Method of preparing a wound care device
The present invention relates to method of preparing an absorbent wound care device comprising an active agent on a wound contacting surface, such as e.g. a protein or an enzyme, by the use of electrospraying, and a wound care device obtained by said method. The invention further relates to a wound care device comprising Thrombin and a polyurethane foam, and a method of treating bleeding.
1. A method of preparing an absorbent wound care device comprising the steps of:
a) providing a wound care device comprising a polyurethane foam absorbent element, said element having a wound contacting surface and opposite thereof a backing surface;
b) providing an active agent comprising thrombin dissolved in an aqueous alcohol solution, wherein the alcohol is present in the aqueous solution from 15 to 30 percent v/v;
c) electrospraying the active agent comprising thrombin dissolved in the aqueous alcohol solution onto the wound contacting surface of the polyurethane foam absorbent element to form a layer of thrombin on only the wound contacting surface without penetration into the polyurethane foam to provide a thrombin coated wound contacting surface treated polyurethane foam; and
d) drying the treated polyurethane foam, wherein the thrombin is immediately released from the coated layer of thrombin deposited onto the wound contacting surface under physiological conditions.
2. The method according to claim 1 , wherein the electrospraying of step c) comprises:
providing a stationary charged spray nozzle with the active agent comprising thrombin;
providing an opposing stationary neutral unit; and
moving the wound contacting surface of the polyurethane foam absorbent element between the spray nozzle and the neutral unit, wherein the active agent comprising thrombin is deposited onto the wound contacting surface.
3. The method according to claim 2 , wherein the stationary charged spray nozzle is negatively charged.
4. The method according to claim 1 , wherein the active agent comprising thrombin is recombinant human thrombin, pro-thrombin, prodrugs of thrombin, or prodrugs of pro-thrombin.
5. The method according to claim 1 , wherein the aqueous alcohol solution is an aqueous methanol, ethanol, propanol, or isopropanol solution.
6. The method according to claim 5 , wherein the aqueous alcohol solution is an aqueous ethanol solution.