Foams for oxygen delivery to wounds
View Patent ↗There is provided a composition comprising covalently linked segments of for example, polycaprolactone and polyethylene glycol that are linked by a cross-linker. Such a composition foams in the presence of a catalyst and a solution containing an oxygen forming chemical like hydrogen peroxide. The foamed composition retains oxygen for delivery to, for example, a wound, where it aids in healing.
1. A foamable composition comprising a prepolymer comprising covalently linked segments of polycaprolactone and polyethylene glycol, a cross-linking agent connecting the polycaprolactone and the polyethylene glycol; a peroxide solution containing 20 wt. % peroxide; and a peroxide decomposition catalyst; wherein the cross-linking agent comprises an isocyanate prepolymer or a cross-linker with isocyanate content between 0.01 wt. % and 40 wt. % and an acid value between 0.01 mg and 100 mg of KOH/g of sample, wherein the cross-linking agent is present in an amount of between 1 wt. % and 3 wt. % based on the amount of prepolymer comprising covalently linked segments of polycaprolactone and polyethylene glycol, wherein the composition is capable of forming a foam that delivers 24.4 to 25.3 parts per million of oxygen within 24 hours.
2. The foamable composition of claim 1 , wherein the polycaprolactone is biodegradable with a weight loss of greater than 10 wt. % in 10 days, without the release of toxic products from the biodegradation.
3. The foamable composition of claim 1 , wherein a polymer matrix formed from the covalently linked segments of polycaprolactone and polyethylene glycol exhibits greater than or equal to 20 percent nominal hydration exposed to the peroxide solution.
4. The foamable composition of claim 1 , wherein the peroxide in the peroxide solution is hydrogen peroxide.
5. The foamable composition of claim 1 , wherein the peroxide decomposition catalyst is selected from the group consisting of sodium carbonate, magnesium carbonate, manganese and silver.