Permanent, removable tissue markings

• US 20070107625A1
• Filed: 01/08/2007
• Published: 05/17/2007
• Est. Priority Date: 11/20/1998
• Status: Active Grant

• Current Assignee: The General Hospital Corporation (Mass General Brigham, Inc.)
• Original Assignee: Freedom-2, Inc.
• Inventors: Anderson, Richard, Drill, Craig, Mlynarczyk-Evans, Susanna
• Granted Patent: US 7,285,364 B2
• Time in Patent Office: Days
• US Class Current: 106/31.140
• CPC Class Codes: A61K 2800/412 Microsized, i.e. having sizes between 0.1 and 100 microns
• CPC Class Codes: A61K 2800/438 Thermochromatic; Photochromic; Phototropic
• CPC Class Codes: A61K 2800/56 Compounds, absorbed onto or entrapped into a solid carrier, e.g. encapsulated perfumes, inclusion compounds, sustained release forms
• CPC Class Codes: A61K 2800/624 by macromolecular compounds
• CPC Class Codes: A61K 8/0241 Containing particulates characterized by their shape and/or structure see also A61K8/04, A61K8/11, and A61K8/14, further aspects are classified in A61K2800/40 and subcodes
• CPC Class Codes: A61Q 1/025 Semi-permanent tattoos, stencils, e.g. "permanent make-up"
• CPC Class Codes: A61Q 19/04 for chemically tanning the skin topical sun or radiation screening or tanning preparations A61Q17/04
• CPC Class Codes: C09D 11/00 Inks
• CPC Class Codes: C09D 11/02 Printing inks C09D11/30 takes precedence
• CPC Class Codes: C09D 11/037 characterised by the pigment
• CPC Class Codes: C09D 11/50 Sympathetic, colour changing or similar inks
• CPC Class Codes: Y10S 430/145 Infrared
• CPC Class Codes: Y10S 430/165 Thermal imaging composition
• CPC Class Codes: Y10T 428/2991 Coated
• CPC Class Codes: Y10T 428/2993 Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]

Abstract

The present invention provides microparticles that create permanent tissue markings, such as tattoos, designed in advance for change and/or removal on demand, as well as methods for implanting the microparticles in tissue and changing and/or removing the resulting markings. Colored microparticles are constructed with specific electromagnetic absorption and/or structural properties that facilitate changing and/or removing tissue markings made using the microparticles by applying specific energy (such as electromagnetic radiation from a laser or flash-lamp) to the tissue marking site.

Claims

1. A tissue marking ink comprising:

a particle comprising;

(a) a chromophore, which is bleachable upon exposure to a bleaching agent; and

(b) a submicroparticle comprising a bleaching agent,

wherein the submicroparticle is ruptured upon exposure to a specific energy when the particle is within a tissue; and

a carrier.

2. The ink of claim 1, wherein the bleaching agent is a peroxide, a hypochlorite, an excited oxygen species, or a free radical.

3. The ink of claim 1, wherein the chromophore is pH-sensitive, and the bleaching agent is an acid, a base, or a buffer capable of effecting a pH transition within the particle to bleach the chromophore.

4. The ink of claim 1, wherein the specific energy is electromagnetic radiation.

5. The ink of claim 1, wherein the specific energy is infrared or near-infrared radiation.

6. The ink of claim 1, wherein the chromophore has an average particle size of less than about 50 nm.

7. The ink of claim 1, wherein the particle further comprises:

an indispersible, biologically inert coating; and

a core enveloped within the coating, wherein the core comprises the chromophore.

8. The ink of claim 7, wherein the coating comprises a metal oxide, silica, glass, fluorocarbon resin, organic polymer, wax, or a combination thereof.

9. The ink of claim 1, wherein the submicroparticle containing the bleaching agent or the coating enveloping the bleaching agent contains a discrete absorption component, which allows the bleaching agent to leach out and come into contact with the chromophore upon exposure to the specific energy.

10. The ink of claim 9, wherein the discrete absorption component is selected from the group consisting of Schott filter glass, graphite, carbon, a metal oxide, an acrylate polymer, and a urethane polymer.

11. The ink of claim 1, wherein the particle is from about 50 nm to about 100 microns in size.

12. The ink of claim 1, wherein the particle is from about 15 nm to about 500 nm in size.

13. The ink of claim 1, wherein the carrier comprises at least one of alcohol, water, or glycerin.

14. A method of applying a tissue marking, the method comprising:

providing the tissue marking ink of claim 1;

and

implanting said ink into a tissue to form a tissue marking,

wherein an appearance of the chromophore changes upon exposure to a specific energy when the chromophore is within the tissue.

15. The method of claim 14, wherein the specific energy is electromagnetic radiation.

16. The method of claim 14, wherein the specific energy is infrared or near-infrared radiation.

17. A method for altering a tissue marking implanted in tissue, wherein the tissue marking comprises the ink of claim 1, the method comprising exposing the tissue marking to the specific energy for a sufficient time to rupture the submicroparticle, thereby altering the appearance of the chromophore.

18. The method of claim 17, wherein the specific energy is electromagnetic radiation.

19. The method of claim 17, wherein the specific energy is infrared or near-infrared radiation.