Process for preparing a synthetic foam having a controlled particle distribution

1. A process for preparing a synthetic foam having a controlled distribution of particles, said process comprising:

dissolving at least one synthetic polymer in one or more solvents to form a solution;

contacting particles with the solution to form a homogeneous polymer/particles mixture; and

freeze-drying the polymer/particles mixture to form the synthetic foam having a controlled distribution of particles by:

cooling the homogeneous polymer/particles mixture to a freezing point of the one or more solvents in less than 60 s; and subsequently

subliming the one or more solvents of the polymer/particles mixture such that the synthetic foam comprises a homogeneous distribution of the particles.

2. The process according to claim 1 , wherein the process further comprises pre-cooling the polymer/particles mixture to a temperature within 5° C. of the freezing point of the one or more solvents prior to the step of freeze-drying.

3. The process according to claim 1 , wherein the step of freeze-drying is further defined as:

cooling the homogeneous polymer/particles mixture to the freezing point of the one or more solvents in less than 60 s; subsequently increasing the temperature of the homogeneous polymer/particles mixture above the freezing point of the one or more solvents; subsequently cooling the homogeneous polymer/particles mixture to below the freezing point of the one or more solvents to re-freeze the polymer/particles mixture; and subsequently

subliming the one or more solvents of the polymer/particles mixture such that the synthetic foam comprises the homogeneous distribution of particles.

4. The process according to claim 1 , wherein the at least one synthetic polymer is selected from the group consisting of polyesters, polyhydroxyacids, polylactones, polyetheresters, polycarbonates, polydioxanes, polyanhydrides, polyurethanes, polyester(ether)urethanes, polyurethane urea, polyamides, polyesteramides, poly-orthoesters, polyaminoacids, polyphosphonates, polyphosphazenes and combinations thereof.

5. The process according to claim 4 , wherein the at least one synthetic polymer comprises a copolymer.

6. The process according to claim 1 , wherein the one or more solvents is selected from the group consisting of acetic acid, benzene, cyclohexane, cyclohexane formic acid, nitrobenzene, phenol, 1,4-dioxane, 1,2,4-trichlorbenzene, dimethyl sulphoxide (DMSO), water and combinations thereof.

7. The process according to claim 1 , wherein the particles have an average size of from 1-1000 μm.

8. The process according to claim 1 , further comprising the step of introducing the polymer/particles mixture into one or more molds prior to the step of freeze-drying.

9. A synthetic foam obtainable by the process of claim 1 .

10. The process according to claim 1 , wherein the at least one synthetic polymer is selected from the group consisting of polyurethanes, polyester(ether)urethanes, polyurethane urea, and combinations thereof.

11. The process according to claim 1 , wherein the one or more solvents comprises cyclohexane and 1,4-dioxane.

12. The process according to claim 1 , wherein:

the at least one synthetic polymer is selected from the group consisting of polyurethanes, polyester(ether)urethanes, polyurethane urea, and combinations thereof; and

the one or more solvents comprises cyclohexane and 1,4-dioxane.

13. The process according to claim 1 , wherein the particles are hemostatic.

14. The process according to claim 3 , wherein the step of cooling is further defined as cooling the polymer/particles mixture in an amount of from 1 to 99 wt. % based on a total weight of the polymer/particles mixture to form a partly frozen polymer/particles mixture.

15. The process according to claim 1 , further comprising the step of agitating the polymer/particles mixture such that the particles are homogeneously distributed in the polymer/particles mixture prior to the step of freeze-drying the homogeneous polymer/particles mixture.

16. The process according to claim 1 , wherein the at least one synthetic polymer is further defined as a polyurethane with the at least one synthetic polymer comprising an amorphous segment and a crystalline segment wherein the amorphous segment comprises a hydrophilic segment.

17. A process for preparing a synthetic foam having a controlled distribution of particles, said process comprising:

dissolving at least one synthetic polymer in one or more solvents to form a solution;

contacting particles with the solution to form a homogeneous polymer/particles mixture;

agitating the homogeneous polymer/particles mixture such that the particles remain homogeneously distributed in the polymer/particles mixture; and

freeze-drying the polymer/particles mixture to form the synthetic foam having a controlled distribution of particles by:

cooling the homogeneous polymer/particles mixture to a freezing point of the one or more solvents in less than 60 s; and subsequently

subliming the one or more solvents of the polymer/particles mixture such that the synthetic foam comprises a homogeneous distribution of the particles.

18. A process for preparing a synthetic foam having a controlled distribution of particles, said process comprising:

dissolving at least one synthetic polymer in one or more solvents to form a solution;

contacting particles with the solution to form a polymer/particles mixture; and

freeze-drying the polymer/particles mixture to form the synthetic foam having a controlled distribution of particles by:

cooling the polymer/particles mixture to a freezing point of the one or more solvents within 60 s to 600 s; and subsequently

subliming the one or more solvents of the polymer/particles mixture such that the synthetic foam comprises one or more layers of the particles in the controlled distribution.