METHOD FOR PREPARING DOUBLE-NETWORK HYDROGEL TUBE WITH COMPLEX STRUCTURE

Abstract

The present invention discloses a method for preparing a double-network hydrogel tube with a complex structure. Iron wires of different sizes are mechanically polished, arranged in different manners, and then immersed into a monomer prepolymer solution, or a monomer prepolymer is poured into a container containing iron wires of different arranged shapes to conduct a polymerization reaction, such that a uniform primary-crosslinked single-network hydrogel film can be rapidly grown on the surface of each iron wire. The hydrogel film is then immersed in a secondary-crosslinking solution for secondary crosslinking to build a double-network hydrogel film. After immersion processing, the wires are drawn out to obtain high-strength hollow double-network hydrogel tubes of different shapes. The hydrogel tube has a diameter of 10 micrometers to a few millimeters, the shape of the tube inner structure is highly controllable, and the tensile strength of the hydrogel tube can be up to 2 MPa.

Claims

1. A method for preparing a double-network hydrogel tube with a complex structure, wherein the method comprises the following sequential steps: 1) immersing polished iron wires of different sizes in a monomer prepolymer solution, or pouring a monomer prepolymer solution into a container containing iron wires of different arranged shapes to conduct a polymerization reaction, such that a uniform chemically-crosslinked hydrogel layer is formed on the surface of each iron wire, aging, and then washing by soaking in pure water to obtain a primary-crosslinked single-network hydrogel film; and 2) immersing iron wires having grown hydrogel films in a secondary-crosslinking solution selected from an aqueous solution of calcium ions, an aqueous solution of magnesium ions, an aqueous solution of ferric ions, or an aqueous solution of tannic acid for 5 min to 20 h, and then drawing the iron wires out to obtain high-strength double-network hydrogel tubes of different shapes.

2. The method according to claim 1, wherein the monomer prepolymer solution consists of a monomer, an initiator, an crosslinking agent, an aqueous polymer or biomacromolecule, and high-purity deionized water, wherein the monomer is one or two of (meth)acrylic acid, acrylamide, hydroxyethyl (meth)acrylate, polyoxyethylene methacrylate, N-isopropylacrylamide, methacrylic sulfonate, chitosan (meth)acrylate, chitosan (meth)acrylate, dimethylaminoethyl methacrylate, sodium alginate methacrylate, methylacryloyl ethylcarboxybetaine, and methylacryloyl ethylsulphobetaine; the initiator is potassium persulfate or ammonium persulfate; the crosslinking agent is N,N-methylene bisacrylamide or (poly)ethylene glycol di(meth)acrylate; the aqueous polymer is polyvinyl alcohol, polyethylene glycol or polyvinylpyrrolidone; and the biomacromolecule is bovine serum albumin, collagen or polypeptide.

3. The method according to claim 2, wherein in the monomer prepolymer solution, the mass fraction of the monomer, the initiator and the crosslinking agent is from 5% to 15%, the molar ratio of the three is 500-1000:1:0.5, the mass fraction of the aqueous polymer is 5-10%, and the balance is deionized water.

4. The method according to claim 2, wherein in the monomer prepolymer solution, the mass fraction of the monomer, the initiator and the crosslinking agent is from 5% to 15%, the molar ratio of the three is 500-1000:1:0.5, the mass fraction of the biomacromolecule is 0.1-1%, and the balance is deionized water.

5. The method according to claim 1, wherein the iron wires are arranged in various ways and may be a single one, arranged in multiple rows, cross-arranged or arranged in an array, so as to obtain a hydrogel tube with a complex shape, and the diameter of the iron wire is 10 m to 3 mm.

6. The method according to claim 1, wherein the polymerization time is 1 to 30 min and the polymerization temperature is 10 C. to 30 C.

7. The method according to claim wherein the concentration of the secondary-crosslinking solution is 0.1-0.6 mol/L.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0024] FIG. 1 is a schematic table of preparations of materials of a double-network hydrogel tube; including the following: [0025] item a1 is a one-component chemically-crosslinked network hydrogel tube; [0026] item a2 is a multi-network hydrogel tube in which the one-component (two-component and multi-component) chemical crosslinking and physical crosslinking cooperate with each other; [0027] item a3 is a multi-network hydrogel tube in which the one-component (two-component and multi-component) chemical crosslinking cooperates with physical interaction; [0028] item b1 is a composite network hydrogel tube in which one component (two components and multiple components) chemical crosslinking and polymer chains physically pass throughout; [0029] item b2 is a multi-network hydrogel tube in which the one-component (two-component and multi-component) chemical crosslinking cooperates with physical interaction; [0030] item b3 is a multi-network hydrogel tube in which the one-component (two-component and multi-component) chemical crosslinking/physical crosslinking/polymer chains physically pass throughout; [0031] item c1 is a two-component and multi-component chemically-crosslinked network hydrogel tube; [0032] item c2 is a multi-network hydrogel tube in which the one-component (two-component and multi-component) chemical crosslinking and physical crosslinking cooperate with each other; [0033] item c3 is a multi-network hydrogel tube in which the one-component (two-component and multi-component) chemical crosslinking/physical crosslinking/polymer chains physically pass throughout; [0034] item d1 is a composite network hydrogel tube in which one component (two components and multiple components) chemical crosslinking and polymer chains physically pass throughout; [0035] item d2 is a multi-network hydrogel tube in which the one-component (two-component and multi-component) chemical crosslinking cooperates with physical interaction; and [0036] item d3 is a multi-network hydrogel tube in which the one-component (two-component and multi-component) chemical crosslinking/physical crosslinking/physical interaction cooperate with each other.

DETAILED DESCRIPTION

[0037] For better understanding of the present invention, the present invention is illustrated through the following Examples:

EXAMPLE 1

Preparation of Hydrogel Tube Having Uniform Size: Acrylic Acid/Acrylamide-Iron Two-Component Chemically-Physically Crosslinked Network Hydrogel Tube

[0038] 1. Formulation of Hydrogel Prepolymer Solution of Acrylic Acid and Acrylamide. Weighed 4.0 g acrylamide, 0.6 g acrylic acid, 0.008 g N,N-bisacrylamide, and 0.02 g potassium persulfate, dissolved in 40 mL water, and purged with nitrogen for 1 h to remove oxygen.

[0039] 2. Formation of Hydrogel Film on Iron Wire. An iron wire having a diameter of 1.6 mm was suspensively immersed into a monomer prepolymer solution, removed from the solution after reacted for 10 min (20 C.), aged for 2 h while being isolated from air, and then immersed in ultrapure water to wash by soaking.

[0040] 3. Physical Coordination Crosslinking in Fe.sup.3+ Solution. The iron wire having grown gel layer was immersed into a 0.06 mol/L Fe.sup.3+ solution and soaked for 2 h, then washed by soaking in pure water for 1 h to remove the iron wire template, and thus a hollow hydrogel tube having a tube diameter of 1.8-2.0 mm and a tube wall thickness of 400-1000 m was obtained, wherein through testing the hollow hydrogel tube had a tensile strength of 1.2-3.0 MPa, which is 1.5 times larger than the original one.

EXAMPLE 2

Preparation of Hydrogel Tube Having Uniform Size: Acrylamide/Hydroxyethyl Methacrylate/Polyvinyl Alcohol Composite Network Hydrogel Tube

[0041] 1. Formulation of Aqueous Solution of Acrylamide/Hydroxyethyl Methacrylate/Polyvinyl Alcohol. Weighed 1 g acrylamide, 6.0 g hydroxyethyl methacrylate, 0.01 g N,N-bisacrylamide, and 0.02 g potassium persulfate, dissolved in 30 mL water, and purged with nitrogen for 1 h to remove oxygen. Then added was a 20 mL aqueous solution of 5% polyvinyl alcohol (polyethylene glycol), stirred uniformly and then placed in an ice-water bath for use.

[0042] 2. Formation of Hydrogel Film on Iron Wire. An iron wire having a diameter of 1.6 mm was suspensively immersed into an aqueous solution of a mixture of acrylamide/hydroxyethyl methacrylate/polyvinyl alcohol, removed from the solution after reacted for 30 min (20 C.), placed in a freeze dryer (20 C.), thawed 3 h later (the freezing-thawing process is continued for 3 times), and the iron wire template was removed to obtain a hollow hydrogel tube having a tube diameter of 2.0-3.0 mm and a tube wall thickness of 800-1200 m.

EXAMPLE 3

Preparation of Hydrogel Tube Having Uniform Size: Hydroxyethyl Methacrylate/Sodium Alginate-calcium Composite Network Hydrogel Tube

[0043] 1. Aqueous Solution of Hydroxyethyl Methacrylate/Sodium Alginate. Weighed 6.0 g, 0.006 g N,N-bisacrylamide, 0.01 g potassium persulfate, dissolved in 50 mL water, added 5.0 g sodium alginate, stirred until the solution became clear, and purged with nitrogen for 1 h to remove oxygen.

[0044] 2. Formation of Hydrogel Film on Iron Wire. An iron wire having a diameter of 4.0 mm was suspensively immersed into an aqueous solution of hydroxyethyl methacrylate/sodium alginate, removed from the solution after reacted for 30 min (20 C.), aged for 2 h while being isolated from air, and then immersed in ultrapure water to wash by soaking.

[0045] 3. Physical Coordination Crosslinking in Ca.sup.2+ Solution. The iron wire having grown gel layer was immersed into a 0.06 mol/L Ca.sup.2+ solution and soaked for 10 h, then washed by soaking in pure water for 1 h to remove the iron wire template, and thus a hollow hydrogel tube having a tube diameter of 4.5-5.5 mm and a tube wall thickness of 1000-1500 m was obtained.

EXAMPLE 4

Preparation of Hydrogel Tube Having Uniform Size: Hydroxyethyl Methacrylate/Polyethylene Glycol/Bovine Serum Albumin-Tannic Acid Composite Network Hydrogel Tube

[0046] 1. Aqueous Solution of Hydroxyethyl Methacrylate/Polyethylene Glycol/Bovine Serum Albumin. Weighed 6.5 g hydroxyethyl methacrylate, 0.015 g N,N-bisacrylamide, and 0.01 g potassium persulfate, dissolved in 30 mL water, and purged with nitrogen for 1 h to remove oxygen. Then added was a 20 mL aqueous solution of 5% polyvinyl alcohol and 0.5 g bovine serum albumin, stirred uniformly and then placed in an ice-water bath for use.

[0047] 2. Formation of Hydrogel Film on Iron Wire. An iron wire having a diameter of 4.0 mm was suspensively immersed into an aqueous solution of a mixture of hydroxyethyl methacrylate/polyethylene glycol/bovine serum albumin, removed from the solution after reacted for 30 min (20 C.), placed in a freeze dryer (20 C.), thawed 2 h later (the freezing-thawing process is continued for 3 times), and the iron wire template was removed to obtain a hydroxyethyl methacrylate/polyethylene glycol/bovine serum albumin hollow hydrogel tube.

[0048] 3. Treatment in Tannic Acid Solution. The hydroxyethyl methacrylate/polyethylene glycol/bovine serum albumin hollow hydrogel tube was immersed into an aqueous solution of 3% tannic acid and soaked for 10 h, then washed by soaking in pure water for 5 h, and thus a hydroxyethyl methacrylate/polyethylene glycol/bovine serum albumin-tannic acid composite network hydrogel tube was obtained.

EXAMPLE 5

Preparation of Acrylic Acid/Acrylamide-Calcium throughout Hydrogel Tube with Complex Shape

[0049] 1. Formulation of Hydrogel Prepolymer Solution of Acrylic Acid and Acrylamide. Weighed 3.5 g acrylamide, 0.6 g acrylic acid, 0.003 g N,N-bisacrylamide, and 0.02 g potassium sulfate, dissolved in 40 mL water, and purged with nitrogen for 1 h to remove oxygen.

[0050] 2. Formation of Hydrogel Film on Iron Wire. Selected iron wires of sizes of 0.3 mm, 0.5 mm, 0.7 mm, 1.2 mm, 1.6 mm, and 4.0 mm were mechanically polished, then coiled and intertwined together, and placed in a specific reaction tank. The monomer prepolymer solution was quickly poured into the reaction tank, removed from the reaction tank after reacted for 10 min (20 C.), aged for 2 h while being isolated from air, and then immersed in ultrapure water to wash by soaking.

[0051] 3. Physical Coordination Crosslinking in Ga.sup.2+ solution: the iron wire having grown gel layer was immersed into a 0.2 mol/L Ga.sup.2+ solution and soaked for 10 h, then washed by soaking in pure water for 2 h to draw out iron wires of different sizes, and thus a through hydrogel tube structure body having a complex shape was obtained.

EXAMPLE 6

Preparation of Thickness Gradient Acrylic Acid/Acrylamide-Calcium Hydrogel Tube

[0052] 1. Formulation of Hydrogel Prepolymer Solution of Acrylic Acid and Acrylamide. Weighed 4.0 g acrylamide, 1.0 g acrylic acid, 0.01 g N,N-bisacrylamide, and 0.02 g potassium persulfate, dissolved in 30 mL water, and purged with nitrogen for 1 h to remove oxygen.

[0053] 2. Formation of Gradient Hydrogel Film on Iron Wire. An iron wire having a diameter of 1.6 mm was vertically and suspensively fixed onto a drawing machine, quickly immersed into a hydrogel prepolymer solution, slowly pulled out from the solution at a withdrawal rate of 1 cm/min after reacted for 1 min (20 C.), and immersed in ultrapure water to wash by soaking after the full iron wire was totally drawn out from the solution

[0054] 3. Physical Coordination Crosslinking in Ca.sup.2+ Solution. The iron wire having grown gel layer was immersed into a 0.06 mol/L Ca.sup.2+ solution and soaked for 5 h, then washed by soaking in pure water for 1 h to remove the copper wire template, and thus a hollow hydrogel tube having a tube wall thickness distributed gradiently was obtained.

EXAMPLE 7

Preparation of Acrylic Acid/Acrylamide-Calcium Hydrogel Tube Having Shape, Crosslinking-Degree and Tube-Wall-Thickness Gradients

[0055] 1. Formulation of Hydrogel Prepolymer Solution of Acrylic Acid and Acrylamide. Weighed 3.0 g acrylamide, 0.5 g acrylic acid, 0.006 g N,N-bisacrylamide, and 0.01 g potassium persulfate, dissolved in 50 mL water, and purged with nitrogen for 1 h to remove oxygen.

[0056] 2. Formation of Hydrogel Film on Iron Wire. A metal having a diameter of 1.6 mm was quickly immersed into a hydrogel prepolymer solution, and then immersed in ultrapure water to wash by soaking after reacted for 10 min (20 C.).

[0057] 3. Physical Coordination Crosslinking in Cu.sup.2+ Solution. The bottom end of the iron wire having grown gel layer was vertically immersed into a 0.06 mol/L Cu.sup.2+ solution, wherein the immersed length was about of the total length, and the iron wire was drawn out after immersed for 10 h, so as to obtain a hydrogel tube having shape, crosslinking-degree and tube-wall-thickness gradients.

EXAMPLE 8

Preparation of Layered (Transverse) Acrylic Acid/Acrylamide-Acrylic Acid/N-Isopropylacrylamide Hydrogel Tube

[0058] 1. Formulation of Prepolymer Solution A Containing Acrylic Acid/Acrylamide and Prepolymer Solution Containing Acrylic Acid/N-Isopropylacrylamide. Prepolymer Solution A: Weighed 3.0 g acrylamide, 2.0 g acrylic acid, 0.002 g N,N-bisacrylamide, and 0.01 g potassium persulfate, dissolved in 50 mL water, and purged with nitrogen for 1 h to remove oxygen. Prepolymer Solution B: Weighed 6.78 g N-isopropylacrylamide, 1.5 g acrylic acid, 0.002 g N,N-bisacrylamide, and 0.02 g potassium persulfate, dissolved in 30 mL water, and purged with nitrogen for 1 h to remove oxygen.

[0059] 2. Formation of Hydrogel Film on Iron Wire. An iron wire having a diameter of 1.6 mm was suspensively immersed into a monomer prepolymer solution A, removed from the solution after reacted for 10 min (20 C.), immersed into a monomer prepolymer solution B, removed from the solution after reacted for 30 min (20 C.), and then immersed in ultrapure water to wash by soaking.

[0060] 3. Post-Enhancement Treatment of Hydrogel Film. The iron wire having layered gel layer grown thereon was immersed into a 0.06 mol/L Ca.sup.2+ solution and soaked for 5 h, drawn out from the solution to remove the iron wire template, then washed by soaking in pure water for 10 h, and thus a layered hollow hydrogel tube having a tube diameter of 2.0-3.0 mm and a tube wall thickness of 2000-3000 m was obtained.

[0061] 4. Description: a variety of hydrogel monomer prepolymer solutions were formulated according to the above steps, and a hydrogel tube having a multi-layer structure was prepared by a continuous immersion growth method.

EXAMPLE 9

Preparation of Radial-Gradient Acrylic Acid/Acrylamide Hydrogel Tube

[0062] 1. Formulation of Hydrogel Prepolymer Solution containing different concentrations of Acrylic Acid/Acrylamide. Prepolymer Solution A: Weighed 3.0 g acrylamide, 2.0 g acrylic acid, 0.003 g N,N-bisacrylamide, and 0.02 g potassium persulfate, dissolved in 10 mL water, and purged with nitrogen for 1 h to remove oxygen. Prepolymer Solution B: Weighed 3.0 g acrylamide, 2.0 g acrylic acid, 0.003 g N,N-bisacrylamide, and 0.02 g potassium persulfate, dissolved in 30 mL water, and purged with nitrogen for 1 h to remove oxygen. Prepolymer Solution C: Weighed 3.0 g acrylamide, 2.0 g acrylic acid, 0.003 g N,N-bisacrylamide, and 0.02 g potassium persulfate, dissolved in 50 mL water, and purged with nitrogen for 1 h to remove oxygen.

[0063] 2. Formation of Hydrogel Film on Iron Wire. An iron wire having a diameter of 1.6 mm was suspensively immersed into a monomer prepolymer solution A, removed from the solution after reacted for 10 min (20 C.), immersed into a monomer prepolymer solution B, removed from the solution after reacted for 20 min (20 C.), then immersed into a monomer prepolymer solution C, immersed in a 0.06 mol/L Fe.sup.3+ solution for 1-2 min to remove the iron wire template, and immersed in ultrapure water to wash by soaking, and thus a radial-gradient hydrogel tube was obtained.