Scaffolds for tissue engineered hair

• US 7,198,641 B2
• Filed: 08/07/2001
• Issued: 04/03/2007
• Est. Priority Date: 08/08/2000
• Status: Expired due to Fees

• Current Assignee: Aderans Research Institute Incorporated
• Original Assignee: Aderans Research Institute Incorporated
• Inventors: Barrows, Thomas H.
• Primary Examiner(s): GHERBI, SUZETTE JAIME J
• Application Number:
  US10/344,185
• Publication Number:
  US 20040054410A1
• Time in Patent Office: 2,065 Days
• Field of Search: 623 1511- 1512, 264/28, 435/395, 435/371, 424/426, 606132-133, 606/187
• US Class Current: 623/15.11
• CPC Class Codes: A61F 2/10 Hair or skin implants
• CPC Class Codes: A61K 35/12 Materials from mammals; Compositions comprising non-specified tissues or cells; Compositions comprising non-embryonic stem cells; Genetically modified cells vaccines or medicinal preparations containing antigens or antibodies A61K39/00
• CPC Class Codes: A61L 2430/18 for hair reconstruction
• CPC Class Codes: A61L 27/18 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/26 Mixtures of macromolecular compounds
• CPC Class Codes: A61L 27/3804 characterised by specific cells or progenitors thereof, e.g. fibroblasts, connective tissue cells, kidney cells
• CPC Class Codes: A61L 27/3813 Epithelial cells, e.g. keratinocytes, urothelial cells
• CPC Class Codes: A61L 27/3869 Epithelial tissues other than skin
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61P 25/10 for petit-mal
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: C12N 2533/40 Polyhydroxyacids, e.g. polymers of glycolic or lactic acid (PGA, PLA, PLGA); Bioresorbable polymers
• CPC Class Codes: C12N 5/0068 General culture methods using substrates for specific animal cell type C12N5/06
• CPC Class Codes: C12N 5/0627 Hair cells

Abstract

Porous, bioabsorbable scaffolds for tissue engineering of human hair follicles, methods for their manufacture and methods of their use in creating new hair.

Claims

1. A porous scaffold comprising a bioabsorbable polymer and hair follicle progenitor cells;

wherein the scaffold is about the shape of a hair follicle;

wherein the porous scaffold comprises a fibrous structure; and

wherein the fibrous structure comprises fibers that are bonded together.

2. The scaffold of claim 1, in which the fibers comprise a core and a sheath, the sheath having a lower melting point than melting point of the core, and the fibers are bonded together by inter-fiber welds at at least one point of contact between the fibers.

3. A method of making a porous scaffold comprising a bioabsorbable polymer and hair follicle progenitor cells, wherein the scaffold is about the shape of a hair follicle, comprising the steps of:

a. providing a bioabsorbable polymer soluble in a first solvent;

b. providing a form comprising a hair follicle shaped region and comprising a material soluble in a second solvent and substantially insoluble in the first solvent;

c. coating the form with particles of a pore-forming substance soluble in the second solvent or in a third solvent;

d. dissolving the bioabsorbable polymer in the first solvent and applying the dissolved polymer to the coated form;

e. removing the first solvent;

f. dissolving the form and the particles in the second solvent;

g. removing the second solvent to form a scaffold; and

h. seeding the scaffold with hair follicle progenitor cells.

4. The method of claim 3, further comprising using the third solvent to remove the particles.

5. A method of making a porous scaffold comprising a bioabsorbable polymer and hair follicle progenitor cells, wherein the scaffold is about the shape of a hair follicle, comprising the steps of:

a. providing a bioabsorbable polymer soluble in a first solvent and substantially insoluble in a second solvent;

b. providing a form comprising a hair follicle shaped region and comprising a material soluble in the second solvent and substantially insoluble in the first solvent;

c. providing a pore-forming substance soluble in both the first and the second solvents;

d. coating the form with a solution comprising the bioabsorbable polymer and the pore-forming substance dissolved in the first solvent;

e. removing the first solvent and causing the pore-forming substance to phase separate from the bioabsorbable polymer;

f. dissolving the form and the pore-forming substance with the second solvent;

g. removing the second solvent to produce a porous scaffold; and

h. seeding the scaffold with hair follicle progenitor cells.

6. The method of claim 5, in which the bioabsorbable polymer comprises a copolymer of d,l-lactide and glycolide, the pore-forming substance comprises poly(ethylene glycol), the form comprises sugar, the first solvent comprises dichloromethane and the second solvent comprises water.

7. A method of making a porous scaffold comprising a bioabsorbable polymer and hair follicle progenitor cells, wherein the scaffold is about the shape of a hair follicle, comprising the steps of:

a. providing a thin, non-woven web of bioabsorbable fibers;

b. placing the web in a two-part mold comprising a first part having cavities and a second part having mating forms, the cavities and mating forms together providing a hair follicle shaped region;

c. closing the mold and applying sufficient heat and pressure to form the web into a porous structure; and

d. removing the web from the mold;

e. die-cutting the scaffold from the web;

f. seeding the scaffold with hair follicle progenitor cells.

8. A method of implanting hair follicle progenitor cells comprising implanting a porous scaffold comprising a bioabsorbable polymer and hair follicle progenitor cells into skin where growth of new hair is desired, wherein the scaffold is about the shape of a hair follicle.

9. The method of claim 8, in which the progenitor cells are obtained from a substructure within a normal hair follicle.

10. The method of claim 9, in which the progenitor cells are cultured prior to seeding the cells on the scaffold.

11. The method of claim 9, wherein the substructure is selected from the group consisting of dermal papilla, dermal sheath and bulge area.

12. The method of claim 8, in which the method of implantation of the scaffold is substantially equivalent to procedures used by hair transplant surgeons to implant single hair grafts into the skin.