# US 11,298,217 B2 · Porous devices and processes for producing same

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- Number: US 11,298,217 B2
- Document ID: US11298217B2
- Status: Granted
- Kind: B2
- Application number: 16/524,541
- Filed: 2019-07-29
- Published: 2019-11-14
- Granted: 2022-04-12
- Earliest claimed: 2014-06-26
- Assignees: Vertera, Inc.
- Applicants: Vertera Inc.
- Inventors: Wei-Hsiang Chang; Stephen Lee Laffoon; Christopher S. D. Lee; David Lee Safranski
- Web page: https://patentgrep.com/patent/US11298217B2

## CPC

- A61F 2/0077: {Special surfaces of prostheses, e.g. for improving ingrowth (A61F2/30767 takes precedence)}
- A61B 6/12: Arrangements for detecting or locating foreign bodies
- A61B 6/50: specially adapted for specific body parts; specially adapted for specific clinical applications
- A61B 90/39: {Markers, e.g. radio-opaque or breast lesions markers}
- A61F 2/44: for the spine, e.g. vertebrae or spinal discs
- A61L 27/18: obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- A61L 27/50: Materials characterised by their function or physical properties {, e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials}
- A61L 27/56: Porous materials, {e.g. foams or sponges}
- A61L 31/06: obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds {(A61L31/041 takes precedence)}
- B29C 44/0461: {by having different chemical compositions in different places, e.g. having different concentrations of foaming agent, feeding one composition after the other}
- B29C 44/3415: {Heating or cooling}
- B29C 67/202: {comprising elimination of a solid or a liquid ingredient}
- C08J 9/0085: {Use of fibrous compounding ingredients (C08J9/0076 takes precedence)}
- C08J 9/26: by elimination of a solid phase from a macromolecular composition or article, e.g. leaching out
- A61B 2090/3966: {Radiopaque markers visible in an X-ray image}
- A61F 2002/0081: {directly machined on the prosthetic surface, e.g. holes, grooves (A61F2/30771 takes precedence)}
- A61F 2002/0086: {for preferentially controlling or promoting the growth of specific types of cells or tissues}
- A61F 2210/0071: thermoplastic
- A61F 2250/0098: radio-opaque, e.g. radio-opaque markers
- A61L 2430/38: for reconstruction of the spine, vertebrae or intervertebral discs
- B29K 2071/00: Use of polyethers {, e.g. PEEK, i.e. polyether-etherketone or PEK, i.e. polyetherketone or derivatives thereof}, as moulding material
- B29L 2031/753: {Medical equipment; Accessories therefor (bloodbags, medical bags B29L2031/7148; artificial eyes B29L2011/0008)}
- B29L 2031/7546: {Surgical equipment}
- C08J 2201/0446: Elimination of NaCl only
- C08J 2371/00: Characterised by the use of polyethers obtained by reactions forming an ether link in the main chain; Derivatives of such polymers
- A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C)
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K)
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES

## Abstract

Devices and methods for making a polymer with a porous layer from a solid piece of polymer are disclosed. In various embodiments, the method includes heating a surface of a solid piece of polymer to a processing temperature and holding the processing temperature while displacing a porogen layer through the surface of the polymer to create a matrix layer of the solid polymer body comprising the polymer and the porogen layer. In at least one embodiment, the method also includes removing at least a portion of the layer of porogen from the matrix layer to create a porous layer of the solid piece of polymer.

## Claims

### Claim 1

A method for generating a medical device that promotes tissue ingrowth, the method comprising:
heating a surface of a solid piece of polymer to a processing temperature below a melting point of the polymer;
holding the processing temperature while applying pressure to displace a porogen layer through the surface of the polymer to create a matrix layer comprising the polymer and the porogen layer; and
removing at least a portion of the porogen layer from the matrix layer thereby forming the medical device comprising at least a portion of the solid piece of the polymer with a porous layer.

### Claim 2 (depends on 1)

The method of claim 1, wherein the at least a portion of the solid piece of the polymer is integrally and directly connected with the porous layer.

### Claim 3 (depends on 1)

The method of claim 1, wherein the porous layer comprises a first percentage of hydroxyl groups that is greater than a second percentage of hydroxyl groups in the solid piece of polymer.

### Claim 4 (depends on 1)

The method of claim 1, wherein the porous layer comprises a first carbon to oxygen atomic ratio that is substantially identical to a second carbon to oxygen atomic ratio of the solid piece of the polymer.

### Claim 5 (depends on 1)

The method of claim 1, wherein the porous layer comprises a first wettability that is greater than the second wettability of the solid piece of the polymer.

### Claim 6 (depends on 1)

The method of claim 1, wherein removing at least a portion of the porogen layer from the matrix layer comprises removing substantially all of the porogen layer.

### Claim 7 (depends on 1)

The method of claim 1, wherein the porous layer comprises a plurality of pores that is substantially spherical and in an irregular distribution pattern.

### Claim 8 (depends on 1)

The method of claim 1, wherein the polymer comprises a thermoplastic polymer.

### Claim 9 (depends on 1)

The method of claim 1, wherein the porosity of the porous layer is between about 61% to about 66%.

### Claim 10 (depends on 1)

The method of claim 1, wherein the interconnectivity of the porous layer is about 99%.

### Claim 11 (depends on 1)

The method of claim 1, wherein an interfacial shear strength between the at least a portion of the solid piece of the polymer and the porous surface layer of the medical device is at least about 17 MPa.

### Claim 12

A method for generating a medical device that promotes tissue ingrowth, the method comprising:
heating a surface of a solid piece of polymer to a processing temperature below a melting point of the polymer;
holding the processing temperature while applying pressure, for a processing time, to displace a porogen layer through the surface of the polymer into the solid piece of polymer by a defined distance to create a matrix layer comprising the polymer and the porogen layer;
removing the applied pressure and heat and cooling the surface of the solid piece of polymer at a predetermined rate; and
removing the porogen layer from the matrix layer thereby forming the medical device comprising at least a portion of the solid piece of the polymer directly connected with a porous layer.

### Claim 13 (depends on 12)

The method of claim 12 further comprising, prior to holding the processing temperature while applying pressure for the processing time, determining the processing time based on a desired interfacial shear strength of the medical device.

### Claim 14 (depends on 12)

The method of claim 12, wherein an interfacial shear strength of the medical device increases substantially linearly with increase of the processing time.

### Claim 15 (depends on 12)

The method of claim 12, wherein the porous layer comprises a first percentage of hydroxyl groups that is greater than a second percentage of hydroxyl groups in the solid piece of polymer.

### Claim 16 (depends on 12)

The method of claim 12, wherein the porous layer comprises a first carbon to oxygen atomic ratio that is substantially identical a second carbon to oxygen atomic ratio of the solid piece of the polymer.

### Claim 17 (depends on 12)

The method of claim 12, wherein the porous layer comprises a first wettability that is greater than the second wettability of the solid piece of the polymer.

### Claim 18 (depends on 12)

The method of claim 12, wherein the porosity of the porous layer is between about 61% to about 66% and the interconnectivity of the porous layer is about 99%.

### Claim 19 (depends on 12)

The method of claim 12, wherein an interfacial shear strength between the at least a portion of the solid piece of the polymer and the porous surface layer of the medical device is at least about 17 MPa.

### Claim 20

A method for generating a medical device that promotes tissue ingrowth, the method comprising:
heating a surface of a solid piece of polymer to a processing temperature below a melting point of the polymer;
holding the processing temperature while applying pressure to displace a porogen layer through the surface of the polymer to create a matrix layer comprising the polymer and the porogen layer; and
removing at least a portion of the porogen layer from the matrix layer thereby forming the medical device comprising at least a portion of the solid piece of the polymer with a porous layer, wherein the porous layer comprises a first percentage of hydroxyl groups that is greater than a second percentage of hydroxyl groups in the solid piece of polymer, and wherein the porous layer comprises a first wettability that is greater than the second wettability of the solid piece of the polymer.