Xylan-based dual network nanocomposite hydrogel, preparation method thereof and use therefor

Abstract

This invention belongs to the technical field of composite materials, and discloses a xylan-based dual network nanocomposite hydrogel, preparation method thereof and use therefor. The method comprises (1) adding graphite oxide powder into deionized water, ultrasonically dispersing to obtain a GO aqueous dispersion; (2) adding xylan into deionized water, heating and stirring to obtain a xylan solution; (3) adding a water-soluble calcium salt, a reaction monomer and the xylan solution into the GO aqueous dispersion, and stirring and dispersing uniformly under an ice-bath condition, then adding an initiator, a crosslinking agent and an accelerator, stirring and mixing uniformly to obtain a mixed solution; and 4) drying and reacting the mixed solution (in the step (3) to obtain a xylan-based dual network nanocomposite hydrogel. The composite hydrogel obtained by this invention has high mechanical property, is biodegradable and biocompatible, and can be used in the field of biomedicine, such as tissue engineering, drug sustained release, cell culture scaffold and cartilage tissue, etc.

Claims

1. A method for preparing a xylan-based dual network nanocomposite hydrogel, comprising the following steps: (1) adding graphite oxide powder into deionized water and ultrasonically dispersing to obtain a graphite oxide aqueous dispersion; (2) adding xylan to deionized water, heating and stirring to obtain a xylan solution; (3) adding a water-soluble calcium salt, a reaction monomer and the xylan solution into the graphite oxide aqueous dispersion, stirring and dispersing uniformly under an ice-bath condition, then adding an initiator, a cross-linking agent and an accelerator, stirring and mixing uniformly to obtain a mixed solution, the reaction monomer is one or more of acrylamide, polyacrylamide, acrylic acid, N-isoacrylamide, and butyl acrylate; and (4) drying and reacting the mixed solution in the step (3) to obtain a xylan-based dual network nanocomposite hydrogel.

2. The method for preparing the xylan-based dual network nanocomposite hydrogel according to claim 1, wherein the mass ratio of Ca.sup.2+-in the water-soluble calcium salt in the step (3) to the graphite oxide powder in the graphite oxide aqueous dispersion is (10-240) mg: (20-60) mg, the mass ratio of the reaction monomer to the xylan is (1-6) g: (0.5-1.5) g, and the mass ratio of the graphite oxide powder in the graphite oxide aqueous dispersion to the xylan is (20-60) mg: (0.5-1.5) g.

3. The method for preparing the xylan-based dual network nanocomposite hydrogel according to claim 1, wherein the water-soluble calcium salt in the step (3) is CaCl.sub.2) or calcium nitrate; the initiator is ammonium persulfate or potassium persulfate; the crosslinking agent is N,N′ methylene bisacrylamide; and the accelerator is tetramethyl ethylene diamine or N,N,N′,N′-tetramethylene ethylene diamine.

4. The method for preparing the xylan-based dual network nanocomposite hydrogel according to claim 1, wherein the drying and reacting in the step (4) is carried out at 50° C.-80° C. for 2 h-6 h; and the heating and stirring in the step (2) is stirring at 75° C.-95° C. for 0.5 h-1.5 h.

5. The method for preparing the xylan-based dual network nanocomposite hydrogel according to claim 1, wherein the concentration of the graphite oxide aqueous dispersion in the step (1) is 0.4 mg/mL-6 mg/mL, and the concentration of the xylan solution in the step (2) is 0.05 g/mL-0.2 g/mL.

6. The method for preparing the xylan-based dual network nanocomposite hydrogel according to claim 1, wherein the mass ratio of the initiator to the reaction monomer in the step (3) is (0.01-0.05) g: (1-6) g; the mass ratio of the crosslinking agent to the reaction monomer in the step (3) is (0.0025-0.03) g: (1-6) g; and the volume-mass ratio of the accelerator to the reaction monomer in the step (3) is (10-50) μL: (1-6) g.

7. The method for preparing a xylan-based dual network nanocomposite hydrogel according to claim 1, wherein the ultrasonically dispersing in the step (1) is carried out at 20° C.-40° C. for 2 h-6 h; and the power of the ultrasound is 100 W-300 W, and the frequency is 25 kHz-80 kHz.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows compression stress-strain curves of hydrogels with different Ca.sup.2+ contents (Comparative Example 1 (1: Ca.sup.2+/GO=0), Example (2: Ca.sup.2+/GO=0.5), Example 2 (4: Ca.sup.2+/GO=2), Example 6 (3: Ca.sup.2+/GO=1) and Example 7 (5: Ca.sup.2+/GO=4));

(2) FIG. 2 shows tensile stress-strain curves of hydrogels with different Ca.sup.2+ content (Comparative Example 1 (1: Ca.sup.2+/GO=0), Example 1 (2: Ca.sup.2+/GO=0.5), Example 2 (4: Ca.sup.2+/GO=2), Example 6 (3: Ca.sup.2+/GO=1) and Example 7 (5: Ca.sup.2+/GO=4)); and

(3) FIG. 3 is a cyclic compression stress-strain curve of the GO/Ca.sup.2+/PAM/XH composite hydrogel in Example 2.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(4) The present invention will be further described in detail below with reference to examples and the drawings, but the embodiments of the present invention are not limited thereto.

Comparative Example 1

(5) A method for preparing a GO/PAM/XH hydrogel material comprises the following steps:

(6) (1) adding 20 mg of graphite oxide powder (GO) into 10 mL of deionized water, and ultrasonically dispersing (100 W, 25 kHz) at 20° C. for 4 h to obtain a GO aqueous dispersion;

(7) (2) weighing 1 g of xylan, dissolving the same in 10 mL of deionized water, and stirring at 85° C. for 1 h to form a uniform xylan solution;

(8) (3) adding 4 g of a monomer acrylamide (AM) and the xylan solution into the GO aqueous dispersion in the step (1), stirring and dispersing uniformly under an ice-bath condition; adding 0.01 g of an initiator ammonium persulfate, 0.008 g of a cross-linking agent N,N′-methylene bisacrylamide and 40 μL of an accelerator tetramethyl ethylene diamine, and stirring uniformly to obtain a mixed solution; and
(4) placing the mixed solution in the step (3) in an oven to react at 50° C. for 2 hours to obtain a composite hydrogel, that is, a GO/PAM/XH hydrogel material. The performance-testing curves of the composite hydrogel are shown as FIG. 1 and FIG. 2.

(9) The GO/PAM/XH composite hydrogel obtained in this Comparative Example had a maximum compressive strength of 0.17 MPa and an elongation of 629% when the compressive deformation reached 95%.

Example 1

(10) A method for preparing a xylan-based dual network nanocomposite hydrogel (GO/Ca.sup.2+/PAM/XH hydrogel) material, comprises the following steps:

(11) (1) adding 20 mg of graphite oxide powder (GO) into 10 mL of deionized water, and ultrasonically dispersing (100 W, 40 kHz) at 20° C. for 4 h to obtain a GO aqueous dispersion;

(12) (2) weighing 1 g of xylan, dissolving the same in 10 mL of deionized water, and stirring at 85° C. for 1 h to form a uniform xylan solution;

(13) (3) adding 27.75 mg of CaCl.sub.2, 4 g of a monomer acrylamide and the xylan solution into the GO aqueous dispersion in the step (1), stirring and dispersing uniformly under an ice-bath condition; adding 0.01 g of an initiator ammonium persulfate, 0.01 g of a crosslinking agent N,N′-methylene bisacrylamide and 50 μL of an accelerator tetramethyl ethylene diamine, and stirring uniformly to obtain a mixed solution; and
(4) placing the mixed solution in the step (3) in an oven to react at 60° C. for 4 h to obtain a xylan-based dual network nanocomposite hydrogel (GO/Ca.sup.2+/PAM/XH composite hydrogel). The performance-testing curves of the composite hydrogel are shown as FIG. 1 and FIG. 2.

(14) The GO/Ca.sup.2+/PAM/XH composite hydrogel obtained in this example was not broken and crushed when the compressive deformation reached 95%, and could recover rapidly after compression. The compressive strength of the hydrogel was 0.184 MPa, and the elongation thereof was 775%.

Example 2

(15) A method for preparing a xylan-based dual network nanocomposite hydrogel (GO/Ca.sup.2+/PAM/XH composite hydrogel) comprises the following steps:

(16) (1) adding 20 mg of graphite oxide powder (GO) into 10 mL of deionized water, and ultrasonically dispersing (200 W, 40 kHz) at 30° C. for 4 h to obtain a GO aqueous dispersion;

(17) (2) weighing 1 g of xylan, dissolving the same in 10 mL of deionized water, and stirring at 85° C. for 1 h to form a uniform xylan solution;

(18) (3) adding 111 mg of CaCl.sub.2, 4 g of a monomer acrylamide and the xylan solution into the GO aqueous dispersion in the step (1), stirring and dispersing uniformly under an ice-bath condition; adding 0.03 g of an initiator ammonium persulfate, 0.01 g of an crosslinking agent N,N′-methylene bisacrylamide and 50 μL of an accelerator tetramethyl ethylene diamine, and stirring uniformly to obtain a mixed solution; and
(4) placing the mixed solution in the step (3) in an oven to react at 60° C. for 4 h to obtain a xylan-based dual network nanocomposite hydrogel (GO/Ca.sup.2+/PAM/XH composite hydrogel). The performance-testing curves of the composite hydrogel are shown as FIGS. 1, 2 and 3.

(19) The GO/Ca.sup.2+/PAM/XH composite hydrogel obtained in this example was not broken and crushed when the compressive deformation reached 95%, and could recover rapidly after compression. The compressive strength of the hydrogel was 1.84 MPa, and the elongation thereof was 1918%.

Example 3

(20) A method for preparing a xylan-based nanocomposite hydrogel (GO/Ca.sup.2+/PAM/XH composite hydrogel) material of this Example comprises the following steps:

(21) (1) adding 4 mg of graphite oxide powder (GO) into 10 mL of deionized water, and ultrasonically dispersing (200 W, 40 kHz) at 30° C. for 2 h to obtain a GO aqueous dispersion;

(22) (2) weighing 1 g of xylan, dissolving the same in 10 mL of deionized water, and stirring at 85° C. for 1 h to form a uniform xylan solution;

(23) (3) adding 22.2 mg of CaCl.sub.2, 4 g of a monomer acrylamide and the xylan solution into the GO aqueous dispersion in the step (1), stirring and dispersing uniformly under an ice-bath condition; adding 0.03 g of an initiator ammonium persulfate, 0.01 g of an crosslinking agent N,N′-methylene bisacrylamide and 20 μL of an accelerator tetramethyl ethylene diamine, and stirring uniformly to obtain a mixed solution; and
(4) placing the mixed solution in the step (3) in an oven to react at 60° C. for 4 h to obtain a xylan-based dual network nanocomposite hydrogel (GO/Ca.sup.2+/PAM/XH composite hydrogel).

(24) The GO/Ca.sup.2+/PAM/XH composite hydrogel obtained in this example was not broken and crushed when the compressive deformation reached 95%, and could recover rapidly after compression. The compressive strength of the hydrogel was 1.1 MPa, and the elongation thereof was 1100%.

Example 4

(25) A method for preparing a carboxymethyl xylan-based nanocomposite hydrogel (GO/Ca.sup.2+/PAM/XH hydrogel) material of this Example comprises the following steps:

(26) (1) adding 60 mg of graphite oxide powder (GO) into 10 mL of deionized water, and ultrasonically dispersing (300 W, 80 kHz) at 40° C. for 6 h to obtain a GO aqueous dispersion;

(27) (2) weighing 1 g of xylan, dissolving the same in 10 mL of deionized water, and stirring at 85° C. for 1 h to form a uniform xylan solution;

(28) (3) adding 166.5 mg of CaCl.sub.2, 4 g of a monomer acrylamide and the xylan solution into the GO aqueous dispersion in the step (1), stirring and dispersing uniformly under an ice-bath condition; adding 0.05 g of an initiator ammonium persulfate, 0.01 g of an crosslinking agent N,N′-methylene bisacrylamide and 50 μL of an accelerator tetramethyl ethylene diamine, and stirring uniformly to obtain a mixed solution; and
(4) placing the mixed solution in the step (3) in an oven to react at 80° C. for 6 h to obtain a xylan-based dual network nanocomposite hydrogel (GO/Ca.sup.2+/PAM/XH composite hydrogel).

(29) The GO/Ca.sup.2+/PAM/XH composite hydrogel obtained in this example was not broken and crushed when the compressive deformation reached 95%, and could recover rapidly after compression. The compressive strength of the hydrogel was 2.3 MPa, and the elongation thereof was 3310%.

Example 5

(30) A method for preparing a xylan-based nanocomposite hydrogel (GO/Ca.sup.2+/PAM/XH composite hydrogel) material comprises the following steps:

(31) (1) adding 60 mg of graphite oxide powder (GO) into 10 mL of deionized water, and ultrasonically dispersing (300 W, 80 kHz) at 30° C. for 6 h to obtain a GO aqueous dispersion;

(32) (2) weighing 1 g of xylan, dissolving the same in 10 mL of deionized water, and stirring at 85° C. for 1 h to form a uniform xylan solution;

(33) (3) adding 166.5 mg of CaCl.sub.2, 4 g of a monomer acrylamide and the xylan solution into the GO aqueous dispersion in the step (1), stirring and dispersing uniformly under an ice-bath condition; adding 0.05 g of an initiator ammonium persulfate, 0.005 g of an crosslinking agent N,N′-methylene bisacrylamide and 50 μL of an accelerator tetramethyl ethylene diamine, and stirring uniformly to obtain a mixed solution; and
(4) placing the mixed solution in the step (3) in an oven to react at 80° C. for 6 h to obtain a xylan-based dual network nanocomposite hydrogel (GO/Ca.sup.2+/PAM/XH composite hydrogel).

(34) The GO/Ca.sup.2+/PAM/XH composite hydrogel obtained in this example was not broken and crushed when the compressive deformation reached 95%, and could recover rapidly after compression. The compressive strength of the hydrogel was 1.63 MPa, and the elongation thereof was 3976%.

Example 6

(35) A method for preparing a xylan-based dual network nanocomposite hydrogel (GO/Ca.sup.2+/PAM/XH composite hydrogel) comprises the following steps:

(36) (1) adding 20 mg of graphite oxide powder (GO) into 10 mL of deionized water, and ultrasonically dispersing (200 W, 40 kHz) at 30° C. for 4 h to obtain a GO aqueous dispersion;

(37) (2) weighing 1 g of xylan, dissolving the same in 10 mL of deionized water, and stirring at 85° C. for 1 h to form a uniform xylan solution;

(38) (3) adding 55.5 mg of CaCl.sub.2, 4 g of a monomer acrylamide and the xylan solution into the GO aqueous dispersion in the step (1), stirring and dispersing uniformly under an ice-bath condition; adding 0.03 g of an initiator ammonium persulfate, 0.01 g of an crosslinking agent N,N′-methylene bisacrylamide and 50 μL of an accelerator tetramethyl ethylene diamine, and stirring uniformly to obtain a mixed solution; and
(4) placing the mixed solution in the step (3) in an oven to react at 60° C. for 4 h to obtain a xylan-based dual network nanocomposite hydrogel (GO/Ca.sup.2+/PAM/XH composite hydrogel). The performance-testing curves of the composite hydrogel are shown as FIGS. 1 and 2.

(39) The GO/Ca.sup.2+/PAM/XH composite hydrogel obtained in this example was not broken and crushed when the compressive deformation reached 95%, and could recover rapidly after compression. The compressive strength of the hydrogel was 0.757 MPa, and the elongation thereof was 942%.

Example 7

(40) A method for preparing a xylan-based dual network nanocomposite hydrogel (GO/Ca.sup.2+/PAM/XH composite hydrogel) material comprises the following steps:

(41) (1) adding 20 mg of graphite oxide powder (GO) into 10 mL of deionized water, and ultrasonically dispersing (200 W, 40 kHz) at 30° C. for 4 h to obtain a GO aqueous dispersion;

(42) (2) weighing 1 g of xylan, dissolving the same in 10 mL of deionized water, and stirring at 85° C. for 1 h to form a uniform xylan solution;

(43) (3) adding 222 mg of CaCl.sub.2, 4 g of a monomer acrylamide and the xylan solution into the GO aqueous dispersion in the step (1), stirring and dispersing uniformly under an ice-bath condition; adding 0.03 g of an initiator ammonium persulfate, 0.01 g of an crosslinking agent N,N′-methylene bisacrylamide and 50 μL of an accelerator tetramethyl ethylene diamine, and stirring uniformly to obtain a mixed solution; and
(4) placing the mixed solution in the step (3) in an oven to react at 60° C. for 4 h to obtain a xylan-based dual network nanocomposite hydrogel (GO/Ca.sup.2+/PAM/XH composite hydrogel). The performance-testing curves of the composite hydrogel are shown as FIG. 1 and FIG. 2.

(44) The GO/Ca.sup.2+/PAM/XH composite hydrogel obtained in this example was not broken and crushed when the compressive deformation reached 95%, and could recover rapidly after compression. The compressive strength of the hydrogel was 0.175 MPa, and the elongation thereof was 630%.

(45) FIGS. 1 and 2 show compressive stress-strain curves and tensile stress-strain curves of hydrogels with different ratios of Ca.sup.2+/GO (Comparative Example 1, Examples 1, 2, 6, and 7), respectively. It can be seen that the content of Ca.sup.2+ has a great influence on the mechanical strength of the GO/PAM/XH composite hydrogel. When 20 mg of GO and 0.01 g of the crosslinking agent are used without Ca.sup.2+, the maximum compressive strength is 0.17 MPa and the maximum elongation is 629% while compressive deformation reaches 95%. However, after a small amount of Ca.sup.2+ (Ca.sup.2+/GO=0.5-2) is introduced into the GO/PAM/XH hydrogel network to form a second network, the mechanical strength of the hydrogel is significantly improved. When the ratio of Ca.sup.2+/GO is increased from 0.5 to 2, and when the compressive deformation reaches 95%, the hydrogel is not broken and crushed, the compressive strength of the hydrogel increases from 0.184 MPa to 1.84 MPa, and the elongation increases from 775% to 1918%. That is, when the amount of Ca.sup.2+ is twice that of GO, the compressive strength is increased to 10 times the original compresseive strength, and the elongation is increased to nearly 3 times the original elongation. This is because Ca.sup.2+ could cross-link with GO to form another layer of network structure, while the XH and AM graft-copolymerized cross-linking network and the Ca.sup.2+ and GO cross-linking network could be connected by covalent bonds, so that GO/Ca.sup.2+/PAM/XH hydrogel exhibits excellent mechanical property as well as very high elasticity and toughness. However, when the amount of Ca.sup.2+ continues to increase (Ca.sup.2+/GO=3-4), the compressive strength and the elongation of the hydrogel both decrease gradually. When the ratio of Ca.sup.2+/GO is increased from 2 to 4, and when the compression deformation reaches 95%, the compressive strength of the hydrogel decreases from 1.84 MPa to 0.37 MPa and the elongation decreases from 1918% to 942%. This is because GO acts as new chemical crosslinking points on one hand, and combines with Ca.sup.2+ to form another network on the other hand. With a further increase of the content of Ca.sup.2+, the chemical crosslinking points relatively decrease, resulting in certain decline of the mechanical property. It can be seen from the above, that the introduction of the network of Ca.sup.2+ and GO can effectively improve the mechanical strength of the hydrogel, and when the ratio of Ca.sup.2+/GO is 2, the highest mechanical strength is obtained.

(46) FIG. 3 is a cyclic compressive stress-strain curve of the GO/Ca.sup.2+/PAM/XH composite hydrogel of Example 2. When the ratio of Ca.sup.2+/GO is 2, the amount of GO is 20 mg, the amount of the cross-linking agent is 0.01 g. Furthermore, when the compressive deformation reaches 70%, the hydrogel is not broken and crushed, and maintains good elasticity. After releasing pressure, the hydrogel can rapidly recover to its original shape. Moreover, after 100 cycles of compressing-releasing, the hydrogel has almost no plastic deformation and decrease in compressive strength. Such high-strength hydrogel is expected to be used in biomedical fields such as tissue engineering, drug sustained release, cell culture scaffolds, and cartilage tissue, etc.

(47) The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above examples, and any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention should all be equivalent replacement modes and be included in the protection scope of the present invention.