Antimicrobial Medical Textiles

Classification of Medical textiles

Medical textiles can be broadly classified into: (a) in vivo and (b) in vitro. In vitro products are commodity/general items whereas: in vivo products have specialty applications and requirements. From requirements and applications point of view, most of the vivo items should be single use products. However, in the case vitro general products, they could be either single use or multiple uses. These products are normally non-sterile items such as hospital drapes and bed linens.

Also based on applications the medical textile can be broadly categorized as follows :

  1. Personal health care/hygienic products: Bedding, clothing, surgical gowns, cloths, wipes surgical curves, surgical hosiery, diapers, etc.
  2. Non-implantable material or medical dressings & auxiliaries: Wound dressing, bandage, plasters, gauge, lint wadding, etc.
  3. Implantable materials: Sutures, vascular grafts, artificial ligaments, and artificial joints.
  4. Extra corporal devices: Artificial kidneys, liver & lungs, etc. The nonwovens are used for the given applications in different forms.

A special additive to produce Antimicrobial textile

Mainly Medical textiles used with barrier effects that are aimed at :

  • preventing contamination of bacteria from patients to employees and vice-versa
  • protecting employees from contamination through biological liquids
  • protecting the environment

Several anti-microbial additives like silver ions already exist, but their effect can quickly disappear as they are destroyed during washing cycles. Output from a new project could lead to a dramatic reduction in hospital-acquired infections. An additive technology that produces anti-bacterial textiles has been developed by a team of researchers led by Devan Chemicals of Belgium. The anti-bacterial textiles can be used to make a range of hospital products such as bed sheets, nurses’ uniforms, pillow cases, other hospital textile products.

Devan’s project is aimed to develop longer-lasting anti-microbial textiles for use in hospitals as they are resistant to microbial attack, and can withstand multiple industrial washing cycles at 80°C. The project’s aim was to cut down on hospital-acquired infections, of which around one-sixth are picked up from textiles. The partners made and tested several textile formulations that incorporated two of Devan’s proprietary molecules: Aegis, a quaternary silane anti-bacterial treatment; and Nanolink, a polymer ‘pre-coat’ that helps to stick the Aegis molecules to the surface.

Aegis offers the advantages of killing several bacteria types, but does not migrate from the surface. Nanolink improves the way that the Aegis molecules stick to the fiber, and helps achieve many wash cycles without losing the anti-microbial effect. Aegis can also keep dust mites at bay, by killing the yeast that they feed on.

The sheets, made from a 50/50 mix of cotton and polyester, were trialed at a hospital in France, while the uniforms were trialed at a hospital in Italy. The Pasteur Institute in Lille tested both for bacterial growth. The treated sheets were found to reduce bacteria by at least 80% even after 50 washes. A similar effect was seen for the uniforms. Devan was one of 44 partners taking part in Flexifunbar, an Euros 11 mln, four-year project set up to develop flexible materials that combined at least two properties – such as flame retardancy, thermal and sound insulation and protection against UV, bacteria and odours. Target applications were identified in building, transport, health and personal protection. The project was instigated by the textiles industry, in order to develop ‘added value’ products that could compete against cheaper imported materials. The researchers hoped to combine several functions into a single material by altering its micro- or nano-structure.