Bone Regeneration Membrane and Method for Forming a Bone Regeneration Membrane

• US 20130138155A1
• Filed: 07/08/2011
• Published: 05/30/2013
• Est. Priority Date: 07/09/2010
• Status: Active Grant

• Current Assignee: Chu Nantes, Nantes Universite
• Original Assignee: Chu Nantes, Universite De Nantes
• Inventors: Layrolle, Pierre, Sohier, Jerome, Hoornaert, Alain
• Granted Patent: US 9,724,144 B2
• Time in Patent Office: Days
• US Class Current: 606/283
• CPC Class Codes: A61B 17/8085 with pliable or malleable elements or having a mesh-like structure, e.g. small strips A61B17/8071, A61B17/8076 take precedence
• CPC Class Codes: A61L 2400/12 Nanosized materials, e.g. nanofibres, nanoparticles, nanowires, nanotubes; Nanostructured surfaces
• CPC Class Codes: A61L 2430/02 for reconstruction of bones; weight-bearing implants
• CPC Class Codes: A61L 31/146 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 31/148 Materials at least partially resorbable by the body

Abstract

A bone regeneration membrane comprising:

• • a dense layer made of resorbable polymer, said dense layer having first and second opposite surfaces and being adapted to form a barrier to cells and soft tissues,
  • a nanofibrillar layer made of resorbable polymer and attached to the first surface of the dense layer, said nanofibrillar layer comprising fibers having a diameter of nanometer size, said fibers being interlaced so as to present an average pore size greater than 10 μm to allow cell permeability and bone tissue regeneration, the nanofibrillar layer having a permeability κ between 0.4*10-9 m² and 11*10-9 m², preferably between 1*10-9 m² and 4*10-9 m², in particular substantially of 2*10-9 m².

Claims

1. A bone regeneration membrane comprising:

a dense layer made of resorbable polymer, said dense layer having first and second opposite surfaces and being adapted to form a barrier to cells and soft tissues,

a nanofibrillar layer made of resorbable polymer and attached to the first surface of the dense layer, said nanofibrillar layer comprising fibers having a diameter of nanometer size, said fibers being interlaced so as to present an average pore size greater than 10 μ

m to allow cell permeability and bone tissue regeneration, the nanofibrillar layer having a permeability K between 0.4*10-9 m² and 11*10-9 m², preferably between 1*10-9 m² and 4*10-9 m², in particular substantially of 2*10-9 m².

2. The bone regeneration membrane according to claim 1, wherein the nanofibrillar layer (3) has a porosity pnl greater than 90%, preferably substantially of 95%.

3. The bone regeneration membrane according to claim 1, wherein the dense layer is a substantially non-porous film.

4. The bone regeneration membrane according to claim 3, wherein the dense layer has a porosity pdl less than 10%, preferably less than 5%.

5. The bone regeneration membrane according to claim 1, wherein the dense layer and the nanofibrillar layer are attached to one another by hydrogen bonds.

6. The bone regeneration membrane according to claim 1, wherein the dense layer has a thickness comprised between 30 μ

m and 70 μ

m, preferably between 45 μ

m and 55 μ

m, and the nanofibrillar layer has a thickness comprised between 200 μ

m and 300 μ

m, preferably between 230 μ

m and 270 μ

m.

7. The bone regeneration membrane according to claim 1, wherein the nanofibrillar layer is composite and incorporates particles adapted to support bone formation, said particles being distributed between the fibers.

8. The bone regeneration membrane according to claim 7, wherein the particles are calcium phosphate particles.

9. A method for forming a bone regeneration membrane, comprising the steps of:

forming, at room temperature, a dense layer made of resorbable polymer, said dense layer having first and second opposite surfaces and being adapted to form a barrier to cells and soft tissues,

forming, at room temperature, a nanofibrillar layer made of resorbable polymer, said nanofibrillar layer comprising fibers having a diameter of nanometer size, the step of forming the nanofibrillar layer comprising the steps of;

mixing the resorbable polymer with a solvent to obtain a polymer solution, feeding a spray nozzle with said polymer solution,

projecting said polymer solution through said nozzle with a gas jet adapted to pump the polymer solution by depression, wherein the projected resorbable polymer precipitates and solidifies by evaporation of the solvent to form the fibers interlaced so as to present an average pore size greater than 10 μ

m to allow cell permeability and bone tissue regeneration, the nanofibrillar layer having a permeability κ

between 0.4*10<sup>−

9</sup> m² and 11*10<sup>−

9</sup> m², preferably between 1*10<sup>−

9</sup> m² and 4*10<sup>−

9</sup> m², in particular substantially of 2*10<sup>−

9</sup> m²,

depositing the fibers on a collecting surface,

attaching, at room temperature, said nanofibrillar layer to the first surface of the dense layer.

10. The method according to claim 9, wherein the step of forming the dense layer comprises the steps of:

mixing the resorbable polymer with a solvent to obtain a polymer solution,

casting said polymer solution onto a collecting surface,

spreading said polymer solution on the collecting surface, wherein the cast and spread resorbable polymer precipitates and solidifies by evaporation of the solvent to form a substantially non-porous film.

11. The method according to claim 10, wherein the nanofibrillar layer is deposited on the first surface of the dense layer as collecting surface during the step of spreading the polymer solution, the step of attaching the nanofibrillar layer to the first surface of the dense layer comprising the formation of hydrogen bonds as the polymer of which the dense layer is made precipitates and solidifies by evaporation of the solvent.

12. The method according to claim 9, wherein at the step of projecting the polymer solution, the polymer solution is directly projected onto the first surface of the dense layer, and at the step of depositing the fibers, the fibers are directly deposited on the first surface of the dense layer as collecting surface, the step of attaching the nanofibrillar layer to the first surface of the dense layer comprising the formation of hydrogen bonds as the polymer of which the nanofibrillar layer is made precipitates and solidifies by evaporation of the solvent.

13. The method according to claim 9, wherein the step of forming a nanofibrillar layer further comprises, at the step of projecting the polymer solution, spraying particles adapted to support bone formation.

14. The method according to claim 9, further comprising a step of sterilising the bone regeneration membrane.