# US 8,771,582 B2 · Electrospinning process for making a textile suitable for use as a medical article

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- Number: US 8,771,582 B2
- Document ID: US8771582B2
- Status: Granted
- Kind: B2
- Application number: 13/303,319
- Filed: 2011-11-23
- Published: 2012-03-22
- Granted: 2014-07-08
- Earliest claimed: 2005-03-04
- Assignees: BioScurfaces, Inc.; Clemson University; Rhode Island Board of Education
- Applicants: Matthew D. Phaneuf; Philip J. Brown; Martin J. Bide
- Inventors: Matthew D. Phaneuf; Philip J. Brown; Martin J. Bide
- Web page: https://patentgrep.com/patent/US8771582B2

## CPC

- D01F 6/62: from polyesters
- A61K 9/0092: {Hollow drug-filled fibres, tubes of the core-shell type, coated fibres, coated rods, microtubules or nanotubes}
- B29C 48/05: Filamentary, e.g. strands
- D01D 1/02: Preparation of spinning solutions
- D01D 5/0038: {the fibre formed by solvent evaporation, i.e. dry electro-spinning}
- D04H 1/435: Polyesters
- D04H 1/728: by electro-spinning {(electro-spinning methods and apparatus D01D5/0007)}
- D04H 3/011: Polyesters
- D04H 3/02: characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments
- D04H 3/16: with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion
- A61K 9/70: Web, sheet or filament bases {; Films; Fibres of the matrix type containing drug (hollow drug-filled fibres A61K9/0092)}
- B29C 48/022: {characterised by the choice of material}
- D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- 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)
- D01D: MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D04H: MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL (weaving D03; knitting D04B; braiding D04C; net-making D04G; sewing D05B; tufting D05C; finishing non-woven fabrics D06); FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING {; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION}(non-woven fabrics having an intermediate or external layer of a different kind, e.g. of woven fabric, B32B)

## Abstract

The present invention is a bioactive, nanofibrous material construct which is manufactured using a unique electrospinning perfusion methodology. One embodiment provides a nanofibrous biocomposite material formed as a discrete textile fabric from a prepared liquid admixture of (i) a non-biodegradable durable synthetic polymer; (ii) a biologically active agent; and (iii) a liquid organic carrier. These biologically-active agents are chemical compounds which retain their recognized biological activity both before and after becoming non-permanently bound to the formed textile material; and will become subsequently released in-situ as discrete freely mobile agents from the fabric upon uptake of water from the ambient environment.

## Claims

### Claim 1

An electrospinning perfusion method for forming a fabricated textile suitable for use as a medical article, said method comprising the steps of:
dissolving a non-biodegradable polymer and a pre-chosen biologically-active agent in an organic solvent to provide an admixture, the dissolving step occurring at an ice-cold temperature;
permitting the admixture to warm to a temperature between about 20° C. and about 50° C.;
loading the admixture into an electrospinning perfusion assembly comprised of at least one perfusion instrument which can be set at a specified flow rate;
perfusing said admixture onto a target surface at the specified flow rate, the step of perfusing occurring at a temperature between about 20° C. and about 50° C. to provide a perfused material;
removing the perfused material from the target surface to form a nanofibrous fabricated textile.

### Claim 2 (depends on 1)

The method as recited in claim 1, wherein the nanofibrous fabricated textile has a longitudinal axis, the method further comprising the steps of:
stretching the nanofibrous fabricated textile along the longitudinal axis after it has been removed from the target surface to apply a set strain; and
removing residual organic solvent from the stretched nanofibrous fabricated textile while the set strain is applied.

### Claim 3 (depends on 2)

The method as recited in claim 2, wherein the step of removing the residual organic solvent is accomplished by treatment with ethanol.

### Claim 4 (depends on 2)

The method as recited in claim 2, wherein the nanofibers are tubes and, after the stretching step, the nanofibers have an inner diameter that remains uniform over their length, the inner diameter being less than 1 mm.

### Claim 5 (depends on 1)

The method as recited in claim 1, wherein the perfusion instrument has a needle, the method including the step of positioning the needle and the target surface a distance apart of between 10 cm and 40 cm.

### Claim 6

An electrospinning perfusion method for forming a fabricated textile suitable for use as a medical article, said method comprising the steps of:
dissolving a non-biodegradable polyester or polyurethane and a pre-chosen biologically-active agent in hexafluoroisopropanol to provide an admixture, the dissolving step occurring at an ice-cold temperature;
loading the admixture into an electrospinning perfusion assembly comprised of at least one perfusion instrument which can be set at a specified flow rate, the perfusion instrument having a spinneret sized to produce nanofibers with a diameter of less than about 2 micrometers;
perfusing said admixture through the spinneret and onto a target surface at the specified flow rate, the step of perfusing occurring at a temperature between 15° C. and 30° C. to provide a perfused admixture comprising polymeric fibers with a diameter of less than about 2 micrometers;
removing the perfused admixture from the target surface to form a nanofibrous fabricated textile which consists essentially of the non-degradable polyester or polyurethane and the pre-chosen biologically-active agent, the biologically active agent being releasably entrapped within the non-degradable polyester or polyurethane.

### Claim 7 (depends on 6)

The method as recited in claim 6, wherein the ice-cold temperature is between 0° C. and 5° C.

### Claim 8 (depends on 6)

The method as recited in claim 6, wherein the nanofibrous fabricated textile has a longitudinal axis, the method further comprising the steps of:
stretching the nanofibrous fabricated textile along the longitudinal axis after it has been removed from the target surface to provide a set strain; and
removing residual hexafluoroisopropanol from the stretched nanofibrous fabricated textile while the set strain is applied.

### Claim 9 (depends on 6)

The method as recited in claim 6, wherein the biologically active agent is maintained at a temperature below about 50° C. during the steps of dissolving, loading, perfusing and removing such that the biologically active agent maintains the same biological activity after the method as it had before the method.

### Claim 10

An electrospinning perfusion method for forming a fabricated textile suitable for use as a medical article, said method comprising the steps of:
dissolving a non-biodegradable polymer and a pre-chosen biologically-active agent in an organic solvent to provide an admixture, the dissolving step occurring at temperature of about 4° C.;
permitting the admixture to warm to a temperature between about 20° C. and about 25° C.;
loading the admixture into an electrospinning perfusion assembly comprised of at least one perfusion instrument which can be set at a specified flow rate;
perfusing said admixture onto a target surface at the specified flow rate, the step of perfusing occurring at a temperature between about 20° C. and about 25° C. to provide a perfused material;
removing the perfused material from the target surface to form a nanofibrous fabricated textile.