The use of woven multilayer dressing for wound healing Abstract

The use of woven multilayer dressing for wound healing Abstract:
This paper represents a structure of woven multilayer dressing. The dressing was developed by multilayer woven design using CCI sample loom. The comparison was done with available sample to ensure performance of the new wound healing dressing. The physical test like wettability ,air permeability test were conducted for indication of test comparison. The showed that good air permeability and wetting time of developed sample than available sample. This study shows a new way to produce a wound healing dressing.
Introduction:
Wound management of modern dressing is now giving more attention on providing optimal moist condition. Optimal moist condition can stimulate reepithelialization of tissues.
An ideal dressing should have gaseous permutation and beneficial for soaking up wound exudate quickly. The wound dressing should be non- poisonous, non- coherent, non- irritant to wound surface area and to give impede so that further tissue loss does not happen.
The dressings are selected on the basis of skin layer damaged area and amount of wound exudate. Hydrogel dressings ara made of hydrophilic polymer matrix like chitosan, dextran or collagen gel pad. The cooling gel In the dressing alleviate pain from the wound for temporary.
Alginate dressings are made of alginate which is extracted from seaweeds. These dressing
Can absorb exudate 20 times than their own weight .By soaking up excess amount of fluid create a gel and helps to promote the regeneration process of tissue. Frequent changes of them can lead to cause too much dryness or microbial interfused in the wound area.

Foam dressings are comprises of two layers- hydrophilic polyurethane foam and polyurethane film that helps to achieve higher moisture vapor transmission rate. These dressings absorb wound exudate from the damaged area and by letting water vapour enter into the wound surface create an environment for moist condition that promotes healing.

Transparent dressing are made of polyurethane sheet and became of its semi permeable nature it cann’t absorb any liquid but it can absorb moisture. These dressings protect the wound from microbial invasion and inaccessible to bacteria and others contaminate.
Gauzes are open weave fabric usually cotton ,function as an absorbent breathable and preventive pad for wound . They are suitable for minor injury. But it is difficult to withdraw from wound contact area.

Several dressing were developed according to literature. Nonwoven techniques were adopted for developing wound healing dressing. A multilayer dressing was developed with fiber with having three layers. The first layer was made in wrap knitting technique with silver plated nylon yarn. The second and third layer were made by non-woven process with different ratio of nylon and rayon fiber. Needle punching method was used to laminate three layers.
Another development of dressing was made of polyurethane sheet as moisture transmission cover layer. Gel forming fiber such as sodium alginate was used as absorbent layer and placed between cover layer. Hydro entangling method was used to bind the layers.

A development of dressing was multilayer island dressing .The wound contacting layer was made of polyurethane which acted as non absorbent , non adhering . The polymeric film was impregnated with antimicrobial agents like silver and outer layer was made of poly olefin.
Cotton web was used as absorbent material which was sandwiched between the layers. Ultrasonic welding method was used to bond the layers.

Materials and method:
100% cotton was used as warp and weft yarn on this experiment. CCI TECH INC sample loom was to produce the dressing. The available sample was paraffin dressing which was collected from local area.

A multilayer dressing comprises multiple number of layers of fiber in which diversified feature can be incorporated for each layer.

In the figure cross sectional view is shown. In the top and bottom layer plain weave was used. Center stich was used to connect both layers. In the figure weave plan is shown.In the figure available sample is shown. The developed multilayer dressing was compared with available sample for confirmation of performance of the sample.

Air permeability test:
The air permeability test was conducted on the basis of ASTM 377 method.TEXTTESTER INSTRUMENT was used to determine air permeability of the dressing.
Absorbency: The absorbency of the dressing was conducted on the basis of BS EN 13726-1 method. According to method, the sample specimen was 5cm x 5cm.A test solution was prepared with 2.298 gm sodium chloride and 0.368 gm calcium chloride adding at 1 liter of grade 3 water which as comparable as human serum. The sample was added in the warmed solution (37 DEGREE C) having 40 times mass of the dressing. The solution was kept at incubator for 30 min at 37 C. After 30 minutes the sample was hanged on and allowed removed excess water for 30 seconds. The absorbency was determined by using the following equation.

Absorbency (g/100 cm) = (B-A)/25 *100
Vertical wicking test:

Air permeability :
Air permeability test measure the amount of air flow pass through vertically in the surface area under a definite air pressure . Air permeability is needed to create ventilated ambience for wound dressing. The test result is showed in figure. It can be seen that air permeability of

developed woven dressing is more than available sample.

Finding:
A new design is use for wound healing dressing manufacturing. Physical test is conducted to compare with available sample .The test result of new developed sample is found better than available sample.
Limitations;:
Only cotton yarn was for manufacturing of dressing. Different types of yarn wasn’t possible to use for making of dressing. Others test like moisture vapour transmission rate ,thermal conductivity ,absorbency test for wound dressing were not performed .Sterilization wasn’t done because of scarcity of autoclave machine.

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