when tissue grows in them and forms a composite.

Non-implantable medical textiles

Non-implants like wound dressing are placed next to the wound surface. They are required to possess the following properties.
  • Flexible, breathable, comfortable and soft material
  • Healing properties, regulated mainly with substances which are applied or added to the dressing
  • Causing no mechanical injury to a granulating wound
  • Low adherence
  • Stable spatial structure
  • Easy penetration of wound exudate into the absorbing dressing

Wound care products made of fibres that hold more water in a swollen structure, the dressings are capable of absorbing more wound exudate, hence extending the duration of dressing use. When the fibres absorb water into their structure and swell, the spaces between the fibres in the dressing are closed, thus prohibiting liquid from lateral spreading and preventing maceration of the areas surrounding the wound surface. 

For textile-based compression bandage, the main product performance is the force-elongation behaviour, and the elastic properties, which depends on the fabric structure, yarn composition, and fibre type.

Extra-corporeal devices:

The fibre-based membrane used in extra-corporeal devices is made of hollow fibres. The key properties of the material used for extra-corporeal devices are:

  • Artificial Kidney-
    • Blood compatibility,
    • Selective permeability
    • Suppression of complementary activation (inflammation)
  • Artificial Liver-
    • Blood compatibility
    • Adsorptive activity
  • Mechanical Lung-
    • Blood compatibility
    • Gas exchange effect
    • Suppression of blood/ plasma leak

3. Benefits of medical textiles

The versatility of fibres and textiles with adjustable mechanical properties make them an ideal material for applications in and around the body. Textile products have many unique characteristics and excellent qualities, such as strength, extensibility, flexibility, air and moisture permeability, availability in three-dimensional structures, variety in fibre length, fineness, cross-sectional shape and geometry, and absorbency, etc.
The use of textile materials for medical devices and products is advantageous owing to the inherent unique properties of textile materials and the precisely controlled manufacturing processes to obtain various structural features. Some of the parameters that can be engineered to suit medical applications include:

  • Fibre diameter, yarn thickness, and fabric density for porosity
  • Cross-sectional shape of fibres like round, tri-lobal, star-shaped for desired surface texture
  • Two- or three-dimensional textile structure – woven, braided, knitted, nonwoven, composites
  • Chemical and physical modification of fibre for desired functionality
Advantages of healthcare and hygiene medical textiles:
  • Prevents healthcare-associated infections (HAI)
  • Material can be disposable or reusable
  • Compatible with various sterilisation techniques
  • Barrier protection properties can be engineered
  • Protects users from static electricity
  • Breathability
  • Flexible and comfortable

Advantages of textile implants:
  • Inherent porous nature provides the required space for the fibrous connective tissue to grow into for achieving full-wall healing
  • Woven structures provide strength with high dimensional stability and low permeability to blood, specially for large-diameter blood vessels
  • Velour woven fabrics produce three-dimensional loose surface structures as the framework for tissue attachment and ingrowth

Advantages of textile non-implants:

  • Nonwovens are an excellent material for wound dressing as they provide an effective barrier against bacteria and airborne contaminants, and can be easily adapted to required specifications.
  • Bandages can be moulded suiting the shape and structure of required application area

Advantages of textile in extra-corporeal devices:
  • Porosity of textile material and hollow fibres can be engineered as required
  • Coated textiles are a cost-efficient solution
  • Possibility of recyclability of the material


4. Recent Developments in Medical textiles

Medical textiles is an emerging field with a new generation of products being created with technologies for nanomaterials, plasma treatment, biomaterials, and advanced materials. Research and development activities focus on new materials or modifications, and advancements in textile structures. Materials such as shape memory polymers, super absorbents, biodegradable material, active textiles for wound healing, etc. Textile structure advancement that has been biomedically significant is electrospun fibrous membranes, particularly those nanofiber-sized membranes as scaffolds for tissue engineering and regeneration. 

Textiles with integrated electronic circuits for smart application is also seeing a rise. For example, textiles with integrated sleep monitoring sensors, light-emitting fabric for photodynamic therapy, monitoring body parameters like breathing, heart activity, muscle activity, blood pressure, blood oxygen saturation, body movement, sweat analysis, etc. 

Technical developments in active implants, tissue engineering, spinal implants, and the socio-economic changes in developing countries, as well as the change in the age structure of the industrialized nations, are expected to augment the market growth in the near future.

In the next article, you will receive insights on the material and textile structure that propel the application of textiles in the medical industry.


References

  • Qin, Y., 2016. Medical textile materials. Woodhead Publishing: s.n.
  • Rajendran, S. & Anand, S. C., 2006. Contribution of textiles to medical and healthcare products and developing innovative medical devices. International Journal of Fibre & Textile Research, Volume 31, pp. 215-229.
  • Rossi, R. M. et al., 2019. Mechanical properties of medical textiles. In: P. Schwartz, ed. Structure and Mechanics of Textile Fibre Assemblies. s.l.: Woodhead Publishing, pp. 301-340.

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