Medical silicone rubber, its preparation method and medical prostheses

Abstract

This invention proposes a medical silicone rubber, its preparation method, and a medical prosthesis, relating to the field of prosthesis technology. The preparation method of the medical silicone rubber includes the following steps: mixing vinyl polysiloxane, mercapto polysiloxane, a photoinitiator, an antibacterial agent, an emulsifier, modified silica, and a salt solution; performing a crosslinking reaction under light irradiation; and drying to obtain a photocurable silicone rubber; and then subjecting the photocurable silicone rubber to desalination treatment to obtain the medical silicone rubber. The modified silica is a hydrophobic fumed silica surface-modified with hexamethyldisilazane. In this invention, by adding a salt solution, the formed silicone rubber contains moisture, which is removed during subsequent drying to form pores. Simultaneously, part of the salt solution evaporates to form salt crystals, resulting in salt particles within the reacted silicone rubber, increasing the porosity of the medical silicone rubber and reducing its toxicity to biological tissues.

Description

Technical Field

[0001] This invention relates to the field of prosthetic materials technology, and in particular to a medical silicone rubber, its preparation method, and a medical prosthesis. Background Technology

[0002] Liquid silicone rubber, a type of silicone rubber, is made from polydimethylsiloxane as the base rubber. Due to its excellent high-temperature resistance, solvent resistance, hydrophobicity, flame retardancy, oxidation resistance, corrosion resistance, and good biocompatibility, polydimethylsiloxane materials are widely used in many fields such as medical devices, cosmetic surgery, food, and the automotive industry.

[0003] Currently, silicone rubber implants are being used more and more widely in the medical and cosmetic fields. However, the elasticity of the silicone rubber currently used often fails to meet people's needs.

[0004] In the existing technology, medical foam silicone rubber is usually used to solve these problems. However, medical foam silicone rubber requires the use of organic foaming agents, and the crosslinking agents are usually heavy metal crosslinking agents, which may remain in the medical foam silicone rubber and may endanger the health of users after implantation. Summary of the Invention

[0005] The main objective of this invention is to provide a medical silicone rubber, its preparation method, and a medical prosthesis, with the aim of improving the porosity of the medical silicone rubber and reducing its toxicity to biological tissues.

[0006] To achieve the above objectives, this invention proposes a method for preparing medical-grade silicone rubber, comprising the following steps:

[0007] Vinyl polysiloxane, mercapto polysiloxane, photoinitiator, antibacterial agent, modified silica and salt water solution are mixed, crosslinked under light irradiation, and dried to obtain light-cured silicone rubber;

[0008] The photocurable silicone rubber is desalted to obtain medical silicone rubber.

[0009] The modified silica is a hydrophobic fumed silica surface-modified with hexamethyldisilazane.

[0010] In one embodiment, the mass ratio of vinyl polysiloxane, mercapto polysiloxane, photoinitiator, antibacterial agent, modified silica and salt water solution is (30~80): (5~20): (1~10): (0.1~5): (1~5): (5~20).

[0011] In one embodiment, the brine solution comprises an aqueous solution of sodium chloride and / or an aqueous solution of potassium chloride, and the total mass concentration of the brine solution is 20% to 25%.

[0012] In one embodiment, the photoinitiator includes at least one selected from 1-hydroxy-cyclohexyl-phenyl ketone and 2-hydroxy-2-methyl-phenylacetone; and / or,

[0013] The antibacterial agent includes a silver ion antibacterial agent.

[0014] In one embodiment, the vinyl polysiloxane contains 1% to 20% vinyl in molar proportion; and / or,

[0015] In the thiol polysiloxane, the molar percentage of thiol groups is 1% to 20%.

[0016] In one embodiment, during the crosslinking reaction under light irradiation:

[0017] The reaction temperature is 40℃~80℃; and / or,

[0018] The reaction time is 2 h to 4 h.

[0019] The present invention also proposes a medical silicone rubber, comprising a medical silicone rubber prepared according to the aforementioned preparation method.

[0020] The present invention also proposes a medical prosthesis comprising an outer shell, a core, and an injection layer disposed between the outer shell and the core, the injection layer being used to fill physiological saline, the outer shell comprising medical silicone rubber as described above, and the core comprising silicone gel.

[0021] In one embodiment, the outer shell includes an outer layer and an inner layer, the outer layer being made of medical-grade silicone rubber as described above, and the inner layer being a non-porous silicone rubber layer;

[0022] The inner layer and the outer layer are interconnected.

[0023] In one embodiment, the medical prosthesis includes a breast prosthesis.

[0024] In the technical solution of this invention, by adding a salt solution, moisture is present inside the silicone rubber formed during the crosslinking reaction. This moisture is removed during the subsequent drying process to form pores. Simultaneously, during the crosslinking reaction, part of the salt solution evaporates to form salt crystals, resulting in salt particles inside the silicone rubber. These salt crystals are removed in the subsequent desalting step to form pores, thereby increasing the porosity of the medical silicone rubber and reducing the toxicity of residual foaming agents to biological tissues caused by conventional foaming agents. By using a photoinitiator, the crosslinking reaction can occur under light irradiation, lowering the required reaction temperature and reducing thermal aging of the silicone rubber due to high temperatures. The use of modified silica improves compatibility with polysiloxanes and enhances the tear resistance and hardness of the photocured silicone rubber. The use of an emulsifier ensures thorough mixing and dispersion of the components, thereby improving the uniformity of pore dispersion in the medical silicone rubber. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A cross-sectional structural schematic diagram of an embodiment of the medical prosthesis provided by the present invention;

[0027] Figure 2 This is a cross-sectional structural schematic diagram of another embodiment of the medical prosthesis provided by the present invention.

[0028] Explanation of icon numbers

[0029] 100. Medical prosthesis; 1. Outer shell; 11. Outer layer; 12. Inner layer; 2. Injection layer; 3. Core.

[0030] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them.

[0032] It should be noted that, unless specific conditions are specified in the embodiments, conventional conditions or conditions recommended by the manufacturer should be followed. Reagents or instruments whose manufacturers are not specified are all commercially available products. Furthermore, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. In addition, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, such a combination should be considered non-existent and not within the scope of protection claimed by this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0033] Liquid silicone rubber, a type of silicone rubber, is made from polydimethylsiloxane as the base rubber. Due to its excellent high-temperature resistance, solvent resistance, hydrophobicity, flame retardancy, oxidation resistance, corrosion resistance, and good biocompatibility, polydimethylsiloxane materials are widely used in many fields such as medical devices, cosmetic surgery, food, and the automotive industry.

[0034] Currently, silicone rubber implants are being used more and more widely in the medical and cosmetic fields. However, the elasticity of the silicone rubber currently used often fails to meet people's needs.

[0035] In the existing technology, medical foam silicone rubber is usually used to solve these problems. However, medical foam silicone rubber requires the use of organic foaming agents, and the crosslinking agents are usually heavy metal crosslinking agents, which may remain in the medical foam silicone rubber and may endanger the health of users after implantation.

[0036] In view of this, the present invention proposes a method for preparing medical-grade silicone rubber, comprising the following steps:

[0037] Vinyl polysiloxane, mercapto polysiloxane, photoinitiator, antibacterial agent, emulsifier, modified silica and salt water solution are mixed, crosslinked under light irradiation, and dried to obtain light-cured silicone rubber;

[0038] The photocurable silicone rubber is desalted to obtain medical silicone rubber.

[0039] The modified silica is a hydrophobic fumed silica surface-modified with hexamethyldisilazane.

[0040] In the technical solution of this invention, by adding a salt solution, moisture is present inside the silicone rubber formed during the crosslinking reaction. This moisture is removed during the subsequent drying process to form pores. Simultaneously, during the crosslinking reaction, part of the salt solution evaporates to form salt crystals, resulting in salt particles inside the silicone rubber. These salt crystals are removed in the subsequent desalting step to form pores, thereby increasing the porosity of the medical silicone rubber and reducing the toxicity of residual foaming agents to biological tissues caused by conventional foaming agents. By using a photoinitiator, the crosslinking reaction can occur under light irradiation, lowering the required reaction temperature and reducing thermal aging of the silicone rubber due to high temperatures. The use of modified silica improves compatibility with polysiloxanes and enhances the tear resistance and hardness of the photocured silicone rubber. The use of an emulsifier ensures thorough mixing and dispersion of the components, thereby improving the uniformity of pore dispersion in the medical silicone rubber.

[0041] Furthermore, in one embodiment, in the step of mixing vinyl polysiloxane, mercapto polysiloxane, photoinitiator, antibacterial agent, modified silica and salt solution, ultrasonic dispersion is used to mix the substances to improve the homogeneity of the system, so that the salt solution is evenly distributed in the system.

[0042] In one embodiment, the mass ratio of vinyl polysiloxane, mercapto polysiloxane, photoinitiator, antibacterial agent, emulsifier, modified silica, and saline solution is (30~80):(5~20):(1~10):(0.1~5):(1~5):(1~5):(5~20). In the technical solution of this invention, the content of silicone rubber is adjusted by regulating the mass ratio of each component, thereby adjusting the antibacterial properties and porosity of the medical silicone rubber.

[0043] In one embodiment, the salt solution comprises an aqueous solution of sodium chloride and / or an aqueous solution of potassium chloride, and the total mass concentration of the salt solution is 20% to 25%. In the technical solution of this invention, by using a salt solution with a mass concentration of 20% to 25%, it is ensured that during the crosslinking reaction, the water in the salt solution evaporates upon heating, the salt precipitates out, and salt particles are embedded in the generated silicone rubber.

[0044] In one embodiment, the photoinitiator includes at least one of 1-hydroxy-cyclohexyl-phenyl ketone and 2-hydroxy-2-methyl-phenylacetone. In the technical solution of the present invention, by using at least one of 1-hydroxy-cyclohexyl-phenyl ketone and 2-hydroxy-2-methyl-phenylacetone as the photoinitiator, high thermal stability and no yellowing phenomenon are observed, which can improve the thermal stability of the medical silicone rubber and reduce thermal aging during use.

[0045] In one embodiment, the antibacterial agent includes a silver ion antibacterial agent. In the technical solution of the present invention, by employing a silver ion antibacterial agent, silver ions can effectively inhibit the growth of various bacteria, fungi, and viruses. The silver ion antibacterial agent can continuously release silver ions, thereby providing a long-lasting antibacterial effect.

[0046] In one embodiment, the vinyl polysiloxane has a vinyl content of 1% to 20% in molar proportion. In the technical solution of this invention, by adjusting the molar proportion of vinyl in the vinyl polysiloxane, the photocuring reaction rate and crosslinking density are adjusted to obtain a suitable viscosity.

[0047] In one embodiment, the molar percentage of thiol groups in the thiol polysiloxane is 1% to 20%. In the technical solution of this invention, using thiol polysiloxane as a thiol donor in the thiol ene photocuring reaction system can improve the reaction rate and has good compatibility with vinyl polysiloxane.

[0048] In one embodiment, during the crosslinking reaction under light irradiation: the reaction temperature is 40℃~80℃; and / or, the reaction time is 2 h~4 h. In the technical solution of this invention, by adjusting the reaction temperature to 40℃~80℃, the crosslinking reaction to synthesize silicone rubber can be accelerated. If the temperature is below 40℃, the reaction rate is too slow; if the temperature is above 80℃, localized boiling of water will occur in the reaction system during the reaction process, affecting the uniformity of the system. By controlling the reaction time to 2 h~4 h, the degree of reaction can be increased, thereby increasing the yield of medical silicone rubber. The above-mentioned reaction temperature and reaction time can be defined separately or simultaneously. When defined simultaneously, both the reaction rate and the degree of reaction can be improved simultaneously.

[0049] This invention also proposes a medical silicone rubber, comprising a medical silicone rubber prepared according to the aforementioned preparation method. Since this medical silicone rubber adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated further here.

[0050] The present invention also proposes a medical prosthesis 100, see reference. Figure 1 It includes an outer shell 1, a core 3, and an injection layer 2 disposed between the outer shell 1 and the core 3. The injection layer 2 is used to fill physiological saline. The outer shell 1 includes medical silicone rubber as described above, and the material of the core 3 includes silicone gel.

[0051] In the technical solution of the present invention, by using the medical silicone rubber as the outer shell 1, after the medical prosthesis 100 is implanted, human tissue can grow and develop in the pores within the medical silicone rubber, so that the human tissue can attach to the medical prosthesis 100, thereby fixing the medical prosthesis 100 and reducing the displacement of the medical prosthesis 100; by using the injection layer 2, a filling liquid can be injected into the injection layer 2. In the technical solution of the present invention, the filling liquid is physiological saline to prevent the impact on the human body when the filling liquid leaks. Furthermore, the injection volume of the filling liquid in the injection layer 2 can be adjusted according to needs, thereby adjusting the thickness of the injection layer 2 and thus adjusting the size of the medical prosthesis 100.

[0052] In one embodiment, the outer shell 1 includes an outer layer 11 and an inner layer 12. The material of the outer layer 11 includes medical silicone rubber as described above, and the inner layer 12 is a non-porous silicone rubber layer. The inner layer 12 is cross-linked with the outer layer 11.

[0053] In the technical solution of the present invention, by using non-porous silicone rubber as the inner layer 12, the inner layer 12 can deform to a certain extent without producing pores when adjusting the size of the injection layer 2, thereby reducing the occurrence of liquid leakage in the injection layer 2. At the same time, the outer layer 11 has a certain porosity to accommodate the growth of human tissue and thus reduce the displacement of the medical prosthesis 100.

[0054] In one embodiment, the medical prosthesis 100 includes a breast prosthesis.

[0055] In the technical solution of the present invention, the medical prosthesis 100 is used as a breast prosthesis and can be implanted into the body. The medical silicone rubber on the outer shell 1 has a porous structure that can accommodate the growth of human tissue, thereby fixing the medical prosthesis 100, reducing the displacement of the medical prosthesis 100, and improving the adhesion rate of the medical prosthesis 100. The injection layer 2 can adjust the injection volume as needed, thereby adjusting the size of the breast prosthesis.

[0056] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0057] Example 1

[0058] This embodiment provides a medical-grade silicone rubber, and the specific steps are as follows:

[0059] Step 1: Mix 60 parts of vinyl polysiloxane and 10 parts of mercapto polysiloxane using simple mechanical stirring until homogeneous;

[0060] Step 2: Add 5 parts of 1-hydroxy-cyclohexyl-phenyl ketone, 0.5 parts of silver ion antibacterial agent, 3 parts of Tween-80, 3 parts of modified silica and 10 parts of 25% sodium chloride solution to the above mixture and ultrasonically disperse for 20 min;

[0061] Step 3: Heat the mixture from Step 2 under 365nm ultraviolet light to 60℃, keep the temperature constant and stir for 4 h, and then dry at 105℃ for 30 min to obtain photocurable silicone rubber.

[0062] Step 4: Desalinate the photocurable silicone rubber from Step 3 to obtain medical silicone rubber.

[0063] Example 2

[0064] This embodiment provides a medical prosthesis, such as... Figure 1 As shown.

[0065] The breast implant consists of an outer shell, a core, and an injection layer disposed between the outer shell and the core. The injection layer is used to fill physiological saline. The outer shell includes an outer layer and an inner layer. The material of the outer layer includes the medical silicone rubber provided in Example 1. The inner layer is non-porous silicone rubber. The outer layer and the inner layer are cross-linked and bonded by a silicone rubber adhesive. The material of the core is silicone gel.

[0066] Example 3

[0067] This embodiment provides a medical prosthesis, such as... Figure 2 As shown.

[0068] The breast implant consists of an outer shell, an inner core, and an injection layer disposed between the outer shell and the inner core. The injection layer is used to fill with saline solution. The material of the outer shell includes the medical silicone rubber provided in Example 1, and the material of the inner core is silicone gel.

[0069] Comparative Example 1

[0070] This comparative example provides a silicone rubber produced by Jinan Chensheng Silicone Rubber Co., Ltd.

[0071] Comparative Example 2

[0072] This comparative example provides a silicone rubber, the preparation method of which is similar to that of Example 1, except that in step 2, 10 parts of 25% sodium chloride solution are replaced with 2.5 parts of sodium chloride powder.

[0073] Comparative Example 3

[0074] This comparative example provides a medical prosthesis whose structure is similar to that of Example 2, except that the outer layer is made of silicone rubber provided in Comparative Example 1.

[0075] Comparative Example 4

[0076] This comparative example provides a medical prosthesis whose structure is similar to that of Example 2, except that the outer layer is made of the silicone rubber provided in Comparative Example 2.

[0077] Performance testing

[0078] The mechanical properties of the silicone rubber materials provided in Example 1, Comparative Example 1, and Comparative Example 2 were tested using the following methods:

[0079] Shrinkage rate: The shrinkage rate was tested using the density method. The density before and after curing was tested according to the national standard GB / T 15223-2008, and the shrinkage rate was calculated.

[0080] Mechanical strength: The tensile strength and elongation at break of the material obtained after light curing were tested according to GB / T9341 standard.

[0081] The performance test results are shown in Table 1.

[0082] Table 1. Mechanical property test results of the silicone rubber materials provided in Example 1, Comparative Example 1, and Comparative Example 2

[0083]

[0084] Biocompatibility testing

[0085] One hundred mice were divided into four groups of 25 each; three groups of mice were injected with the prostheses provided in Example 2, Comparative Example 3 and Comparative Example 4, respectively, while the fourth group of mice underwent sham surgery.

[0086] After 4 weeks of normal feeding conditions, the survival rate of mice was calculated, and the test results are shown in Table 2.

[0087] Table 2. Biocompatibility test results of the prostheses provided in Example 2, Comparative Example 3, and Comparative Example 4

[0088]

[0089] As shown in the table above, the survival rates of mice in the experimental group and the control group were basically the same, which indicates that the medical prosthesis provided in Example 2 had virtually no impact on the survival of mice, and that the medical silicone rubber provided in Example 1 had good biocompatibility.

[0090] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for preparing medical-grade silicone rubber, characterized in that, Includes the following steps: Vinyl polysiloxane, mercapto polysiloxane, photoinitiator, antibacterial agent, emulsifier, modified silica and salt water solution are mixed, crosslinked under light irradiation, and dried to obtain light-cured silicone rubber; The photocurable silicone rubber is desalted to obtain medical silicone rubber. The modified silica is a hydrophobic fumed silica surface-modified with hexamethyldisilazane. In the step of mixing vinyl polysiloxane, mercapto polysiloxane, photoinitiator, antibacterial agent, emulsifier, modified silica, and salt solution, reacting them under light irradiation, and drying to obtain light-cured silicone rubber: The mass ratio of vinyl polysiloxane, mercapto polysiloxane, photoinitiator, antibacterial agent, emulsifier, modified silica and salt solution is: (30~80): (5~20): (1~10): (0.1~5): (1~5): (1~5): (5~20); In the step of mixing vinyl polysiloxane, mercapto polysiloxane, photoinitiator, antibacterial agent, emulsifier, modified silica, and salt solution, and reacting them under light irradiation, followed by drying to obtain light-cured silicone rubber: The brine solution comprises an aqueous solution of sodium chloride and / or an aqueous solution of potassium chloride, and the total mass concentration of the brine solution is 20% to 25%.

2. The method for preparing medical silicone rubber as described in claim 1, characterized in that, In the step of mixing vinyl polysiloxane, mercapto polysiloxane, photoinitiator, antibacterial agent, emulsifier, modified silica, and salt solution, and reacting them under light irradiation, followed by drying to obtain light-cured silicone rubber: The photoinitiator includes at least one of 1-hydroxy-cyclohexyl-phenyl ketone and 2-hydroxy-2-methyl-phenylacetone; and / or, The antibacterial agent includes silver ion antibacterial agents; and / or, The emulsifier includes at least one of Tween-80 and dimethyl silicone oil.

3. The method for preparing medical silicone rubber as described in claim 1, characterized in that, In the step of mixing vinyl polysiloxane, mercapto polysiloxane, photoinitiator, antibacterial agent, emulsifier, modified silica, and salt solution, and reacting them under light irradiation, followed by drying to obtain light-cured silicone rubber: In the vinyl polysiloxane, the molar percentage of vinyl is 1% to 20%; and / or, In the thiol polysiloxane, the molar percentage of thiol groups is 1% to 20%.

4. The method for preparing medical silicone rubber as described in claim 1, characterized in that, In the step of mixing vinyl polysiloxane, mercapto polysiloxane, photoinitiator, antibacterial agent, emulsifier, modified silica, and salt solution, and reacting them under light irradiation, followed by drying to obtain light-cured silicone rubber: The reaction temperature for crosslinking under light irradiation is 40℃~80℃; and / or, The reaction time for crosslinking under light irradiation is 2 to 4 hours.

5. A medical-grade silicone rubber, characterized in that, It includes the preparation method of medical silicone rubber as described in any one of claims 1 to 4.

6. A medical prosthesis, characterized in that, It includes a shell, a core, and an injection layer disposed between the shell and the core, the injection layer being used to fill physiological saline, the shell comprising medical silicone rubber as described in claim 5, and the core comprising silicone gel.

7. The medical prosthesis as described in claim 6, characterized in that, The outer shell includes an outer layer and an inner layer, the outer layer being made of the medical silicone rubber as described in claim 5, and the inner layer being a non-porous silicone rubber layer; The inner layer and the outer layer are interconnected.

8. The medical prosthesis as described in claim 7, characterized in that, The medical prostheses include breast prostheses.

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