Patent Application
20180161478
The present, invention relates to a polymeric-based barrier membrane with form memory which is used in periodontitis treatment, comprises bioactive agents; and a production method of the said membrane.
Periodontitis is a chronic-inflammatory disease which is caused by microorganisms, destroys periodontal tissues and accordingly results in loss of teeth. Purpose of periodontal treatment is not only to stop progressing periodontal disease and also to enable destroyed periodontal tissues to change back into their former states by also realizing periodontal regeneration. Periodontal surgical methods being used nowadays result in repair of periodontal tissues rather than their regeneration.
Methods of Guided Tissue Regeneration (GTR) and Guided Bone Regeneration (GBR) are commonly used in recent years in order to realize periodontal regeneration. In GTR/GBR methods, periodontal regeneration is provided by various membranes developed. Aim of using membrane is to generate barrier between hard tissue and soft tissue. Thereby, migration of epithelial cells to the damaged area is prevented and periodontal regeneration is provided in the damaged area at the same time. Otherwise, epithelial cells migrate to the damaged area and prevent bone regeneration here.
Membranes to be used in GTR/GBR technique need to meet some requirements such as biocompatibility, biodegradability, flexibility and mechanical strength. Aim in these methods is to prevent migration of epithelial cells to damaged area and enable the tooth to recuperate by realizing bone regeneration in the damaged area. For this purpose, various membranes which can resorb or not are used. However, these membranes developed remain incapable in terms of some features required to be included. Among these, there are problems such as: poor mechanical strength, the fact that formation of new bone tissue is not supported sufficiently in the damaged area, rate of resorption is not at desired level, bacterial infection cannot be prevented and epithelial cell migration cannot be avoided. Manipulation difficulties experienced in membrane implantation used is one of the greatest problems of dentists using available commercial products.
The Chinese patent document no. CN102423506, an application in the state of the art, discloses that nanofiber membranes consisting of biodegradable polymer, cellulose nanocrystals and an active medicine are manufactured so as to be used in periodontitis treatment. The invention described in the said document discloses that membrane is manufactured by electrostatic spinning method and there is chitosan in its content.
An objective of the present invention is to realize a barrier membrane which provides fast, efficient coating with a composition and characteristics very similar to the hydroxyapatite composition in bone; and a production method of the said barrier membrane.
Another objective of the present invention is to realize a barrier membrane wherein no reduction occurs in dimension of hydroxyapatite particles; and a production method of the said barrier membrane.
Another objective of the present invention is to realize a barrier membrane wherein epithelial cell migration is prevented and inflammation is avoided; and a production method of the said barrier membrane.
Another objective of the present invention is to realize a barrier membrane which is biodegradable, has form memory and osteogenic activity, supports bone regeneration, prevents epithelial cell migration and eliminates inflammation, can be produced easily and inexpensively; and a production method of the said barrier membrane.
“A Barrier Membrane Used in Periodontitis Treatment (1) and a Production Method Thereof (100)” realized to fulfil the objectives of the present invention is shown in the figures attached, in which:
The components illustrated in the figures are individually numbered, where the numbers refer to the following:
1. Barrier Membrane
2. PCL Nanofiber Coating
3. Non-Porous Surface
4. HA Coating+BMP-6
5. Porous Surface
100. Method
The biodegradable barrier membrane with form memory (1) used in periodontitis treatment, consisting of chitosan, comprises:
The membrane (1) developed by the present invention has chitosan content and it is of form memory and biodegradable nature.
The non-porous surface (3) comprised by the membrane (1) contacts the soft tissue of the tooth where periodontitis treatment will be administered and there is PCL nanofiber coating (2) on thereof.
The porous surface (5) comprised by the membrane (I) is located on the part that will contact the hone tissue and there is a BMP-6 impregnated HA coating (4) on thereof.
In a preferred embodiment of the invention, the non-porous surface (3) is coated with a PCL nanofiber coating (2) comprising an antibacterial agent which is preferably metronidazole.
The inventive method (100) comprises steps of:
In the inventive method (100), the step of preparing chitosan solution (101) is carried out by dissolving the chitosan—which has preferably 1.1% weight/volume, high molecular weight, deacetylation degree of ≥85%—in acetic acid solution of 1% by volume for 24 hours.
In a preferred embodiment of the invention, the step of coating the non-porous surface (3) of the membrane (1) with PCL nanofibers comprising antibacterial agent by utilizing electro spinning method (107) is carried out by preparing PLC (11% weight/volume, Mn: 70,000-90,000 g/g-mol) upon being mixed within HFIP (Hexafloro-2-propanol) for 24 hours; adding 5%, 10% and 15% (by weight) metronidazole into the PLC structure In order to eliminate the inflammation in the soft tissue; placing the obtained solution into the pump syringe in the electro spinning assembly; and coating the membrane (1) surface with PCL nanofibers for 7 minutes under optimized conditions (107).
In a preferred embodiment of the invention, the method (100) is carried out by adding silica gel—preferably in 150-250 μm diameter—into the solution in order to create pores on a surface of the membrane (1) by adding silica gel at different proportions in order to create pore (102); mixing the solution obtained after adding silica gel preferably for 1 hour and leaving the obtained solution for drying at room temperature (22±2° C.) upon being put into Petri dishes in preferably 5 cm diameter; taking the membrane (1) from the Petri dish and keeping it in 5% NaOH solution (weight/volume) in drying-oven (ES 500, Nüve) of 80° C. for preferably 2 hours and washing it with distilled water at room temperature until a neutral washing solution is obtained. The silica gels are enabled to dissolve inside the solution homogeneously by mixing the solution wherein silica gel is added.
In a preferred embodiment of the invention, the step of coating the porous surface (5) with hydroxyapatite by microwave-assisted biomimetic method (104) is carried out by preparing artificial body fluid solution in order to obtain HA; precipitating the membrane (1) inside 100 ml 10× SBF (Artificial body fluid) solution wherein no NaHCO3 is added in vacuum drying oven in order to contact all pores with a SBF (Artificial body fluid); transferring it to 100 mL 10× SBF (Artificial body fluid) solution wherein NaHCO3 is added; and coating the surface with hydroxyapatite by means of microwave at optimized conditions (preferably 600 W, 30 s×9 repeat) (105). HA structure with a composition closest to the bone is obtained under optimized conditions.
Preparing artificial body fluid solution is performed by dissolving the first five salt components given in the Table-1 inside 800 mL distilled water in magnetic stirrer respectively and then completing the volume to 1000 mL.
In a preferred embodiment of the method (100) realized by the present invention, the glass plate surface in 5×5 cm2 dimension is coated with double-sided foam tape for the purpose of coating only the porous surface (5) of the membrane (1) by HA and then the membrane (1) is adhered to the glass plate such that the porous surface (5) of the membrane (1) will be on the upper side and the membrane (1) is attached by plastic clips from its sides in order to prevent the membrane (1) from remove from the surface with liquid medium and the temperature effect.
In an exemplary embodiment of the method (100) realized by the present invention, the step of coating the porous surface (5) with hydroxyapatite by microwave-assisted biomimetic method (104) is carried out by performing coating process for four times by continuing to coat in fresh SBF medium every time in order to obtain sufficient coating on the surface. Washing is performed with distilled water for 1 minute in order to remove undesired phases occurring on the membrane (1) surface between each coating. After the final coating, the membrane (1) is washed with ethanol, distilled water for 10 minutes, 10 minutes respectively. Afterwards, the membrane (1) is kept in −20° C. for one day and dried method (100) comprises the step of keeping the membrane (1) in glycerine solution of 20% (volume/volume) for 30 minutes (106) after the freeze drying process. Following the glycerine treatment (106), the membrane (1) is left for drying at room temperature. Embrittlement of chitosan is eliminated with this application and thereby its manipulability is facilitated both in vitro and in vivo.
In a preferred embodiment of the invention, the step of loading bone morphogenic protein-6 (BMP-6) to the HA coated membrane (1) surface (108) is carried out by impregnation method by utilizing electrostatic interaction between HA and BMP-6 molecules. In a preferred embodiment of the invention, the said step (108) is carried out by dissolving 2.5 μg BMP-6 inside 750 μL PBS (phosphate buffered saline) comprising 2% 0.1 (weight/volume) bovine serum albumin (BSA); taking 30 μL from the obtained solution such that it will contain 100 ng BMP-6; find dripping it to the HA coated membrane (1) surface and keeping the membrane (1) in CO2 (5%) incubator at 37° C.
In the inventive membrane (1) and method (100), efficiency of BMP-6 in periodontal regeneration is ensured and osteoblastic cells are enabled to support cellular functions upon being loaded to membranes. In addition, porous chitosan supports proliferation and tissue regeneration of the membrane surface (5) consisting of biomimetic HA and BMP-6. With the method (100) developed by the present invention, it is ensured that PCL nanofibers are prevented from removing from the surface at physiological medium conditions and release of antibacterial agent loaded to their structures is provided by enabling them to attach to the membrane surface with solvent interaction by coating the non-porous surface (3) of the chitosan membrane with PCL nanofibers comprising antibacterial agent (metronidazol) by utilizing electro spinning method in order to prevent epithelial cells migration and inflammation.
Within these basic concepts, it is possible to develop a great variety of embodiments of the inventive “A Barrier Membrane Used in Periodontitis Treatment (1) and a Production Method Thereof (100)”; it cannot be limited to the examples disclosed herein and it is essentially according to the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015/06080 | May 2015 | TR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/TR2016/000071 | 5/18/2016 | WO | 00 |
