Orbicular tissue expander

1. A tissue stretching device comprising:

a bottom solid support comprising a fluid chamber therein, said fluid chamber having a fluid inlet and fluid outlet;

an expandable membrane attached to said bottom solid support and configured to be in fluid communication with a fluid in said chamber, wherein said expandable membrane is configured to undergo orbicular expansion in the presence of fluid pressure in said chamber;

a top solid support having a substantially circular opening therein;

a perimeter member further defining said substantially circular opening of said top solid support and configured to hold edges of a tissue onto the expandable membrane during the orbicular expansion of the center of the tissue;

wherein the bottom solid support is configured to attach to the top solid support, and

wherein said expandable membrane and said perimeter member are situated between said bottom solid support and said top solid support.

2. The device of claim 1 , wherein said perimeter member comprises a friction surface to hold the tissue onto the expandable membrane during the expansion.

3. The device of claim 1 , wherein said perimeter member comprises protrusions sized to puncture and/or penetrate the tissue to hold the tissue onto the expandable membrane during the expansion.

4. The device of claim 1 , wherein said expandable membrane comprises an expandable polymer.

5. The device of claim 1 , wherein said top solid support further comprises a chamber configured to hold media, said media in fluid communication with a tissue being stretched in said device.

6. The device of claim 1 , wherein said perimeter member comprises one or more O-rings to provide a fluid seal between said perimeter member and said top solid support.

7. The device of claim 1 , wherein the device is configured to stretch skin tissue.

8. The device of claim 1 , wherein opening of said perimeter member is circular and has a diameter of from 1 to 20 centimeters.

9. The device of claim 1 , wherein the opening of said perimeter member is circular and has a diameter of from 5 to 15 centimeters.

10. The device of claim 2 , wherein the friction surface of said perimeter member comprises a rough pattern.

11. The device of claim 1 , wherein said device further comprises a pressure detector and/or controller operatively associated with the fluid of said fluid chamber.

12. The device of claim 11 , wherein the pressure detector and/or controller is configured to regulate pressure applied to the tissue by the expandable membrane.

13. A method of orbicularly stretching a tissue comprising:

attaching the tissue into the device of claim 1 ; and

stretching the tissue with the device, to thereby orbicularly stretch the tissue.

14. The method of claim 13 , wherein the tissue is skin tissue.

15. The method of claim 14 , wherein said skin tissue comprises an epidermal tissue layer and a dermal tissue layer, and wherein said skin tissue has an epidermal surface and a dermal surface.

16. The method of claim 15 , wherein said attaching is carried out by placing the skin tissue with the epidermal surface in direct contact with said expandable membrane, and overlaying said tissue with the perimeter member on the dermal surface.

17. The method of claim 16 , wherein the stretching is carried out over a time of from 1 hour to 1 or 2 weeks.

18. The method of claim 13 , wherein the stretching comprises applying a fluid pressure of from 1 to 10 psi to said tissue.

19. A method of treating a skin wound on a subject in need thereof, comprising:

providing a skin tissue harvested from a donor;

stretching the skin tissue with the device of claim 1 to form an orbicularly stretched skin tissue; and then

grafting the orbicularly stretched skin tissue onto said subject, to thereby treat the skin wound.

20. The method of claim 19 , wherein the skin tissue is autologous.