Silk fibroin molded body and manufacturing method

Abstract

The present disclosure provides a fibroin molding element that can be easily molded without the hassle of lamination, and a molding element that is mainly composed of silk fibroin and has a bulk density of 0.70 g / cm. 3 ~1.20g / cm 3 The present invention provides a method for producing a fibroin molded article, characterized by:

Description

[Technical Field]

[0001] [Technical field]

[0002] This disclosure relates to a silk fibroin molding substrate and a method for manufacturing the same. [Background technology]

[0003] [Background technology]

[0004] International Patent Application Publication No. 2017 / 047503 provides a molded article obtained by filling a mold with a protein powder containing natural spider silk protein, which is silk fibroin, or polypeptides derived from natural spider silk protein, and heating and pressurizing it. [Overview of the project]

[0005] [Summary of Disclosure]

[0006] When using silk fibroin powder as a base material for molded bodies, it is prone to scattering and adhering to surrounding surfaces. This makes it difficult to fill the mold with a stable amount, resulting in inconsistent filling amounts, unstable dimensions of the molded body, or insufficient filling, which prevents sufficient pressure from being applied to the silk fibroin within the mold, leading to problems such as inadequate transfer of the mold's surface shape and reduced strength of the molded body.

[0007] This disclosure provides a stable moldable silk fibroin molding substrate and a method for manufacturing a molded silk fibroin article.

[0008] Specifically, in this disclosure, the bulk density is approximately 0.70 g / cm³. 3 ~1.20g / cm 3 The present invention provides a molding substrate containing silk fibroin as the main component. In one embodiment, the substrate has a thickness of about 100 μm or more. In another embodiment, the substrate has a β-sheet content of less than about 10%, and / or a moisture content of about 2 to about 15%.

[0009] In a further embodiment, the substrate may be cylindrical, polygonal, spherical, or hemispherical. In yet another embodiment, it may contain silk fibroin as the main component and have a bulk density of approximately 0.70 g / cm³. 3 ~Approximately 1.20g / cm 3 The present invention provides a packaged set of molding bodies containing multiple molding bodies. In a further embodiment, the set of bodies includes a package made of paper, resin, rubber, or metal.

[0010] In yet another embodiment, an aqueous solution of silk fibroin containing less than 10 g of silk fibroin is dispensed, this solution is freeze-dried, and the resulting freeze-dried material has a bulk density of approximately 0.70 g / cm³. 3 ~Approximately 1.20g / cm 3 A method for molding silk fibroin is provided, which includes compressing the compressed body until it reaches a certain state and then heating and pressurizing the compressed body.

[0011] In another embodiment of the molding method, the amount of solids in the dispensed aqueous solution is equal to or 1 / N of the weight of the molded body.

[0012] According to this disclosure, silk fibroin has a bulk density of approximately 0.70 g / cm³. 3 ~Approximately 1.20g / cm 3 Because it is compressed to this extent, compared to silk fibroin powder, scattering and adhesion to the surroundings are suppressed, and the amount of filling into the mold is constant. Also, because the amount of filling is constant, the dimensions of the molded body are constant, the transferability of the molded body to the mold shape is improved, and the decrease in the mechanical strength of the molded body is suppressed.

[0013] These and other embodiments, subjects, features, and advantages of this disclosure will become apparent upon reading the following detailed description of exemplary embodiments of this disclosure in conjunction with the accompanying drawings and the provided claims. [Brief explanation of the drawing]

[0014] [Brief description of the drawing]

[0015] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate various embodiments, objects, features, and advantages of the present disclosure.

[0016] [Figure 1] It is a schematic diagram of a mold for forming silk fibroin.

[0017] [Figure 2] It is a diagram showing a block for freeze-drying.

[0018] [Figure 3A] and [Figure 3B] It is a diagram showing a cross-section of the freeze-drying block of FIG. 2.

[0019] [Figure 4] It is a diagram showing components of a process for obtaining a silk fibroin forming body.

[0020] Throughout the drawings, unless otherwise specified, the same reference numerals and signs are used to indicate similar features, elements, components, or parts of the illustrated embodiments. Further, the present disclosure is described in detail with reference to the drawings, which is done in relation to exemplary embodiments for explanation. It is intended that changes and modifications can be made to the illustrated exemplary embodiments without departing from the true scope and spirit of the present disclosure defined by the appended claims. Further, each of the described embodiments can be manufactured or used in combination with any other described embodiment.

Mode for Carrying Out the Invention

[0021] [Detailed Description of Embodiments]

[0022] This disclosure describes several embodiments and relies on patents, patent applications, and other references for details known to those skilled in the art. Therefore, when a patent, patent application, or other reference is cited or repeated herein, it is understood that they are incorporated herein by reference in their entirety for all purposes, not just for the purpose of the described proposal.

[0023] The base material for the silk fibroin molded body of this embodiment contains silk fibroin and has a bulk density in the range of 0.70 g / cm[[ID=⑤]] 3 [[ID=⑥]]~1.20 g / cm[[ID=⑦]] 3 [[ID=⑧]]The base material for the molded body (forming base material) is a base material used when forming a functional solid material mainly composed of silk fibroin into a desired shape. [[ID=⑨]] [[ID=⑩]]

[0024] [[ID=⑪]] [[ID=⑫]]By using the protein composition as the base material for the molded body, the protein molded body of this embodiment can be formed. Specifically, by adjusting the bulk density to be in the range of 0.70 g / cm[[ID=⑬]] 3 [[ID=⑭]]~1.20 g / cm[[ID=⑮]] 3 [[ID=⑯]]Since the base material for the silk fibroin molded body has appropriate strength and weight, scattering and adhesion are suppressed. [[ID=⑰]] [[ID=⑱]]

[0025] [[ID=⑲]] [[ID=⑳]]Hereinafter, silk fibroin, adjustment of bulk density, and molding will be described. [[ID=㉑]] [[ID=㉒]]

[0026] [[ID=㉓]] [[ID=㉔]][Silk fibroin][[ID=㉕]] [[ID=㉖]]

[0027] [[ID=㉗]] [[ID=㉘]]Silk fibroin is a fibrous protein that can be extracted from cocoons and / or nests. The extraction of silk fibroin can be carried out, for example, by the method described in WO2006 / 101223. [[ID=㉙]] [[ID=㉚]]

[0028] [[ID=㉛]] [[ID=㉜]]Silk fibroin generally has the characteristic of a high proportion of glycine, alanine, serine, and tyrosine. Silk fibroin can exemplify silk fibroin derived from organisms classified into the order Lepidoptera, Hymenoptera, or Araneae. Also, it may be silk fibroin obtained by genetic recombination technology. [[ID=㉝]]

[0029] Furthermore, additives may be added to silk fibroin, provided that they do not impair its properties.

[0030] [Adjusting bulk density]

[0031] If the bulk density is low, the tablet compression strength will be low, and the tablets will easily break apart and scatter when placed in the mold. Therefore, the bulk density should be 0.70 g / cm³. 3 More than 0.90g / cm 3 Above, or 1.00 g / cm³ 3 The above is necessary. On the other hand, if the bulk density is too high, the surface transferability will deteriorate during molding, so the bulk density should be 1.20 g / cm³. 3 It must be less than 1.10 g / cm³. 3 It is desirable that the bulk density be less than [a certain value]. There are no particular restrictions on the method for adjusting the bulk density of silk fibroin, but examples include adjusting the bulk density by crushing and compressing the silk fibroin powder, or drying the silk fibroin aqueous solution before it is produced as powder or after the powder has been redissolved to create a low-bulk-density porous silk fibroin material, and then compressing this to the desired bulk density to obtain a molding base material.

[0032] The former method for adjusting bulk density will be explained.

[0033] Silk fibroin's bulk density decreases when it is crushed to reduce its particle size; therefore, the bulk density can be adjusted by controlling the particle size. Jet mills, pin mills, hammer mills, etc., can be used for crushing. Compression increases the bulk density of silk fibroin. The bulk density can be adjusted by controlling the compression pressure. Compression machines and tablet presses can be used for compression.

[0034] Next, we will explain the latter method for adjusting bulk density.

[0035] There are no particular limitations on the method for dissolving silk fibroin in water. For example, since silk fibroin has low solubility in water, one possible method is to dissolve silk fibroin in a high-concentration lithium bromide aqueous solution, then desalinate it by dialysis to prepare a silk fibroin aqueous solution.

[0036] There are no particular limitations on the method for drying an aqueous solution of silk fibroin, as long as the solvent can be removed without decomposing the silk fibroin. Examples include air drying, hot drying, vacuum drying, spray drying, and freeze-drying. The advantage of freeze-drying is that the decomposition of silk fibroin is suppressed because the solution is frozen at a low temperature and the solvent is removed by sublimation. For example, one method for forming silk fibroin involves dispensing an aqueous solution of silk fibroin containing less than 10 g of silk fibroin, freeze-drying the solution, and obtaining a bulk density of approximately 0.70 g / cm³. 3 ~Approximately 1.20g / cm 3The process includes compressing the resulting freeze-dried material and heating and pressurizing the compressed material until it reaches a certain consistency. This process can utilize blocks 31 and 32, as shown in Figure 2. Block 31 can be used to freeze-dry a single portion of the fibroin aqueous solution, while block 32 can be used to freeze-dry multiple portions of the silk fibroin aqueous solution simultaneously. Through-holes 33 in each of blocks 31 and 32 are configured to receive one or more portions of the fibroin aqueous solution before freezing. Cross-sectional views of blocks 31 and 32 are provided in Figures 3A and 3B. In Figure 3A, blocks 31 and 32 include through-holes 33 into which the silk fibroin aqueous solution 21 is injected. Member 34 acts as a stopper at one end of the through-hole 33, holding the silk fibroin aqueous solution within the through-hole 33. In Figure 3B, freeze-drying is performed, resulting in freeze-dried silk fibroin 22 remaining in the through-holes 33 of blocks 31 and 32. Member 34 is still present as a stopper at one end of the through-hole 33. Figure 4 shows the molding process for obtaining a moldable body. Freeze-dried silk fibroin 22 is introduced into a mold 35 having through holes and a member 36 for holding the introduced material inside the through holes. The bulk density of the introduced material is adjusted by compressing the freeze-dried silk fibroin 22 with a piston 37 to obtain a moldable body 24. The compression pressure is not limited, but may be, for example, 30 MPa.

[0037] In addition to bulk density, the structure of the silk fibroin molding substrate will be described from the viewpoint of tablet hardness. The tablet hardness of the silk fibroin molding substrate may be between 10 and 130. Within this range, it is possible to obtain the effects of this disclosure by preventing scattering when placed in the mold and ensuring good surface transferability. In further embodiments, the tablet hardness of the silk fibroin molding substrate may be between 20 and 120, or between 30 and 115.

[0038] In one embodiment, the moisture content after drying is approximately 2-15%, as this increases the fluidity during fibroin molding and improves surface transferability.

[0039] Since surface transferability deteriorates as β-sheet formation progresses after drying, in one embodiment, the β-sheet ratio is less than 10%.

[0040] Furthermore, when drying, it is desirable to divide the material into uniform liquid volumes, or to divide it into aqueous solutions in amounts equivalent to the amount of silk fibroin needed for one molding cycle, or 1 / N (where N is an integer), and then dry it. Generally, weighing liquids is more accurate than weighing powders, so dividing the aqueous solution into fixed-quantity portions and drying them allows for more accurate weighing than weighing after drying. To simplify weighing, N can typically be 2, 3, or 5 or less. It is also desirable that the weight of silk fibroin in the dissolved silk fibroin aqueous solution be around 10g or less.

[0041] The silk fibroin molding substrate can be formed into a cylindrical, polygonal prism, spherical, or hemispherical shape. This is because, when obtaining the silk fibroin molding substrate by adjusting the bulk density through compression, uniform pressure can be applied to the silk fibroin, and the hardness and other properties of the molding substrate can be maintained uniformly within the molding substrate. When uniaxial compression is performed to obtain the silk fibroin molding substrate, the shape of the molding substrate may be cylindrical. When performing uniaxial compression, certain conditions are provided so that the height (thickness) of the molding substrate is 3 times or less and 0.1 times or more the diameter (or width or length) for uniform compression. Furthermore, the height (thickness) of the silk fibroin molding substrate may be 1 mm or more. This is because if the silk fibroin molding substrate is too thin, there may be limitations on the shape of the molded product after using this substrate for molding. The thickness of the substrate may further be 1.5 mm or more, or 2.0 mm or more.

[0042] [Molding]

[0043] A silk fibroin molded body can be obtained by placing a silk fibroin molding material with adjusted bulk density into a mold and heating and pressurizing it. Figure 1 is a schematic diagram of an example of a mold that can be used for molding silk fibroin. The mold consists of a temperature-controllable member 3 with a through hole and upper and lower pistons 1 and 2. A silk fibroin molded body can be obtained by placing the silk fibroin molding material into member 3 and compressing it by moving the pistons 1 and 2 up and down.

[0044] The heating and pressurizing process can be performed at 70°C to 200°C or 100°C to 150°C. Below 70°C, the proteins will not integrate sufficiently, resulting in insufficient strength for the molded body. On the other hand, above 200°C, protein degradation will begin, potentially reducing strength. Pressurization can be performed at 10 MPa or higher. Below 10 MPa, the proteins will not integrate sufficiently, resulting in insufficient strength for the molded body. Pressurization may also be performed at 50 MPa or higher.

[0045] Furthermore, after reaching a predetermined pressure, the time for maintaining that pressure may be 0 to 60 minutes, or 10 to 30 minutes. Additionally, after removal from the mold, heat treatment may be performed at 70°C to 150°C. Heat treatment promotes crystallization, improving strength and dimensional stability.

[0046] [Measurement Method]

[0047] The measurement methods required for this disclosure are described below.

[0048] Bulk density was determined using the bead substitution method. Specifically, quartz sand (0.3-0.5 mm) whose weight had been measured beforehand was placed in a volumetric measuring instrument, and then silk fibroin was added to the instrument. The bulk density was estimated from the increase in the weight and volume of the instrument.

[0049] The hardness of the prepared tablets was measured using a load cell type tablet hardness tester (PC-30, Okada Seikou Co., Ltd.).

[0050] The β-sheet ratio was measured using FT-IR (Frontier MIR NIR / Spotlight 400, Perkin Elmer) over a range of 1500-1800 cm. -1 Measure the absorbance within the range of 1600-1650 cm -1 The peak wavelength N was read, and the β-sheet ratio was calculated using the formula in Equation 1.

[0051] Beta sheet ratio (%) = (1641-N) / 20 × 100 Equation 1

[0052] Equation 1 is used because the peak wavelength in the amorphous state is 1641 cm⁻¹. -1 Therefore, in the fully crystallized state, it is 1621 cm³. -1 This is because...

[0053] The flexural modulus was measured using an Instron universal testing machine (Model 5582, Instron Corporation). The distance between the three support points for three-point bending was fixed at 27 mm, and the measurement speed was set to 1 mm / min. The flexural modulus was determined from displacements (strains) ranging from 0.05% to 0.25%.

[0054] Surface roughness was measured using a surface roughness meter (SurfCorder SE3500, Kosaka Research Institute Co., Ltd.), and the ten-point average roughness Rzjis was measured in accordance with JIS B0601-1994.

[0055] [Examples]

[0056] [Example 1]

[0057] After washing the silkworm cocoons with water, they were boiled in a 0.02 mol / L sodium carbonate aqueous solution for 30 minutes to refine them. After drying, the refined silk fibroin was added to a 9.3 mol / L LiBr aqueous solution and dissolved by stirring at 60°C for 4 hours. Desalting was performed using a Sekisui Chemical dialysis flask 30 / 32 (molecular weight cutoff 12000-14000). The desalted fibroin aqueous solution was diluted with pure water to a concentration of 5%.

[0058] The obtained 5% fibroin aqueous solution was divided into 26.4 ml portions into containers, as shown in Figure 2. In Figure 2, reference numerals 31 and 32 indicate blocks for subsequent freeze-drying, respectively. Reference numeral 33 indicates a hole for injecting the silk fibroin aqueous solution.

[0059] The dispensed fibroin solution was freeze-dried using a freeze-dryer (FD-550P) manufactured by Tokyo Rikakikai Co., Ltd. (Figure 3). Figures 3A and 3B show cross-sectional views of the freeze-drying block shown in Figure 2, respectively. Reference numeral 21 indicates the silk fibroin aqueous solution before freeze-drying, and reference numeral 22 indicates the freeze-dried silk fibroin. Reference numeral 34 indicates the component for holding the fibroin solution in place. Under the freeze-drying conditions, the solution was frozen at -30°C, then the atmosphere was reduced in pressure, and the temperature was raised to -6°C for 100 hours of freeze-drying. The bulk density was measured to be 0.03 g / cm³. 3 That was the case.

[0060] Next, one portion of freeze-dried silk fibroin was placed into a mold having a cylindrical through-hole with a diameter of 5 mm, pressurized at 25°C and 30 MPa, and then removed to obtain a moldable body (Figure 4). In Figure 4, reference numerals 35 and 36 indicate the mold for obtaining the moldable body. Reference numeral 37 indicates the compression piston. Reference numeral 24 indicates the moldable body of silk fibroin obtained through this process. The same molds used for freeze-drying blocks 31, 32, and 34 may also be used as molds for obtaining the moldable body.

[0061] The bulk density of the resulting molding material was measured to be 1.02 g / cm³. 3 The β-sheeting rate was measured to be 5%. The moisture content was measured to be 7%. The tablet hardness was measured to be 103N, and a moldable base material with good hardness that does not collapse even when held with tweezers was obtained. Multiple moldable base materials obtained in this way may be placed together in a packaging and proceed to the main molding process. The packaging material may be paper, resin, rubber, metal, etc.

[0062] Next, the molding body was molded by heating and pressurizing. The mold used had a rectangular prism-shaped through-hole with a length of 35 mm and a width of 15 mm. The piston used had a surface roughness Rz of 0.2 μm. The molding body was placed in the mold, which had been preheated to 125°C, and pressurized at a pressure of 100 MPa for 30 seconds. The mold was then allowed to cool to 25°C. The silk fibroin molded body was removed from the mold, and the surface roughness of the surface that had come into contact with the piston was measured to be 2.3 μm, indicating good surface transfer.

[0063] [Example 2]

[0064] A silk fibroin molding substrate was obtained using the same procedure as in Example 1, except that freeze-dried silk fibroin was pressurized at 20 MPa. The bulk density of the obtained molding substrate was measured to be 0.72 g / cm³. 3 The β-sheet ratio was measured to be 5%. The moisture content was measured to be 7%. The tablet hardness was measured to be 34N, and a moldable base material with good hardness that does not collapse even when held with tweezers was obtained.

[0065] A silk fibroin molded article was obtained using the same procedure as in Example 1. The surface roughness was measured to be 2.2 μm, indicating good surface transfer.

[0066] [Comparative example A]

[0067] A silk fibroin molding substrate was obtained by the same procedure as in Example 1, except that freeze-dried silk fibroin was pressurized at 2 MPa. The bulk density of the obtained molding substrate was measured to be 0.50 g / cm³. 3 The β-sheeting rate was measured to be 5%. The moisture content was measured to be 7%. The tablet hardness was measured to be 10N or less. Furthermore, when held with tweezers, it crumbled into numerous fragments, resulting in poor handling.

[0068] The disintegrated fragments were collected, and a silk fibroin molded body was obtained using the same procedure as in Example 1. The surface roughness was measured to be 2.3 μm, indicating good surface transfer.

[0069] [Example 3]

[0070] A silk fibroin molding substrate was obtained using the same procedure as in Example 1, except that freeze-dried silk fibroin was pressurized at 80 MPa. The bulk density of the obtained molding substrate was measured to be 1.20 g / cm³. 3 The β-sheeting rate was measured to be 5%. The moisture content was measured to be 7%. The tablet hardness was measured to be 114N, and a moldable base material with good hardness that does not collapse even when held with tweezers was obtained.

[0071] A silk fibroin molded article was obtained using the same procedure as in Example 1. The surface roughness was measured to be 2.3 μm, indicating good surface transfer.

[0072] [Comparative example B]

[0073] A silk fibroin molding substrate was obtained using the same procedure as in Example 1, except that freeze-dried silk fibroin was pressurized at 120 MPa. The bulk density of the obtained molding substrate was measured to be 1.28 g / cm³. 3 The β-sheeting rate was measured to be 5%. The moisture content was measured to be 7%. The tablet hardness was measured to be 132N, and a moldable base material with good hardness that does not collapse even when held with tweezers was obtained.

[0074] A silk fibroin molded article was obtained using the same procedure as in Example 1. The surface roughness was measured to be 17.2 μm. This is thought to be because the bulk density of the molding material increased and it became hard, resulting in insufficient surface transfer.

[0075] [Example 4]

[0076] Freeze-dried silk fibroin was held in a 100°C environment for 4 minutes, and then left at 23°C and 50% relative humidity for 48 hours. A silk fibroin molding substrate was then obtained using the same procedure as in Example 1, except that it was subsequently pressurized at 20 MPa. The bulk density of the obtained molding substrate was measured to be 1.03 g / cm³. 3 The β-sheeting rate was measured to be 8%. The moisture content was measured to be 7%. The tablet hardness was measured to be 95N, and a moldable base material with good hardness that does not collapse even when held with tweezers was obtained.

[0077] A silk fibroin molded article was obtained using the same procedure as in Example 1. The surface roughness was measured to be 2.3 μm, indicating good surface transfer.

[0078] [Example 5]

[0079] Freeze-dried silk fibroin was kept in a 90°C environment for 3 minutes, then left at 23°C and 50% relative humidity for 30 minutes. A silk fibroin molding substrate was then obtained using the same procedure as in Example 1, except that it was subsequently pressurized at 20 MPa. The bulk density of the obtained molding substrate was measured to be 1.09 g / cm³. 3 The β-sheeting rate was measured to be 5%. The moisture content was measured to be 2%. The tablet hardness was measured to be 75N, and a moldable base material with good hardness that does not collapse even when held with tweezers was obtained.

[0080] A silk fibroin molded article was obtained using the same procedure as in Example 1. The surface roughness was measured to be 2.3 μm, indicating good surface transfer.

[0081] [Example 6]

[0082] Freeze-dried silk fibroin was left at 23°C and 80% relative humidity for 12 hours. Then, a silk fibroin molding substrate was obtained using the same procedure as in Example 1, except that it was subsequently pressurized at 20 MPa. The bulk density of the obtained molding substrate was measured to be 1.12 g / cm³. 3The β-sheeting rate was measured to be 5%. The moisture content was measured to be 15%. The tablet hardness was measured to be 89N, and a moldable base material with good hardness that does not disintegrate even when held with tweezers was obtained.

[0083] A silk fibroin molded article was obtained using the same procedure as in Example 1. The surface roughness was measured to be 2.4 μm, indicating good surface transfer.

[0084] [Example 7]

[0085] A silk fibroin molding substrate was obtained using the same procedure as in Example 4, except that the holding time in a 100°C environment was changed from 4 minutes to 7 minutes. The bulk density of the obtained molding substrate was measured to be 1.02 g / cm³. 3 The β-sheet content was measured to be 13%. The moisture content was measured to be 7%. The tablet hardness was measured to be 68N, and although deformation was observed when strongly squeezed with tweezers, a moldable base material with sufficient hardness to not collapse was obtained.

[0086] A silk fibroin molded article was obtained using the same procedure as in Example 1. The surface roughness was measured to be 2.9 μm, indicating good surface transfer.

[0087] [Example 8]

[0088] A silk fibroin molding substrate was obtained using the same procedure as in Example 5, except that the holding time in a 90°C environment was changed from 3 minutes to 5 minutes. The bulk density of the obtained molding substrate was measured to be 1.04 g / cm³. 3 The β-sheet content was measured to be 5%. The moisture content was measured to be 1%. The tablet hardness was measured to be 47N, and although deformation was observed when strongly squeezed with tweezers, a moldable base material with sufficient hardness to not collapse was obtained.

[0089] A silk fibroin molded article was obtained using the same procedure as in Example 1. The surface roughness was measured to be 4.2 μm, indicating good surface transfer.

[0090] [Example 9]

[0091] Freeze-dried silk fibroin was left at 23°C and 80% relative humidity for 24 hours. Then, a silk fibroin molding substrate was obtained using the same procedure as in Example 1, except that it was subsequently pressurized at 20 MPa. The bulk density of the obtained molding substrate was measured to be 1.02 g / cm³. 3 Yes, it was found. The β-sheeting rate was measured to be 5%. The moisture content was measured to be 17%. The tablet hardness was measured to be 41N, and a moldable base material with good hardness that does not disintegrate even when held with tweezers was obtained.

[0092] A silk fibroin molded article was obtained using the same procedure as in Example 1. The surface roughness was measured to be 3.6 μm, indicating good surface transfer. The results of the examples and comparative examples are summarized in Tables 1A and 1B, where X = poor, △ = fair, ○ = good, and ◎ = very good. [Table 1] [Table 2]

Claims

1. A molding material having silk fibroin as its main component, with a bulk density of 0.70 g / cm³. ３ ~1.20 g / cm ３ A molding base material characterized by being such.

2. The molding body according to claim 1, characterized in that the thickness of the body is 1 mm or more.

3. The molding body according to claim 1, characterized in that the β-sheet ratio of the body is less than 10%.

4. The molding body according to claim 1, characterized in that the moisture content of the body is 2 to 15%.

5. The molding body according to any one of claims 1 to 4, characterized in that the body is cylindrical, polygonal, spherical, or hemispherical.

6. A molding substrate having silk fibroin as its main component, characterized in that its tablet hardness is 10 or more and 130 or less.

7. The molding body according to claim 6, characterized in that the tablet hardness is 30 or more and 115 or less.

8. The molding body according to claim 6, characterized in that the thickness of the body is 1 mm or more.

9. The molding body according to claim 6, characterized in that the β-sheet ratio of the aforementioned body is less than 10%.

10. The molding body according to claim 6, characterized in that the moisture content of the body is 2 to 15%.

11. The molding body according to any one of claims 6 to 10, characterized in that the body is cylindrical, polygonal, spherical, or hemispherical.

12. The process involves freeze-drying an aqueous solution of silk fibroin, Bulk density is 0.7 g / cm³ ３ ~1.2 g / cm ３ The process involves compressing the freeze-dried material until it reaches a certain state, A method for manufacturing a silk fibroin molding substrate containing silk fibroin.

13. The method for producing a silk fibroin molding substrate according to claim 12, characterized in that the freeze-drying step is carried out using an aqueous solution of silk fibroin dispensed so that the solid content concentration is 10 g or less.

14. Bulk density is 0.70 g / cm³ ３ ~1.20 g / cm ３ This involves setting a molding body containing silk fibroin as the main component into a mold, A molding method comprising obtaining a silk fibroin molded article by heating and pressurizing the aforementioned molding base.

Images