Anti-microbial foams containing polymer-stabilized silver nanoparticles
View Patent ↗An absorbent wound dressing comprises a hydrophilic porous substrate and polymer-stabilized silver nanoparticles distributed throughout the porous substrate. The silver nanoparticles have a particle size d 50 in the range of about 45 nm to about 85 nm and the silver nanoparticles are present in the substrate in an amount of about 0.16% to about 1.5% by weight of the total weight of the substrate. The wound dressing produces a 7-day log reduction of 4 or more for bacteria in accordance with the Modified AATCC Test Method 100. The wound dressing is also non-cytotoxic in accordance with ISO 10993-5 standard procedure for medical device cytotoxicity assessment.
1. An absorbent wound dressing comprising:
a hydrophilic porous substrate; and
polymer-stabilized silver nanoparticles distributed throughout the porous substrate, the silver nanoparticles having a particle size d 50 in the range of about 45 nm to about 85 nm and the silver nanoparticles being present in the substrate in an amount of about 0.16% to about 1.5% by weight of the total weight of the substrate;
wherein the wound dressing produces a 7-day log reduction of 4 or more for bacteria in accordance with the Modified AATCC Test Method 100;
wherein the wound dressing is non-cytotoxic in accordance with ISO 10993-5 standard procedure for medical device cytotoxicity assessment; and
wherein the hydrophilic porous substrate comprises open-celled windows and closed-celled windows.
2. The wound dressing of claim 1 , wherein the silver nanoparticles are present in an amount from about 0.75% to about 1.5% by weight of the substrate.
3. The wound dressing of claim 1 , further comprising one or a combination of polyhexamethylene biguanide (PHMB) and chlorhexidine gluconate (CHG).
4. The wound dressing of claim 1 , wherein the polymer-stabilized silver nanoparticles are distributed substantially uniformly throughout the substrate.
5. The wound dressing of claim 1 , wherein the wound dressing produces a 24-hour log reduction of 2 or more for fungal species.
6. The wound dressing of claim 1 , wherein the wound dressing produces a 7-day log reduction of 4 or more for gram-negative bacteria.
7. The wound dressing of claim 1 , wherein the wound dressing produces a 7-day log reduction of 4 or more for gram-positive bacteria.
8. The wound dressing of claim 1 , wherein:
the silver nanoparticles are present in an amount of 0.25% by weight of total weight of the hydrophilic porous substrate; and
the hydrophilic porous substrate comprises polyhexamethylene biguanide (PHMB) in an amount of 1.00% by weight of the hydrophilic porous substrate.
9. The wound dressing of claim 1 , wherein:
the silver nanoparticles are present in an amount of about 0.75% by weight of total weight of the hydrophilic porous substrate; and
the hydrophilic porous substrate comprises polyhexamethylene biguanide (PHMB) in an amount of about 0.50% by weight of the hydrophilic porous substrate.
10. The wound dressing of claim 1 , wherein:
the silver nanoparticles are present in an amount of about 0.10% to about 2.00% by weight of the hydrophilic porous substrate; and
the hydrophilic porous substrate comprises polyhexamethylene biguanide (PHMB) in an amount of about 0.10% to about 2.00% by weight of the hydrophilic porous substrate.
11. The wound dressing of claim 1 , wherein:
the silver nanoparticles are present in an amount of about 0.10% to about 2.00% by weight of the total weight of the hydrophilic porous substrate;
the hydrophilic porous substrate comprises polyhexamethylene biguanide (PHMB) in an amount of about 0.10% to about 2.00% by weight of the hydrophilic porous substrate, and
the hydrophilic porous substrate comprises chlorhexidine gluconate (CHG) in an amount of about 0.10% to about 2.00% by weight of the hydrophilic porous substrate.
12. The wound dressing of claim 1 , wherein:
the silver nanoparticles are present in an amount of about 0.10% by weight of the hydrophilic porous substrate; and
the hydrophilic porous substrate comprises polyhexamethylene biguanide (PHMB) in an amount of about 0.75% to about 1.50% by weight of the hydrophilic porous substrate.
13. The wound dressing of claim 1 , wherein the hydrophilic porous substrate comprises a polyurethane foam.
14. An absorbent wound dressing comprising:
a hydrophilic porous substrate;
polymer-stabilized nanoparticles distributed throughout the porous substrate, wherein the nanoparticles are comprised of elemental silver;
polyhexamethylene biguanide (PHMB); and
chlorhexidine gluconate (CHG);
wherein the wound dressing produces a 7-day log reduction of 4 or more for bacteria in accordance with the Modified AATCC Test Method 100;
wherein the wound dressing is non-cytotoxic in accordance with ISO 10993-5 standard procedure for medical device cytotoxicity assessment; and
wherein the hydrophilic porous substrate comprises open-celled windows and closed-celled windows.
15. The wound dressing of claim 14 , wherein the hydrophilic porous substrate comprises a polyurethane foam.