The present application claims priority from the provisional application filed on 15.2.2011 and numbered as 424/CHE/2011 for the invention titled 'COCONUT FIBRE AS A SUTURE MATERIAL' and relates to the use of coconut fibre of a green coconut as a biocompatible biomaterial suitable for suturing purposes in human beings, being an economic, viable and green alternative to traditional materials used for suturing. In the present invention coconut {Cocos nucifera) fiber has been considered as a natural suture material.

BACKGROUND OF THE INVENTION;

Biomaterials are materials such as polyester, metals (stainless steel), animal or plant fibre. However, Biomaterials may have substances that may be toxic, and eUcit harmful reactions in humans which may vary from person to person. The ability of a substance to exist within, or alongside Uving things without harming them is very important, therefore, the need to determine its biocompatibiUty is vital for human consumption. The goal of biocompatibility is to obtain the desired effect of the material in the application for what it is intended. Interaction of various blood components with biomaterials occurs immediately after implantation. It is therefore a pre-requisite that these biomaterials do not interfere with coagulation nor with the factors that regulate it. In addition, death of blood cells, or hemolysis by the implant should not occur, A biomaterial should therefore be a material (implant) that will not trigger any allergic response in the body. Today there are over 2,000 different biomaterials used as dental, prosthesis and suture materials. Till date not one of these biomaterials is 100% compatible with all human beings. Some people could be allergic to certain materials, and others may be sensitive to them. Unlike food allergies, which can be controlled by removing the allergen from the diet, if a person is allergic to a biomaterial, the same method cannot be followed as the biomaterial, whether placed in or over one's body, resides permanently there. The implanted biomaterial therefore can and will trigger a bio response in the body.

Allergies to biomaterials may not result in problems to a majority of people but if the body is allergic to any of the different materials used, then this could present a serious health hazard.

A surgical suture is used to close the edges of a wound or incision and to repair damaged tissues. There are many kinds of sutures, with different properties suitable for various uses. Sutures can be divided into two main groups. These are absorbable and non-absorbable. An absorbable suture decomposes in the body. It degrades as a wound or incision heals. A non-absorbable suture resists the body's attempt to dissolve it. Non -absorbable sutures may be removed by a surgeon after a surface incision has healed. Sutures are made from both man-made and natural materials. Natural suture materials include silk, cat gut etc., Synthetic sutures are made from a variety of textiles such as nylon or polyester formulated as nylon or polyester specifically for surgical use. Absorbable synthetic , sutures are made from polyglycolic acid. Most of the synthetic suture materials have proprietary names such as Dexon and Vicrly. The water resistant material Goretex has been used for surgical sutures, and other sutures are made from thin metal wire.

Coconut is one of the greatest gifts of nature. Coconuts are great blood purifiers. Many people's lives have been saved in third world countries by coconut. The water inside the coconut is not the same thing as coconut milk, a popular creamy product which is actually made with the flesh of the coconut. Coconut water is crisp, cool, and refreshing, and it is often used in drinks in tropical regions. It is also high in minerals, making it to promote quality health in the society.

The fibrous outer shell is sometimes used as a fiber as well. This fiber is known as coir. Coconut trees can also provide timber for construction projects, and a source of fuel.

Coconut fibers are available everywhere in India, but its uses have not been fully utilized. It is the scope of this invention to come up with this novel use for coconut fibre.

PRIOR ART:

Given hereinbelow are a few of the materials that are being currently used for suturing, which constitutes the known prior art in the world.

The scope of this invention i.e. the use of coconut fibre of green coconut as a suitable material for sutures has never been thought of, nor has been used as a cheaper, safer, economically viable and easily available material till date.

ABSORBABLE SUTURES

Catgut: This material is a collagen preparation produced from the intestinal submucosa of sheep or cattle. If treated with chromate, catgut has greater resistance to body digestion, and its tensile strength is increased. Catgut sutures pass smoothly through tissues and hold knots well. However, there is proof that Catgut can sometimes cause a considerable tissue reaction in the host.

Polyglycolic acid:

This is a synthetic absorbable material made by polymerizing hydroacetic acid a braided suture is produced. The material absorbs by hydrolysis and breaks down over a predictable period. These sutures knot well, and for a given size are stronger than catgut and cause less tissue reactivity.

Polylactic acid sutures:

These have similar properties to polyglycolic material, but are made from lactic acid

NON-ABSORBABLE SUTURES

Silk: This protein filament is either twisted or braided; it creates a moderate tissue reaction and fibrosis. Though it is considered to be non¬absorbable, it disappears slowly from the tissues, and loses its tensile strength rather more rapidly. It knots well and handles easily, but is less attractive now that synthetic sutures have been introduced. Natural nonabsorbable silk surgical suture is a nonabsorbable, sterile, flexible multifilament thread composed of an organic protein called fibroin. This protein is derived from the domesticated species Bombyx mori (B. mori) of the family Bombycidae. Natural nonabsorbable silk surgical suture is indicated for use in soft tissue. The highest quality of non-absorbable stitch is Prolene®. The surgeon uses only Prolene® on the surface because the body neither recognizes it nor reacts to it with redness. Prolene® is a monofilament, meaning it is not made of braids of smaller strands in which bacteria can hide or tissues can grow and get caught. When its time for removal of the sutures, the removal of these sutures is rarely felt by the patients.

Prolene is a synthetic, nonabsorbable polypropylene suture. It is indicated for skin closure and general soft tissue approximation and ligation. Its advantages include high tensile strength, minimal tissue reactivity, and slipperiness (allowing easy removal from tissues). Disadvantages include high plasticity, high expenses, and difficulty of use compared to standard nylon sutures. Prolene sutures are intended to be durable and long lasting.

Prolene commonly is used in both human and veterinary medicine for skin closure and is used in cardiovascular, ophthalmic and neurological procedures.

Metal sutures; Stainless steel is very strong, its knots hold well and minimal tissue reaction results. However, its handling characteristics are less than nylon and polypropylene.

DESIGN FACTORS OF SUTURE

Sutures are designed to meet many different needs. Sutures for abdominal surgery are different from sutures used in cataract surgery. Since no type of sutures is ideal for every operation, surgeons and medical designers have come up with sutures with varying qualities. One may be more absorbable but less flexible, while another is exceedingly strong but perhaps somewhat difficult to knot. This gives surgeons many options. Designing of a new suture have to take into account many factors. The rate the suture degrades is important, not only along the length of the suture but at the knot. Some sutures need to be elastic, so that they will stretch and not break. Others need to be rigid. Suture manufacturers use specially designed machines to test and study sutures. New sutures designs are also tested by subjecting them to chemical tests, such as soaking them in various solutions, and testing on animals.

ADVANTAGES OF THE INVENTION:

Coconut coir can be used as an effective suture material with good tensile strength. It is easily available and less expensive than routinely used Prolene/silk. It is very cost effective for Medical doctors and Veterinary doctors to use it for suturing cuts or wounds. Thousands of suture fibres (Immature) can take from single green coconut which is thrown as a waste and it is highly biocompatible. The suture material for different mechanical strength as is required, depending upon the site of the injury can be manufactured by altering the diameter of the fibre.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS:

Visual Results of the Inspection carried out from the day of surgery till healing. Wound healed in four days for coconut coir and six days for silk braided (Diamond super stitch thread). Silk braided (Diamond super stitch thread) is used for control.

PICTURE 1: Winster rat sutured with Silk braided (Diamond super stitch thread) on the top and Coconut coir in the bottom. PICTURE 2: After the Healing on 4'^ day, the coconut coir (Thin fibre) 1 wears away (splitted out from skin) but silk braided (Black color on top) still present.

PICTURE 3 After the 6th day, the silk braided came out of the surface but the coconut coir (Thick fibre) still remains.

DETAILED DESCRIPTION OF THE INVENTION:

Coconut fibre is known as coir fibre. The fibre is extracted from the fibrous outer shell of a coconut. The individual fibre cells are narrow and hollow, with thick walls made of cellulose. They are pale when immature but later become hardened and yellowed as a layer of lignin is deposited on their walls. Mature brown coir fibres contain more lignin and less cellulose.

COIR PREPARATION: The Green Coconuts are plucked from the tree and the coir is removed from the shell of the nut. The coir is soaked in water for 24 - 48 hours. This is done to clean and allow the fibre to be separated into strands. The coir strands are then soaked into 70 % (Iso-propyl alcohol) alcohol for sterilization and decolourization for 5 hours. ' This is repeated till the brown colour is completely removed from the coir. Generally, this process is repeated about 3 to 5 times. The coir is then removed and dried in a hot air oven between 40 - 50°C for 1 hour. After drying the coir, moist heat sterilization is done using autoclave. BIO-COMPATIBILTY TESTS;

1) MECHANICAL TESTING: Tensile strength of Coconut fibre is tested using MTS machine (Mechanical testing and simulation).

The above table column suggests that thinner the diameter lesser the tensile strength and thicker the diameter greater the tensile strength. For thicker diameter coir, two knots are sufficient to close cut or wound and thinner needs 4 to 5 knots.

2) CYTOTOXICITY TEST: Small pieces of fibre (100 [J L extract per ml of culture media) added to Balb/c 3T3 cell line with DMEM media and incubate for 48 hrs at 37 c at 5% C02 level and later check with trypan blue for cell viability (Dye exclusion method) and proved to be non-cytotoxic.

3) SKIN CLOSURE TECHNIOUE: The sterilized fibre and control (Nylon/silk/ prolene) is used as a suture on the two cuts (about 4 cm long) and (0.5 - 0.6cm deep) on the back of 10 winster rats (Cut made artificially). Individual suturing for 10 more winster rats was done in which 5 rats for control (nylon/prolene) and 5 rats for coconut coir was done separately for hematological and histo-pathological studies. The suturing is done when the winster rats were under general anesthesia. After the suturing, the rats were injected with antibiotic.

4) i) VISUAL INSPECTON : wound healed in four days for coconut coir and six days for silk braided (Diamond super stitch thread).

ii) HEMATOLOGICAL EVALUATION: Total WBC count, Hemoglobin, Differential count for the winster rats before and after suturing. Depends upon the wound healing (Time period), the cell count varies. Faster healing leads to faster normal cell counts.

iii) HISTOLOGICAL EVALUATION: This is performed 1, 2, 3, 4, 5, 6, 7,15th day after suturing with coir.



The number of knots for a monofilament is normally 6 or more but using the material of the present invention can be brought down to 4. The number of knots for multistrand sutures are normally 6 but with the use of the material of the present invention, can be brought down to 2. This leads to less thread consumption, leading to direct economic benefit.

We claim:

1. A natural non-absorbable, non-cytotoxic suture material made from Goir fibre extracted from green coconuts manufactured by extracting the fibre from green coconut manually; soaking the same in water for 24 - 48 hours for cleaning the fibre and to enable separation of the individual strands; soaking the individual strands in 70% alcohol for sterilization and decolourization for 5 hours; repeating the process of sterilization and decolorisation till the strands becomes translucent in colour; the said strands undergoing moist heat sterilization in an autoclave; removing thestrands and drying the same in an hot air oven between 40 - 50°C for 1 hour to remove any remaining moisture; packing the same in in sterile packing units.

2. A suturing material as claimed in claim 1, wherein the individual strand length is between 18-25 cms.

3. A suturing material as claimed in Claim 1, wherein the diameter of the individual strands varies from from 0.108mm to 0.263 mm.

4. A suturing material as claimed in Claim 3, being a monofilament when diameter is between 0.108-0.130mm.

5. A suturing material as claimed in Claim 1, wherein the individual strand tensile strength is 1.01 N to 7.40 N.

6. A suturing material as claimed in Claim 1, leads to less thread consumption as the number of knots required for any procedure is far lower than the commercially available threads. A suturing material as Claim 1, which is cheaper to manufacture than all current available suture materials resulting in a distinct economic advantage as compared to the current existing available products.

7. A suturing material as claimed in Claim 1 can be used as monofilaments or as multi strands, depending on the site of injury.

8. The biocompatible biomaterial suitable for suturing purposes in human beings and animals as substantially herein described.