CN114835862A - A hydrogel tissue-engineered labral scaffold and its photocuring 3D printing preparation method, and photosensitive resin - Google Patents

Abstract

The invention discloses a high-strength anti-swelling hydrogel tissue engineering labral support, a preparation method for photocuring 3D printing, and a photosensitive resin. The raw material components of the photosensitive resin used for printing the bracket are calculated in parts by mass, and the contents are as follows: polyurethane methacrylate emulsion: 10-50 parts, water-soluble photo-curable monomer 10-30 parts, oil-soluble photo-curable monomer 10-30 parts parts, 10-30 parts of sulfonic acid group-containing photocurable monomer, and 0.1-5 parts of photoinitiator. The printed hydrogel scaffold was immersed in a zirconium ion solution for post-processing to obtain a high-strength anti-swelling hydrogel scaffold. The hydrogel labral support of the present invention has a porous structure and has excellent mechanical properties. . The results of animal in vivo experiments show that the hydrogel labral scaffold has the functions of protecting articular cartilage and promoting cartilage regeneration and repair.

Description

A kind of hydrogel tissue engineering labral scaffold and its photocuring 3D printing preparation method, photosensitive resin

technical field

The invention belongs to the technical field of tissue engineering, and in particular relates to a high-strength anti-swelling hydrogel tissue engineering labral support, a preparation method for photocuring 3D printing, and a photosensitive resin.

Background technique

The acetabular labrum is a fibrocartilaginous structure attached to the acetabular rim and is connected to the transverse acetabular ligament at the acetabular notch to form a complete annular structure. Acetabular labral tear is the most common hip injury, and can be found in 90% of hip arthroscopy procedures [Arthroscopy, 2005, 21, 1496-1504]. one of the common reasons. The acetabular labrum has the function of stabilizing the hip joint and regulating synovial fluid balance [Am J Sport Med, 2013, 41, 1750-1756]. Due to the special tissue structure of the acetabular labrum, there is no nerve and lymphatic system, and only the peripheral 1/3 has blood supply, so the labrum itself lacks effective repair ability, and it is difficult to recover after injury. The injury of the acetabular labrum can lead to instability of the hip joint and uneven distribution of synovial fluid in the joint, which reduces the hydrostatic pressure of synovial fluid in the joint cavity and increases the internal stress of the hip joint, thereby accelerating the aging and degeneration of the hip joint. , eventually forming osteoarthritis. It will not only cause long-term hip pain in patients, but also lead to symptoms such as mechanical locking in daily life, and may be accompanied by a certain degree of limitation of joint mobility. For athletes, acetabular labrum injuries can affect their training and competition, significantly reduce their performance levels, and eventually lead to the end of their sports careers [Am J Sport Med, 2013, 41, 444-460]; for non-athletic groups , its damage will cause joint dysfunction, affecting daily life and work, and can lead to severe osteoarthritis and even joint disability in the long run. It can be seen that further research on acetabular labrum injury has very important clinical significance.

The current treatment methods for acetabular labral injury mainly include labral resection, labral suture, and labral reconstruction. In the early postoperative period after labrumectomy, the patient's pain can be significantly relieved, but the partial absence of the labrum can affect the integrity of the labrum, thereby significantly affecting its physiological function. Studies have shown that even a small portion of the labrum is removed, resulting in a substantial loss of its physiological function and a more than 50% reduction in the ability to regulate fluid pressure conduction within the joint. Labral suture also has certain limitations. Since only the peripheral 1/3 of the acetabular labrum is rich in blood supply, the labrum can be healed only after the basal suture is sutured. The poor self-repair ability of the acetabular labrum limits the clinical application of labral suture repair. Labrum reconstruction, as an emerging surgical method for the treatment of acetabular labral injury, can protect the cartilage at the defect site very well. At present, autologous tendon transplantation is commonly used in clinical practice, that is, the autologous tendon is trimmed into a cylindrical shape and fixed in the missing part of the labrum with thread anchors to replace the labrum tissue. Clinical studies confirmed that the functional score of patients was partially improved after labrum reconstruction with autologous tendon. However, labral reconstruction surgery still suffers from pain at the site of autologous tendon extraction and limited access. Tissue engineering technology provides a good choice for the further development of the current labral reconstruction surgery, so as to solve the shortcomings of the existing surgical methods. The biocompatible bioscaffold material is made as a graft, and it is implanted into the tissue defect site to repair the defect of the tissue or even the organ, so as to replace the defective tissue to exert its biological function. The ideal bioscaffold material should have the following characteristics: 1. It has a certain initial strength and good mechanical properties, and is close to the mechanical strength of the natural labral tissue, the maximum tensile strength should be in the range of 4-12 MPa, and the tensile elasticity The modulus is in the range of 26-30 MPa; 2. It has good histocompatibility and less rejection; 3. Porous structure, repair cells can enter the gaps of repair materials, so that stem cells can adhere, proliferate and differentiate. However, current related studies have not found an ideal tissue engineering material for labral tissue repair.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a high-strength anti-swelling hydrogel tissue-engineered labral support and a preparation method thereof by photocuring 3D printing.

The tissue engineered labrum prepared by the invention has good biocompatibility, and the in vivo experiment proves that it has good in vivo stability, and the prepared labrum support has mechanical properties similar to the natural labrum. In addition, the present invention adopts photocuring 3D printing with the highest printing accuracy, and the prepared labral support has a smooth surface, and can customize a labral support with a specific three-dimensional structure and a porous structure.

The light-curing 3D printing preparation method of the high-strength anti-swelling hydrogel tissue engineering labral stent provided by the present invention comprises the following steps:

1) Prepare a photosensitive resin, the raw material components of the photosensitive resin are as follows in parts by mass:

Waterborne polyurethane (meth)acrylate emulsion 10 to 50 parts

10～30 parts of water-soluble photocurable monomer

Oil-soluble photocurable monomer 10～30 parts

10～30 parts of photocurable monomer containing sulfonic acid group

Photoinitiator 0.1 to 5 parts;

2) Perform photocuring 3D printing on the photosensitive resin in step 1) to obtain a labrum model blank;

3) The labrum model green body is immersed in a zirconium ion solution for post-processing, and finally a high-strength anti-swelling hydrogel tissue-engineered labral scaffold is obtained.

In step 1) of the above method, the polyurethane (meth)acrylate emulsion is firstly reacted with diisocyanate and hydroxyl-terminated polyol and diol with hydrophilic group or by diisocyanate and hydroxyl-terminated polyol. It reacts with a polyol containing a hydrophilic segment to obtain an isocyanate group-terminated prepolymer; then reacts with a hydroxyl-containing (meth)acrylate to prepare a polyurethane (meth)acrylate resin, which is then emulsified to prepare a water-based polyurethane (Meth)acrylate emulsion.

Wherein, the diisocyanate is selected from at least one of hydrogenated phenylmethane diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate.

The hydroxyl-terminated polyol is selected from at least one of polyether polyol, polyester polyol, and polyolefin polyol.

According to an embodiment of the present invention, the polyether polyol is selected from at least one of polyethylene glycol, polypropylene glycol, and polytetrahydrofuran glycol.

According to an embodiment of the present invention, the polyester polyol is selected from the group consisting of polycaprolactone diol, polylactic acid diol, polyethylene adipate diol, and polybutylene adipate diol. at least one.

According to an embodiment of the present invention, the polyolefin polyol is selected from polybutadiene diols.

According to an embodiment of the present invention, the hydroxyl-terminated polyol has a number average molecular weight of 1000-10000 g/mol.

The diol with a hydrophilic group is selected from one of 2,2-dimethylolpropionic acid and N-methyldiethanolamine.

The hydrophilic segment-containing polyol is selected from the group consisting of polyethylene glycol and polyethylene glycol-polypropylene glycol block copolymer.

The hydroxyl-containing (meth)acrylate is selected from at least one of hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate.

The water-based polyurethane (meth)acrylate emulsion can be specifically prepared according to a method comprising the following steps:

S1: In the presence of a catalyst, diisocyanate is mixed with a hydroxyl-terminated polyol, a diol with a hydrophilic group or a polyol containing a hydrophilic segment and an organic solvent, and a stepwise addition polymerization reaction occurs to obtain an isocyanate-terminated polyol. Terminated polyurethane resin;

S2: react the above-prepared isocyanate group-terminated polyurethane resin with a hydroxyl-containing (meth)acrylate, and add a polymerization inhibitor during the reaction to obtain water-based polyurethane (meth)acrylate;

S3: Emulsify the water-based polyurethane (meth)acrylate prepared above to obtain a water-based polyurethane (meth)acrylate emulsion with a solid content of 10-30% (specifically, 25%), and the emulsion particle size is 20-200 nm ( preferably 20 to 60 nm).

According to an embodiment of the present invention, the catalyst is a tertiary amine (such as triethylenediamine, bis(dimethylaminoethyl) ether) or an organometallic catalyst (such as stannous octoate, n-butyltin laurate, carboxylate) bismuth acid);

According to an embodiment of the present invention, the organic solvent is selected from at least one of acetone and tetrahydrofuran;

According to an embodiment of the present invention, the polymerization inhibitor is selected from at least one of hydroquinone and p-methoxyphenol;

According to an embodiment of the present invention, in the step S1, the amount of the catalyst used is 200-600 ppm; the reaction temperature of the polymerization reaction is 50-100°C, and the reaction time is 1-12 h;

According to an embodiment of the present invention, in the step S2, the amount of the polymerization inhibitor used is 50-1000 ppm; the reaction temperature of the reaction is 50-100°C, and the reaction time is 1-12 h;

The molar ratio of the diisocyanate, the hydroxyl-terminated polyol, the diol with a water-based group or the polyol containing a hydrophilic segment, and the hydroxyl-containing (meth)acrylate is 1: (0.3-0.5): (0.3-0.5): (0.4-0.8).

In the present invention, the water-soluble photocurable monomer is selected from at least one of acrylamide, N-isopropylacrylamide, acrylic acid, methacrylic acid, and N-vinylpyrrolidone;

In the present invention, the oil-soluble photocurable monomer is selected from hydroxyethyl acrylate, isobornyl acrylate, 2-phenoxyethyl acrylate, acrylonitrile, butyl acrylate, methyl methacrylate, 1, At least one of 6-hexanediol diacrylate, propylene glycol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, and pentaerythritol tetraacrylate;

The photocurable monomer containing sulfonic acid group is selected from 2-acrylamide-2-methylpropanesulfonic acid, sodium p-styrene sulfonate, sodium vinyl sulfonate, potassium 3-sulfopropyl acrylate , at least one of carrageenan;

The photoinitiator is selected from (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, (2 , at least one of ethyl ,4,6-trimethylbenzoyl)phosphonate, benzophenone, isopropylthioxanthone, and 2,4-dimethylthioxanthone.

In the above method step 1), the preferred raw material components of the photosensitive resin are as follows in parts by mass:

Waterborne polyurethane (meth)acrylate emulsion 30 to 50 parts

20～30 parts of water-soluble photocurable monomer

Oil-soluble photocurable monomer 10～25 parts

10～25 parts of photocurable monomer containing sulfonic acid group

1 to 2 parts of photoinitiator

According to an embodiment of the present invention, the parts by mass of each component in the raw material of the photosensitive resin are: water-based polyurethane (meth)acrylate emulsion-1 40 parts, acrylamide 20 parts, isobornyl acrylate 19 parts, 20 parts of 2-acrylamido-2-methylpropanesulfonic acid and 1 part of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

According to an embodiment of the present invention, the parts by mass of each component in the raw material of the photosensitive resin are: waterborne polyurethane (meth)acrylate emulsion-145 parts, acrylamide 20 parts, isobornyl acrylate 22 parts, 11 parts of 2-acrylamido-2-methylpropanesulfonic acid, and 2 parts of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide.

According to an embodiment of the present invention, the parts by mass of each component in the raw material of the photosensitive resin are: water-based polyurethane (meth)acrylate emulsion-2 45 parts, N-isopropylacrylamide 20 parts, acrylic isopropyl acrylate 10 parts of bornanyl ester, 24 parts of potassium salt of 3-sulfopropyl acrylate, 1 part of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

According to an embodiment of the present invention, the parts by mass of each component in the raw material of the photosensitive resin are: water-based polyurethane (meth)acrylate emulsion-2 34 parts, N-isopropylacrylamide 30 parts, acrylonitrile 10 parts, 25 parts of sodium vinylsulfonate, 1 part of (2,4,6-trimethylbenzoyl) diphenylphosphine oxide.

The present invention also provides a preparation method of the above-mentioned photosensitive resin.

The preparation method of the above-mentioned photosensitive resin provided by the present invention includes the following steps: weighing water-based polyurethane (meth)acrylate emulsion, water-based photocurable monomer, oil-soluble photocurable monomer, photoinitiator and light absorber in proportion , poured into a blender, and prepared by mixing with an ultrasonic cell disintegrator in the dark.

In step 3) of the above method, the post-processing process is as follows: the labral support blank prepared by printing is soaked in a zirconium ion solution for three days, and then placed in deionized water for three days. The concentration of zirconium ions in the zirconium ion solution is 0.01-0.3 mol/L.

The method further includes the step of sterilizing the obtained high-strength anti-swelling hydrogel tissue-engineered labral scaffold.

The high-strength anti-swelling hydrogel tissue-engineered labral stent prepared by the above method also belongs to the protection scope of the present invention.

In addition, the photosensitive resin provided above also belongs to the protection scope of the present invention.

The present invention also provides the application of the above-mentioned photosensitive resin.

The application of the photosensitive resin provided by the present invention is its use in photocuring 3D printing, especially in photocuring three-dimensional molding (SLA), digital light processing photocuring 3D printing (DLP), continuous liquid interface (CLIP) printing use in.

And, the application of the photosensitive resin in the preparation of a hydrogel tissue engineering labral scaffold.

Compared with the prior art, the present invention has the following advantages:

(1) The hydrogel labral stent provided by the present invention has excellent mechanical properties, anti-swelling properties and porous structure, and its mechanical properties are similar to the natural labrum;

(2) The hydrogel labral stent provided by the present invention has good biocompatibility and in vivo stability;

(3) The preparation of the hydrogel labral support of the present invention adopts the method of photocuring 3D printing, the printing precision is high, and its three-dimensional structure can be precisely controlled.

Description of drawings

Figure 1 shows a labral support model fabricated by digital light processing (DLP) 3D printing.

FIG. 2 is the mechanical stretching curve of the labral support and the natural labrum printed in Examples 1-4.

Fig. 3 is a photograph of the labral stent implanted in the porcine acetabular joint of Example 1, and the MRI T2 image examination photograph 8 weeks after operation.

Figure 4 is an anatomical photo of the labral stent of Example 1 implanted in the porcine acetabular joint 8 weeks after the operation.

Fig. 5 is a HE-stained photo of the joint synovial tissue around the scaffold implanted in pigs.

Figure 6 shows the changes of the acetabulum and femoral head 8 weeks after the direct excision of the labrum of the pig.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited to the following embodiments. The methods are conventional methods unless otherwise specified. The raw materials can be obtained from open commercial sources unless otherwise specified.

Example 1

A kind of preparation of water-based polyurethane methacrylate emulsion, the concrete steps are as follows:

In a 1 L round bottom flask equipped with mechanical stirring, nitrogen introduction tube, thermometer and dropping funnel, add 22.2 g (0.1 mol) isophorone diisocyanate (IPDI) followed by 20.0 g (0.01 mol) polyhexanol. A mixture of lactone diol (molecular weight 2000), 40.0 g (0.02) polyethylene glycol (molecular weight 2000), 6.03 g (0.045 mol) 2,2-dimethylolpropionic acid and catalyst 0.04 g n-butyltin laurate Add dropwise to the there-necked flask, keep the temperature of the reaction system in the flask at 90 °C. After the dropwise addition, the mixture continued to react, tetrahydrofuran was added to the system to reduce the viscosity, and the degree of reaction was monitored by Fourier infrared. 0.05 mol) of hydroxyethyl methacrylate was added dropwise to the system, while maintaining the system temperature at 60 °C. After the dropwise addition is completed, the reaction is continued until the characteristic absorption peak of the isocyanate group in the infrared spectrum disappears completely, that is, the urethane acrylate is obtained. The temperature of the system was lowered to room temperature, triethylamine was added to neutralize the carboxyl group in the molecular chain, 284 g of deionized water was added dropwise under high-speed stirring (800 r/min), and the organic solvent was removed by distillation under reduced pressure. Aqueous polyurethane methacrylate emulsion-1 with a content of 25% (average particle size measured by dynamic light scattering is 45 nm).

Preparation of photosensitive resin for photocurable 3D printing hydrogel:

First, take by weighing the raw materials according to the formula ratio: the raw material components of the photosensitive resin are as follows in parts by weight:

Waterborne Polyurethane Methacrylate Emulsion - 1 40 parts

Acrylamide 20 servings

19 parts of isobornyl acrylate

2-Acrylamido-2-methylpropanesulfonic acid 20 parts

Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide 1 part

Then, each component was poured into a stirrer in sequence, and the photosensitive resin was obtained by an ultrasonic cell crusher under the condition of avoiding light.

Printing of the labral support:

The prepared photosensitive resin was introduced into the resin tank of the DLP 3D printing equipment for model printing. The printing parameters of the 3D printer were set according to the resin curing speed and depth, and a model with a smooth surface and high precision was obtained. After printing, the support was removed from the sample, placed in ethanol for sonication for 10 min, and then placed in a UV box for curing for 15 min to obtain a labral stent blank. After that, the labral stent blank was immersed in a zirconium ion solution (concentration 0.1 mol/L) for three days, and then in deionized water for three days. Finally, a 3D printed high-strength anti-swelling hydrogel labral stent was obtained.

Example 2

A kind of preparation of water-based polyurethane acrylate emulsion, the concrete steps are as follows:

In a 1 L round bottom flask equipped with mechanical stirring, nitrogen introduction tube, thermometer and dropping funnel, add 16.8 g (0.1 mol) hexamethylene diisocyanate (HDI), then 30.0 g (0.015 mol) polyhexanol A mixture of lactone diol (molecular weight 2000), 45.0 g (0.015 mol) polytetrahydrofuran diol (molecular weight 3000), 6.7 g (0.05 mol) 2,2-dimethylolpropionic acid and 0.02 stannous octoate dropwise Dropwise into the there-necked flask, keep the temperature of the reaction system in the flask at 90 °C. After the dropwise addition, the mixture continued to react, tetrahydrofuran was added to the system to reduce the viscosity, and the degree of reaction was monitored by Fourier transform infrared spectroscopy. 0.04 mol) of hydroxyethyl acrylate was added dropwise to the system while maintaining the system temperature at 55 °C. After the dropwise addition is completed, the reaction is continued until the characteristic absorption peak of the isocyanate group in the infrared spectrum disappears completely, that is, the urethane acrylate is obtained. The temperature of the system was lowered to room temperature, ammonia water was added to neutralize the amine groups in the molecular chain, 309 g of deionized water was added dropwise under high-speed stirring (800 r/min), and the organic solvent was removed by distillation under reduced pressure, and finally the solid content was obtained. It is a 25 % aqueous polyurethane methacrylate emulsion-2 (average particle size measured by dynamic light scattering is 58 nm).

Preparation of photosensitive resin for photocurable 3D printing hydrogel:

First, take by weighing the raw materials according to the formula ratio: the raw material components of the photosensitive resin are as follows in parts by weight:

Waterborne Polyurethane Acrylate Emulsion - 2 45 parts

Acrylamide 20 servings

22 parts of isobornyl acrylate

2-Acrylamido-2-methylpropanesulfonic acid 11 parts

(2,4,6-trimethylbenzoyl)diphenylphosphine oxide 2 parts

Then, each component was poured into a stirrer in sequence, and the photosensitive resin was obtained by an ultrasonic cell crusher under the condition of avoiding light.

Printing of the labral support:

The prepared photosensitive resin was introduced into the resin tank of the DLP 3D printing equipment for model printing. The printing parameters of the 3D printer were set according to the resin curing speed and depth, and a model with a smooth surface and high precision was obtained. After printing, the support was removed from the sample, placed in ethanol for sonication for 10 min, and then placed in a UV box for curing for 15 min to obtain a labral stent blank. After that, the labral stent blank was immersed in a zirconium ion solution (concentration 0.1 mol/L) for three days, and then in deionized water for three days. Finally, a 3D printed high-strength anti-swelling hydrogel labral stent was obtained.

Example 3

A kind of preparation of water-based polyurethane acrylate emulsion, the concrete steps are as follows:

In a 1 L round-bottomed flask equipped with mechanical stirring, nitrogen introduction tube, thermometer and dropping funnel, add 16.8 g (0.1 mol) hexamethylene diisocyanate (HDI) followed by 100.0 g (0.05 mol) polyethylene A mixture of diol (molecular weight 2000), 60.0 g (0.03 mol) polypropylene glycol (molecular weight 2000), and 0.02 g n-butyltin laurate was added dropwise to the three-necked flask, while the temperature of the reaction system in the flask was maintained at 90 °C. After the dropwise addition, the mixture continued to react, and the degree of reaction was monitored by Fourier infrared. When the infrared characteristic absorption peak of the isocyanate group was no longer reduced, 0.1 g of hydroquinone and 4.64 g (0.04 mol) of hydroxyethyl acrylate were added together. The mixture was added dropwise to the system while maintaining the system temperature at 55°C. After the dropwise addition is completed, the reaction is continued until the characteristic absorption peak of the isocyanate group in the infrared spectrum disappears completely, that is, the urethane acrylate is obtained. The temperature of the system was lowered to room temperature, 544 g of deionized water was added dropwise under high-speed stirring (800 r/min), and the organic solvent was removed by distillation under reduced pressure, and finally a water-based polyurethane acrylate emulsion-3 with a solid content of 25 % was obtained. (Dynamic light scattering test has an average particle size of 46 nm).

Preparation of photosensitive resin for photocurable 3D printing hydrogel:

First, take by weighing the raw materials according to the formula ratio: the raw material components of the photosensitive resin are as follows in parts by weight:

Waterborne Polyurethane Acrylate Emulsion - 3 45 parts

N-isopropylacrylamide 20 parts

Isobornyl Acrylate 10 parts

3-sulfopropyl acrylate potassium salt 24 parts

Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide 1 part

Then, each component was poured into a stirrer in sequence, and the photosensitive resin was obtained by an ultrasonic cell crusher under the condition of avoiding light.

Printing of the labral support:

The prepared photosensitive resin was introduced into the resin tank of the DLP 3D printing equipment for model printing. The printing parameters of the 3D printer were set according to the resin curing speed and depth, and a model with a smooth surface and high precision was obtained. After printing, the support was removed from the sample, placed in ethanol for 10 min of ultrasound, and then placed in a UV oven for 15 min of curing to obtain a labral stent blank. After that, the labral stent blank was soaked in a zirconium ion solution (concentration 0.1 mol/L) for three days, and then in deionized water for three days, and finally a 3D printed high-strength anti-swelling hydrogel labral stent was obtained.

Example 4

A kind of preparation of water-based polyurethane acrylate emulsion, the concrete steps are as follows:

In a 1 L round bottom flask equipped with mechanical stirring, nitrogen introduction tube, thermometer and dropping funnel, add 22.2 g (0.1 mol) isophorone diisocyanate (IPDI) followed by 40.0 g (0.04 mol) polyethylene A mixture of diol (molecular weight 1000), 75.0 g (0.015 mol) polyethylene glycol (molecular weight 5000), 60.0 g (0.03 mol) polycaprolactone diol (molecular weight 2000), 0.02 g n-butyltin laurate dropwise Dropwise into the there-necked flask, keep the temperature of the reaction system in the flask at 90 °C. After the dropwise addition, the mixture continued to react, and the degree of reaction was monitored by Fourier infrared. When the characteristic absorption peak of the isocyanate group was no longer reduced, 0.1 g of hydroquinone and 3.90 g (0.03 mol) of hydroxyethyl methacrylate were added to the mixture. The ester mixture was added dropwise to the system while maintaining the system temperature at 55°C. After the dropwise addition is completed, the reaction is continued until the characteristic absorption peak of the isocyanate group in the infrared spectrum disappears completely, that is, the urethane acrylate is obtained. The temperature of the system was lowered to room temperature, 603 g of deionized water was added dropwise under high-speed stirring (800 r/min), and the organic solvent was removed by distillation under reduced pressure, and finally an aqueous polyurethane acrylate emulsion-4 with a solid content of 25 % was obtained. (Dynamic light scattering test has an average particle size of 52 nm).

Preparation of photosensitive resin for photocurable 3D printing hydrogel:

First, take by weighing the raw materials according to the formula ratio: the raw material components of the photosensitive resin are as follows in parts by weight:

Waterborne Polyurethane Acrylate Emulsion - 4 34 parts

N-isopropylacrylamide 30 parts

Acrylonitrile 10 parts

25 parts of sodium vinyl sulfonate

(2,4,6-trimethylbenzoyl)diphenylphosphine oxide 1 part

Then, each component was poured into a stirrer in sequence, and the photosensitive resin was obtained by an ultrasonic cell crusher under the condition of avoiding light.

Printing of the labral support:

The prepared photosensitive resin was introduced into the resin tank of the DLP 3D printing equipment for model printing. The printing parameters of the 3D printer were set according to the resin curing speed and depth, and a model with a smooth surface and high precision was obtained. After printing, the support was removed from the sample, placed in ethanol for sonication for 10 min, and then placed in a UV box for curing for 15 min to obtain a labral stent blank. After that, the labral stent blank was immersed in a zirconium ion solution (concentration 0.1 mol/L) for three days, and then in deionized water for three days. Finally, a 3D printed high-strength anti-swelling hydrogel labral stent was obtained.

Comparative Example 1

Preparation of photosensitive resin for photocurable 3D printing hydrogel:

First, take by weighing the raw materials according to the formula ratio: the raw material components of the photosensitive resin are as follows in parts by weight:

45 parts of water-based polyurethane acrylate emulsion-1 (same as Example 1)

Acrylamide 44 servings

Isobornyl Acrylate 10 parts

(2,4,6-trimethylbenzoyl)diphenylphosphine oxide 1 part

Then, each component was poured into a stirrer in sequence, and the photosensitive resin was obtained by an ultrasonic cell crusher under the condition of avoiding light.

Printing of hydrogel samples:

The prepared photosensitive resin was introduced into the resin tank of the DLP 3D printing equipment for model printing. The printing parameters of the 3D printer were set according to the resin curing speed and depth, and a model with a smooth surface and high precision was obtained. After the printing was completed, the support was removed from the sample, placed in ethanol for sonication for 10 min, and then placed in a UV box for curing for 15 min to obtain a hydrogel scaffold.

Comparative Example 2

The hydrogel sample obtained in Comparative Example 1 was soaked in deionized water for three days to obtain a hydrogel sample after swelling equilibrium.

For the evaluation of the mechanical properties of the labral stents prepared in the above examples and comparative examples, the mechanical properties of the printed labral stents and hydrogel samples were evaluated according to the GB/T2567-2008 test standard, including tensile strength and elongation at break. The results are shown in Table 1.

Table 1

Table 1 shows the mechanical properties and water content results of the hydrogel samples prepared in Examples and Comparative Examples. The results of the examples show that the hydrogel has excellent mechanical properties and anti-swelling properties after the formation of ionic coordination bonds between sulfonic acid groups and zirconium ions. The hydrogel in the comparative example does not contain sulfonic acid groups. After soaking in deionized water, the hydrogel swells by 1.6 times, and the mechanical properties decrease significantly.

Figure 1 shows a labral support model fabricated by digital light processing (DLP) 3D printing.

FIG. 2 shows the mechanical tensile curves of the labral support and the natural labrum printed in Examples 1-4, and the tensile strength is similar to that of the natural labrum.

In vivo effect verification of labral stent:

After 6-month-old male pigs were anesthetized and skin sterilized, an S-shaped incision was made at the hip joint site. After the hip joint capsule was incised, the labrum was exposed, and a 1.5 cm-long lip defect was made with a scalpel. Afterwards, the hydrogel labral stent was implanted into the defect and fixed with sutures.

Figure 3 shows the implantation of the labral scaffold of Example 1 into the pig acetabular joint, and the MRI T2 image examination photograph 8 weeks after the operation. The figure shows (indicated by the arrow) that the labral scaffold is structurally intact in the joint space, and the articular cartilage is intact. No obvious damage was seen, and autologous tissue had grown around the stent.

Fig. 4 is implantation of the labral support of Example 1 into the pig acetabular joint, anatomical photos 8 weeks after the operation, no obvious osteoarthritis was found in the acetabulum and femoral head cartilage within 8 weeks after the operation, and the articular cartilage was in good condition. The hydrogel stent of the present invention plays a good role in protecting the articular cartilage.

Figure 5 is a HE staining photo of the joint synovium tissue around the stent. The results show that the synovium is in good condition and there is no obvious inflammatory reaction.

Figure 6 shows the direct excision of the labrum of the pig, and no autologous tissue growth was found in the acetabulum and femoral head 8 weeks after the operation.

The hydrogel tissue engineering labrum scaffold prepared by the invention has good biocompatibility and in vivo stability, its mechanical properties are similar to the natural labrum, and the printing precision is high, and the labrum with specific three-dimensional structure and porous structure can be customized bracket.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, and substitutions can be made in these embodiments without departing from the principle and spirit of the invention and variations, the scope of the present invention is defined by the appended claims with full equivalents.

Claims (10)

1. The photosensitive resin comprises the following raw materials in parts by weight: 10-50 parts of water-based polyurethane (methyl) acrylate emulsion, 10-30 parts of water-soluble photocuring monomer, 10-30 parts of oil-soluble photocuring monomer, 5-20 parts of sulfonic acid group-containing photocuring monomer and 0.1-5 parts of photoinitiator.

2. The photosensitive resin according to claim 1, wherein: the aqueous polyurethane (methyl) acrylate emulsion is prepared by reacting diisocyanate with hydroxyl-terminated polyol and dihydric alcohol with hydrophilic groups or polyol containing hydrophilic chain segments to obtain isocyanate-terminated prepolymer, then reacting with hydroxyl-containing (methyl) acrylate to prepare polyurethane methacrylate resin, and emulsifying to obtain aqueous polyurethane (methyl) acrylate emulsion;

the water-based light-cured monomer is at least one selected from acrylamide, N-isopropyl acrylamide, acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxyethyl methacrylate and N-vinyl pyrrolidone;

the oil-soluble light-cured monomer is at least one selected from isobornyl acrylate, 2-phenoxyethyl acrylate, acrylonitrile, butyl acrylate, methyl methacrylate, 1, 6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate and pentaerythritol tetraacrylate;

the light-cured monomer containing the sulfonic acid group is selected from at least one of 2-acrylamide-2-methylpropanesulfonic acid, sodium p-styrene sulfonate, sodium vinyl sulfonate, 3-sulfopropyl acrylate potassium salt and carrageenan;

the photoinitiator is selected from at least one of (2,4, 6-trimethylbenzoyl) diphenylphosphine oxide, phenyl bis (2,4, 6-trimethylbenzoyl) phosphine oxide, ethyl (2,4, 6-trimethylbenzoyl) phosphonate, benzophenone, isopropyl thioxanthone and 2, 4-dimethyl thioxanthone.

3. The photosensitive resin according to claim 2, wherein: the diisocyanate is at least one selected from hydrogenated phenyl methane diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate;

the hydroxyl-terminated polyol is selected from at least one of polyether polyol, polyester polyol and polyolefin polyol;

the dihydric alcohol with the hydrophilic group is selected from one of 2, 2-dimethylolpropionic acid and N-methyldiethanolamine;

the polyalcohol containing the hydrophilic chain segment is selected from at least one of polyethylene glycol and polyethylene glycol-polypropylene glycol block copolymer;

the (methyl) acrylic ester containing hydroxyl is selected from at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate and hydroxypropyl methacrylate.

4. The photosensitive resin according to claim 3, wherein: the polyether polyol is selected from at least one of polyethylene glycol, polypropylene glycol and polytetrahydrofuran glycol;

the polyester polyol is selected from at least one of polycaprolactone diol, polylactic acid diol, polyethylene glycol adipate diol and polybutylene adipate diol;

the polyolefin polyol is selected from polybutadiene diols;

the hydroxyl-terminated polyol has a number average molecular weight of 1000-10000 g/mol.

5. The photosensitive resin according to any one of claims 1 to 4, wherein: the waterborne polyurethane (methyl) acrylate emulsion is prepared by the following steps:

s1: in the presence of a catalyst, diisocyanate is mixed with hydroxyl-terminated polyol, dihydric alcohol with a water group or polyol containing a hydrophilic chain segment and an organic solvent to perform a stepwise addition polymerization reaction to obtain isocyanate-terminated polyurethane resin;

s2: reacting the prepared isocyanate group-terminated polyurethane resin with hydroxyl-containing (methyl) acrylate, and adding a polymerization inhibitor during the reaction to obtain waterborne polyurethane (methyl) acrylate;

s3: emulsifying the prepared waterborne polyurethane (methyl) acrylate to obtain a waterborne polyurethane (methyl) acrylate emulsion with the solid content of 15-30%.

6. The photosensitive resin according to claim 5, wherein: the catalyst is tertiary amine or organic metal catalyst;

the organic solvent is at least one of acetone and tetrahydrofuran;

the polymerization inhibitor is selected from at least one of hydroquinone and p-methoxyphenol;

in the step S1, the dosage of the catalyst is 200-600 ppm; the reaction temperature of the polymerization reaction is 50-100 ℃, and the reaction time is 1-12 h;

in the step S2, the using amount of the polymerization inhibitor is 50-1000 ppm; the reaction temperature is 50-100 ℃, and the reaction time is 1-12 h;

the molar ratio of the diisocyanate, the hydroxyl-terminated polyol, the dihydric alcohol with the water group or the polyol with the hydrophilic chain segment to the (methyl) acrylate with the hydroxyl is 1: (0.3-0.5): (0.3-0.5): (0.4-0.8).

7. The method for preparing the photosensitive resin of any one of claims 1 to 6, comprising the steps of: weighing the aqueous polyurethane (methyl) acrylate emulsion, the water-soluble photocuring monomer, the oil-soluble photocuring monomer, the sulfonic acid group-containing photocuring monomer and the photoinitiator according to the proportion, pouring the mixture into a stirrer, and uniformly mixing the mixture by an ultrasonic cell crusher under the condition of keeping out of the sun.

8. Use of a photosensitive resin of any one of claims 1-6 in the preparation of hydrogel-type tissue engineering labral scaffolds and other biomedical fields.

9. A method for preparing a photo-curing 3D printing of a hydrogel type tissue engineering labrum bracket comprises the following steps:

s1: photocuring 3D printing of the photosensitive resin of any one of claims 1-6 to give a labrum model blank;

s2: and soaking the labrum model blank in a zirconium ion solution for three days, and then placing the labrum model blank in deionized water for three days to obtain the hydrogel type tissue engineering labrum bracket.

10. A hydrogel-type tissue-engineering labral scaffold prepared by the method of claim 9.

Images