Synthetically spun silk nanofibers and a process for making the same

• US 6,110,590 A
• Filed: 06/12/1998
• Issued: 08/29/2000
• Est. Priority Date: 04/15/1998
• Status: Expired due to Fees

• Current Assignee: University of Akron
• Original Assignee: University of Akron
• Inventors: Hudson, Steven D., Zarkoob, Shahrzad, Eby, R. K., Reneker, Darrell H., Ertley, Dale
• Primary Examiner(s): EDWARDS, NEWTON O
• Application Number:
  US09/096,904
• Time in Patent Office: 809 Days
• Field of Search: 442/221, 442/364, 530/353, 8/127.6
• US Class Current: 428/364
• CPC Class Codes: C07K 14/43586 from silkworms
• CPC Class Codes: D01D 5/0038 the fibre formed by solvent evaporation, i.e. dry electro-spinning
• CPC Class Codes: D01F 4/02 from fibroin
• CPC Class Codes: Y10T 428/249921 Web or sheet containing structurally defined element or component
• CPC Class Codes: Y10T 428/2913 Rod, strand, filament or fiber

Abstract

A silk nanofiber composite network produced by forming a solution of silk fiber and hexafluroisopropanol, wherein the step of forming is devoid of any acid treatment, where the silk solution has a concentration of about 0.2 to about 1.5 weight percent silk in hexafluroisopropanol, and where the silk is selected from Bombyx mori silk and Nephila clavipes silk; and electrospinning the solution, thereby forming a non-woven network of nanofibers having a diameter in the range from about 2 to about 2000 nanometers.

Claims

1. A non-woven network of synthetically-spun silk nanofibers produced by the process comprising the steps of:

forming a solution of silk and hexafluroisopropanol, wherein said step of forming is devoid of any acid treatment, where the silk solution has a concentration of about 0.2 to about 1.5 weight percent silk in hexafluroisopropanol, and where said silk is selected from Bombyx mori silk and Nephila clavipes silk; and

elctrospinning the solution, thereby forming a non-woven network of nanofibers having a diameter in the range of about 2 to about 2000 nanometers.

4. A network of claim 1, wherein said silk nanofibers are electrospun from a solution containing dissolved Nephila clavipes silk.

5. A network of claim 1, wherein said silk nanofibers are electrospun from a solution containing dissolved Bombyx mori silk.

6. A network of claim 4, wherein said Nephila clavipes silk is major ampullate silk.

10. A network of claim 1, wherein said method of electrospinning includes horizontally drawing a stream of said silk solution though an electrified field.

13. A network of claim 1, wherein said solution contains between about 0.5 and about 1.3 percent by weight Nephila clavipes silk.

14. A network of claim 1, wherein said solution contains between about 0.8 and about 1.2 percent by weight Nephila clavipes silk.

15. A network of claim 1, wherein said solution contains between about 0.5 and about 1.2 percent by weight Bombyx mori silk.

16. A network of claim 1, wherein said solution contains between about 0.7 and about 0.8 percent by weight Bombyx mori fiber.

17. A network of claim 1, wherein the diameter of the nanofibers is in the range of about 20 to 200 nanometers.

20. A network of claim 4, wherein the diameter of the nanofiber is at least one order of magnitude smaller than naturally produced Nephila clavipes fiber.

21. A network of claim 5, wherein the diameter of the nanofiber is at least three orders of magnitude smaller than naturally produced Bombyx mori fiber.

2. A network of synthetically-spun silk nanofibers produced by the process comprising:

forming a solution of silk and solvent, where the silk solution has a concentration of about 0.2 to about 1.5 weight percent silk in the solvent; and

electrospinning the solution, thereby forming a non-woven network of nanofibers having a diameter in the range of about 30 to about 2000 nanometers.

7. A network of claim 2, wherein said silk nanofibers are electrospun from a solution containing dissolved Nephila clavipes silk.

8. A network of claim 2, wherein said silk nanofibers are electrospun from a solution containing dissolved Bombyx mori silk.

9. A network of claim 7, wherein said Nephila clavipes silk is major ampullate silk.

11. A network of claim 2, wherein said method of electrospinning includes horizontally drawing a stream of said silk solution though an electrified field.

19. A network of claim 2, wherein the diameter of the nanofibers is in the range of about 40 to 80 nanometers.

3. A network of synthetically-spun silk nanofibers produced by the process comprising:

forming a solution of silk and solvent, wherein said step of forming is devoid of any acid treatment, where the silk solution has a concentration of about 0.2 to about 1.5 weight percent silk in solvent, and where said silk is selected from Bombyx mori silk and Nephila clavipes silk; and

elctrospinning the solution, thereby forming a non-woven network of nanofibers consisting essentially of Bombyx mori silk or Nephila clavipes silk having a molecular weight significantly similar to the molecular weight of naturally occurring Bombyx mori silk and Nephila clavipes silk.

12. A network of claim 3, wherein said method of electrospinning includes horizontally drawing a stream of said silk solution though an electrified field.

18. A network of claim 3, wherein the diameter of the nanofibers is in the range of about 20 to 200 nanometers.