High-internal-phase emulsion and graded porous material prepared from high-internal-phase emulsion

Abstract

The invention discloses a high-internal-phase emulsion and a graded porous material prepared from the high-internal-phase emulsion, the high-internal-phase emulsion comprises an oil phase and a water phase, the oil phase comprises a polymeric monomer, a crosslinking monomer, a foaming pore-forming auxiliary agent, an emulsifier and an initiator; according to the invention, the foaming pore-forming auxiliary agent is introduced into the high internal phase emulsion with a water-in-oil (W / O) structure, and the foaming pore-forming auxiliary agent is uniformly dispersed in an oil phase, so that the emulsification of the high internal phase emulsion is not influenced, and the integrity of a first-level foam skeleton structure formed after curing is not influenced; meanwhile, the foaming pore-forming auxiliary agent can be decomposed or volatilized at the polymerization temperature, gas is formed, pores are formed, and a large number of communicated micropores are formed in the continuous support, so that the obtained porous material has a first-stage macroporous structure and a second-stage microporous structure at the same time.

Description

Technical Field

[0001] This invention belongs to the field of emulsion polymerization technology, specifically relating to a high internal phase emulsion and the hierarchical porous material obtained therefrom. Background Technology

[0002] 3D cell culture, which can simulate the physiological microenvironment in vivo, has become one of the core technologies in biological cell research, tissue culture, organoid culture, drug screening and other engineering. As a key carrier for 3D cell culture, porous scaffolds need to meet the following requirements at the same time: First, they need to provide a large enough space for cells to adhere, multiply and form tissue-like or even organoid structures; second, they need to have efficient material transport channels to enable the rapid transfer of nutrients and oxygen and the timely removal of metabolic waste.

[0003] High internal phase emulsion (HIPE) has an internal phase volume fraction exceeding 74%, making it an ideal system for preparing porous scaffolds. After solidification, it can form large-sized interconnected pores supported by a continuous phase, which can meet the space requirements for cell growth. However, the continuous phase of traditional HIPE porous materials is mostly a dense structure or contains only a few random micropores. Material transport can only rely on diffusion between large-sized interconnected pores, which is slow and inefficient. This leads to cell death inside the scaffold due to nutrient deficiency and waste accumulation, limiting its application in the culture of thick tissue blocks. Currently, there is no suitable solution.

[0004] Therefore, we hope to develop a high internal phase emulsion-based hierarchical porous material to meet the urgent needs in the field of 3D cell culture scaffolds. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a high internal phase emulsion and a hierarchical porous material obtained therefrom.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a high internal phase emulsion, the high internal phase emulsion comprising an oil phase and an aqueous phase, wherein the oil phase comprises polymeric monomers, crosslinking monomers, foaming and pore-forming aids, emulsifiers and initiators.

[0008] This invention introduces a foaming and pore-forming aid into a water-in-oil (W / O) emulsion with a high internal phase. The foaming and pore-forming aid is uniformly dispersed in the oil phase, which does not affect the emulsification of the high internal phase emulsion, nor does it affect the integrity of the primary cell skeleton structure formed after curing.

[0009] Moreover, the high internal phase emulsion provided by this invention can achieve simultaneous curing and pore formation. During the heating and curing process, the polymeric monomers and crosslinking monomers included in the oil phase undergo polymerization reactions to form a continuous scaffold of porous materials. At the same time, the foaming and pore-forming aids can decompose or volatilize at the polymerization temperature to form gas and create pores, forming a large number of interconnected micropores, i.e., secondary pores, inside the continuous scaffold.

[0010] Preferably, the content of the foaming and pore-forming aid is 5-30% based on the total mass of the oil phase as 100%, for example, 5%, 10%, 15%, 20%, 25%, 30%, etc.

[0011] Preferably, the foaming temperature of the foaming and pore-forming aid is 60-80℃, such as 60℃, 62℃, 65℃, 68℃, 70℃, 72℃, 75℃, 78℃, 80℃, etc.

[0012] The foaming and pore-forming aid described in this invention has a foaming temperature within the polymerization and curing temperature range, which enables the high internal phase emulsion to subsequently cure and form pores simultaneously, forming a hierarchical porous material. Moreover, the primary pore skeleton structure of the formed hierarchical porous material is complete and has superior mechanical properties.

[0013] If the foaming temperature of the foaming pore-forming aid is below 60℃, the pore-forming aid will foam prematurely before the initiator initiates polymerization, which can easily lead to the rupture of the emulsion system and destroy the initial formation of the primary cell skeleton. If the foaming temperature is above 80℃, the pore-forming aid will foam only after the polymer skeleton has been completely cured, and it will be unable to form interconnected secondary micropores inside the skeleton. In addition, high temperature can easily cause the skeleton to shrink or become brittle, affecting the structural integrity.

[0014] Preferably, the foaming and pore-forming aid includes volatile solvent-based pore-forming agents and / or decomposition-based foaming pore-forming agents.

[0015] Preferably, the solvent-based porogen includes N,N-dimethylformamide.

[0016] Preferably, the decomposing foaming pore-forming agent includes ammonium bicarbonate and / or azodicarbonamide.

[0017] The solvent-based porogen described in this invention is characterized by easy volatility, insolubility in the oil phase, and no impact on emulsification. Furthermore, it possesses the advantages of precise matching between evaporation and foaming temperatures, no residue, and no impact on cell viability. Therefore, when applied to the preparation of porous materials, it can form secondary micropores within the pore size. These secondary micropores have a pore size of 5-20 μm, which neither affects the integrity and mechanical properties of the primary pore structure nor compromises the high connectivity and high mass transport efficiency of the secondary micropores.

[0018] The solvent-based porogen described in this invention has a decomposition temperature that matches its curing temperature, and the decomposition products are non-toxic and do not affect emulsification.

[0019] Preferably, the initiator is a thermal initiator, and more preferably, the initial decomposition temperature of the thermal initiator is ≤60℃, such as 60℃, 59℃, 55℃, 52℃, 50℃, 48℃, 45℃, 42℃, 40℃, 35℃, etc.

[0020] This invention introduces a thermal initiator with an initial decomposition temperature below 60°C and a foaming and pore-forming agent with a temperature of 60-80°C into a high internal phase emulsion. The two work together to achieve initial curing at a temperature below 60°C to form a preliminary polymer skeleton. Then, at a temperature of 60-80°C, the polymer skeleton further solidifies while the pore-forming agent volatilizes or decomposes, forming secondary micropores inside the polymer skeleton. Ultimately, this ensures that the curing reaction and the pore-forming step proceed simultaneously, resulting in a stable primary and secondary cell structure.

[0021] In this invention, the oil phase, aqueous phase, emulsifier, and initiator in the high internal phase emulsion are all conventionally used components in high internal phase emulsions. This invention does not impose excessive limitations; it is sufficient to introduce a foaming and pore-forming aid into the oil phase to meet application requirements. This invention only provides illustrative examples:

[0022] In this invention, the oil phase includes polymeric monomers, crosslinking monomers, and foaming and pore-forming agents, which are exemplarily listed herein:

[0023] Preferably, the polymeric monomer accounts for 5-97% of the weight of the oil phase, such as 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 97%, etc., and more preferably 40-80%. It may contain at least one water-insoluble monofunctional alkyl acrylate or alkyl methacrylate, vinyl monomer or biodegradable polymeric monomer.

[0024] Preferably, the functional alkyl acrylate or alkyl methacrylate includes C4-C18 alkyl acrylate and / or C2-C18 alkyl methacrylate.

[0025] Preferably, the vinyl monomers include styrene, vinyl chloride, vinylidene chloride, isoprene, and chloroprene, etc.

[0026] Preferably, the biodegradable polymeric monomers include PLA prepolymer (polylactic acid prepolymer), PCL prepolymer (polycaprolactone prepolymer), or PLGA prepolymer (polylactic acid-glycolic acid copolymer prepolymer).

[0027] Preferably, the crosslinking agent accounts for about 2-40% of the oil phase by weight, such as 2%, 5%, 10%, 20%, 30%, 40%, etc., and more preferably 2-30%; this type of crosslinking monomer includes any one or a combination of at least two of acrylate, methacrylate or divinylbenzene crosslinking agents containing two or more double bonds.

[0028] Preferably, the crosslinking agent is a multifunctional crosslinking monomer, including ethylene glycol dimethacrylate (EGDMA), hexanediol diacrylate (HDDA), polyethylene glycol diacrylate (PEGDA), trimethylolpropane trimethacrylate (TMPTA), divinylbenzene, etc.

[0029] Similarly, the present invention does not limit the amount or specific type of emulsifier; any HLB value that can meet the requirements of high internal phase emulsion is acceptable.

[0030] Preferably, the emulsifier includes any one or a combination of at least two of Span 80, Span 60, polyglycerol ricinoleate, polyglycerol stearate, and polyglycerol oleate.

[0031] Preferably, the amount of emulsifier added is 1-20% of the mass of the oil phase, such as 1%, 2%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, etc.

[0032] Similarly, this invention does not limit the amount of initiator used; any amount of initiator that meets the requirements of high internal phase emulsion polymerization can be used in this invention. The initiator can be an oil-soluble initiator or a water-soluble initiator. Examples of this invention are listed below:

[0033] Preferably, the initiator is an oil-soluble initiator, and the amount of the oil-soluble initiator added is 0.05-10% of the mass of the oil phase, such as 0.05%, 1%, 2%, 5%, 10%, etc.

[0034] Preferably, the initiator is a water-soluble initiator, and the amount of the initiator can be 1-20% of the molar amount of the polymerizable monomer in the oil phase, such as 1%, 2%, 5%, 10%, 15%, 20%, etc., or 0.001-10% of the mass of the aqueous phase, such as 0.001%, 0.01%, 0.1%, 1%, 2%, 5%, 10%, etc.

[0035] The initiator of the present invention is preferably a thermal initiator, and preferably includes any one or a combination of at least two of benzoyl peroxide (BPO), azobisisobutyronitrile (AIBN), lauroyl peroxide (LPO), dicumyl peroxide (DCP), and tert-butyl peroxide (TBHP).

[0036] In this invention, the aqueous phase is also a conventional choice in the art, and this invention does not impose excessive limitations, but only provides an exemplary description:

[0037] In this invention, the aqueous phase includes deionized water and may also include water-soluble electrolytes. Introducing water-soluble electrolytes into the aqueous phase can reduce the solubility of oil phase components in water and maintain the structural stability of the water-in-oil system.

[0038] Preferably, the water-soluble electrolyte comprises chlorides or sulfates of alkaline earth metals (e.g., calcium or magnesium) or chlorides or sulfates of alkali metals (e.g., sodium).

[0039] Preferably, the amount of water-soluble electrolyte added is 0.2-40% based on the total mass of the aqueous phase as 100%, for example, 0.2%, 1%, 2%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, etc.

[0040] Preferably, the aqueous phase accounts for 75-97% of the total volume of the high internal phase emulsion, such as 75%, 78%, 80%, 82%, 85%, 88%, 90%, 92%, 95%, 97%, etc.

[0041] In this invention, the mass ratio of the oil phase to the water phase is 1:(3-10), for example, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, etc.

[0042] In a second aspect, the present invention provides a method for preparing a high internal phase emulsion as described in the first aspect, the method comprising: mixing an emulsifier and an initiator with an oil phase to obtain an oil phase mixture; and adding an aqueous phase dropwise to the oil phase mixture and mixing to obtain the high internal phase emulsion.

[0043] Preferably, the preparation method includes:

[0044] (1) Mix emulsifier, polymerizing monomer, crosslinking monomer and initiator (oil-soluble initiator) to obtain oil phase mixture. Preferably, the stirring speed of the mixing is 500-1000 rpm, such as 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, etc., and the mixing time is preferably 10-30 min, such as 10 min, 15 min, 20 min, 25 min, 30 min, etc., and the mixing temperature is preferably 25-35℃, such as 25℃, 28℃, 30℃, 32℃, 35℃, etc.

[0045] (2) Mix deionized water and optionally an electrolyte to obtain an aqueous phase. Preferably, the mixing stirring rate is 500-1000 rpm, such as 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, etc., and the mixing time is preferably 5-20 min, such as 5 min, 8 min, 10 min, 15 min, 20 min, etc.

[0046] (3) The aqueous phase is added dropwise to the oil phase mixture. After the addition is complete, stirring is continued to obtain the high internal phase emulsion. The dropwise addition rate is preferably 2-10 mL / s, such as 2 mL / s, 3 mL / s, 4 mL / s, 5 mL / s, 6 mL / s, 7 mL / s, 8 mL / s, 9 mL / s, 10 mL / s, etc. The stirring rate is preferably 800-1500 rpm, such as 800 rpm, 1000 rpm, 1200 rpm, 1500 rpm, etc. After the aqueous phase is added dropwise, stirring is continued for 5-20 min, such as 5 min, 8 min, 10 min, 12 min, 15 min, 18 min, 20 min, etc.

[0047] Thirdly, the present invention provides a hierarchical porous material prepared from the high internal phase emulsion described in the first aspect.

[0048] The high internal phase emulsion of the present invention contains a foaming and pore-forming aid. During curing, the foaming and pore-forming aid forms secondary micropores on the polymer skeleton through volatilization or decomposition. Therefore, the resulting hierarchical porous material can simultaneously have "large-size primary interconnected pores" and "small-size secondary interconnected micropores".

[0049] In this invention, the pore size of the "large-size primary interconnecting pores" of the hierarchical porous material is 20-300 μm, preferably 40-120 μm, with a connectivity rate ≥85% and a pore wall thickness of 2-20 μm; the pore size of the "small-size secondary interconnecting micropores" is 1-40 μm, preferably 5-20 μm, with a porosity of 30-60%; preferably, the compressive modulus of the hierarchical porous material is 0.5-5 MPa.

[0050] Fourthly, the present invention provides a method for preparing a hierarchical porous material as described in the third aspect, the method comprising:

[0051] The high internal phase emulsion described in the first aspect is subjected to gradient heating and solidification to obtain the hierarchical porous material.

[0052] This invention provides a high internal phase emulsion with a water-in-oil (W / O) structure, in which a foaming and pore-forming aid is introduced. By controlling the curing temperature and time, the simultaneous occurrence of "primary emulsion foaming and secondary foaming micropores" during the heating and curing process is achieved, resulting in a hierarchical porous material with both "large-size primary interconnected pores" and "small-size secondary interconnected micropores". This overcomes the limitation of existing high internal phase emulsions, which can only prepare foamed materials with a single pore size.

[0053] Preferably, the gradient heating curing method includes: heating at 40-60℃ for 2-4 h, heating at 60-80℃ for 1-3 h, and finally curing at 80-90℃ for 0.5-2 h.

[0054] In this invention, the 40-60℃ can be 40℃, 42℃, 45℃, 48℃, 50℃, 52℃, 55℃, 58℃, 60℃, etc.; the 2-4 h can be 2 h, 2.2 h, 2.5 h, 2.8 h, 3 h, 3.2 h, 3.5 h, 3.8 h, 4 h, etc.; the 60-80℃ can be 60℃, 62℃, 65℃, 68℃, 70℃, 72℃, 75℃, 78℃, 80℃, etc.; the 1-3 h can be 1 h, 1.2 h, 1.5 h, 1.8 h, 2 h, 2.2 h, 2.5 h, 2.8 h, 3 h, etc.; the 80-90℃ can be 80℃, 82℃, 85℃, 88℃, 90℃, etc.; and the 0.5-2 h can be 0.5 h, 0.8 h, 1 h, 1.2 h, 1.5 h, etc. h, 1.8 h, 2 h, etc.

[0055] In the gradient heating curing method provided by this invention, at 40-60°C, the initiator decomposes to initiate monomer polymerization and form a preliminary polymer skeleton. Then, at 60-80°C, the porogen volatilizes or decomposes, forming secondary micropores on the polymer skeleton. Finally, at 80-90°C, the polymer skeleton is completely cured, and the porogen volatilizes or decomposes completely, forming a stable hierarchical cell structure of primary macropores and secondary micropores.

[0056] Preferably, the preparation method further includes cooling to room temperature after curing, washing to remove residual emulsifiers, unreacted monomers and pore-forming agents, etc., and preferably also includes drying, preferably vacuum drying.

[0057] Fifthly, the present invention provides the application of the high internal phase emulsion as described in the first aspect or the hierarchical porous material as described in the third aspect in cell culture or daily chemical hygiene products.

[0058] The "large-size primary interconnecting pores" in the hierarchical porous material provided by this invention can serve as cell growth scaffolds, while the "small-size secondary interconnecting micropores" can serve as material transport channels. This solves the problem that the "single porous structure" in current 3D cell culture scaffolds cannot simultaneously meet the needs of cell growth space and material transport and exchange. It is applicable to biomedical fields such as 3D cell culture and tissue engineering.

[0059] Specifically, the porous material can be used in the field of sanitary napkins, dressings and other daily chemical hygiene products. One or more layers of porous material with the same or different pore sizes are used as the core of sanitary napkins, dressings and other daily chemical hygiene products. Through its high porosity, high connectivity and controllable pore size, it can absorb, guide, lock water, prevent backflow or slow release liquids such as water, menstrual blood, blood, body fluids, and nutrients, so that the product has excellent properties such as thinness, dryness, long-lasting effect and slow release.

[0060] The porous material with a hierarchical interconnected pore structure provided by this invention has the following advantages:

[0061] (1) Forming a novel porous material structure: A pore-forming agent is introduced into the oil phase of a water-in-oil emulsion to achieve the simultaneous preparation of "primary pores and secondary micropores", resulting in a composite multi-level interconnected pore with both scaffold and material transport functions. This preparation method does not require secondary processing and is simple, avoiding damage to the scaffold structure caused by secondary processing.

[0062] (2) Performance balance between primary pores and secondary micropores: Dense primary pores stabilize the fiber wall and provide a stable substrate for secondary micropores. The secondary micropore structure is formed simultaneously during the curing process and its formation does not affect the overall mechanical strength of the scaffold, thus solving the problem of the difficulty in achieving both high porosity and high mechanical strength.

[0063] (3) Precise control of hierarchical structure: By controlling the type and amount of pore-forming agent and the gradient curing temperature curve, the size and porosity of the two-stage pores can be precisely controlled to achieve precise matching of the functions of "first-stage growth and second-stage transport". Attached Figure Description

[0064] Figure 1 This is a SEM image of the cross-section of the hierarchical porous material obtained in Example 1 of the present invention. Detailed Implementation

[0065] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0066] Unless otherwise specified, the raw materials involved in the following specific embodiments of the present invention are all conventional materials in the art, and can be purchased from commercially available products. Some raw material information is as follows:

[0067] PCL prepolymer: NatureWorks, model 6800;

[0068] PLA prepolymer: NatureWorks, model 4032;

[0069] PLGA prepolymer: Sigma-Aldrich, model 75 / 25;

[0070] TMPTA, EGDMA, divinylbenzene: Maclean, 98% purity;

[0071] Span 80, Span 60: Walter, UK.

[0072] Example 1

[0073] This embodiment provides a high internal phase emulsion and a hierarchical porous material, as follows:

[0074] (1) High internal phase emulsion, as follows:

[0075] Oil phase: 60 parts PCL prepolymer, 20 parts TMPTA, 10 parts ammonium bicarbonate, 4 parts AIBN and 6 parts Span 80;

[0076] Aqueous phase: deionized water + 5 wt% calcium chloride, oil phase to aqueous phase mass ratio is 1:5;

[0077] The preparation method is as follows: PCL prepolymer, TMPTA, Span 80, ammonium bicarbonate and AIBN are stirred at 600 rpm for 20 min to form a homogeneous oil phase; under stirring at 600 rpm, the aqueous phase is added dropwise to the oil phase at 3 mL / s and then stirred for another 15 min to form a stable high internal phase emulsion.

[0078] (2) Preparation of porous materials:

[0079] The high internal phase emulsion was injected into a polytetrafluoroethylene mold (5 cm × 5 cm × 0.5 cm), and then placed in an oven for heating and curing. The curing process was carried out at 60℃ for 2 h, 80℃ for 1.5 h, and 85℃ for 1 h.

[0080] After washing with deionized water, the material was vacuum dried at 60°C for 12 h to obtain a hierarchical porous material.

[0081] Example 2

[0082] This embodiment provides a high internal phase emulsion and a hierarchical porous material.

[0083] The difference from Example 1 is that in this example, ammonium bicarbonate is replaced with an equal mass of azodicarbonamide.

[0084] Examples 3-6

[0085] This embodiment provides a high internal phase emulsion and a hierarchical porous material.

[0086] The difference from Example 1 is that in this example, the amount of ammonium bicarbonate added is adjusted so that the mass percentage of ammonium bicarbonate in the oil phase is 5% (Example 3), 30% (Example 4), 2% (Example 5), and 35% (Example 6).

[0087] Example 7

[0088] This embodiment provides a high internal phase emulsion and a hierarchical porous material.

[0089] The difference from Example 1 is that in this example, the curing method in step (2) is to keep warm at 80°C for 4.5 h.

[0090] Example 8

[0091] This embodiment provides a high internal phase emulsion and a hierarchical porous material, as follows:

[0092] (1) High internal phase emulsion:

[0093] Oil phase: 60 parts PLA prepolymer, 20 parts EGDMA, 10 parts ammonium bicarbonate, 4 parts BPO and 6 parts Span 80;

[0094] Aqueous phase: deionized water + 5 wt% calcium chloride, oil phase to aqueous phase mass ratio is 1:5;

[0095] The preparation method is the same as in Example 1.

[0096] (2) Preparation of porous materials:

[0097] The high internal phase emulsion was injected into a polytetrafluoroethylene mold (5 cm × 5 cm × 0.5 cm), and then placed in an oven for heating and curing. The curing process was carried out at 40℃ for 4 h, 60℃ for 3 h, and 90℃ for 0.5 h.

[0098] After washing with deionized water, the material was vacuum dried at 60°C for 12 h to obtain a hierarchical porous material.

[0099] Example 9

[0100] This embodiment provides a high internal phase emulsion and a hierarchical porous material, as follows:

[0101] (1) High internal phase emulsion:

[0102] Oil phase: 60 parts PCL prepolymer, 20 parts EGDMA, 10 parts ammonium bicarbonate, 4 parts AIBN and 6 parts Span 80;

[0103] Aqueous phase: deionized water + 5 wt% calcium chloride, oil phase to aqueous phase mass ratio is 1:5;

[0104] The preparation method is the same as in Example 1.

[0105] (2) Preparation of porous materials:

[0106] The high internal phase emulsion was injected into a polytetrafluoroethylene mold (5 cm × 5 cm × 0.5 cm), and then placed in an oven for heating and curing. The curing process was carried out at 50°C for 3 h, 70°C for 2 h, and 80°C for 2 h.

[0107] After washing with deionized water, the material was vacuum dried at 60°C for 12 h to obtain a hierarchical porous material.

[0108] Comparative Example 1

[0109] This comparative example provides a high internal phase emulsion and a hierarchical porous material.

[0110] The difference from Example 1 is that ammonium bicarbonate is not added in this comparative example.

[0111] Comparative Example 2

[0112] This comparative example provides a high internal phase emulsion and a hierarchical porous material.

[0113] The difference from Example 1 is that in this comparative example, ammonium bicarbonate is replaced with toluene.

[0114] Performance testing

[0115] The performance of the samples provided in the examples and comparative examples was tested using the following methods:

[0116] (1) Cell structure: The diameter of 50 primary pores and 100 secondary pores were randomly measured using a scanning electron microscope (SEM, TESCAN MIRA3) and the connectivity rate (number of connected pores / total number of pores × 100%) was calculated.

[0117] Figure 1 The image shows a cross-sectional SEM image of the hierarchical porous material obtained in Embodiment 1 of the present invention. As can be seen from the image, the porous material provided by the present invention simultaneously possesses "large-size primary interconnected pores" and "small-size secondary interconnected micropores".

[0118] (2) Mechanical strength: universal testing machine (Instron 5967), sample size 10mm×10mm×5mm, compression rate 1mm / min, and the stress at 8% strain is taken as the compressive modulus;

[0119] (3) Biocompatibility survival rate: Inoculation with BMSCs (1×10 5Cells per mL were cultured for 7 days, and cell viability was tested using the CCK-8 assay.

[0120] (4) Material transport efficiency: FITC fluorescent probe (1 mg / mL, dimethyl sulfoxide) was dropped onto the material surface (5 mm thick), and the diffusion distance within 2 h was observed by confocal microscopy to calculate the transport rate (μm / h).

[0121] The test results are as follows:

[0122] Table 1

[0123]

[0124] As shown in Table 1, the porous materials obtained by this invention all have uniform primary macropores and secondary micropores. The material transport rate (72-95 μm / h) is significantly higher than that of the comparative examples 1-2 (35-38 μm / h) without secondary pores, and the cell survival rate is ≥92%, proving that the hierarchical pore structure can simultaneously meet the needs of cell growth and material transport.

[0125] The present invention has been illustrated through the above embodiments, but the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A high internal phase emulsion, characterized in that, The high internal phase emulsion comprises an oil phase and an aqueous phase, wherein the oil phase comprises polymeric monomers, crosslinking monomers, foaming and pore-forming aids, emulsifiers, and initiators.

2. The high internal phase emulsion according to claim 1, characterized in that, The content of the foaming and pore-forming aid is 5-30% based on the total mass of the oil phase as 100%.

3. The high internal phase emulsion according to claim 1 or 2, characterized in that, The foaming temperature of the foaming and pore-forming aid is 60-80℃.

4. The high internal phase emulsion according to any one of claims 1-3, characterized in that, The foaming and pore-forming aids include volatile solvent-based pore-forming agents and / or decomposing foaming and pore-forming agents; Preferably, the solvent-based porogen includes N,N-dimethylformamide; Preferably, the decomposing foaming pore-forming agent includes ammonium bicarbonate and / or azodicarbonamide.

5. The high internal phase emulsion according to any one of claims 1-4, characterized in that, The mass ratio of the oil phase to the water phase is 1:(3-10); And / or, based on the total mass of the oil phase being 100%, the mass percentage of the emulsifier is 1-20%; And / or, based on the total mass of the oil phase being 100%, the initiator has a mass percentage content of 0.5-10%; And / or, the initiator is a thermal initiator, preferably the initial decomposition temperature of the thermal initiator is ≤60°C.

6. A method for preparing a high internal phase emulsion as described in any one of claims 1-5, characterized in that, The preparation method includes: mixing an emulsifier and an initiator with an oil phase to obtain an oil phase mixture; adding an aqueous phase dropwise to the oil phase mixture and mixing to obtain the high internal phase emulsion.

7. A hierarchical porous material, characterized in that, It is prepared from the high internal phase emulsion according to any one of claims 1-5.

8. A method for preparing a hierarchical porous material as described in claim 7, characterized in that, The preparation method includes: The high internal phase emulsion of any one of claims 1-5 is subjected to gradient heating and solidification to obtain the hierarchical porous material.

9. The preparation method according to claim 8, characterized in that, The gradient heating curing method includes: heating at 40-60℃ for 2-4 hours, heating at 60-80℃ for 1-3 hours, and finally curing at 80-90℃ for 0.5-2 hours.

10. The use of a high internal phase emulsion as described in any one of claims 1-5 or a hierarchical porous material as described in claim 7 in cell culture or daily chemical hygiene products.

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