Method for preparation of tissue adhesive patches
Inventors
Laub, Orgad • Cohen, Eran • Schwartz, Yotam
Assignees
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Publication Number
US-11771799-B2
Publication Date
2023-10-03
Expiration Date
Abstract
A method of production of a tissue sealing patch is disclosed. The method comprises applying a vacuum to a heated work surface; applying a solution of a biocompatible polyurethane polymer to the work surface and spreading it over the work surface with a polymer blade; evaporating the solvent; heating the work surface above the softening temperature of the polymer; spreading powdered tissue sealant material over the polymer film; incorporating the tissue sealant material to a depth of 20-60 μm in the film by pressing on a release sheet placed over the powder and polymer film; removing the release sheet from the adhesive patch material; releasing the vacuum; cooling said work surface; and removing the adhesive patch material from said work surface. The biocompatible polymer preferably comprises PEG-caprolactone-lactic acid units connected by urethane linkages, the PEG having a molecular weight of 3000-3500 amu, and a CL:LA:PEG ratio of 34:2:1.
Core Innovation
The disclosed invention relates to improved tissue/hemostatic adhesive patches and to a method for preparing such a tissue adhesive patch. The patch includes a non-permeable biocompatible polymer film backing formed from a biocompatible polyurethane polymer selected from polyethylene glycol-polycaprolactone copolymers, polyethylene glycol-DL-lactide copolymers, and polyethylene glycol-polycaprolactone-DL-lactide copolymers. Powdered tissue sealant material is spread over the polymer film and at least partially incorporated into a surface of the polymer film to form a film of adhesive patch material.
A central aspect of the invention is control of the powdered tissue sealant incorporation depth during preparation, wherein pressure through a top release sheet incorporates the powdered tissue sealant material into the polymer film to a depth between 20 μm and 60 μm. The disclosure emphasizes that sealing performance and degradation are driven by the polymer composition and the sealant embedding/incorporation depth.
The disclosure characterizes resulting adhesive behavior and degradation. Comparative results described indicate that incorporation to a depth of about 20–60 μm yields much higher adhesive force than shallower incorporation or deeper incorporation, and that patch failure mode shifts to adhesive failure at the sealant–tissue interface. The degradation time is tunable, and the disclosure additionally states that adhesive strength is largely independent of fibrin concentration, thereby enabling reduced sealant loading.
Claims Coverage
The independent claim covers a method of preparing a tissue adhesive patch using a vacuum-heated work surface, a coated non-permeable biocompatible polyurethane polymer film, and incorporation of powdered tissue sealant into the polymer film to a specified incorporation depth. The independent claim presents 3 inventive features, and the dependent claims refine the polyurethane composition, sealant loading and layer thickness, powdered sealant options, and treatment contexts to specified leak types.
Vacuum-heated coating to form a non-permeable polymer film
heating to a predetermined temperature a work surface in connection with a source of vacuum, engaging said vacuum to said work surface, applying to said work surface a solution of a biocompatible polyurethane polymer selected from polyethylene glycol-polycaprolactone copolymers; polyethylene glycol-DL-lactide copolymers; and polyethylene glycol-polycaprolactone-DL-lactide copolymers; adjusting a polymer blade to a predetermined height above said work surface; spreading said solution with said polymer blade; evaporating said solvent thereby creating a non-permeable biocompatible polymer film characterized by a thickness; heating said work surface above said softening temperature
Pressure incorporation of powdered tissue sealant via top release sheet
spreading powdered tissue sealant material over said polymer film, placing over said polymer film a top release sheet over said powder and polymer film, applying pressure to said top release sheet so as to at least partially incorporate said powdered tissue sealant material into a surface of said polymer film, thereby forming a film of adhesive patch material, removing said top release sheet from said film, releasing said vacuum, cooling said work surface to room temperature, and removing said adhesive patch material from said work surface
Sealant incorporation depth between 20 μm and 60 μm
incorporating said powdered sealant material into said surface of said polymer film to a depth of between 20 μm and 60 μm
Overall claim coverage centers on preparing a tissue adhesive patch by forming a non-permeable biocompatible polyurethane film on a vacuum-heated work surface and then incorporating powdered tissue sealant into the polymer film by pressure through a top release sheet, where the incorporation depth is between 20 μm and 60 μm. Dependent claims further specify a particular polyethylene glycol–polycaprolactone–DL-lactide copolymer composition, add quantitative constraints for sealant amount and sealant layer thickness, define fibrinogen/thrombin-based powdered sealant options with threshold limits, and narrow the leak-treatment context to specific leak types.
Stated Advantages
Higher adhesive force is achieved when the powdered tissue sealant is incorporated to a depth of about 20–60 μm versus shallower or deeper incorporation.
Patch failure mode shifts to adhesive failure at the sealant–tissue interface.
Adhesive strength is largely independent of fibrin concentration, enabling reduced sealant loading.
Degradation time is tunable, with an example degradation time described as about 10–14 days.
Documented Applications
Treating fluid leaks by applying/activating the patch for leak types selected from arterial bleeding, organ tissue bleeding, bile anastomosis, cerebrospinal fluid leak, dura leak, or an air leak in damaged lung tissue.
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