CHAPTER 2015-12-04آ  quinoline alkaloids, pyridine alkaloids, pyrrolidine alkaloids, tropane alkaloids,

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    CHAPTER 2

    CURATIVE MEDICAL TEXTILES REVIEW

    2.1 INTRODUCTION

    The curative textiles arena is the highlighted newborn area of

    medical textiles. Though the literature specific to the curative textiles is not

    rich, there have been many research works related to textiles coated with

    herbal products and chemicals. Curative textiles are a merger between textiles

    and curative components. Curative textiles can be broadly classified into two

    types: curative function performed by the regular textile material and textiles

    augmented with external curative components. The curative components

    could either be a natural product or a synthetic compound. The era of multi-

    functional textiles started with the introduction of antimicrobial textiles.

    Compounds with antimicrobial activity would add an additional functionality

    to the textile material. But such textiles cannot be considered as curative

    textiles as their role is mainly preventive in nature and their support is only

    secondary to the healing process. In case of curative textiles, the role played

    by the multi-function textiles is vital and primary.

    The developments in the field of coated textiles were made possible

    due to the development in the coating and processing technologies. The

    coating method is crucial in order to deliver the coated component in the right

    way. Starting from dip-dry and pad-dry-cure processes to the recent nano

    particle-coating process, there has been an enormous improvement in the

    field. With the advent of concepts such as eco-friendliness and bio-

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    compatibility herbal products are being preferred over synthetic chemical

    compounds. The herbal components have also low side effects compared to

    the synthetic chemicals. The extraction methods used in the herbal medicinal

    system have vastly grown. Sophisticated instruments and precise characterizations

    have been put in place. Since herbal medicines are related to human health, a

    high degree of accuracy is required in their characterization. Advanced

    chromatography and spectrometry techniques are being used at all levels.

    Application of curative textiles and their evaluation is also of equal

    importance. Though the necessity for the evaluation is high, there are only a

    few methods available for the evaluation. The need for innovation in the

    evaluation methods for the curative textiles has to be addressed.

    2.2 MEDICAL TEXTILES

    Medical textile is one of the emerging areas in the field of technical

    textiles. Sanitary napkins, incontinence diapers, surgical bandages, wound

    dressings, healthcare textiles, sutures, vascular grafts, heart valves, artificial

    tendon, artificial joints, artificial kidneys are examples of medical textiles.

    Surgical bandages and various dressings are classical examples of textiles

    used in the treatment of ailments. Developments in textile based dressings

    with self-healing property have been tried by coating them with several

    chemical and natural products thus making them take the functional role

    (Gupta et al 2010). Dressings such as adhesive dressings, collagen dressings,

    composites, hydrogel and hydrocolloid dressings, alginate based dressings,

    burn therapy dressings are commercially available.

    2.3 SURGICAL BANDAGES

    Surgical Bandages are also called as Medical Devices. Bandages

    could be elastic as well as non-elastic. Based on the function and properties

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    bandages can be classified into three major categories namely, fixation,

    support and compression. Fixation bandages are elastic in nature and they are

    used to hold the dressings or medicaments in place. Support bandages are

    used to provide support to tissues and ligaments. Compression bandages can

    be classified again depends on the amount of compression it produces.

    2.3.1 Compression Bandages

    Compression therapy is used in treating phlebological and

    lymphological disorders such as varicose veins, leg ulcers, eczema and

    oedema (Bleckena et al 2005) and other musculoskeletal disorders. The most

    common practice used by medical practitioners in the compression therapy is

    the usage of compression bandages. Based on the amount of compression

    required for the treatment, the stretch of the bandage is determined. Resting

    pressure applied on the affected part by bandage creates compression enabling

    the venous pressure to be regulated. The blood flow in the vein is controlled

    and there by the disorders is managed. Use of compression bandages in the

    treatment of venous ulcers has been reviewed thoroughly (Cullum et al 1997;

    Lee et al 2006). Such bandages come under Class 1 medical devices.

    Compression bandages are classified based on four important aspects such as

    pressure, number of layers, components and elastic properties (Partsch et al

    2008). Elastic compression crepe bandages are termed ―long stretch

    bandages‖ and the elasticity, as per DIN 61632 standards, is defined as the

    percentage elongation of the material following application of a force of

    10 N/cm width of the bandage. The pressure developed beneath a

    compression bandage is governed by the tension in the fabric that is exerted

    when the bandage is applied. One way of creating fabric tension is by using

    the stretch yarns and the other method is by using textured and crimped

    inelastic yarns (Cooper et al 1965) and thus extensibility of the bandage plays

    the major role in imparting pressure and is an indication of the ability of

    compression.

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    2.3.2 Fixation Bandages

    Fixation bandages are simple elastic bandages and take the profile

    of the body part and are also called as ―Contour bandages‖. They have high

    elasticity and have open structure. They are normally applied as a second

    layer over a wound dressing. They are multi-purpose bandages and can be

    used for various bandaging applications.

    2.3.3 Narrow Weaving

    This form of weaving is used normally for tapes and bandage

    fabrics. The width of the fabric ranges from 1 cm to 20 cm. The loom is also

    called as needle loom due to its weft insertion mechanism which involves a

    reciprocating needle on a cam. The warp yarns can be let off from beams as

    well as from creels. The weft is inserted as a double-pick. The selvedge can

    also be secured at one end by a crotchet stitch using a binder yarn and a

    needle. The looms are capable of high-speed weft insertion with 900 double

    picks per minute.

    2.3.4 Coated Bandages and Coating Methods

    Bandages as substrate are also coated to enhance the amount of

    compression and also to widen their functionality. Zinc-Paste bandages,

    cohesive and adhesive bandages are examples for such bandages. Besides the

    coated compression bandages, there exist also medicated wound dressings.

    The coating could either be the synthetic chemicals, latex /rubber or medicinal

    products. Shear spreading, dip-dry, pad-dry-cure and spray drying are the

    common methods used for coating the additives on the bandage surface.

    Microcapsules can be coated on textile surfaces in various ways

    and this section discusses them in detail. Conventional coating methods such

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    as blade-on air, blade-on-roll, screen coating and dosing roller have been

    discussed by Ghosh (2006). Printing and digitial coating can also be used for

    coating microcapsules on textiles. Dip-dry, pad-dry-cure, spray coating, printing,

    Textiles coated with silver are used in the treatment of atopic

    dermatitis (Haug et al 2006). Antiseptic, antimicrobial and anti-inflammatory

    effects have been observed in the silver coated textiles.

    2.4 PLANT RESOURCES

    Plants are a sustainable source of medicinal products especially in

    traditional medical practices. Plants contain active substances such as

    alkaloids, tannins etc., produced during their secondary metabolism which

    serve as a potential reservoir of medicinal products (Bourgaud et al 2001; Parr

    1989; Croteau et al 2000). There are number of methods such as solvent

    extraction and steam distillation to extract the active substances from the plant

    parts (Ong Eng Shi 2004; Mukherjee 2002). The traditional method of

    extracting oils (medicial tars) from the woody parts such roots, stem bark and

    branches has been reported by Kargioğlu et al (2010), Julin (2008), Lindborg

    (2009). The traditional practitioners of Indian medicine extract the stem part

    of medicinal plants by a crude pyrolysis method and use the extracted oily

    substance in the treatment of pain, inflammation and other musculoskeletal

    disorders. There are numerous medicinal plants available for the treatment of

    diseases ranging from headache to cancer.

    2.4.1 Secondary Metabolites (Tolonen 2003)

    Secondary metabolites of plants are found only in certain species

    and family. The presence of a particular metabolite is

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