Patent Application
20230263934
The present disclosure relates to wound dressings used for the treatment of wounds defined as open wounds when they become chronic in the health sector.
The present disclosure more specifically relates to a wound dressing material and a production method thereof, wherein the inventive wound dressing material comprises graphene-based 2,3 dialdehyde bacterial cellulose and is capable of supporting the cells in the wound area to heal chronic, i.e. non-healing wounds (e.g. bedsores), eliminating the risk of infection development in an open wound.
The world of medicine frequently encounters wounds that are defined as open wounds when these wounds do not heal and become chronic. Wounds such as these, i.e. bedsores (pressure ulcers) or wounds stemming from diabetes, or non-healing wounds stemming from circulatory disorders severely reduce the patients' quality of life. Conventional wound dressing materials are used in order to support the healing process of such wounds. Conventionally, materials used for wound care and treatment include materials such as natural and synthetic bandages, hydrophilic cotton, roll bandages, and medical gauzes. The reason underlying the use of such wound dressings is to allow the wound exudate to vaporize, thereby allowing the wound to dry and preventing bacterial growth in the wound medium. However, these conventional approaches fail to provide the optimal environment and conditions necessary for tissue regeneration. Nowadays, it is known for a fact that maintaining the warm and wet environment created around the wound is necessary for the regeneration of the tissue in the wound area. Therefore, nowadays materials that allow the movement of epithelial cells during the healing process of the wound, enable the oxygen circulation therein, prevent bacterial contamination, and allow for creating optimal ambiance conditions are being developed and used. In more advanced nano-technological materials, however, it is a much more preferred approach where the material is absorbed by the body after the epithelial cell proliferation has reached a certain level while enabling the movement of epithelial cells during the healing process as mentioned above. Such modern materials provide a much faster and successful wound healing process. A frequently implemented method for providing antimicrobial properties to wound dressing materials involves adding silver nanoparticles either to wound dressing material or to the structure of the material.
There is a number of commercially available wound dressings comprising various raw materials. While some of these feature a hydro-colloidal structure, some have a hydrogel structure. This particular difference stems from the fact that these two different materials of different properties (i.e. hydro-colloidal and hydrogel) are specific to two different wound types (i.e. dry or exudated). Generally, hydrogels are used either as elastic films (sheets) or amorphous gels. Nowadays, hydrogels used in the form of films have many of the optimal wound dressing properties. Moreover, these film-shaped hydrogels in the form of thin layers may be cut and prepared in conformity with the shape of the wound due to their convenient structure. When hydrogel dressings are applied to a dry wound surface, they moisturize the wound, thereby creating the ideal wet environment required for the healing of the wound. Another advantage of these hydrogels is that they may easily be shaped and cleaned from the surface of the wound. Wound dressing materials with hydrogel properties may be obtained from a number of natural or synthetic polymers with hydrophilic and water-swelling properties such as cross-linked carboxymethyl cellulose, modified starch, alginate, or pectin. However, many of the commercially available hydrogel wound dressings are made of synthetic polymers. Needless to say, there are also a considerable number of wound dressing materials produced by using natural polymers. However, these materials prepared by using such natural polymers are subjected to various chemical processes in order to create a hydrogel membrane. Removal of the used chemicals from the prepared film layer subsequent to said chemical processes requires an additional process step, and of course, brings along additional costs. It is known for a fact that undesired chemical residue may induce cytotoxic, allergic, or even mutagenic effects in cells located in the area of application.
The list provided below shows the respective literature publications, which have been determined as a result of the search conducted and which form the state of the art, on bacterial cellulose wound dressing materials and graphene.
Azarniya, A., Eslahi, N., Mahmoudi, N., & Simchi, A. (2016). Effect of graphene oxide nanosheets on the physicomechanical properties of chitosan/bacterial cellulose nanofibrous composites. Composites Part A: Applied Science and Manufacturing, 85, 113-122.
Czaja, W., Krystynowicz, A., Bielecki, S., & Brown Jr, R. M. (2006). Microbial cellulose—the natural power to heal wounds. Biomaterials, 27(2), 145-151.
Chook, S. W., Chia, C. H., Zakaria, S., Ayob, M. K., Huang, N. M., Neoh, H. M., & Jamal, R. (2015). Antibacterial hybrid cellulose-graphene oxide nanocomposite immobilized with silver nanoparticles. RSC Advances, 5(33), 26263-26268.
de Moraes, A. C. M., Andrade, P. F., de Faria, A. F., Simões, M. B., Salomão, F. C. C. S., Barros, E. B., & Alves, O. L. (2015). Fabrication of transparent and ultraviolet shielding composite films based on graphene oxide and cellulose acetate. Carbohydrate polymers, 123, 217-227.
Fan, Z., Liu, B., Wang, J., Zhang, S., Lin, Q., Gong, P., . . . & Yang, S. (2014). A novel wound dressing based on Ag/graphene polymer hydrogel: effectively kill bacteria and accelerate wound healing. Advanced Functional Materials, 24(25), 3933-3943.
Gürsu, H., Gencten, M., & Şahin, Y. (2017). One-step electrochemical preparation of graphene-coated pencil graphite electrodes by cyclic voltammetry and their application in vanadium redox batteries. ELectrochimica Acta, 243, 239-249.
Gürsu, H., Gençten, M., & Şahin, Y. (2018). Preparation of N-doped graphene-based electrode via the electrochemical method and its application in vanadium redox flow battery. International Journal of Energy Research, 42(12), 3851-3860.
Hakkarainen, T., Koivuniemi, R., Kosonen, M., Escobedo-Lucea, C., Sanz-Garcia, A., Vuola, J., . . . & Yliperttula, M. (2016). Nanofibrillar cellulose wound dressing in skin graft donor site treatment. Journal of controlled release, 244, 292-301.
Hoon, R., Oster, G. A., Damien, C., Wang, J., & Serafica, G. (2005). U.S. Patent Application No. 10/864,804.
Kaplan, E., Ince, T., Yorulmaz, E., Yener, F., Harputlu, E., & Laçin, N. T. (2014). Controlled delivery of ampicillin and gentamycin from cellulose hydrogels and their antibacterial efficiency. Journal of Biomaterials and Tissue Engineering, 4(7), 543-549.
Laçin, N. T. (2014). “Development of biodegradable antibacterial cellulose-based hydrogel membranes for wound healing.” International journal of biological macromolecules 67: 22-27.
Lin, W. C., Lien, C. C., Yeh, H. J., Yu, C. M., & Hsu, S. H. (2013). Bacterial cellulose and bacterial cellulose-chitosan membranes for wound dressing applications. Carbohydrate polymers, 94(1), 603-611.
Luo, H., Ao, H., Li, G., Li, W., Xiong, G., Zhu, Y., & Wan, Y. (2017). Bacterial cellulose/graphene oxide nanocomposite as a novel drug delivery system. Current Applied Physics, 17(2), 249-254.
Luo, H., Xie, J., Wang, J., Yao, F., Yang, Z., & Wan, Y. (2018). Step-by-step self-assembly of 2D few-layer reduced graphene oxide into the 3D architecture of bacterial cellulose for a robust, ultralight, and recyclable all-carbon absorbent. Carbon, 139, 824-832.
Maneerung, T., Tokura, S., & Rujiravanit, R. (2008). Impregnation of silver nanoparticles into bacterial cellulose for antimicrobial wound dressing. Carbohydrate polymers, 72(1), 43-51.
Picheth, G. F., Pirich, C. L., Sierakowski, M. R., Woehl, M. A., Sakakibara, C. N., de Souza, C. F., . . . & de Freitas, R. A. (2017). Bacterial cellulose in biomedical applications: a review. International journal of biological macromolecules, 104, 97-106.
Shaw, H., & Linnane, P. G. (2010). U.S. Pat. No. 7,759,539. Washington, DC: U.S. Patent and Trademark Office.
Shao, W., Liu, H., Liu, X., Wang, S., & Zhang, R. (2015). Anti-bacterial performances and biocompatibility of bacterial cellulose/graphene oxide composites. RSC Advances, 5(7), 4795-4803.
Solway, D. R., Consalter, M., & Levinson, D. J. (2010). Microbial cellulose wound dressing in the treatment of skin tears in the frail elderly. Wounds, 22(1), 17.
Sahin Y, Humus GÜRSU, Metin GENÇTEN, “A method in order to generate graphene-based electrode”, TURKEY, Patent, PCT/TR2017/050121, October 2017
Unnithan, A. R., Gnanasekaran, G., Sathishkumar, Y., Lee, Y. S., & Kim, C. S. (2014). Electrospun antibacterial polyurethane-cellulose acetate-zein composite mats for wound dressing. Carbohydrate polymers, 102, 884-892.
Wu, J., Zheng, Y., Song, W., Luan, J., Wen, X., Wu, Z., . . . & Guo, S. (2014). In situ synthesis of silver-nanoparticles/bacterial cellulose composites for slow-released antimicrobial wound dressing. Carbohydrate polymers, 102, 762-771.
Zhu, W., Li, W., He, Y., & Duan, T. (2015). In-situ bio-preparation of biocompatible bacterial cellulose/graphene oxide composites pellets. Applied Surface Science, 338, 22-26.
Neither the domestic nor the foreign publications disclose a wound dressing material comprising both bacterial cellulose and graphene in the structure thereof as in the present disclosure.
Furthermore, the respective research conducted in this regard showed no similar commercialized product available in the market. There are both domestic and foreign scientific publications available—as stated above—in which various cellulose wound dressings are disclosed. However, since there is no wound dressing that comprises both materials together, the inventive wound dressing provides novelty by this technical element. In addition thereto, a production method has been developed for the production of such wound dressing materials.
Furthermore, the inventors have discovered that the inventive wound dressing material produced by means of the inventive production method supports the cells in the wound area for the healing process of chronic, i.e. non-healing wounds and eliminates the risk of infection development in an open wound.
The object of the present disclosure is to provide a graphene-based 2,3 dialdehyde bacterial cellulose wound dressing material and a production method thereof, that is capable of supporting the cells in the wound area for the care and treatment of chronic, i.e. non-healing wounds (e.g. bedsores), and of eliminating the risk of infection development in an open wound. The inventive graphene-based cellulose wound dressing is a dressing that comprises hydrogel and graphene derivatives of film type having 2,3 dialdehyde bacterial cellulose structure, and antimicrobial effects. Graphene-based materials need to provide antibacterial and physical properties to a wound dressing. At least one embodiment of the present disclosure stimulates the healing of chronic, i.e.
non-healing wounds (e.g. bedsores).
Graphene derivatives to be used in the inventive wound dressing may be one or more materials selected from; graphene and graphene materials doped with —N, —S, —Cl, —P, —B, —F, —Si, —Ti; graphene oxide and graphene oxide materials doped with —N, —S, —Cl, —P, —B, —Si, —F; graphene derivatives with functionalized —Si, —B2O3 —NH2, —ClO3, —B2O3, —P2O5 groups. More preferably, graphene derivatives synthesized with Yucel's Method as disclosed in the respective literature.
The present disclosure relates to a wound dressing material developed for wound dressings that support the cells in the wound area for the treatment of wounds and eliminates the risk of infection development in open wounds, wherein the present disclosure discloses a wound dressing material comprising graphene-based 2,3 dialdehyde bacterial cellulose.
The graphene material to be used herein may be one or more materials selected from; graphene and graphene materials doped with —N, —S, —Cl, —P, —B, —F, —Si, —Ti; graphene oxide and graphene oxide materials doped with —N, —S, —Cl, —P, —B, —Si, —F; graphene derivatives with functionalized —Si, —B2O3 —NH2, —ClO3, —B2O3, —P2O5 groups.
Another novel property at least one embodiment of the present disclosure is that it comprises a method for preparing graphene-loaded 2,3 dialdehyde bacterial cellulose wound dressing material for wound dressings that supports cells in the wound area for the treatment of chronic wounds and that eliminates the risk of infection development in open wounds. In general, the inventive method for preparing wound dressing material comprising graphene-loaded 2,3 dialdehyde bacterial cellulose comprises the following process steps:
As mentioned in the preparation method, different graphene or graphene derivatives may be one or more materials selected from; graphene and graphene materials doped with —N, —S, —Cl, —P, —B, —F, —Si, —Ti; graphene oxide and graphene oxide materials doped with —N, —S, —Cl, —P, —B, —Si, —F; or graphene derivatives with functionalized —Si, —B2O3 —NH2, —ClO3, —B2O3, —P2O5 groups.
A method implemented in previous studies of inventors is used in the production stage of the bacterial cellulose as provided in the preparation method.
Cellulose is a biopolymer naturally available in large quantities in plant structures. As cellulose may be obtained from a vegetative source, it may also be produced by bacteria. The bacterial cellulose (BC) used in the present disclosure is produced via a previously implemented method. Two different media are prepared for the production of the bacterial cellulose. One of the two media is a medium that will be prepared for inoculum formation. It is prepared so as to contain 25 g/L of the medium, 3 g/L of Peptone, and 5 g/L of yeast extract, the pH value thereof is adjusted to 5.0 via 1 M hydrochloric acid (HCl) and sterilized by autoclaving for 20 minutes at 120° C. 25 mL of the medium is transferred to Erlenmeyer flasks of 100 mL, and Acetobacter xylinum (ATCC 10245) bacteria are added thereto. The obtained media are agitated at 30° C. and 150 rpm for a duration of 2-3 days, thereby obtaining the inoculum. The medium necessary for the production of cellulose for inoculums is prepared so as to contain 20 g/L of glucose, 10 g/L of Peptone, 10 g/L of yeast extract, 8 mM of KH2PO4, and 12 mM of K2HPO4, the pH value thereof is adjusted to 5.0 via 1 M hydrochloric acid (HCl) and sterilized by autoclaving for 20 minutes at 120° C. Inoculum is added to the medium being divided into glass containers, at a ratio of 1/10, and left for incubation at 30° C. for a duration of 7 days. Membranes are kept inside 1 M of NaOH in a water bath adjusted to 80° C. for 2 hours in order to purify the cellulose membranes formed on the surface of the glass from bacterial and cellular impurities. Subsequently, they are washed with distilled water until the pH value thereof reaches 7.0. Prepared membranes are autoclaved and preserved. The production of bacterial cellulose was optimized as a result of previous studies conducted by our group (Lacin 2014).
The second stage of the inventive method for preparing wound dressing material comprising graphene-loaded 2,3 dialdehyde bacterial cellulose in which graphene derivatives are synthesized and characterized via Yucel's Method is performed as stated below.
Synthesis of graphene-based materials is performed via a method called Yucel's Method (H. Gürsu vd. 2019) which is a method developed by the team of inventors. Graphene and derivatives thereof (graphene derivatives comprising graphene and graphene doped with —N, —S, —Cl, —P, —B, —F, —Si, and functional groups such as —NO3, —NH2, —ClO3, —B2O3, —P2O5) are synthesized by our group by using the all of the aforementioned methods.
A conventional triple electrode system is used for preparing graphene-based materials from graphite-based materials via the electrochemical Yucel's Method. Ag/AgCl, calomel, Hg/HgSO4 are used as the reference electrode, while Pt is used as a counter electrode and a graphite-based electrode is used as the working electrode. Solutions comprising salts, monoprotic, polyprotic acids, bases and mixtures thereof containing various functional groups in their structures are used as the electrolyte within a concentration range between 0.0001 M-10 M. Unlike the literature, voltage ratings being worked with for graphene production via electrochemical method are low and requires applying less energy. The synthesis method is implemented between (−3 V)-(+6 V) working potential range; in a scanning rate value between 0.001 V/s-1V/s and in a cycle changing between 1-500.
In summary, the second stage of the inventive method for preparing wound dressing material comprising graphene-loaded 2,3 dialdehyde bacterial cellulose in which graphene derivatives are synthesized via Yucel's Method comprises the following process steps;
The third stage of the inventive method for preparing wound dressing material comprising graphene-loaded 2,3 dialdehyde bacterial cellulose comprises preparing and characterizing graphene-doped wound dressing materials.
Studies conducted in the field of tissue engineering have proven that bacterial cellulose is the ideal material for 3D printing with nanofibrils. Being able to control the mechanical properties of bacterial cellulose materials is among its most important advantages. In this context, preparation and analysis of cellulose nanofibrils for 3D bioprinters were reported by Torres-Rendon et al. The work of Torres-Rendon et al. demonstrated that the obtained hydrogels may be processed, printed in different shapes and structures obtained after the printing processes are rehydrated (Torres-Rendon vd. 2016).
The preliminary studies have concluded that graphene types affect cell growth positively.
A graphite rod as the working electrode, to be used in the tests mentioned above, was obtained via Yucel's Method, inside nitric acid solutions such that it has a potential between 1.0 and +2.3 V, between −0.7 and +2.3 V, and between 0 and +2.3 V, and inside the Ag/AgCl (at 3M KCl) mixture at room temperature (25° C.) in 100 voltammetric cycles (with a scanning rate of 50 mV/s) to produce approximately 1.0 g of graphene powder. Graphene-based materials are named as; graphite (G), N-doped graphene oxide (M0), N-doped graphene1 (M1), N-doped graphene2 (M2), N-doped graphene3 (M3), and N-doped graphene4 (M4).
Cell viability and immunology assays were performed on the N-doped graphene- and graphene oxide-based materials and the results obtained are provided above. In this context, (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay, which is a colorimetric method, was performed on the L929 cell line for the cell viability assay. Graphene samples at a concentration of 0.2 g/mL were used for MTT and IL-1β assays. Respective test results indicated that all graphene groups induced cell proliferation.
Bacterial cellulose and graphene derivatives were separately produced by our group. Bacterial cellulose solutions comprising graphene in a range between 1% and 15% by weight (with heteroatom) and other graphene derivative concentrations will be prepared in preparation of graphene-doped bacterial cellulose wound dressings.
The inventive graphene-based bacterial cellulose wound dressing appeals to a large market volume in the health sector. The production of bacterial cellulose is already being carried out on an industrial scale. Wound dressing materials with graphene content will be produced on an industrial scale by implementing the inventive method developed as an alternative to the industrial production method utilized at present.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020/13979 | Sep 2020 | TR | national |
This application is a National Phase entry of International Application No. PCT/TR2020/051079 under § 371 and claims the benefit of TR Patent Application No. 2020/13979, filed Sep. 3, 2020, which is hereby incorporated by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/TR2020/051079 | 11/11/2020 | WO |
