Hemostatic material and spray
Inventors
Freier, Thomas • Montenegro, Rivelino • Grube, JR., Wayne
Assignees
Publication Number
US-12263185-B2
Publication Date
2025-04-01
Expiration Date
2039-02-04
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Abstract
A hemostatic material and a method of treating a bleeding wound of a human or an animal include a hemostatic powder for application to the wound. The hemostatic powder comprises a first part consisting of a native chitosan base and a second part consisting of a chitosan salt, where the first and the second parts form the main component of the hemostatic powder, or at least 50% of a total weight of the hemostatic powder, and the second part forms a layer that at least partially coats the first part. The hemostatic powder may be provided in a hemostatic spray formulation that comprises a mixture of the hemostatic powder dispersed in a liquefied gas for release from a cannister onto the wound. A treatment method involves applying the hemostatic spray formulation directly to the wound. Other embodiments are also disclosed.
Core Innovation
The invention provides a hemostatic material comprising at least two parts: a first part consisting of a native chitosan base and a second part consisting of a chitosan salt, where the second part forms a layer that at least partially coats the first part, and together they form at least 50% of the total weight of the hemostatic material. This configuration results in enhanced binding capacity with blood components compared with a physical mixture of the native chitosan base and its salt, and both parts are essentially non-soluble in blood. The native chitosan base is at least partially non-soluble in water, while the chitosan salt part is at least partially soluble in water.
The invention also includes a hemostatic spray formulation wherein the hemostatic powder formed of the coated chitosan particles is dispersed within a liquefied gas propellant inside a canister, allowing for precise application onto bleeding wounds. This spray formulation delivers a rapid decrease in temperature upon application, inducing vasoconstriction to facilitate hemostasis. The particles have a mean diameter of less than 0.2 mm, providing a larger surface area that enhances electrostatic interactions between positively charged chitosan and negatively charged blood cells, improving hemostatic efficacy.
The problem being addressed arises from current limitations in existing hemostatic agents used for controlling severe bleeding, especially in trauma and combat scenarios. Severe bleeding wounds remain a leading cause of preventable deaths in both military and civilian contexts due to difficulties in rapid and effective hemorrhage control. Existing products such as solid foam-like dressings or loose powders have drawbacks like inconsistent efficacy, difficult application, and reduced effectiveness in adverse conditions. There is a need for a hemostatic material and delivery method that offer improved hemostatic properties, ease of application on complex wound structures, stability, and accelerated blood clotting.
The invention solves this problem by providing a novel chitosan-based hemostatic composition with a uniquely active material comprising native chitosan base particles surface-modified with chitosan salt layers, combined with a spray delivery system that allows for controlled, precise application even in challenging environments. This approach maximizes physicochemical interactions with blood, reduces blood loss, shortens bleeding time, maintains activity only in the presence of blood (not water), and applies cold via rapid temperature drop to induce vasoconstriction. These features collectively enable faster and more effective hemorrhage control.
Claims Coverage
The patent contains multiple independent claims that cover the composition of the hemostatic material, the hemostatic spray formulation, and the method of treating bleeding wounds, featuring key inventive aspects.
Hemostatic material with native chitosan base partially coated by chitosan salt layer
The hemostatic material comprises a native chitosan base having a chemically modified surface forming a chitosan salt layer that at least partially encapsulates the base. The chitosan polymers of the base and salt are interpenetrating, providing enhanced binding capacity with blood components compared to physical mixtures. The base is at least partially non-soluble in water, the salt at least partially soluble in water, both essentially non-soluble in blood, and together form at least 50% of the material by weight.
Hemostatic spray formulation of coated native chitosan particles dispersed in propellant
A spray formulation comprising a hemostatic powder formed of a plurality of native chitosan particles that are at least partially coated with chitosan salt, dispersed within a liquefied gas (propellant) in a canister for release onto a bleeding wound. The particles have a mean diameter less than 0.2 mm, providing a larger surface area for enhanced blood binding. The powder is active only in the presence of blood, and release causes rapid temperature decrease producing vasoconstriction.
Method of treating bleeding wounds by application of coated native chitosan material spray
A method for treating bleeding wounds by applying the hemostatic material that includes native chitosan base partially coated with chitosan salt. The method involves spraying the hemostatic powder formulation from a canister onto the bleeding wound, where the application causes a rapid temperature drop that induces vasoconstriction, enhancing hemostasis. The native chitosan base is at least partially non-soluble and has a low degree of acetylation to maximize amine groups promoting physicochemical interactions with blood.
The claims collectively define a novel native chitosan-based hemostatic material with a surface coating of chitosan salt for improved binding, formulated as a fine particle spray in a propellant to enable effective, rapid, and precise hemorrhage control, along with a method of application that leverages these material properties and spray delivery advantages for wound treatment.
Stated Advantages
Significantly accelerated rate of hemostasis compared to applying native chitosan base or chitosan salt alone or their physical mixtures.
Maximum electrostatic potential and binding capacity towards blood cells due to low degree of acetylation and transformation of amine groups into ammonium cationic moieties.
Smaller particle size with higher surface area leading to improved physico-chemical interactions and enhanced hemostatic activity.
Precise application on deep, complex three-dimensional wound architectures, including under adverse environmental conditions such as wind.
Short-term but significant vasoconstriction induced by rapid temperature decrease on application, further facilitating bleeding control.
The hemostatic spray formulation is active only in presence of blood and does not cause viscosity changes in aqueous solutions, thus preserving specificity.
Documented Applications
Treatment of bleeding wounds of humans or animals, including severe trauma wounds where rapid hemorrhage control is critical.
Use in military and civilian emergency care settings and combat support hospitals for managing massive bleeding.
Applications in surgical treatments, particularly in cardiovascular surgical procedures.
Use as a hemostatic spray formulation enabling application from a distance and under adverse conditions, suitable for wounds with complex or deep architectures.
Control of parenchymal hemorrhage in liver injury models, demonstrated in animal tests.
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