Scaffolds for tissue engineered hair

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.