Antimicrobial superabsorbent compositions
Inventors
Hall, Thomas • COX, Sophie Constance • GROVER, Liam Michael • Kershaw, David
Assignees
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Publication Number
US-11730168-B2
Publication Date
2023-08-22
Expiration Date
Abstract
A composition has an enzyme that is able to convert a substrate to release hydrogen peroxide; a substrate for the enzyme; and a superabsorbent component, such as a superabsorbent polymer. The composition is in the form of a powder and may form a gel on contact with water.
Core Innovation
The invention describes hydrogen-peroxide–generating antimicrobial compositions that are provided as a powder and comprise an enzyme that is able to convert a substrate to release hydrogen peroxide, together with a substrate for the enzyme, and a superabsorbent component. The superabsorbent component forms a hydrogel upon water contact, so that water exposure enables release of hydrogen peroxide from the enzyme/substrate system within the hydrogel-forming powder-based composition.
A key aspect of the invention is storage stability of the dry composition by limiting free water in the powder, so that the composition preferably contains substantially no hydrogen peroxide or only trace hydrogen peroxide prior to dilution. The powder is further defined by controlling particle size using mean and/or modal particle diameter constraints of 3000 μm or less, and by defining superabsorbent swelling/absorption capacity constraints for the superabsorbent component.
The described powder composition is also characterized by excluding peroxidase, and can include particular optional solutes and protective agents, such as sugar solutes and freeze-drying protective agents. The antimicrobial performance described in the document includes activity against pathogens including MRSA, including biofilm-associated infections, with hydrogen-peroxide–mediated antimicrobial action indicated by powder-to-gel formation and hydrogen peroxide detection.
In the described embodiments, the hydrogen-peroxide–generating enzyme system is exemplified using oxidoreductase such as glucose oxidase, with purified sugars such as D-glucose as substrate and optionally additional sugars such as fructose or precursor-substrates. The document further describes sterilization by irradiation of the compositions, and reports gel rheology effects related to superabsorbent selection and amount upon dilution.
Claims Coverage
The independent claims include a sterile powder composition with an enzyme/substrate hydrogen-peroxide–generating system and a superabsorbent component, explicitly excluding peroxidase. The main claim coverage centers on a set of inventive feature constraints comprising the core ingredient combination and several refinements, with additional dependent-claim features addressing optional component presence/absence and packaging/dispensing configuration.
Sterile hydrogen-peroxide–releasing enzyme/substrate powder without peroxidase
A sterile composition comprising an enzyme able to convert a substrate to release hydrogen peroxide, the substrate for the enzyme, and a superabsorbent component, wherein the composition is in the form of a powder and does not contain any peroxidase.
Powder particle-size limitation
The sterile composition has a powder with a mean and/or modal particle diameter of 3000 μm or less.
Superabsorbent component defined by absorption capacity
The superabsorbent component has an absorption capacity of at least 10 g/g.
Powder particle-size range refinement
The powder has a mean and/or modal particle diameter in the range of 100 μm to 2000 μm.
Substrate defined as a sugar
The substrate is a sugar.
Optional inclusion/exclusion of blood clotting, catalase activity, zinc oxide, and coagulation factors
The composition optionally lacks catalase activity, comprises a blood clotting agent and/or a coagulation factor, and optionally does not contain zinc oxide.
Airtight container with sealed dispensing apertures
An airtight container holds the composition and has one or a plurality of dispensing apertures that are sealed or covered before use.
Overall, the claim set is directed to a sterile powder formulation that combines a hydrogen-peroxide–releasing enzyme/substrate system with a superabsorbent component, while explicitly excluding peroxidase. Coverage is further defined by powder particle-size constraints, absorption-capacity constraints for the superabsorbent, specifying the substrate class as a sugar, and optionally constraining other biological component activities and additives, with an additional packaging feature using an airtight container with sealed dispensing apertures.
Stated Advantages
Storage stability of the dry composition by limiting free water so that the composition contains substantially no or trace hydrogen peroxide until dilution.
Antimicrobial activity through hydrogen-peroxide release after powder-to-gel formation upon water contact.
Documented Applications
Antimicrobial use including activity against biofilm-associated infections.
Wound-care use, including wound dressing applications as described in the document.
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