KR101927637B1 - Biological machine using self-folding of multi-layered hydrogel and preparing method thereof - Google Patents

Abstract

The present invention relates to a bio-robot using multi-layer hydrogel self-folding and a method of manufacturing the bio-robot, and more particularly, to a bio-robot having a multi-layer hydrogel, Engineering and biomedical engineering.
In addition, the contractile force of differentiated canaliculus cells was 0.31 ± 0.32 μN by patterning Fibronectin in a circular pattern on the legs by microcontact printing (μCP) method, while Fibronectin in a linear pattern of 100 μm thickness The contractile force of the differentiated canaliculus cells is 1.12 ± 0.30 μN, and when they are patterned in the circular pattern, they can have strong contractile force of the canaliculus cells about 3.6 times. Therefore, A living body robot having a driving ability can be provided.

Description

TECHNICAL FIELD [0001] The present invention relates to a bio-robot using a multi-layer hydrogel self-folding method and a manufacturing method thereof,

The present invention relates to a bio-robot using multi-layered hydrogel self-folding and a method for manufacturing the same.

Research on a biological machine for realizing a mechanism of various living bodies by binding a biomaterial such as a living cell to soft materials having flexibility and sufficient strength is actively under way.

Recently, a study on sting ray-like robots made by cultivating cardiomyocytes in a body made of polymeric polydimethylsiloxane (PDMS) was introduced in Science magazine.

Genetic manipulation was applied to the myocardial cell to express the light-sensitive ion channel protein (ChR2), and it was designed so that the light stimulus could be redirected when given to the sting ray. In addition, studies using skeletal muscle cells have been actively carried out, and various forms of bio-robots have been developed using biomaterial complexes and three-dimensional printing methods.

Such cell-based bio-robots can be driven without internal power engines, and thus are attracting attention in a variety of applications where miniaturization is indispensable.

One of the most important factors in the development of biological robots is to improve the operating efficiency of the robot by optimizing the bonding force between the cells and the soft materials used in the robot body. Therefore, a hydrogel that can simulate the physical properties of the extracellular matrix (ECM) in vivo is emerging as a soft substance of the bio-robot body.

Hydrogels are generally designed to allow a hydrophilic polymer to form a 3D network structure and contain a large amount of water inside. Since its structure and properties are similar to extracellular matrix in vivo, it has been widely applied to various fields such as tissue engineering, drug delivery and food industry.

Controlling the type, concentration, and degree of cross-linking of the polymer can control the mechanical properties of the hydrogel to have a stiffness and swelling ratio suitable for the application cell or bio-robot design.

However, there is a problem that external power or internal power engine is required for driving and it is difficult to miniaturize accordingly, and conventional elastic materials for realizing flexible operation are difficult to manufacture with a size of several micro or less.

Accordingly, the multi-layer hydrogel based self-converting bio-robot has not been widely used in the field of drug delivery, tissue engineering, environmental engineering, and biomedical engineering.

Korean Patent Publication No. 2013-0043488 (March 30, 2013).

The present invention relates to a bio-robot capable of self-transformation using a multilayer hydrogel and a method of designing the bio-robot. The leg portion of the bio-robot is a multi-layer hydrogel containing temperature, pH, or light- , It is possible to control the curvature of the leg part by self-folding by controlling the temperature, pH, or the degree of introduction of the light-sensitive polymer, react with myoblasts without external energy supply, The purpose of the present invention is to provide a living body robot for exercise.

In order to accomplish the above object, the present invention provides a method of manufacturing a semiconductor device comprising a plurality of spaced apart temperature, pH, or light sensitive hydrogel layers; And a base hydrogel layer laminated on the plurality of temperature, pH, or light-sensitive hydrogel layers, wherein the plurality of temperature, pH, or light-sensitive hydrogel layers are patterned with fibronectin Wherein the multi-layer hydrogel is a multi-layer hydrogel.

The present invention also provides a method for preparing a photoresist composition, which comprises preparing a solution of a precursor for preparing a photoresist, a pH or a photoresponsive hydrogel by adding an acrylic monomer, a temperature, a pH, or a photosensitive monomer to a solvent and then adding a UV initiator; Dissolving an acrylic monomer in a solvent and adding a crosslinking agent to prepare a precursor solution for preparing a base hydrogel; Preparing a plurality of temperature, pH, or light-sensitive hydrogel layers by photopolymerizing the temperature, pH, or precursor solution for preparing a light-sensitive hydrogel on a cover glass patterned with a plurality of distances of five-necked nectin; And photopolymerizing the precursor solution for preparing a base hydrogel on the plurality of temperature, pH, or light-sensitive hydrogel layers to prepare a base hydrogel layer.

The present invention also provides a method of manufacturing a semiconductor device comprising a plurality of spaced apart temperature, pH, or light sensitive hydrogel layers; And a base hydrogel layer laminated on the plurality of temperature, pH, or light sensitive hydrogel layers, wherein the plurality of temperature, pH, or light sensitive hydrogel layers are patterned with fibronectin Wherein the curved shape is a curved shape having a radius of curvature by controlling temperature, pH, or light, and provides a bio-robot using the multilayer hydrogel self-folding.

The present invention can be utilized in various fields such as drug delivery, tissue engineering, environmental engineering, and biomedical engineering by designing a leg portion of a bio-robot having various curvature radii using a multi-layer hydrogel of a three-dimensional structure.

In addition, the contractile force of differentiated canaliculus cells was 0.31 ± 0.32 μN by patterning Fibronectin in a circular pattern on the legs by microcontact printing (μCP) method, while Fibronectin in a linear pattern of 100 μm thickness The contractile force of the differentiated canaliculus cells is 1.12 ± 0.30 μN, and when they are patterned in the circular pattern, they can have strong contractile force of the canaliculus cells about 3.6 times. Therefore, A living body robot having a driving ability can be provided.

Brief Description of the Drawings Figure 1 is a production flow diagram of a bio-robot including differentiation of a C2H12 myoblast with a multilayer hydrogel containing temperature sensitivity;
2 is a view showing a self-folding phenomenon of a hydrogel composed of two layers having different swelling ratios;
FIG. 3 is a graph showing the relationship between the concentration of the NIPAM monomer and the NIPAM monomer, which is a temperature-sensitive monomer, in a concentration of 10 wt% (w / v) based on the volume of deionized water as a solvent, (●: 25 ° C, ■: 37 ° C) and (▲) represents the swelling degree of the hydrogel prepared only with the AAm monomer;
4 is a view showing the radius of curvature of the multilayer hydrogel of the present invention;
5 is a view showing alignment of canalicular cells of a leg portion of a living body robot according to the present invention; And
FIG. 6 is a diagram showing a prototype of a bio-robot according to the present invention, which is a self-folding multi-layer hydrogel, and a physical property test result thereof.

Hereinafter, a bio-robot using the multi-layer hydrogel self-folding according to the present invention and a method for manufacturing the same will be described in detail.

The inventors of the present invention have found that a multi-layer hydrogel-based bio-robot can be utilized in the field of drug delivery, tissue engineering, environmental engineering, and biomimetic engineering by optimizing the driving ability of the multi-layer hydrogel.

The present invention provides a process for the preparation of a composition comprising a plurality of distant temperature, pH, or light sensitive hydrogel layers; And a base hydrogel layer laminated on the plurality of temperature, pH, or light-sensitive hydrogel layers, wherein the plurality of temperature, pH, or light-sensitive hydrogel layers are patterned with fibronectin Wherein the multi-layer hydrogel is a multi-layer hydrogel.

The temperature, pH, or light-sensitive hydrogel layer may be formed of a thermosensitive polymer, a pH-sensitive polymer, or a light-sensitive polymer grafted to a polyacrylic polymer, but is not limited thereto.

The temperature-sensitive polymer may be any one of poly (N-isopropylacrylamide) and poly (N, N-dimethyl acrylamide), but is not limited thereto.

The pH-sensitive polymer may be any one selected from the group consisting of methacrylic acid-methyl methacrylate copolymer, methacrylic acid-methyl acrylate copolymer, and methacrylic acid-methyl acrylate-methyl methacrylate copolymer But is not limited thereto.

The light-sensitive polymer may be selected from the group consisting of poly (2,2-dimethoxy nirobenzyl methacrylate-r-methyl methacrylate-r-poly (ethylene glycol) methacrylate) r-methyl methacrylate-r-poly (ethylene glycol) methacrylate (PDMP).

The base hydrogel layer may be made of a polyacrylic polymer, but is not limited thereto.

The plurality of temperature, pH, or light-sensitive hydrogel layers and the base hydrogel layer may have an average thickness of 80 to 120 탆, but are not limited thereto.

The present invention also provides a method for preparing a photoresist composition, which comprises preparing a solution of a precursor for preparing a photoresist, a pH or a photoresponsive hydrogel by adding an acrylic monomer, a temperature, a pH, or a photosensitive monomer to a solvent and then adding a UV initiator; Dissolving an acrylic monomer in a solvent and adding a crosslinking agent to prepare a precursor solution for preparing a base hydrogel; Preparing a plurality of temperature, pH, or light-sensitive hydrogel layers by photopolymerizing the temperature, pH, or precursor solution for preparing a light-sensitive hydrogel on a cover glass patterned with a plurality of distances of five-necked nectin; And photopolymerizing the precursor solution for preparing a base hydrogel on the plurality of temperature, pH, or light-sensitive hydrogel layers to prepare a base hydrogel layer.

The temperature sensitive monomer may be any of N-isopropylacrylamide or N, N-dimethyl acrylamide, but is not limited thereto.

The pH-sensitive monomer may be at least two selected from the group consisting of methacrylic acid, methyl methacrylate, and methyl acrylate, but is not limited thereto.

The light sensitive monomer may be two or more selected from the group consisting of 2,2-dimethoxynitrobenzyl methacrylate, methyl methacrylate, and poly (ethylene glycol) methacrylate, but is not limited thereto.

The acrylic monomer may be at least one selected from the group consisting of methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-hydroxyethyl methacrylate, acrylic acid, acrylamide, (N-isopropylacrylamide), but is not limited thereto.

The step of preparing the temperature, pH, or precursor solution for preparing a light-sensitive hydrogel comprises fixing the acrylic monomer, the temperature, the pH, or the photosensitive monomer to 10 wt% (w / v) To 8 wt% (w / v), and a temperature, pH, or 2 to 8 wt% (w / v) of a photosensitive monomer.

The step of preparing the precursor solution for preparing a base hydrogel may be a step of dissolving 8 to 10% by weight (w / v) of an acrylic monomer based on the volume of the solvent, but is not limited thereto.

The step of preparing the temperature, pH, or light-sensitive hydrogel layer and the step of preparing the base hydrogel layer may be performed using a 3D printing technique, but the present invention is not limited thereto.

The present invention also provides a method of manufacturing a semiconductor device comprising a plurality of spaced apart temperature, pH, or light sensitive hydrogel layers; And a base hydrogel layer laminated on the plurality of temperature, pH, or light sensitive hydrogel layers, wherein the plurality of temperature, pH, or light sensitive hydrogel layers are patterned with fibronectin Dimensional hydrogel self-folding, which is a curved type having a curvature radius by controlling temperature, pH, or light.

Hereinafter, a bio-robot using multi-layer hydrogel self-folding according to the present invention and a method for manufacturing the same will be described in more detail with reference to the following examples. However, the present invention is not limited by these examples.

Example 1 Preparation of a Three-Dimensional Multi-Layer Hydrogel

1. Preparation of Precursor Solution for the Preparation of Thermosensitive Hydrogels

The total concentration of acrylamide (Sigma, hereinafter 'AAm') monomer and isopropylacrylamide (Sigma, hereinafter, 'NIPAM') monomer was adjusted to 10% by weight (w / v) based on the volume of deionized water as a solvent , And a first hydrogel pre-polymer solution was prepared by adding 8 wt% (w / v) of AAm monomer and 2 wt% (w / v) of NIPAM monomer based on the volume of deionized water as a solvent .

Hydroxy-1- [4- (2-hydroxyethoxy) phenyl] -2-methyl-1- (2-hydroxyethyl) -thiophene as a UV initiator, based on the volume of dimethyl sulfoxide A UV initiator solution was prepared by adding 10 wt% (w / v) propanone (Irgacure 2959, Sigma).

A precursor solution for the preparation of a temperature-sensitive hydrogel was prepared by adding 0.2 wt% (w / v) of a UV initiator solution to the second hydrogel pre-polymer solution based on the volume of the first hydrogel pre-polymer solution.

2. Preparation of precursor solution for preparing base hydrogel

A second hydrogel pre-polymer solution was prepared by adding 10 wt% (w / v) of AAm monomer based on the volume of deionized water as a solvent and dissolving.

Then, by adding 2.0% by weight (w / v) of methylene bisacrylamide (N, N'-methylenebisacrylamide, Sigma, hereinafter referred to as MBA) as a crosslinking agent on the basis of the volume of the second hydrogel- A precursor solution for preparing a gel was prepared.

3. Manufacture of multilayer hydrogel using 3D printer

Thereafter, the precursor solution for producing a base hydrogel and the precursor solution for preparing a temperature-sensitive hydrogel were respectively photopolymerized by a bottom-up method to prepare a multilayer hydrogel.

Specifically, a precursor solution for producing a thermosensitive hydrogel was photopolymerized according to an image file designed with a CAD (CAD) on a cover glass patterned with Fibronectin using a DLP 3D printer (SPACE D, 3D Factory) The temperature sensitive hydrogel was polymerized.

The temperature-sensitive hydrogel is composed of a temperature-sensitive polymer, poly-NIPAM, grafted to poly-AAm.

Thereafter, a precursor solution for producing a base hydrogel was photopolymerized in the same manner as above to polymerize a base hydrogel layer having a thickness of 100 탆 on a temperature-sensitive hydrogel layer to prepare a three-dimensional multi-layer hydrogel.

Example 2 Preparation of a Three-Dimensional Multi-Layer Hydrogel

The total concentration of AAm monomer and NIPAM monomer was fixed at 10 wt% (w / v) based on the volume of deionized water as a solvent, and 6 wt% of the AAm monomer (w / v) as a volume of deionized water as a solvent and NIPAM A three-dimensional multi-layered hydrogel was prepared under the same conditions as in Example 1, except that 4 wt.% (W / v) of monomer was added and dissolved to prepare a first hydrogel pre-polymer solution.

Example 3 Preparation of a Three-Dimensional Multi-Layer Hydrogel

The total concentration of AAm monomer and NIPAM monomer was fixed to 10% by weight (w / v) based on the volume of deionized water as a solvent, and 4% by weight (w / v) of AAm monomer based on the volume of deionized water as a solvent and NIPAM A three-dimensional multi-layer hydrogel was prepared under the same conditions as in Example 1, except that 6 wt% (w / v) monomer was added and dissolved to prepare a first hydrogel pre-polymer solution.

<Example 4> Production of a multi-layer hydrogel having a three-dimensional structure

Based on the volume of deionized water as a solvent, the total concentration of the AAm monomer and the NIPAM monomer was fixed at 10 wt% (w / v), 2 wt% of the AAm monomer (w / v) A three-dimensional multi-layer hydrogel was prepared under the same conditions as in Example 1, except that the first hydrogel pre-polymer solution was prepared by adding 8 wt% (w / v) of a monomer and dissolving the monomer.

Example 5 Preparation of a Three-Dimensional Multi-Layer Hydrogel

Except that 9 wt% (w / v) of AAm monomer was added and dissolved to prepare a second hydrogel pre-polymer solution based on the volume of deionized water as a solvent. Layered hydrogel of the three-dimensional structure was prepared under the same conditions.

Example 6 Preparation of a Three-Dimensional Multi-Layer Hydrogel

The total concentration of AAm monomer and NIPAM monomer was fixed at 10 wt% (w / v) based on the volume of deionized water as a solvent, and 6 wt% of the AAm monomer (w / v) as a volume of deionized water as a solvent and NIPAM A three-dimensional multi-layer hydrogel was prepared under the same conditions as in Example 5, except that 4 wt.% (W / v) of monomer was added and dissolved to prepare a first hydrogel pre-polymer solution.

Example 7 Preparation of a Three-Dimensional Multi-Layer Hydrogel

The total concentration of AAm monomer and NIPAM monomer was fixed to 10% by weight (w / v) based on the volume of deionized water as a solvent, and 4% by weight (w / v) of AAm monomer based on the volume of deionized water as a solvent and NIPAM A three-dimensional multi-layered hydrogel was prepared under the same conditions as in Example 5, except that 6 wt.% (W / v) of monomer was added and dissolved to prepare a first hydrogel pre-polymer solution.

Example 8 Preparation of a Three-Dimensional Multi-Layer Hydrogel

Based on the volume of deionized water as a solvent, the total concentration of the AAm monomer and the NIPAM monomer was fixed at 10 wt% (w / v), 2 wt% of the AAm monomer (w / v) A three-dimensional multi-layered hydrogel was prepared under the same conditions as in Example 5 except that the first hydrogel pre-polymer solution was prepared by adding 8 wt% (w / v) of a monomer and dissolving the monomer.

Example 9 Preparation of a Three-Dimensional Multi-Layer Hydrogel

Except that 8% by weight (w / v) of AAm monomer was added and dissolved to prepare a second hydrogel pre-polymer solution based on the volume of deionized water as a solvent. Layered hydrogel of the three-dimensional structure was prepared under the same conditions.

Example 10 Preparation of a Three-Dimensional Multi-Layer Hydrogel

The total concentration of AAm monomer and NIPAM monomer was fixed at 10 wt% (w / v) based on the volume of deionized water as a solvent, and 6 wt% of the AAm monomer (w / v) as a volume of deionized water as a solvent and NIPAM A three-dimensional multi-layered hydrogel was prepared under the same conditions as in Example 9, except that 4 wt.% (W / v) of the monomer was added and dissolved to prepare a first hydrogel pre-polymer solution.

Example 11 Preparation of a Three-Dimensional Multi-Layer Hydrogel

The total concentration of AAm monomer and NIPAM monomer was fixed to 10% by weight (w / v) based on the volume of deionized water as a solvent, and 4% by weight (w / v) of AAm monomer based on the volume of deionized water as a solvent and NIPAM A three-dimensional multi-layered hydrogel was prepared under the same conditions as in Example 9, except that 6 wt.% (W / v) monomer was added and dissolved to prepare a first hydrogel pre-polymer solution.

Example 12 Preparation of a Three-Dimensional Multi-Layer Hydrogel

Based on the volume of deionized water as a solvent, the total concentration of the AAm monomer and the NIPAM monomer was fixed at 10 wt% (w / v), 2 wt% of the AAm monomer (w / v) A three-dimensional multi-layer hydrogel was prepared under the same conditions as in Example 9, except that the first hydrogel pre-polymer solution was prepared by adding 8 wt% (w / v) of a monomer and dissolving the monomer.

Example 13: Design of a living body robot

A bio-robot capable of self-conversion was designed using a three-dimensional multi-layer hydrogel prepared according to Examples 1 to 12.

1 (a) to 1 (d), the cells are in a curvature-free form in order to uniformly sow and settle the cells. When the operating temperature is reached (see FIG. 1 (f) (Fig. 1 (e)). Thereafter, it was inverted so as to be able to drive (see Fig. 1 (f)).

The multi-layer hydrogel of a three-dimensional structure has a 3D network structure and can contain a large amount of moisture therein. It can have three-dimensional structure composed of two layers of legs and a single layer of the body, linearly patterning adhesive protein fibronectin to attach muscle roots to legs, and inducing differentiation into root canal cells do.

The biological robot can be manufactured by inducing the self-folding of the three-dimensional multi-layer hydrogel at the stimulation temperature (37 ° C).

A thermosensitive hydrogel was prepared on a patterned coverglass of two leg portions having a thickness of 100 占 퐉, a length of 3 mm and a width of 1.5 mm (see Fig. 1 (a)).

Thereafter, a second hydrogel layer was prepared with polyacrylamide alone (Fig. 1 (b)) with a thickness of 100 占 퐉 for the leg portion and 200 占 퐉 for the body portion.

Self-folding of the multilayer hydrogel was induced at a stimulation temperature (37 ° C) after seeding of C2C12 myofibroblasts on a three-dimensional multilayer hydrogel at room temperature (25 ° C) (see FIG. 1 (f) .

After the cultivation of C2C12 myofibroblast, the multilayer hydrogel portion of the three-dimensional structure at the stimulation temperature (37 DEG C) is shaped as shown in Fig. 6 (a) by self-folding. As shown in Fig. 6 (b), the root canal cells were arranged in accordance with the pattern shape.

Experimental Example 1 Multilayer hydrogel analysis

The weight (W _s ) of the three-dimensional multi-layer hydrogel was determined by immersing the multi-layer hydrogel of the three-dimensional structure prepared according to Examples 1 to 12 in distilled water for at least 12 hours and sufficiently swollen, (W _d ) after drying for at least 6 hours at room temperature, and the swelling ratio (Q _m ) was calculated as shown in the following formula (1).

[Formula 1]

FIG. 2 illustrates the self-folding phenomenon of a hydrogel composed of two layers having different swelling ratios. As shown in the formula 1, the swelling ratio indicates the extent to which the hydrogel contains water and swells. When there is no difference in swelling ratio at room temperature (25 ° C), when the swelling ratio difference occurs at the stimulation temperature (37 ° C), the multi-layer hydrogel of three-dimensional structure is curved by self-folding.

FIG. 3 is a graph illustrating the effect of the present invention on fixing the total concentration of the AAm monomer and the NIPAM monomer as a temperature-sensitive polymer at a concentration of 10 wt% (w / v) based on the volume of deionized water as a solvent and changing the content of the NIPAM monomer And the swelling ratio of the prepared multi-layer hydrogel of the three-dimensional structure is shown.

Specifically, referring to FIG. 3, it can be seen that as the content of NIPAM monomer increases, the temperature sensitivity of the hydrogel also increases. This is because the hydrogel shrinks at the stimulation temperature (37 ° C) above the LCST because the low critical solution temperature (LCST) of the polymerized poly-NIPAM is 32 ° C.

Therefore, it is possible to control the swelling ratio of the three-dimensional multi-layer hydrogel by fixing the total concentration of the AAm monomer and the temperature-sensitive polymer monomer NIPAM and changing the content of the temperature-sensitive monomer.

The thermosensitive hydrogel layer, which is the bottom layer of the three-dimensional multi-layer hydrogel, is a mixture of AAm monomer and NIPAM monomer and is temperature-sensitive because the temperature-sensitive polymer poly-NIPAM is grafted to poly-AAm , And the top layer, the base hydrogel layer, is a three-dimensional multi-layer hydrogel prepared by cross-linking AAm monomers alone. At this time, the desired curvature of the multi-layer hydrogel by self- The composition ratio of each layer is important.

For example, a temperature-sensitive hydrogel polymerized with a precursor solution for preparing a temperature-sensitive hydrogel containing 4 wt% (w / v) of AAm monomer and 6 wt% (w / v) of NIPAM monomer (content ratio 4: In the case of a three-dimensional multi-layer hydrogel composed of a layer (lower layer) and a base hydrogel layer (upper layer) polymerized with a precursor solution for producing a base hydrogel including 10 wt% (w / v) 3) and a sufficient swelling ratio difference (1405-1236 = 169) to self-fold at stimulation temperature (37 ° C).

However, in this case, a swelling ratio difference (1386-1312 = 74) occurs even at room temperature (25 ° C), resulting in a problem of having curvature rather than a flat three-dimensional multi-layer hydrogel at room temperature (25 ° C).

Therefore, in order to design a hydrogel having a swelling ratio suitable for the upper layer, the swelling ratio was measured while varying the concentration of the AAm monomer.

Referring to FIG. 3, it can be seen that the swelling ratio increases when the concentration of the AAm monomer is decreased.

Specifically, the swelling ratio of the base hydrogel layer (upper layer) prepared as a precursor solution for producing a base hydrogel containing 9 wt% (w / v) of AAm monomer alone is about 1390, which is suitable for selection as an upper layer Able to know.

In order to predict the self-folding degree of the three-dimensional multi-layer hydrogel prepared according to Examples 1 to 12, a bimetallic strip curvature equation was applied to calculate the curvature radius r) was calculated.

[Formula 2]

In Eq. 2, E ₁ and E ₂ are the elastic moduli of the multi-layered hydrogel layers, t ₁ and t ₂ are the thicknesses of the respective sides, and Δε is the elastic modulus of the multilayered hydrogel Layer expansion ratio (S).

The mechanical properties of the three-dimensional multi-layer hydrogel prepared according to Examples 1 to 12 were measured using a universal testing machine (UTM, DrTech).

For the compressive strength measurement, the compressive strength was measured by standardizing the 3 - dimensional multi - layer hydrogel with a diameter of 8 mm and a height of 1 mm. Universal material testing machine was set value of the same applies to the measurement distance test rate of 10%, a test speed of 0.5 mm / min, and the load range of 1.0 kg _f.

Using the equation 2, the curvature radius r of the multi-layer hydrogel can be calculated.

Specifically, a temperature-sensitive hydrogel layer polymerized with a precursor solution for preparing a temperature-sensitive hydrogel including 4 wt% (w / v) AAm monomer and 6 wt% (w / v) NIPAM monomer (content ratio 4: (A lower layer) and a base hydrogel layer (upper layer) polymerized with a precursor solution for producing a base hydrogel including 9 wt% (w / v) of AAm monomer alone (Example 7 (K = 1 / r = 0.021 mm ^-1 ) with a radius of curvature of about 47.0 mm at room temperature (25 ° C).

However, since the compressive strength of each layer is 35 kPa (E ₁ ), 60 kPa (E ₂ ), and the expansion ratio is 0.159 (S ₁ ) and 0.210 (S ₂ ) at the stimulation temperature (37 ° C) 5.3 mm, and the leg portion of the living body robot has an appropriate curvature. The experimental measured curvature value is about 6.3 mm as shown in Figure 4 (4).

However, when using a precursor solution for the production of a temperature-sensitive hydrogel comprising 2 wt% (w / v) AAm monomer and 8 wt% (w / v) NIPAM monomer (content ratio 2: 8) At the stimulation temperature (37 ° C), the curvature radius is less than 0.5 mm (critical curvature: the radius of curvature of the hydrogel with 3 mm length is completely spherical), so that the multi-layer hydrogel of the three- (See FIG. 4).

Therefore, it has been confirmed that various self-conversion devices can be designed by controlling the compositions of the hydrogel layers or locally hydrogels constituting the multilayered structure.

&Lt; Experimental Example 2 >

Patterned hydrogel was prepared to confirm the driving ability of the three - dimensional multi - layer hydrogel according to the degree of alignment of canalicular cells.

Circular patterns (diameter: 500 μm) and linear patterns (thickness: 500 μm, and 100 μm) were prepared with polydimethylsiloxane (DOW CORNING, hereinafter referred to as "PDMS") stamps using a soft lithography technique.

To attach myoblasts to a three-dimensional multi-layer hydrogel, 0.2 mg / ml of fibronectin (Sigma, hereinafter referred to as 'Fn'), an adhesive protein from human plasma, was added to a polyethylene glycol- acryl, 5000 g / mol, Laysan Bio, Inc.) 5.0 mg / ml was added to synthesize the Fn-linker solution.

The prepared Fn-linker solution was poured onto the PDMS stamp, and after 2 hours had elapsed, the remaining solution was removed and the PDMS stamp was placed on a cover glass (18 x 18 mm, Marienfeld) to transfer the pattern to the cover glass.

Thereafter, a cover glass prepared by pretreating with a pretreatment solution prepared by adding 3- (trimethoxysilyl) propyl methacrylate (Sigma, 0.4%) to acetic acid was prepared.

The hydrogel solution was placed on a cover glass on which the pattern was transferred, and covered with a pre-treated cover glass. The pretreatment cover glass used was used to position the pattern on the hydrogel surface.

Bovine serum (FBS) and 10% fetal bovine serum (FBS) were added to DMEM medium (Dulbecco's modified eagle medium, Biowest, hereinafter referred to as 'DMEM') in 75 cm ² flasks The cells were cultured in a 5% CO ₂ environment at 37 ° C using a culture medium supplemented with 100% penicillin-streptomycin (100 ×, Biowest, hereinafter referred to as 'P / S').

The cultured myoblasts were dispensed on the surface of the temperature-sensitive hydrogel layer patterned at a concentration of 5 x 10 &lt; ⁴ &gt; per 40 [mu] l and cultured for 7 days. To induce differentiation into canaliculus cells on the 6th day of culture, the culture medium was replaced with DMEM medium supplemented with 10% horse serum (BiHest, hereinafter referred to as 'HS') and 1% P / S. The culture was replaced every two days and the behavior of cells was observed with an optical microscope (Nikon Eclipse TS100).

To confirm the driving ability of the three - dimensional multi - layer hydrogel according to the degree of alignment of canalicular cells, a biologically patterned hydrogel was prepared.

As shown in FIG. 5 (a), Fn (4.6 × 10 ^-9 g / μm ² ) was patterned using a micro-contact printing (μCP) (Thickness: 500 탆, and 100 탆), respectively, on a cover glass.

The precursor solution for producing a base hydrogel was polymerized by polymerizing a precursor solution for preparing a temperature-sensitive hydrogel on a cover glass to polymerize a hydrogel layer (lower layer) having a thickness of 100 탆. The precursor solution for preparing a base hydrogel was polymerized by the above- Layered hydrogel of a three-dimensional structure was prepared by polymerizing a base hydrogel layer having a thickness of 100 mu m.

When C2C12 myoblasts were cultured in the patterned hydrogel, it was confirmed that they formed cell clusters in the same pattern as the pattern (see Fig. 5 (b)). On the 6th day of culture, the cells proliferate and become full in each pattern. From this time, the C2C12 myofibroblasts differentiate into root canal cells under the differentiation culture medium (see Fig. 5 (c)).

It is generally known that the degree of alignment of cells and tissues in the body such as nerve, myocardium, skeletal muscle, cornea, and blood vessel tissue has a great influence on its function. In particular, the degree of cell alignment in the skeletal muscle is essential to maximize tissue contractile force. Therefore, in the present invention, the degree of alignment of canalicular cells according to the pattern was confirmed.

As can be seen from the fluorescence image of FIG. 5 (c), only 31% of the canalic cells having an angle of deviation of less than 20 deg. The canaliculus cells differentiated in the linear pattern (thickness: 500 μm) slightly increased to 47%.

However, the canalicule differentiated from the linear pattern (thickness: 100 ㎛) improved the degree of alignment to as much as 91% of the total number of canaliculus cells with angular deviation of less than 20 °. This result corresponds to the previous result that the patterned extracellular matrix exhibiting anisotropy affects the structure and differentiation of the cytoskeleton.

<Experimental Example 3> Immunostaining

The myofibroblasts were dispensed into the multilayer hydrogel, washed twice with phosphate buffered saline (PBS) buffer solution 10 days later, and resuspended in 4% (v / v) form for 10 minutes at room temperature (25 ° C) Fixation with aldehyde solution.

The cells were treated with 0.2% (v / v) Triton-X 100 (Triton-X 100, Sigma) solution for 10 minutes to enhance cell permeability.

Cells were blocked with 1% (w / v) bovine serum albumin (Sigma, hereinafter 'BSA') solution for 30 minutes and then washed again with PBS buffer.

The cells were then treated with anti-myosin heavy chain (MF-20) at 4 ° C for 12 hours and then incubated with anti-mouse IgG (Invitrogen) at 37 ° C, Phialoidin (Sigma), 4,6-diamidino-2-phenylindole (Sigma, hereinafter referred to as &quot; FITC &quot;) tagged with fluorescein isothiocyanate DAPI ') for 12 hours.

The stained cells were observed using a fluorescent microscope (Nikon Eclipse Ti) and images were analyzed with Image J software.

<Experimental Example 4> Driving of a biological robot

Electrostimulation was performed at 1 Hz to 20 V using an electric applicator (AGF3011C, Tektronics) in a 6-well plate equipped with electrodes, and the contraction activity of the canaliculus cells was synchronized and synchronized with electrical stimulation.

The contraction and relaxation processes of the three-dimensional multilayer hydrogel by electric stimulation were observed through a stereoscope (Olympus SZ61).

Electrical stimulation at 20 V at 1, 2, and 5 Hz shrinks the canaliculus cells on average 1.01, 2.03, and 4.97 times per second.

The contractile force was measured as shown in Fig. 6 (d) by applying electrical stimulation to the multi-layer hydrogel into which the root canal was introduced at 20 V and 1 Hz.

[Formula 3]

In Equation 3, F denotes the contraction force of the canalicular cells, k _h denotes the stiffness of the multilayer hydrogel, and δ denotes the distance difference of the hydrogel vertex when the contraction state is reached from the relaxation state do.

[Formula 4]

The strength of the multilayer hydrogel is determined by the compressive strengths (E ₁ and E ₂ ), the thicknesses (t ₁ , t ₂ ), and the hydrogel layer (upper layer) of the temperature-sensitive hydrogel layer (lower layer) and the base hydrogel layer Can be obtained through the length (L) and the width (w).

The temperature-sensitive hydrogel layer (lower layer) had a density of 63 × 10 ³ N / m ² at room temperature (25 ° C.) 35 from the magnetic pole temperature ^{(37 ℃) × 10 3 N} / m has a compression strength of ^2, the base hydrogel layer (upper layer) is 60 × 10 ³ has a compression strength N / m ² (see Fig. 6 (e)) .

The k _h value of the three-dimensional multi-layer hydrogel is 0.0068 N / m at room temperature (25 ° C) and 0.0050 N / m at stimulation temperature (37 ° C), respectively. The degree of shrinkage by electrical stimulation was measured according to the pattern type, and the shrinkage force was calculated by the equation (4) and shown in FIG. 6 (f).

The contraction force of the canaliculus cells differentiated by the circular pattern (diameter: 500 ㎛) was 0.31 ± 0.32 μN, while the contraction force of the canaliculus cells differentiated into the linear pattern (thickness: 100 ㎛) was 1.12 ± 0.30 μN, I was able to confirm that it was strong.

It can be seen that when normalized by the cell number per unit area introduced according to the pattern, the shrinking force is about 5.67 times stronger.

In this way, the result of measuring the mechanical force generated by the canalic cells introduced into the hydrogel can be utilized not only in the biological robot driving research but also in the actual skeletal muscle simulation research.

The self-folding phenomenon of the three-dimensional multi-layer hydrogel applied to the present invention and the bio-robot movement due to the cancellous cell contraction can be applied to various types of actuating devices and bio-microelectromechanical systems (bioMEMS) It is expected.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is to be understood that various modifications and changes may be made without departing from the scope of the appended claims.

The present invention was made by the task No. NRF-2014R1A1A1005710 under the support of the Ministry of the Future Creation Sciences of the Republic of Korea. The research institute of the above-mentioned subject is Korea Research Foundation and the name of the research project is "basic research project / Research (Type 1) ", the project title is" Biomimetic Chameleon Nanotransporter Fabrication and Application ", and the main organization is Soongsil University Industry-Academic Collaboration Foundation, Research Period 2014.05.01. ~ 2017.04.30.

Claims (16)

A plurality of spaced temperature, pH, or light sensitive hydrogel layers; And
And a base hydrogel layer laminated on the plurality of temperature, pH, or light-sensitive hydrogel layers,
The plurality of temperature, pH, or light-sensitive hydrogel layers may be formed,
A multi-layer hydrogel of three-dimensional structure, characterized by being patterned with fibronectin. The method according to claim 1,
The temperature, pH, or light-sensitive hydrogel layer may be,
A multi-layer hydrogel of three-dimensional structure, characterized in that the temperature-sensitive polymer, the pH-sensitive polymer, or the light-sensitive polymer is grafted to the polyacrylic polymer. The method of claim 2,
The temperature-
A multi-layered hydrogel of three-dimensional structure, characterized in that it is any one of poly (N-isopropylacrylamide) or poly (N, N-dimethyl acrylamide). The method of claim 2,
The pH-
Wherein the copolymer is any one selected from the group consisting of a methacrylic acid-methyl methacrylate copolymer, a methacrylic acid-methyl acrylate copolymer, and a methacrylic acid-methyl acrylate-methyl methacrylate copolymer. Multilayer hydrogel of dimensional structure. The method of claim 2,
The light-
(2,2-dimethoxy nirobenzyl methacrylate-r-methyl methacrylate-r-poly (ethyleneglycol) methacrylate) [poly (2,2-dimethoxy nitrobenzyl methacrylate- r-poly (ethylene glycol) methacrylate (PDMP). The method according to claim 1,
Wherein the base hydrogel layer comprises:
A multi-layer hydrogel having a three-dimensional structure, characterized by comprising a polyacrylic polymer. The method according to claim 1,
The plurality of temperature, pH, or light-sensitive hydrogel layers and base hydrogel layers may be,
A multi-layer hydrogel of three-dimensional structure, characterized in that the average thickness is 80 to 120 탆. Preparing a precursor solution for preparing a temperature, a pH, or a light-sensitive hydrogel by adding an acrylic monomer, a temperature, a pH, or a photosensitive monomer to the solvent and then adding a UV initiator;
Dissolving an acrylic monomer in a solvent and adding a crosslinking agent to prepare a precursor solution for preparing a base hydrogel;
Preparing a plurality of temperature, pH, or light-sensitive hydrogel layers by photopolymerizing the temperature, pH, or precursor solution for preparing a light-sensitive hydrogel on a cover glass patterned with a plurality of distances of five-necked nectin; And
Photopolymerizing the precursor solution for preparing a base hydrogel on the plurality of temperature, pH, or light-sensitive hydrogel layers to prepare a base hydrogel layer
Wherein the multi-layer hydrogel is a three-dimensional structure. The method of claim 8,
The temperature-
N, N-dimethylacrylamide, N-isopropylacrylamide or N, N-dimethylacrylamide. The method of claim 8,
The pH-
Wherein the hydrophilic polymer is at least two selected from the group consisting of acrylic acid, methacrylic acid, methyl methacrylate, and methyl acrylate. The method of claim 8,
The photo-
Wherein the polymer is at least two selected from the group consisting of 2,2-dimethoxynitrobenzyl methacrylate, methyl methacrylate, and poly (ethylene glycol) methacrylate. The method of claim 8,
The acrylic monomer may contain,
Acrylates such as methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-hydroxyethyl methacrylate, acrylic acid, acrylamide, and N-isopropylacrylamide ). &Lt; / RTI &gt; A method for preparing a multi-layer hydrogel of a three-dimensional structure, comprising the steps of: The method of claim 8,
The step of preparing the temperature, pH, or precursor solution for preparing a photosensitive hydrogel may include:
(W / v) and a temperature, pH, or light sensitive monomer (s) in a total amount of 10% (w / v) 2 to 8 wt% (w / v) is added to the aqueous solution. The method of claim 8,
Preparing the precursor solution for preparing a base hydrogel,
(W / v) of an acrylic monomer in an amount of 8 to 10% by weight based on the volume of the solvent. The method of claim 8,
The step of preparing the temperature, pH, or light-sensitive hydrogel layer and the step of preparing the base hydrogel layer,
Wherein the method comprises using a 3D printing technique. A plurality of spaced temperature, pH, or light sensitive hydrogel layers; And
And a base hydrogel layer laminated on the plurality of temperature, pH, or light-sensitive hydrogel layers,
The plurality of temperature, pH, or light-sensitive hydrogel layers may be formed,
It is patterned with fibronectin,
Wherein the curved shape is a curved shape having a radius of curvature by controlling temperature, pH, or light, and a multi-layer hydrogel self-folding structure using a three-dimensional structure.

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