Conductive biomimetic skin scaffold material with self-repairing function and a method of preparing the same

Abstract

A method for preparing a conductive biomimetic skin scaffold material with self-repairing function includes the following steps: adding 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride to a homogeneous dispersion of acidified carbon nanotubes, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), and gelatin to cross-link to obtain a conductive composite colloid; and injecting the conductive composite colloid into a mold, aging at −4-4° C. for 12-24 hours, and then soaking in a phosphate-buffered saline (PBS) solution with a pH of 7.0-7.4 for 12-24 hours to obtain the conductive biomimetic skin scaffold material.

Claims

1. A method for preparing a conductive biomimetic skin scaffold material with self-repairing function, comprising the following steps: adding 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride to a homogeneous dispersion of acidified carbon nanotubes, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), and gelatin to cross-link to obtain a conductive composite colloid; and injecting the conductive composite colloid into a mold, aging at −4-4° C. for 12-24 hours, and then soaking in a phosphate-buffered saline (PBS) solution with a pH of 7.0-7.4 for 12-24 hours to obtain the conductive biomimetic skin scaffold material.

2. The method according to claim 1, further comprising: dispersing 1.0-5.0 mL of a PEDOT:PSS solution and 1.0-5.0 mL of a 0.05-1.0 g/mL acidified carbon nanotube solution in 10.0-50.0 mL of water to obtain a mixture; adding 1.0-10.0 g of gelatin to the mixture to evenly disperse the mixture; adding 1.0-5.0 mL of a 0.02-0.5 g/mL 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride aqueous solution to the mixture; and stirring the mixture at 30-60° C. to obtain the conductive composite colloid.

3. The method according to claim 1, further comprising: (1) adding 10.0-50.0 mL water, 1.0-5.0 mL a PEDOT:PSS solution, and 1.0-5.0 mL of a 0.05-1.0 g/mL acidified carbon nanotube solution to a reactor to form a mixture, and ultrasonicating the mixture at 50-100 W, 40 kHz, for 30-120 minutes; (2) adding 5.0-20.0 g of gelatin to the mixture, stirring the mixture at 30-60° C. for 30-120 minutes to evenly disperse the mixture; and (3) dissolving 0.1-0.5 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) powder in 1.0-5.0 mL water to obtain a 0.02-0.5 g/mL EDC solution; adding 0.1-2.0 mL of the EDC solution slowly to the mixture of step (2), stirring for 30-120 minutes to at 30-60° C. to obtain the conductive composite colloid.

4. The method of claim 1, wherein the gelatin is derived from a fetal bovine acellular dermal matrix.

5. The method of claim 1, further comprising: reacting 1.0-5.0 g of multi-walled carbon nanotubes, 50.0-250.0 g of 98% concentrated H.sub.2SO.sub.4, and 20.0-100.0 g of 65-68% HNO.sub.3 at 50-100° C. for 5-15 hours to obtain an acidified carbon nanotube solution.

6. The method of claim 5, further comprising: centrifugating the acidified carbon nanotube solution at a speed of 1000 to 5000 rpm for 10-60 minutes, and filtering; adding 100.0-500.0 mL of water, centrifugating at 5000-8000 rpm for 10-60 minutes, and filtering; adding 100.0-500.0 mL of water, centrifugating at 8000-10000 rpm for 10-60 minutes; and freeze-drying to obtain the acidified carbon nanotubes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

(2) In the drawings:

(3) FIG. 1 shows a conductive biomimetic skin scaffold material: the material has good plasticity, conductivity, tensile and compression properties;

(4) FIG. 2 is a scanning electron micrograph (SEM) of the conductive biomimetic skin scaffold material: the material has a porous structure with a pore size of about 200 μm, which can provide 3D space for the growth of skin tissue cells;

(5) FIG. 3 is a diagram that shows in vitro swelling performance of the conductive biomimetic skin scaffold material: the material has good swelling performance, and can fully absorb wound exudate and reduce the risk of bacterial infection;

(6) FIG. 4 shows the self-healing property of the conductive biomimetic skin scaffold material: cutting a circular shaped conductive biomimetic skin scaffold material in a radius direction, self-healing at 37° C., the material being almost completely healed after 10 minutes, indicating healing properties;

(7) FIG. 5 shows the biocompatibility (MTT) test results of the conductive biomimetic skin scaffold material: the material has high biocompatibility.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

(8) Reference will now be made in detail to embodiments of the present invention, example of which is illustrated in the accompanying drawings.

Example 1

(9) (1) Preparation of acidified carbon nanotube dispersion: accurately weighing 1.0 g of multi-walled carbon nanotubes (MWCNTs), 50.0 g of concentrated H.sub.2SO.sub.4 (98%), and 100 g of HNO.sub.3 (65-68%), placing them in a three-necked flask, and heating to 50° C. for 15 hours; after the reaction is complete, conducting gradient speed centrifugation, the conditions of gradient speed centrifugation: (1) centrifugating at 5000 rpm for 60 min and filtering; (2) adding 100.0 mL of ultrapure water, centrifugating at 8000 rpm for 60 min, and filtering; (3) adding 100.0 mL of ultrapure water, centrifugating at 10000 rpm for 60 min, repeating each centrifugation step 3 times, freeze-drying to obtain the acidified carbon nanotube powder; weighing 0.1 g of the acidified carbon nanotube powder and ultrasonicating it in 200 mL of H.sub.2O for 0.5 h to prepare 0.05% (m/v) acidified carbon nanotube dispersion for later use;

(10) (2) Preparation of acidified carbon nanotube/PEDOT:PSS composite dispersion: accurately measuring 10.0 mL of ultrapure water in a single-necked flask, and accurately pipetting 1.0 mL of PEDOT:PSS solution and 5.0 mL of 0.05% acidified carbon nanotube dispersion into the flask, ultrasonicating at 50 W, 40 kHz for 30 min;

(11) (3) Preparation of gelatin-based composite conductive gel solution: accurately weighing 2.0 g of gelatin and adding mixture of step (2), heating up to 30° C., stirring at constant temperature for 30 minutes to completely dissolving the gelatin and uniformly disperse the resulted mixture;

(12) (4) Preparation of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) cross-linked gelatin-based composite conductive gel: accurately weighing 0.1 g of EDC powder and dissolving it in 5.0 mL of H.sub.2O to obtain 2% (m/v) EDC solution; accurately pipetting 2.0 mL of 2% EDC solution and slowly adding into the composite solution system of step 3, and continuing to stir at a constant temperature for 30 minutes to obtain an EDC crosslinked modified gelatin-based composite conductive gel solution;

(13) (5) Pouring the conductive gel solution of step (4) into a custom-made polytetrafluoroethylene mold, and placing it in a refrigerator at −4° C. for 24 h; the soaking it in a PBS solution with a pH of 7.0 for 12 h to obtain a conductive biomimetic skin scaffold material with self-repair function.

(14) FIG. 1 shows a conductive biomimetic skin scaffold material. The material has good plasticity, conductivity, tensile and compression properties. As shown in FIG. 2, the material has a porous structure with a pore size of about 200 μm, which can provide 3D space for the growth of skin tissue cells. As shown in FIG. 3, the material has good swelling performance, and can fully absorb wound exudate and reduce the risk of bacterial infection. As shown in FIG. 4, the material has self-healing property. As shown in FIG. 5, the material has high biocompatibility.

Example 2

(15) (1) Preparation of acidified carbon nanotube dispersion: accurately weighing 3.0 g of multi-walled carbon nanotubes (MWCNTs), 50.0 g of concentrated H.sub.2SO.sub.4 (98%), and 20 g of HNO.sub.3 (65-68%), placing them in a three-necked flask, and heating to 80° C. for 10 hours; after the reaction is complete, conducting gradient speed centrifugation, the conditions of gradient speed centrifugation: (1) centrifugating at 3000 rpm for 30 min and filtering; (2) adding 300.0 mL of ultrapure water, centrifugating at 6500 rpm for 30 min, and filtering; (3) adding 300.0 mL of ultrapure water, centrifugating at 9000 rpm for 30 min, repeating each centrifugation step 4 times, freeze-drying to obtain the acidified carbon nanotube powder; weighing 0.5 g of the acidified carbon nanotube powder and ultrasonicating it in 100 mL of H.sub.2O for 1 h to prepare 0.5% (m/v) acidified carbon nanotube dispersion for later use;

(16) (2) Preparation of acidified carbon nanotube/PEDOT:PSS composite dispersion: accurately measuring 50.0 mL of ultrapure water in a single-necked flask, and accurately pipetting 3.0 mL of PEDOT:PSS solution and 2.5 mL of 0.5% acidified carbon nanotube dispersion into the flask, ultrasonicating at 80 W, 40 kHz for 80 min;

(17) (3) Preparation of gelatin-based composite conductive gel solution: accurately weighing 5.0 g of gelatin and adding mixture of step (2), heating up to 45° C., stirring at constant temperature for 60 minutes to completely dissolving the gelatin and uniformly disperse the resulted mixture;

(18) (4) Preparation of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) cross-linked gelatin-based composite conductive gel: accurately weighing 0.25 g of EDC powder and dissolving it in 2.5 mL of H.sub.2O to obtain 10% (m/v) EDC solution; accurately pipetting 1.0 mL of 10% EDC solution and slowly adding into the composite solution system of step 3, and continuing to stir at a constant temperature for 60 minutes to obtain an EDC crosslinked modified gelatin-based composite conductive gel solution;

(19) (5) Pouring the conductive gel solution of step (4) into a custom-made polytetrafluoroethylene mold, and placing it in a refrigerator at 0° C. for 18 h; the soaking it in a PBS solution with a pH of 7.2 for 18 h to obtain a conductive biomimetic skin scaffold material with self-repair function.

Example 3

(20) (1) Preparation of acidified carbon nanotube dispersion: accurately weighing 5.0 g of multi-walled carbon nanotubes (MWCNTs), 150.0 g of concentrated H.sub.2SO.sub.4 (98%), and 50 g of HNO.sub.3 (65-68%), placing them in a three-necked flask, and heating to 100° C. for 5 hours; after the reaction is complete, conducting gradient speed centrifugation, the conditions of gradient speed centrifugation: (1) centrifugating at 1000 rpm for 10 min and filtering; (2) adding 100.0 mL of ultrapure water, centrifugating at 5000 rpm for 10 min, and filtering; (3) adding 500.0 mL of ultrapure water, centrifugating at 8000 rpm for 10 min, repeating each centrifugation step 3 times, freeze-drying to obtain the acidified carbon nanotube powder; weighing 1.0 g of the acidified carbon nanotube powder and ultrasonicating it in 50 mL of H.sub.2O for 2 h to prepare 2.0% (m/v) acidified carbon nanotube dispersion for later use;

(21) (2) Preparation of acidified carbon nanotube/PEDOT:PSS composite dispersion: accurately measuring 25.0 mL of ultrapure water in a single-necked flask, and accurately pipetting 5.0 mL of PEDOT:PSS solution and 1.0 mL of 2.0% acidified carbon nanotube dispersion into the flask, ultrasonicating at 100 W, 40 kHz for 120 min;

(22) (3) Preparation of gelatin-based composite conductive gel solution: accurately weighing 10.0 g of gelatin and adding mixture of step (2), heating up to 60° C., stirring at constant temperature for 120 minutes to completely dissolving the gelatin and uniformly disperse the resulted mixture;

(23) (4) Preparation of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) cross-linked gelatin-based composite conductive gel: accurately weighing 0.5 g of EDC powder and dissolving it in 1 mL of H.sub.2O to obtain 50% (m/v) EDC solution; accurately pipetting 1.0 mL of 50% EDC solution and slowly adding into the composite solution system of step 3, and continuing to stir at a constant temperature for 120 minutes to obtain an EDC crosslinked modified gelatin-based composite conductive gel solution;

(24) (5) Pouring the conductive gel solution of step (4) into a custom-made polytetrafluoroethylene mold, and placing it in a refrigerator at 4° C. for 12 h; the soaking it in a PBS solution with a pH of 7.4 for 24 h to obtain a conductive biomimetic skin scaffold material with self-repair function.

(25) It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.