Exploring the Diverse Applications of Medical Textile Engineering

  Medical Textile Engineering:

Definition of Medical Textile:

Medical textile has been designed for any kind of medical application, including implantable application. An important and growing part of the textile industry is the medical, hygiene, and health sector. This improvement in growth is due to the development and improvement of knowledge in both the textile and medical sectors. This leads to developing textile products that will be suitable for medical and surgical applications and should possess a combination of the following properties:

• Strength
• Flexibility 
• Sometimes moisture and air permeability

 Materials include natural fiber, monofilament as well and multi-filament yarns

Introduction of Medical Textile

We all know about Medical Textiles. This medical textile is an important part of Technical Textiles Today's article is about the allied industry of medical textiles ie raw materials. One of the medical textile raw materials is non-woven fabric. I write more on trending topics. This topic is related to Medical Equipment. This Meditech Equipment is in the current light line. What is Non-Woven today? Let's discuss why this is more important for Meditech

"Two or more Long and Shot Staple fibers are combined to form a fabric through chemical, mechanical, heat, and solvent processes. We call this fabric Non-Woven. To make it Non-Woven, the fiber does not need to be converted into yarn or yarn, besides Weaving and Knitting are hassle-free. After use it is recycled through the proper process. It is basically environment friendly and mostly single-use.

Non-woven fabric requires no sewing. It is important for medical textiles. If the fabric is sewn, holes are automatically created at the place of stitching During various surgeries and treatment of viruses, doctors can be infected by viruses and bacteria coming through the hole.

Let us mention some properties of non-woven for which they can be used in Meditech.

Absorbency, elasticity, flexibility, washability, thermal insulation, filter, usability,

Ability to resist bacteria and viruses.

Besides, we mention the names of some fibers used in non-woven:

Cotton, polyester, polypropylene, Viscose glass, Polyamide, Lyocell.

Due to the above qualities of Non-Woven Fabric and its ability to contract and expand, it is also used as a raw material for organs, bones, vascular system, and skin replacement using various technologies. Fabrics made from cotton non-woven are cotton (soft, and absorbent).

Better for use due to quality.

We see non-woven fabric more as Meditech Equipment in Hospital, Nursing Homes, Schools, etc Besides, its acceptability is also high due to Single Use, Limited life, and cheapness.

Now let's look at some applications of Non-Woven in Medical Textiles:

Isolation gowns, Surgical gowns, surgical covers, Surgical masks, Caps, Medical Packaging, bath wipes, shoe covers, plasters, and drug delivery.

Note that we can make Mask and PPE which is very important nowadays.

Researchers from MIT (Massachusetts Institute of Technology) and Sweden have worked together to develop a new robotic textile product that can be incorporated into clothing.

The robotic textile product is unique, it can sense stretching and compression and can also express immediate touch feedback.

This product is used to improve the breathing capacity of asthmatic patients, singers and athletes

Classification of Medical Textile :

The number of applications is huge and diverse, ranging from a single thread suture to complex composite structures for bone replacements, and from the simple cleaning wipe to advanced barrier fabrics used in operation rooms. Thus the textiles used for medical and surgical purposes can be classified as follows:

• Non-plantable materials- Wound dressing, bandages, plasters etc;
• Extracorporeal Devices- Artificial kidney, liber, and lung, etc.
• Implantable Materials: Suture, vascular grafts, artificial filaments, artificial joints, etc.
• Healthcare/Hygiene Products: Bedding, clothing, surgical gowns, clothes, wipes etc.

The majority of the healthcare products are disposable whereas some are reused. The medical product based on textiles was around 76$ in the year 2000.

Fiber used in medicine can be classified as follows:

1. According to the source of origin

• Natural- Cotton and silk are the most widely used.
• Synthetic- Viscose, polyester, polyamide, poly tetra fluoro ethylene (PTFE), polypropylene, carbon, glass and so on

2. According to biological resistance

• Biodegradable- These fibers are absorbed by the body within 2-3 months after implementation and include cotton, viscose rayon, polyamide, polyurethane, collagen, alginate, and polypropiolactone.
• Nonbiodegradable fibers that are absorbed by the body slowly and take more than six months to degrade are considered non-biodegradable. Non-biodegradable fibers include polyester, polypropylene, PTFE, and carbon. 

Fiber used in medical textile materials should fulfill the following criteria:

• The fibers must be non-toxic
• Must be non-allergenic
• Must be non-carcinogenic
• Must be able to be sterilized without impairing any change in their physical or chemical characteristics
• Where necessary it should be biodegradable
• Where necessary it should be non-biodegradable
• It must be compatible with most living systems
• It should be versatile in its physical form i.e. powder, aqueous solution, films, shaped objects, fibers, and sponges
• Vehicles for transforming and delivering drugs

Application of fiber in medical textiles:

• Traditionally cotton, silk, and viscose have long been used for medical and surgical purposes. One such area of application is wound care, where moisture and liquid exuding from the wound are absorbed by the fibrous structure to promote healing in relatively dry conditions
• However, after healing small fibrous elements protruding from the wound dressing are usually trapped in the pores of the newly formed tissues 
• Research show that a wound under moist condition would in fact heal better and faster, which would also remove the problem of fibers being trapped in the healing wound.
• The concept of moist healing has since been responsible for the development of many fibers which have vastly improved wound management techniques and patient care.

Some Technical Fibers for Medical Textile:

A variety of polymers such as collagen, alginate, chitin, and chitosan have been used as essential materials for modern wound dressings.

Collagen Fiber

• Collagen which has been obtained from bovine skin is used to produce biodegradable fibers used as suture which is as strong as silk. The fiber can also be converted to a transferred gel-like film structure used as a contact lens which has very good oxygen permeability.
• Alginate (originated from seaweeds) and chitin (obtained from shrimp shells) are widely used for the treatment of wound healing. Chitin non-woven fabric is used as artificial skin.
• Alginate Fibers are naturally occurring, high molecular weight carbohydrates or polysaccharides obtained from seaweeds that have been found used in medical textiles.

  

  Alginate Sustainable Fiber

  
  
• Chemically, alginate is copyright made from a-i glucuronic and b-d- mannuronic acid. It is made into fibers by extruding sodium alginate into a calcium chloride bath where calcium alginate filaments precipitate. The filaments are then drawn, washed, and dried. Upon contact with wound fluid, these fibers are partially converted to water-soluble sodium alginate that swells to form a gel around the wound, thus keeping the wound moist during the healing period. They can then easily be removed once the treatment is complete.
• Artificial Polymers form by a crosslinking copolymer of acrylic acid. They have claimed to have superior absorption properties to alginate particularly when used under pressure.

  

  Artificial Polymers

  
  
• Hydrocell, a derivative of Acordi's environmentally friendly Lyocell, is also claimed to be more absorbent than sodium alginate, taking up to 35 times its own weight of water whilst remaining intact. 

  

  Lyocell Fibers

  
  
• Chitin is another polysaccharide that after Lyocell, is the most abundantly available natural polymer. It is found in the outer shells of shrimps and crabs in combination with protein and

  

  Flow Chart of Chitin

  
  
  minerals. Medicinal and medical use of this polymer has been realized seriously since the early 1970s. High-purity chitin, from which protein, heavy metals, and pyrogens have been removed, can be used for a range of applications from food additives for controlling cholesterol levels in blood to artificial skin into which tissues can safely grow. A derivative of chitin has better processability and is now extensively available in fiber form. The particular appeal of both chitin and chitosan within biochemical applications is due to their beings.
• Finally, Collagen, a protein-based polymer that is collected from bovine skin and has traditionally been used in hydrogel or gelatine form for making jellies and sausage casing, is now available in fiber form. It is very strong and completely biodegradable. Besides wound care, fiber-based structures in synthetic or natural form are used in extracorporeal devices that may be used to purify blood in kidneys, create artificial livers, and function as mechanical lungs, as well as finding use in suture materials, artificial ligaments, cartilages, and cardiovascular implants. In general, healthcare and hygiene products have applications that cover a wide spectrum from disposable items to surgical uniforms and hospital bedding and all are becoming increasingly important across the world as the need to produce efficient and effective medical care increases.  

Non-plantable materials in Medical Textile Engineering:

These materials are used for external applications on the body and may or may not make contact with skin. The following table illustrates a wide range of materials used as non-implantable medical textiles,

1. Wound Care Products: The purpose of these products are to provide protection against infection, absorb blood and exudates, promote healing, and in some instance apply medicine to the wound.

• Common wound dressings are composite materials consisting of an absorbent layer held between a contact layer and a flexible base material. The absorbent pad absorbs blood or liquids and provides a cushioning effect to protect the wound.
• The wound contact layer should prevent adherence of the dressing to the wound and easily be removed without disturbing new tissue growth.
• The base materials are normally coated with acrylic adhesive to provide how the dressing is applied to the wound. 
• The use of collagen, alginate, and chitin fibers contributes significantly to the healing process.

Non-implantable Materials:

• Woundcare absorbent pad (cotton, viscose) - Non-woven
• wound contact layer (silk, polyamide, polyethylene) -Knitted, Woven, Non-woven
• Woundcare Base material (Viscose, plastic film)- Non-woven, Woven
• Bandages simple inelastic/elastic (Cotton, viscose, polyamide) -Woven, knitted, non-woven
• Light support (Cotton, viscose, elastic yarns) - Woven, knitted, non-woven
• Compression (Cotton, polyamide, elastomeric yarns) - Woven, knitted
• Orthopaedic (Cotton, viscose, polyester, polyurethane foam, polypropylene) -Woven, non-woven
• Plasters (Viscose, plastic films, cotton, polyester, glass, polypropylene)- Knitted, woven, non-woven
• Gauzes (Cotton, viscose) - Woven, non-woven
• Lint (cotton) - Woven
• Wadding- (Viscose, cotton linter, wood pulp)- Non-woven

Application of Textile Engineering:

If we think that textiles are only limited to clothes or garments then it is a misconception. Times have changed, along with the expansion of the textile industry. Textiles are not limited to clothes anymore. A person touches textiles every moment from waking up to going to sleep.

80% of people don't know that textile engineering job is not cloth engineering. It is a complete manufacturing-based process where an engineer has to work from machine setup to process control, product development, gear mechanism, and maintenance. Spinning engineers need to know how to program inputs. Wet processing engineers are first-rate chemical engineers.

Although the concept of textile is very old, textile engineering is a new branch of engineering. Textile engineering is the first choice of many students interested in engineering these days. The journey of textile engineering subject in Bangladesh was a landmark step. Why is this subject opened in Bangladesh despite many other subjects? The only answer to this question is a timely decision.

First, we discuss the familiar form of textile engineering. First of all, everyone thinks it's cloth engineering. Yes of course cloth is discussed but engineers control the entire production system, they are not involved in cutting or sewing the cloth. Besides, one of the jobs related to this industry is merchandising. This job is very interesting if you have good communication and negotiation skills. There will be contact with people from many countries and cultures, and even opportunities to travel to many countries for the sake of work. Along with this, there will be a good opportunity to become an entrepreneur if you work in the textile industry. As a textile engineer, the first few years in the industry may be tough, but if you work hard, this is where you can progress the fastest. And to be honest, all engineers have to work very hard to improve. I can also say that textile engineers work in the biggest sector of Bangladesh, branding Bangladesh all over the world. Only Textile Engineers of Bangladesh have started branding with the “Made in Bangladesh” tag at the international level. Many of us who are used to watching Hollywood movies may not know that famous celebrities know Bangladesh as a famous brand. Most of the big brands such as Reebok, Nike, D&G, Levi's, Puma, and even the U.S. Army's camouflage dress will be threatened if they cannot get products from Bangladesh. The international community has declared Bangladesh's textile sector as the “next China”. And these are not just empty bullies. Very few people outside this sector get the opportunity to work in such a powerful sector, that too in the country with a six-digit salary.

The scope of work of a textile engineer is vast. A textile engineer,

1) Develops all types of Wear starting from General Wear.

2) Use and develop Nano-Technology in space technology for space travel. NASA scientists who have been working to send people into space for a long time have engaged numerous textile engineers in research to make space suits and nanofiber, carbon fiber shields.

3) Medi Textile: It makes artificial blood vessels, tendons, ligaments, artificial organs, modern bandages, scaffolds for tissue engineering, etc., which are actually also known as Biotextile. Currently, textile engineers are working on the development of many implants, tissue engineering, artificial arteries, and ligaments. This fact is unbelievable but true. If you don't believe it, you can visit the website of SHINSHU UNIVERSITY in Japan. This university can be said to be a pioneer in Asia in textile research, whose Department of Medical Science is under the Faculty of Textile Science. Here many implants, bio bio-compatible product development have been worked on.

4) At present various high-performance fibers such as glass, aramid, and carbon fiber which are reducing the use of metal can be known by reading this topic.

5) Another topic is e-textiles/smart textiles. This is a very popular topic these days. It deals with wearable electronic products or wearable technologies. You can watch videos on this subject by typing an e-textile on YouTube. I'm sure once you start watching these videos, you'll leave everything else behind and want to rant about these things.

6) Those who are interested in aircraft or aeronautics must have an idea about the parts of an aircraft. According to the 2019 Circular of Aircraft Maintenance Engineering of the Australian Government (Civil Aviation Safety Authority), the parts of an airplane are mainly divided into three categories. Mechanical, Avionics, and Structural. Structural engineers mainly work with high-tech composite materials such as carbon, boron, and Kevlar, which are used in space vehicles and Formula 1 cars.

As a textile engineer works with chemicals and polymers, he can work with composite materials for advanced research.

7) Besides, there is immense opportunity to work with smart textiles and automotive textiles.

Smart Tex

Medical Textile in Bangladesh

For a few days, I have noticed several Facebook post regarding why BGMEA or Garments Manufacturers doesn’t take the initiative to make PPE (Isolation Gowns) for Healthcare Personnel.

First of all, in Bangladesh, we don’t have any Medical Textile/Technical Fabric/Garments Manufacturer. It is a prerequisite to follow the CDC, NPPTL Guideline, and ASTM/ISO Testing Protocol while developing this protective clothing. This fabric should have barrier properties i.e. Fluid resistance and breathability (water vapor permeability) to provide better protection & comfort for healthcare personnel.

It needs to pass several standardized Testing protocols like Blood penetration resistance (ASTM F1670) and viral penetration resistance (ASTM F1671).

Only coated Polypropylene or Polyethylene Flim fabric could meet ASTM Test protocol.

Also making these Isolation Gowns is very crucial due to Fit and put on/take off facilities and seam Leakage protection, as microorganism penetration can occur in any part of the garment, including the seam area.

For Surgical & respirator masks (N/KN 95, 99, 100, FFP1, 2, 3) we don't have the facilities to manufacture these also, these all are medical textiles, and the manufacturer needs to have FDA and NIOSH approval, even NIOSH approval number, Model No. need to be labeled on this.

So, it would be more dangerous for healthcare personnel if the Isolation Gowns were not sourced from authorized bodies. But if we think something is better than nothing, that is different.