WOUND HEALING DEVICE

• US 20080275409A1
• Filed: 04/30/2008
• Published: 11/06/2008
• Est. Priority Date: 05/01/2007
• Status: Active Grant

• Current Assignee: Brigham and Women's Hospital Incorporated
• Original Assignee: Brigham and Women's Hospital Incorporated
• Inventors: Orgill, Dennis P., Kane, Bartholomew J.
• Granted Patent: US 8,057,446 B2
• Time in Patent Office: Days
• US Class Current: 604/305
• CPC Class Codes: A61B 2010/008 Interstitial fluid
• CPC Class Codes: A61F 13/0203 with fluid retention members
• CPC Class Codes: A61F 13/05 specially adapted for use with sub-pressure or over-pressure therapy, wound drainage or wound irrigation, e.g. for use with negative-pressure wound therapy [NPWT]
• CPC Class Codes: A61M 1/916 specially adapted for deep wounds
• CPC Class Codes: A61M 1/92 with liquid supply means
• CPC Class Codes: A61M 1/95 with sensors for exudate composition
• CPC Class Codes: A61M 1/96 Suction control thereof
• CPC Class Codes: A61M 2205/3303 Using a biosensor
• CPC Class Codes: A61M 2205/3324 PH measuring means

Abstract

Methods and devices transmit micromechanical forces locally on the millimeter to micron scale for promoting wound healing. Micromechanical forces can selectively be applied directly to tissue, in some embodiments, by using microchambers fluidically connected to microchannels. Each chamber, or in some cases, group of chambers, may be associated with a valve to control vacuum pressure, positive pressure, liquid delivery, and/or liquid removal from each chamber or group of chambers. Application of embodiments of the invention may shorten wound-healing time, reduce costs of therapy, enable restoration of functional tissue, and reduce the need for more invasive therapies, including surgery.

Claims

1. An apparatus for promoting tissue growth comprising:

a biocompatible matrix having a plurality of microstructures, each microstructure being constructed and arranged to apply a mechanical stimulus to a tissue surface, wherein the apparatus is configured such that an application of a first mechanical stimulus by a first microstructure of the plurality of microstructures is separately controllable from an application of a second mechanical stimulus by a second microstructure of the plurality of microstructures.

2. An apparatus as in claim 1, wherein the first and second microstructures comprise microchambers which are constructed and arranged to apply a pressure to the tissue surface.

3. An apparatus as in claim 2, wherein the first and second microstructures comprise microchambers which are constructed and arranged to apply a vacuum pressure to the tissue surface.

4. An apparatus as in claim 3, further comprising a vacuum source fluidically connected to the microchambers via channels.

5. An apparatus as in claim 2, further comprising a pressure source fluidically connected to the microchambers to controllably apply pressures to the microchambers, wherein the pressures that are applied to the microchambers are controllable with microfluidic valves which are embedded within the apparatus.

6. An apparatus as in claim 1, wherein the application of the first mechanical stimulus by the first microstructure is controllable to vary the magnitude of the first mechanical stimulus without altering the magnitude of the second mechanical stimulus applied by the second microstructure.

7. An apparatus as in claim 1, wherein the matrix comprises silicone rubber, and each microstructure comprises a microchamber having a width of no more than 10 microns.

8. An apparatus as in claim 1, wherein the matrix comprises a multiplicity of microchambers constructed and arranged to apply a pressure to the tissue surface, each of the microchambers having a width of 10,000 microns or less.

9. An apparatus as in claim 1, further comprising a control system that controls the application of the first mechanical stimulus by the first microstructure and the application of the second mechanical stimulus by the second microstructure.

10. An apparatus as in claim 1, wherein the microstructures are constructed and arranged to apply a mechanical stimulus to a tissue surface using at least one of:

piezoelectric forces, electrostatic forces, magnetic forces, thermal expansion or contraction forces, and chemical expansion or contraction forces.

11. An apparatus as in claim 1, wherein the microstructures are controllable to effect macroscopic contraction of a tissue wound.

12. An apparatus as in claim 11, wherein the microstructures are controllable to effect a macroscopic contraction of a tissue wound by at least 10% and less than 90% in area.

13. An apparatus as in claim 1, further comprising:

a first channel;

a first group of microchambers of the plurality of microstructures, each of the microchambers of the first group being fluidically connected to the first channel;

a second channel different from the first channel; and

a second group of microchambers of the plurality of microstructures, each of the microchambers of the second group being fluidically connected to the second channel;

wherein;

the application of the first mechanical stimulus by the first microstructure comprises the application of mechanical stimuli by each of the microchambers of the first group;

the application of the second mechanical stimulus by the second microstructure comprises the application of mechanical stimuli by each of the microchambers of the second group; and

the apparatus is configured such that is the application of mechanical stimuli by each of the microchambers of the first group is separately controllable from the application of mechanical stimuli by each of the microchambers of the second group.

14. An apparatus for promoting tissue growth, the apparatus comprising:

a biocompatible matrix having a plurality of microchambers constructed and arranged to face a tissue surface, each of the plurality of microchambers forming an enclosed perimeter; and

a plurality of channels, each of the plurality of microchambers being fluidically connected to one or more of the channels.

15. An apparatus as in claim 14, wherein the plurality of channels comprises a plurality of microchannels, and each of the plurality of microchambers is fluidically connected to one or more of the microchannels.

16. An apparatus as in claim 15, wherein at least some of the microchannels are configured to add or remove a fluid from a microchamber such that the microchamber applies a force to the tissue surface.

17. An apparatus as in claim 16, wherein flow of a fluid through a first microchannel is separately controllable from flow of a fluid through a second microchannel.

18. An apparatus as in claim 15, wherein at least some of the microchannels are configured to deliver one or more materials to one or more of the microchambers.

19. An apparatus as in claim 15, wherein at least some of the microchannels are configured to remove one or more materials from one or more of the microchambers.

20. An apparatus as in claim 15, further comprising:

a sensor to sense a tissue condition and provide information to a control system; and

a control system configured to control a parameter of the apparatus based at least in part on the information received from the sensor.

21. An apparatus as in claim 14, further comprising a cell culture chamber which is fluidically connected to at least one of the microchambers via at least one of the channels.

22. An apparatus as in claim 21, wherein the cell culture chamber is embedded in the matrix.

23. An apparatus as in claim 14, wherein the channels are connected to a source of material comprising one or more of:

living cells;

defunctionalized cells;

a wound healing mediator;

a protein;

inorganic materials;

an extracellular matrix material; and

a polymer; and

the channels are configured to deliver the material to the tissue surface via the microchambers.

24. A method of applying mechanical stimuli to a target tissue surface to promote tissue growth, the method comprising:

providing a substrate that includes a tissue-facing surface which includes a plurality of protruding microstructures, the microstructures having a length to width ratio of less than one hundred to one;

contacting and maintaining the tissue-facing surface of the substrate against a target tissue surface with a force such that the protruding microstructures deform the tissue surface.

25. A method as in claim 24, wherein the act of maintaining the contact of the tissue-facing surface against the tissue surface with a force comprises directly attaching the substrate only to an area that does not include the target tissue surface.