Technical Field

The invention refers to a nanofiber solid, flexible and permeable wound dressing formed for cosmetic purposes or for the treatment of open wounds.

Known Version of the Technique

When the current practices are analyzed, it is known that there is a wide variety of wound care products. These are spongy products which are made from various raw materials. Some of them are produced using textile technology. Others use polyurethane as a raw material.

Hydrocoil, another wound dressing used in the technique, is a self-adhesive absorbent hydrocolloid wound dressing with a semi-permeable covering layer that is impermeable to microorganisms and water. Hydrocolloids turn into gel when they come into contact with wound discharge. They create a moist environment that provides a triggering effect on granulation and epithelization. This type of dressing, on the other hand, does not have an effect to remove the wound discharge from the environment since it is semi-permeable.

Another type of wound dressing used recently is in foam form. Foam wound care products generally use polyurethane, which absorbs exudate, as a raw material and does not contain a wound healing component. In this case, there should be no infection on the wound to use the mentioned wound dressing. Moreover, because the fully permeable structure is not provided, the wound discharge cannot be removed from the environment.

One of the patents about this subject in the literature is the application number TR201904572. Within the scope of this invention, biocompatible PVA-gelatin core-shell composite nanofiber tissue scaffold consisting of Polyvinyl Alcohol (PVA or P) and bovine gelatin (GE) to be used as a supportive material in wound and burn treatments is produced using the electrospinning method with environmentally sound green production approach. The tissue must be completely free of bacteria to use the subject product. It is not suitable for bacteria-contaminated or infected wounds. Apart from this, it does not have any controlled molecule release feature.

In patent application numbers TR201517118 and TR201617649, the wound dressings which contain polylactic acid (PLA), a polymer such as polycaprolactone (PCL) and chitosan are obtained by electrospinning method. While PCL is used with the core-shell structure in the application number TR201517118, PLA is used in the patent application number TR201617649.

As a result, it is required to make an improvement in the relevant technical field due to the above-mentioned negativities and the insufficiency of present solutions.

Purpose of the Invention

The present invention refers to a wound dressing that meets the aforementioned requirements, eliminates all disadvantages and brings some additional advantages.

The primary purpose of the invention is to obtain a biocompatible wound dressing with self melting property of the dressing on the wound. Thanks to the formation of a wound dressing from the molecules that are good for the wound, the wound dressing disappears in the wound and it is not required to remove it from the wound. This provides an easy-to-use feature. Moreover, because it is not required to remove the wound dressing, which is the subject of this invention, from the wound, adhesion to the other wound and deformation, which is caused by that, on the skin can be prevented.

Another purpose of the invention is to provide wound dressing with a controlled releasing. In this way, the spontaneous disappearance time of the wound dressing, which is the subject of the invention, can be adjusted and it will make contributions to the rapid healing of the wound because it will release antimicrobial components into the wound environment in a controlled manner.

Wound dressings used in the current technique and applied without cleaning have a negative effect on wound healing. A purpose of the invention is to eliminate the need for wound cleaning before application, thanks to the antibacterial agents in its content such as PHMB and chitosan. While it quickly contributes to wound healing, it also prevents the biofilm formation. Prevention of the biofilm created by bacteria on the wound surface is very important for wound healing. Another purpose of the invention is to obtain a nanofiber textured fully permeable wound dressing thanks to the electrospinning method used in production. In this way, while it removes the fluid formed in the wound from the environment, it also accelerates the wound healing process thanks to its air permeability.

In order to fulfill the abovementioned objectives, a nanofiber solid, flexible and permeable wound dressing formed for cosmetic purposes or for the treatment of open wounds is developed.

Explanation of Figures

Figure-1 shows the SEM image of the wound dressing, which is a preferred arrangement of the invention and prepared with A, B, C and D solutions.

Detailed Explanation of the Invention

In this detailed explanation, the preferred arrangements of wound dressing, which is the subject of the invention, are explained only for a better understanding of the subject and without any restrictive effect.

In its most basic form, it is a nanofiber wound dressing which is selected individually or as a combination from the group of polyvinyl alcohol, polyvinyl acetate and hydrolyzed collagen, chitosan, Poloxamer 188, polyhexanide for cosmetic or medical use.

The most fundamental component of the invention is a solution containing polyvinyl alcohol (PVA), polyvinyl acetate (PCA) and water. This solution is called solution A throughout the invention for an easy understandability. Table 1 shows the raw materials in solution A and a preferred amount of these raw materials that can be used in solution. Solution A should be used to create a nanofiber wound dressing with the electrospinning device. PVA and PCA, which are used in the solution, have a structure that can spin the desired molecule in the magnetic field of the electrospinning device and retain it back into the nanofiber structure. The ratio of PVA and PCA allows to decide how long the molecules that provides healing and are desired to be used will perform a controlled release. Table 1. Table showing the raw materials in the content of solution A

While the invention obtains the most fundamental form of wound dressing, solution A and one or more solutions selected from the solution group - solution B, solution C and solution D - which are explained in detail below are used.

Solution B consists of natural or synthetic polymer and water. The purpose of using natural or synthetic polymers in the solution is to obtain nanofiber composites. Table 2 below shows the natural or synthetic polymers that can be used in solution.

Table 2. Table showing natural and synthetic polymers Hydrolyzed collagen is preferably used in the invention. The subject hydrolyzed collagen may preferably be type I, type II or type III. Type I and type III, which are the most suitable options for tissue and subcutaneous, are preferably preferred in the invention. Hydrolyzed collagen is used to support the existing collagen structure in the hypodermis layer under the skin. It is referred to as solution B for an easy understanding throughout the invention. Table 3 shows the raw materials in solution B and a preferred amount of these raw materials that can be used in solution.

Table 3. Table showing the raw materials in the content of solution B

Solution C is a solution consisting of a natural or synthetic polymer, a solvent that dissolves the said polymer and water. Said natural or synthetic polymer can be selected from those mentioned in Table 2. In the invention, chitosan (Poly-D-Glucosamine) is preferred as a natural or synthetic polymer, and acetic acid solution is preferred as a solvent for solution C. Chitosan can be dissolved in acetic acid. If another polymer is used, it is necessary to use another solvent. Chitosan is preferred because it prevents the formation of bacteria on the surfaces where it has contact, helps to eliminate harmful bacteria and has antibacterial properties. It is important to use chitosan within the specified range as it can affect the nanofiber structure. It is referred to as solution C for an easy understanding throughout the invention. Table 4 shows the raw materials in solution C and a preferred amount of these raw materials that can be used in solution.

Table 4. Table showing the raw materials in the content of solution C Solution D is a solution consisting of a wound care molecule and water. In the invention, preferably poloxamer 188 (Kolliphor P 188), polyhexanide (Polyhexamethylene Biguanide PHMB) are used. Polyhexanide is used for its contribution to wound healing. It is referred to as solution D for an easy understanding throughout the invention. Table 5 shows the raw materials in solution D and a preferred amount of these raw materials that can be used in solution.

Table 5. Table showing the raw materials in the content of solution D

Within the scope of the invention, the solution A and, in addition to solution A, one or more solution which is selected among solution B, solution C and solution D can be combined to obtain a wound dressing. In a preferred arrangement of the invention, 50-99% Solution A can be used. In another preferred arrangement of the invention, the mentioned solution C is used at a maximum rate of 15% in the mixture. Another preferred arrangement of the invention is obtained by applying electro spinning method to 80% Solution A, 5% Solution B, 5% Solution C and 10% Solution D.

Figure-1 shows the SEM image of the wound dressing, which is a preferred arrangement of the invention and prepared with solutions A, B, C and D via electrospinning. The obtained wound dressing has a spider web structure as it can be seen in Figure-1 and the nanofiber structure can be seen in the SEM image.

The production of the wound dressing, which is subject to the invention, is explained in detail below:

Obtaining solution A: Polyvinyl alcohol and Polyvinyl acetate are mixed with cold deionized water for 60 minutes in the proportions specified in Table 1 . Subsequently, the temperature is increased to a range between 50-95°C, preferably to 85°C, and the mixture is mixed until it becomes homogeneous in the mixer heater. The temperature of Polyvinyl alcohol mixture is an important parameter. Polyvinyl alcohol and polyvinyl acetate can be used in the range of 1-20% depending on the controlled release time of the desired wound care material. Obtaining solution B: Hydrolyzed collagen is dissolved in deionized water within the proportions specified in Table 3. It is mixed in a magnetic stirrer to be dissolved homogeneously.

Obtaining solution C: Acetic acid is dissolved in deionized water within the proportions specified in Table 4. Chitosan is added to the solution in a sealed container and mixed in a mixer. The mixed solution C is then mixed in an ultrasonic bath to accelerate the dissolution and make the solution homogeneous.

Obtaining solution D: Poloxamer 188 and polyhexanide are mixed in deionized water within the proportions specified in Table 5 in a separate container.

After the aforementioned solutions are mixed, a wound dressing solution, which absolutely consists of solution A in a usable proportion, is prepared preferably with solution B, solution C and solution D. The said composition is mixed for at least 1 hour to obtain a homogeneous structure. Then, it is mixed for about half an hour in an ultrasonic bath at a temperature which do not exceed 25°C.

After the homogeneous structure is provided, the wound dressing solution, which is taken into an injector, obtains its wound dressing form thanks to the electrospinning method via electrospinning device at a feeding speed of 1 ,5 ml/hour. When the solution, which is formed at a certain speed, reaches adequately suitable magnetic field, it enters into the electronic spinning and glides through the magnetic field and splashes to the non-flammable/non-stick paper to form a nanofiber structure. This application can be performed from 1 hour to 144 hours depending on the thickness of the wound care material. Voltage is 40kv.

The above mentioned process should be carried out at a temperature between 12-25°C. The pH range that can be used for the wound dressing solution is 4.5-7, and the preferred pH range is 5-7. While the process is being carried out, the environment has 70% humidity. The product can be sterilized optionally with the help of gamma or similar rays especially after it is produced.

The wound dressing obtained with solution A, B, C and D is indicated for the treatment of open wounds, burns or diabetic patients undergoing chronic wound treatment. This feature of the wound dressing puts itself to the class III, medical device class. When the solutions A and B are used together, a cosmetic-class care mask can be obtained that is suitable for the face and skin. In another preferred arrangement of the invention, a cosmetic-class face care mask is obtained by combining the solution A with the hyaluronate solution,

In addition to the solutions A and B, when the solutions C and D are used which have wound healing and disinfecting features, the product can be used as a surgical thread which is a wound covering and suture material.