MEDICAL TEXTILES

Medical science has become very advanced from last few decades. More and more techniques are invented to procure better health methods. Use of biomedical textiles for replacing damaged tissues or organs is a result of advanced medical invention. However substitute for defective body part was used to be transplantation of that part or organ, but this is not always possible. Thus use of biotextiles as a substitute to replace and aid for damaged body parts is being utilized by the surgeons and physicians. One of the most important aspect to consider is the bio-compatibility of such textiles with the human body on which they are used. So to evaluate their bio-compatibility testing is done that determines how the human body will react to the specific biomedical textile. Uses of biomedical textiles on human bodies in various forms are as follows:-

Vascular graft implants

Vascular grafts are used as an artificial vein or artery that is implanted in heart to replace the original vein or artery that is blocked or weakened. Veins or arteries upto 6mm-1cm in diameter can be replaced by grafts. Weft or wrap knitting technology is used to make these grafts which are porous in nature that facilitate these grafts to amalgamate with new formed tissues. In order to avoid hemorrhage after the implantation, the knitted grafts with internal and external velour is beneficial, also they could be sealed with patient’s blood after the implantation is done. Teflon is porous in nature and it is known for its anti-clotting and bio-compatibility property. But the problem is thin blood vessels made from Teflon is not so successful as the tube itself as it contains coating of collagen at its inner side. Experiments are carried out to produce vascular grafts which are less than 3mm diameter to achieve better tissue growth, anti-coagulation and better blood compatibility.

Soft tissue implantation

Silk protein, cellulose, chitin, chitosan and collagen are some of the biological polymers which are well matched with the soft tissues. Some of the biological materials which are used for making soft tissues are carbon fibre, silicone rubber and polyurethane. Soft tissues made up of silicone rubber are used in artificial breasts, nose and ears.

Hernia repair

In hernia repair also biomedical textiles are used. Like for instance polypropylene mesh is used for hernia repair. This mesh has resistance to infection and allergies. Expanded version of polytetrafluroethylene is used to make gore-tex soft tissue patch, it is used in hernia repair. These meshes are also used in abdominal wall replacement also.

The fibres could be woven according to the requirement of the patient.

Hard tissue implantation

For hard tissue implantation the special characteristics that are required by polymers are bio-compatibility, better functionality and chemical constancy. Now-a-days orthopedic surgeons prefer to use non-woven fibrous mat which is made up of graphite and Teflon around the orthopedic implants to boost up the tissue growth. These implants are applied to replacement of bones and joints and fixation plates which are utilized for stabilizing fractured bones.

Nerve guidance channel

Polypyrole polymer has the property of electrical conductivity thus is used in the field of nerve regeneration. It is one of the most upcoming thing in the field of biomedical textile research. The nerve guidance channel can be of two types i.e. of single continuous hollow tube and hollow tubes having fibres.

Biomedical textiles in ophthalmology

Even in manufacturing of contact lenses different polymers of textile are used. For making flexible contact lenses silicone rubber is used, for hard contact lenses methyl methacrylate and cellulose acetate butyrate are utilized.

Biomaterials in dentistry

Polymers such as poly methyl methacrylate, polyether polysulfone and polysulfone are used as dental biomaterials. These polymers have the characteristics of non-toxicity, non-solubility in oral fluids, have increased softening point and are easy to manufacture and repair.

Sutures

Sutures are threads that are monofilament or multifilament which are used to sew the open wounds after a surgery. Polybutylene terephthalate suture is being used now-a-days for wound closure as it has soft surface and appropriate strength. There are two types of sutures- biodegradable and non-biodegradable. Non-biodegradable sutures are used to close open wounds and are taken off the skin after the injury is healed. Whereas biodegradable sutures are used to close wounds inside the body. The type of suture used depends upon physical, biological and chemical culture of the tissue where it is to be put into. Biomedical textiles are used in for manufacturing two types of non-absorbable sutures-natural and synthetic. Natural non-absorbable sutures are made from waste silk, cotton, silk or linen. Synthetic sutures are made from polyamide, polyethylene, polypropylene or polyester.