Chitosan dressing for control of bleeding in transurethral prostatectomy
Inventors
Gannett, Cole • JONES, Mattie R. • Winata, Ervelyn • McCarthy, Simon J.
Assignees
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Publication Number
US-12156791-B2
Publication Date
2024-12-03
Expiration Date
Abstract
The present invention relates to a biocompatible, foldable, thin profile, low mass and high surface area, chitosan dressing, optionally modified with catechol, and suitable for treating bleeding in a physiological environment, e.g. bladder, and in particular in connection with the TURP procedure. The characteristics and structures of the chitosan dressing are provided. Methods of making and using the chitosan dressing are also provided.
Core Innovation
The invention provides a chitosan endoluminal hemostatic dressing for transurethral prostatectomy and bladder neck bleeding. The dressing is foldable and thin, with a thickness of 500 microns or less, and is biocompatible. It is deliverable via transurethral and/or balloon catheter delivery for endoluminal use.
The dressing is configured for rapid wetting-based adhesion to bladder/urethral tissue. It uses capillarity and porosity to absorb fluids and support hemostasis, including in anticoagulated patients, while maintaining urethral patency. The dressing further supports controlled slow dissolution enabling non-surgical removal within about 7 days.
In one aspect, the dressing comprises catechol modified chitosan, including catechol installation via N-acylation followed by catechol oxidation to o-quinone and crosslinking. pH and oxygen exposure are used during synthesis and oxidation/crosslinking to tune dissolution resistance and coloration. The disclosure also describes multiple manufacturing routes, including freeze-drying/freeze-phase separation and compression densification.
Claims Coverage
The partial claims provided include two independent claims. They define production routes for a catechol modified chitosan dressing with hemostatic function, specified thickness, and in one claim specified coloration, and a synthesis sequence using pH control and controlled oxygen exposure to drive catechol oxidation and cross-linking without an intermediate drying step.
Catechol modified chitosan dressing production with specified thickness and hemostatic function
A method of producing a catechol modified chitosan dressing comprising at least one of substituting chitosan with about 10% catechol; oxidizing catechol to o-quinone and cross-linking the o-quinone in the chitosan dressing; or freeze-drying, wherein the dressing is hemostatic and has a thickness of 500 microns or less.
Catechol oxidation and cross-linking under controlled oxygen exposure without intermediate drying
A method of producing a catechol modified chitosan dressing comprising synthesizing with chitosan and catechol in an aqueous reaction solution, maintaining a pH at or below pH 5.5, after that increasing the pH of the reaction solution and controlling oxygen exposure to provide catechol oxidation and cross-linking, and drying the reaction solution, wherein the method does not comprise an intermediate drying step between the pH stage at or below pH 5.5 and the step providing catechol oxidation and cross-linking.
Across the independent claims, the inventive coverage centers on producing a catechol modified chitosan dressing that is hemostatic and has a thickness of 500 microns or less, and on controlling synthesis pH and oxygen exposure to achieve catechol oxidation and cross-linking without an intermediate drying step.
Stated Advantages
Hemostatic.
Thin/foldable dressing profile with thickness 500 microns or less.
Rapid wetting-based adhesion to bladder/urethral tissue.
Capillarity and porosity to absorb fluids to enable hemostasis, including in anticoagulated patients.
Maintenance of urethral patency.
Controlled slow dissolution enabling non-surgical removal within about 7 days.
Catechol modification supports tuned dissolution resistance and coloration via pH and oxygen control.
Documented Applications
Hemostatic use for transurethral prostatectomy (TURP) and bladder neck bleeding, delivered endoluminally via transurethral and/or balloon catheter delivery.
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