4D printing gel with customizable deformation and biocompatibility as well as preparation method and application of 4D printing gel

Abstract

The invention provides a 4D printing gel with customizable deformation and biocompatibility. The 4D printing gel is prepared by mixing an aqueous solution of nanocellulose crystals and an aqueous solution of gelatin. According to the composite hydrogel provided by the invention, the used raw materials, namely the nano cellulose crystal and the gelatin, are natural polymers, so that the composite hydrogel has good biological safety. Objects printed by adopting the composite hydrogel have high resolution, customizable shapes can be obtained through 3D printing of different shapes and paths, customizable deformation can be achieved along the printing paths, and good shape fidelity is achieved after drying deformation. Meanwhile, the raw materials belong to natural food sources, so that the prepared composite gel has good biocompatibility and no cytotoxicity, and can be used as a biological material.

Description

Technical Field

[0001] The present invention relates to the technical field of functional materials, and in particular to a 4D printing gel with customizable deformation and biocompatibility, and a preparation method and application thereof. Background Art

[0002] 4D printing technology adds a time dimension to 3D printing technology, allowing printed products to produce beneficial changes in color, shape, etc. as environmental parameters such as humidity and temperature change. Currently, 4D printing, as an emerging technology, has broad application prospects in the fields of biomedicine and bioengineering through customized design of materials that can respond to external stimuli.

[0003] Customizable responsive deformable materials are designed by adding particles that can be arranged in a direction to the gel. At present, the shear force is often used to induce the particles to produce a directional arrangement during the 3D printing process. By adjusting the arrangement of particles in different areas of the gel, the gel undergoes different changes and deformations when stimulated by external stimuli, thereby achieving customizable deformation. This also requires that the customizable directional deformable material has good shear thinning properties so that it can flow smoothly through the nozzle, and should have good viscoelasticity and shape fidelity so that it can be quickly solidified and formed after extrusion and can maintain its own structure for a long time. The application of customizable deformable materials in the biomedical field also requires good biocompatibility, so that the customizable deformable printing material will not be toxic to human tissue.

[0004] However, the materials commonly used in 4D printing still have the following problems: Gels with good biocompatibility cannot maintain good fidelity after printing due to weak cross-linking, and often do not have the ability to customize deformation. Gels with customizable deformation capabilities often use photoinitiators, polyacrylamide, etc. as cross-linking agents, which do not have good biocompatibility, restricting their application in the biomedical field. Summary of the invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a 4D printing gel with customizable deformation and biocompatibility and a preparation method and application thereof, which has customizable deformation, excellent shape fidelity and good biocompatibility and can be used for printing of biomaterials.

[0006] The invention provides a 4D printing gel with customizable deformation and biocompatibility, which is prepared by mixing an aqueous solution of nanocellulose crystals and an aqueous solution of gelatin.

[0007] The aqueous solution of nanocellulose crystals is a colloidal suspension of nanocellulose crystals prepared with water.

[0008] The diameter of the nanocellulose crystals is preferably 1-100 nm; more preferably 10-30 nm.

[0009] The concentration of the aqueous solution of nanocellulose crystals is preferably 2wt% to 10wt%, more preferably 6wt% to 10wt%, and further preferably 6wt% to 8wt%.

[0010] The aqueous solution of gelatin is a colloidal solution of gelatin prepared with water.

[0011] The concentration of the aqueous solution of gelatin is preferably 3 wt% to 6 wt%.

[0012] In the present invention, the gelatin is preferably type A gelatin.

[0013] The volume ratio of the aqueous solution of nanocellulose crystals to the aqueous solution of gelatin is preferably 3:1 to 6:1.

[0014] The 4D printing gel with customizable deformation and biocompatibility provided by the present invention has only nanocellulose crystals and gelatin as raw materials, and the solvent is water, and does not contain organic solvents, so it has better biocompatibility.

[0015] The present invention provides a method for preparing the above-mentioned 4D printed gel with customizable deformation and biocompatibility, comprising the following steps:

[0016] preparing a colloidal suspension of nanocellulose crystals in water;

[0017] Prepare a colloidal solution of gelatin using water;

[0018] The colloidal suspension of the nanocellulose crystals and the colloidal solution of gelatin are mixed to obtain a 4D printed gel with customizable deformation and biocompatibility.

[0019] Preferably, the mixing temperature is 45-65° C., and the mixing time is 1-3 h.

[0020] The present invention provides the use of the above-mentioned 4D printing gel with customizable deformation and biocompatibility as a 4D printing material.

[0021] The present invention has no special limitation on the printing process of the 4D printing material, and may be a printing method well known to those skilled in the art, including but not limited to injection printing, extrusion printing, etc.

[0022] Preferably, the extrusion parameters of the 4D printed gel with customizable deformation and biocompatibility are: nozzle diameter 0.28~0.42 mm, nozzle length 0.5~1.0 inch, extrusion pressure 0.26~0.30 MPa, and moving speed 8~12 mm / s.

[0023] Preferably, the printing parameters of the 4D printed gel with customizable deformation and biocompatibility are: printing spacing 1-3 mm, printing thickness 3-4 layers, and printing angle 0-90°.

[0024] The present invention provides a 4D printing material with customizable deformation and biocompatibility, which is obtained by 4D printing and drying the above-mentioned 4D printing gel with customizable deformation and biocompatibility.

[0025] Preferably, the drying temperature is 55-65° C., and the drying time is 45-60 min.

[0026] Compared with the prior art, the present invention provides a 4D printing gel with customizable deformation and biocompatibility, which is made by mixing an aqueous solution of nanocellulose crystals and an aqueous solution of gelatin. The composite hydrogel provided by the present invention uses raw materials, nanocellulose crystals and gelatin, which are both natural polymers and have good biosafety. Objects printed using the above composite hydrogel have a high resolution, can obtain customizable shapes through 3D printing of different shapes and paths, can achieve customizable deformation along the printing path, and have good shape fidelity after drying and deformation. At the same time, since the raw materials are from natural food sources, the prepared composite gel has good biocompatibility, no cytotoxicity, and can be used as a biomaterial. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The shear thinning property and viscoelastic linearity diagram of the composite gel prepared in Example 1;

[0028] Figure 2 This is an electron microscope image of the 3D printed four-leaf clover in Example 2 and its "blooming" after heating;

[0029] Figure 3 This is an electron microscope image of the 3D printed butterfly in Example 3 and its "wings spread" after heating. DETAILED DESCRIPTION

[0030] In order to further illustrate the present invention, the present invention is described in detail below in conjunction with embodiments. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than for limiting the claims of the invention.

[0031] All raw materials of the present invention have no particular limitation on their sources, and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0032] Example 1

[0033] Preparation of 4D printed gels with customizable deformation and biocompatibility:

[0034] (1) Nanocellulose crystals with a diameter of 30 nm were prepared into colloidal suspensions with mass fractions of 2%, 4%, 6%, 8%, and 10% in deionized water;

[0035] (2) Prepare a colloidal solution of gelatin with deionized water at a mass fraction of 4%;

[0036] (3) Mix the nanocellulose suspension and gelatin solution in a ratio of 4:1 to obtain a mixed gel.

[0037] Steady-state shear rheology and small amplitude oscillation scanning methods were used to detect the properties of the composite gel, such as Figure 1 As shown. Figure 1 It can be seen that the composite gel has good shear thinning properties and viscoelasticity.

[0038] Example 2

[0039] Preparation of 4D printed gels with customizable deformation and biocompatibility:

[0040] (1) Nanocellulose crystals with a diameter of 30 nm were prepared into a colloidal suspension with a mass fraction of 6% using deionized water;

[0041] (2) Prepare a colloidal solution of gelatin with deionized water at a mass fraction of 4%;

[0042] (3) The nanocellulose suspension and gelatin solution were mixed in a ratio of 4:1, the mixed gel solution was stirred at 55 °C for 2 h, and then loaded into a syringe;

[0043] (4) Set the printing parameters as follows: nozzle diameter 0.34 mm, nozzle length 1.0 inch, extrusion pressure 0.28 MPa, and moving speed 10 mm / s;

[0044] (5) After setting the print pattern to a four-leaf clover, use the gel described in (3) to print, set the print spacing to 2 mm, the print thickness to 4 layers, and the print angle to 45°;

[0045] (6) After printing, the printed object was dried at 55°C for 60 min to obtain a flat material in the shape of a four-leaf clover.

[0046] The above-mentioned flat material was heated at 65℃ for 1 h, and the 3D printed four-leaf clover "bloomed" after heating. Figure 2 shown.

[0047] Example 3

[0048] Preparation of 4D printed gels with customizable deformation and biocompatibility:

[0049] (1) Nanocellulose crystals with a diameter of 43 nm were prepared into a colloidal suspension with a mass fraction of 8% using deionized water;

[0050] (2) Prepare a colloidal solution of gelatin with deionized water at a mass fraction of 4%;

[0051] (3) The nanocellulose suspension and gelatin solution were mixed in a ratio of 4:1, the mixed hydrogel solution was stirred at 55 °C for 2 h, and then loaded into a syringe;

[0052] (4) Set the printing parameters as follows: nozzle diameter 0.34 mm, nozzle length 0.5 inches, extrusion pressure 0.26 MPa, and moving speed 12 mm / s;

[0053] (5) After setting the printing pattern to butterfly, print with the gel described in (3), set the printing spacing to 3 mm, the printing thickness to 3 layers, and the printing angle to 0°;

[0054] (6) After printing, the printed object is dried at 65°C for 45 min to obtain a butterfly-shaped flat material.

[0055] The above-mentioned flat material was heated at 65°C for 1 h, and the 3D printed butterfly "spread its wings" after heating. Figure 3 shown.

[0056] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A 4D printed gel with customizable deformation and biocompatibility, made by mixing an aqueous solution of nanocellulose crystals and an aqueous solution of gelatin.

2. The 4D printed gel with customizable deformation and biocompatibility according to claim 1, characterized in that: The diameter of the nanocellulose crystals is 1 to 100 nm; The concentration of the aqueous solution of nanocellulose crystals is 2wt% to 10wt%.

3. The 4D printed gel with customizable deformation and biocompatibility according to claim 1, characterized in that: The concentration of the gelatin aqueous solution is 3 wt% to 6 wt%; The gelatin is type A gelatin.

4. The 4D printed gel with customizable deformation and biocompatibility according to claim 1, characterized in that: The volume ratio of the aqueous solution of nanocellulose crystals to the aqueous solution of gelatin is 3:1-6:

1.

5. The method for preparing the 4D printing gel with customizable deformation and biocompatibility according to any one of claims 1 to 4, comprising the following steps: preparing a colloidal suspension of nanocellulose crystals in water; Prepare a colloidal solution of gelatin using water; The colloidal suspension of the nanocellulose crystals and the colloidal solution of gelatin are mixed to obtain a 4D printed gel with customizable deformation and biocompatibility.

6. The preparation method according to claim 5, characterized in that: The mixing temperature is 45-65° C., and the mixing time is 1-3 h.

7. Use of the 4D printing gel with customizable deformation and biocompatibility as claimed in any one of claims 1 to 4 as a 4D printing material.

8. The use according to claim 7, characterized in that: The extrusion parameters of the 4D printed gel with customizable deformation and biocompatibility are: nozzle diameter 0.28-0.42 mm, nozzle length 0.5-1.0 inch, extrusion pressure 0.26-0.30 MPa, and moving speed 8-12 mm / s; The printing parameters of the 4D printed gel with customizable deformation and biocompatibility are: printing spacing 1-3 mm, printing thickness 3-4 layers, and printing angle 0-90°.

9. A 4D printing material with customizable deformation and biocompatibility, obtained by 4D printing and drying the 4D printing gel with customizable deformation and biocompatibility as described in any one of claims 1 to 4.

10. The 4D printing material with customizable deformation and biocompatibility according to claim 9, characterized in that: The drying temperature is 55-65° C., and the drying time is 45-60 min.

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