CN112844501B - Multi-liquid-core hydrogel microcapsule chip based on double aqueous phases and application thereof - Google Patents

Abstract

The invention provides a multi-liquid-core hydrogel microcapsule chip based on an aqueous two-phase system. The chip mainly comprises a core fluid inlet, a shell fluid inlet, a continuous phase inlet, a core fluid shunt port and a shell fluid shunt port, and the middle layer mainly comprises a continuous phase inlet, a continuous phase channel, a core fluid inlet, a shell fluid inlet, a core channel, a shell channel, a laminar flow channel, a main channel, a reaction channel and a fluid outlet. The invention can controllably prepare the multiliquid-core hydrogel microcapsule based on a two-aqueous-phase system. The stable and uniform double-water-phase microcapsule with controllable appearance is obtained by adjusting the core flow velocity, the shell flow velocity, the continuous phase flow velocity and the like. The chip can realize the preparation of various liquid core microcapsules according to the increase of the number of the core channels and the shell channels, wherein the microcapsules can contain more liquid cores such as a single liquid core, a double liquid core, a three liquid core, a four liquid core and the like. The system is expected to play a role in biological applications such as single cell pairing, cell zoning co-culture, controllable drug release and the like.

Description

A two-phase based multi-liquid core hydrogel microcapsule chip and its application

technical field

The invention relates to the technical field of microfluidics, in particular to a multi-liquid core hydrogel microcapsule chip based on a two-water phase.

Background technique

Hydrogel microcapsules have attracted extensive attention in the fields of biology, pharmacy, and materials chemistry due to their good biocompatibility, permeability, high loading capacity, and tunable responsiveness. Core-shell hydrogel microcapsules are usually prepared by using hydrogel materials such as polyethylene glycol, alginate, and gelatin methacrylamide by hanging drop method, coating method, and droplet microfluidics. Because the microcapsules contain a liquid core and a hydrogel shell, they have excellent biocompatibility and permeability, so they are widely used in cell loading, drug delivery and release, and molecular adsorption. However, because the single-core hydrogel microcapsule is too single in structure, it can only achieve a single load of substances, and it is difficult to satisfy the partition load of a variety of substances. The disadvantage of hydrogel microcapsules with multiple liquid cores is that the microcapsules prepared in this way have poor uniformity and stability, and the preparation process involves operations such as solvent volatilization or temperature polymerization, and the preparation process is very mild. There is an urgent need to propose a simple, flexible and mild method to fabricate multi-liquid core hydrogel microcapsules.

Microfluidics is a technology characterized by precise manipulation of fluids at the micron scale. Microfluidic droplet technology is one of its important branches. Due to its advantages of uniform size, small volume, and flexible use, this technology has been widely used in the fields of biomaterials, tissue engineering, and regenerative medicine. It is still a challenge to realize the fabrication of multi-core hydrogel microcapsules using microfluidic technology. In recent years, the two-phase system has attracted great attention from researchers. A two-phase system is composed of two different polymers with concentrations above a critical value in an aqueous solution. When the interaction energy of the system is higher than the Gibbs free energy of mixing, spontaneous phase separation occurs. Due to the good biocompatibility of the system, it also broadens the application of microfluidic technology in this field. The present invention provides a multi-liquid core hydrogel microcapsule chip based on two aqueous phases.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a multi-liquid core hydrogel microcapsule chip based on two aqueous phases.

The multi-core hydrogel microcapsule preparation chip provided by the present invention is formed by bonding three-layer PDMS chips (upper layer, middle layer and lower layer) formed by conventional soft lithography, and the upper layer adopts a shunt design. The simplicity and complexity avoid the limitation of using multiple pump devices at the same time.

The upper layer of the chip is mainly composed of a core fluid inlet, a shell fluid inlet, a continuous phase inlet, a nuclear fluid split port, a shell fluid split port, and the middle layer is mainly composed of a continuous phase inlet, a continuous phase channel, a core fluid inlet, a shell fluid inlet, and a core channel, Shell channel, laminar flow channel, main channel and reaction channel, fluid outlet, the lower layer is a white board without structure;

The shell fluid distribution port of the upper layer of the chip communicates with the shell fluid inlet of the middle layer of the chip;

The branch fluid inlet of the shell fluid inlet is the shell fluid distribution port, and the branch fluid inlet of the core fluid inlet is the shell fluid distribution port.

The core fluid enters the core fluid inlet from the core fluid inlet through the core fluid shunt port respectively, and flows into the laminar flow channel through the core channel; the shell fluid passes from the shell fluid inlet through the shell fluid shunt port, passes through the shell fluid inlet of the middle layer of the chip, and passes through the shell channel. Flow into the laminar flow channel; continuous flow flows from the continuous phase inlet through the continuous phase inlet of the intermediate layer and flows into the main channel through the continuous phase channel; the core fluid, shell fluid, and continuous fluid finally pass through the channel and the reaction channel, and the prepared multi-liquid core hydrogel micro The bladder flows out of the fluid outlet and collects.

The chip laminar flow channel of the invention has a width of 100-600 μm and a height of 100-500 cm; the main channel has a width of 100-500 μm and a height of 50-500 cm; 400μm, 50-300cm high.

The chip of the present invention can realize the preparation of various liquid-core microcapsules by increasing the number of core channels and shell channels, wherein the microcapsules can contain more than one liquid core, two liquid cores, three liquid cores, four liquid cores, etc. number of liquid nuclei.

The number of the core channels is greater than or equal to 1, and the number of the shell channels (8) is greater than or equal to 1; a multi-liquid core hydrogel microcapsule is realized.

The number of nuclei of microcapsules is ≥1.

The three PDMS layers of the present invention are sealed by plasma treatment for 25s respectively, and the channels are hydrophobically treated with 1H, 1H, 2H, 2H-perfluorooctyltrichlorosilane; the 1H,1H,2H,2H-perfluoro The concentration of octyltrichlorosilane is 0.5%-5%, and the treatment time is 20-60min.

The cores of the multi-liquid core hydrogel microcapsules of the present invention are all aqueous solutions, and the shells are hydrogels.

The multi-liquid core hydrogel microcapsules are prepared based on a two-phase system, and the selected materials have both biocompatibility and stability, the core is dextran (Dex), and the shell is polyethylene glycol (PEG). ; The PEG molecular weight range: 8-20kDa, the concentration range: 10-30%; the Dex molecular weight range: 70k-500kDa, the concentration range: 10-40%;

In order to generate multi-liquid core hydrogel microcapsules, a hydrogel prepolymer can be mixed into the shell fluid. The materials are sodium alginate (NaA) and calcium disodium ethylenediaminetetraacetate (Ca-EDTA). NaA uses Viscosity range: 55-400 cps, concentration range: 0.1-2%, Ca-EDTA used concentration range: 0.1-2%, acetic acid (HAc) was added to the shell fluid continuous phase, used concentration range 0.05-0.25%, in Span 80 is added to the continuous phase to increase the oil-water interface, which is conducive to the formation of stable droplets. The concentration range of Span 80 is 1%-5%. The collection tank uses calcium chloride (CaCl ₂ ) aqueous solution, and the concentration range is 0.5-4% ;

The core fluid, the shell fluid and the continuous phase fluid are respectively passed into the microfluidic chip from the core fluid inlet, the shell fluid inlet and the continuous phase fluid inlet, and the multi-liquid core hydrogel is adjusted by changing the core flow rate, the shell flow rate and the continuous phase flow rate. The size of the microcapsules includes the size of the liquid core and the overall size of the microcapsules; the flow rate range of the core: 0.01-2.0μL/min, the flow rate range of the shell: 1-10μL/min, and the flow rate range of the continuous phase: 10-60μL/min. The invention is combined with the microfluidic technology to realize the flexibility of chip design, and provides a new technical means for preparing the multi-liquid core hydrogel microparticles with excellent biocompatibility. The encapsulation process is simple and the conditions are mild; by adjusting the flow rate of the core fluid, shell fluid, continuous flow, etc., the multi-liquid core hydrogel microcapsules can be obtained with uniform size and controllable morphology, avoiding the uniformity of the preparation of microcapsules reported in the existing literature. In addition, the preparation of multi-core hydrogel microcapsules also provides a technical means for biological applications such as cell compartmentalized culture and drug co-loading.

Description of drawings

Figure 1 is a schematic diagram of preparing a dual-liquid core hydrogel microcapsule chip.

Among them, 1 is the upper continuous phase inlet, 2 shell fluid inlet, 3 core fluid inlet, 4 core fluid split port, 5 shell fluid split port, 6 middle layer continuous phase inlet, 7 middle layer shell fluid inlet, 8 shell channel, 9 middle layer Laminar fluid inlet, 10 nuclear channels, 11 continuous phase channels, 12 laminar flow channels, 13 main channels, 14 reaction channels, 15 fluid outlets.

Figure 2 is a schematic diagram of preparing a three-liquid core hydrogel microcapsule chip.

Among them, 1 is the upper continuous phase inlet, 2 shell fluid inlet, 3 core fluid inlet, 4 core fluid split port, 5 shell fluid split port, 6 middle layer continuous phase inlet, 7 middle layer shell fluid inlet, 8 shell channel, 9 middle layer Laminar fluid inlet, 10 nuclear channels, 11 continuous phase channels, 12 laminar flow channels, 13 main channels, 14 reaction channels, 15 fluid outlets.

Figure 3 is a schematic diagram of preparing a four-liquid core hydrogel microcapsule chip.

Among them, 1 is the upper continuous phase inlet, 2 shell fluid inlet, 3 core fluid inlet, 4 core fluid split port, 5 shell fluid split port, 6 middle layer continuous phase inlet, 7 middle layer shell fluid inlet, 8 shell channel, 9 middle layer Laminar fluid inlet, 10 nuclear channels, 11 continuous phase channels, 12 laminar flow channels, 13 main channels, 14 reaction channels, 15 fluid outlets.

FIG. 4 is a bright-field image (Scale bar: 100 μm) of the dual-core hydrogel microcapsules prepared in Example 4. FIG.

FIG. 5 is a bright-field image (Scale bar: 200 μm) of three-liquid core hydrogel microcapsules prepared in Example 5. FIG.

Detailed ways

Combined with the actual situation, the hydrogel microcapsule chip containing different liquid cores was designed first, and then the PDMS chip was prepared by conventional soft lithography. The present invention will be further described below with reference to the accompanying drawings and embodiments.

Example 1

A two-liquid core hydrogel microcapsule chip based on two aqueous phases.

The chip is formed by bonding three layers of PDMS chips (upper layer, middle layer, lower layer).

Mainly consists of upper continuous phase inlet 1, shell fluid inlet 2, nuclear fluid inlet 3, core fluid split port 4, shell fluid split port 5; intermediate layer continuous phase inlet 6, intermediate layer shell fluid inlet 7, shell channel 8, intermediate layer The nuclear fluid inlet 9, the nuclear channel 10, the continuous phase channel 11, the laminar flow channel 12, the main channel 13, the reaction channel 14, and the fluid outlet 15 are composed;

The core fluid enters the core fluid inlet 9 from the core fluid inlet 3 through the core fluid shunt 4 respectively, and flows into the laminar flow channel 12 through the core channel 10; the shell fluid flows from the shell fluid inlet 2 through the shell fluid shunt 5, and flows through the shell channel 8. Laminar flow channel 12; continuous flow flows from the continuous phase inlet 1 through the continuous phase inlet 6 of the intermediate layer and flows into the main channel 13 through the continuous phase channel 11; the core fluid, the shell fluid, and the continuous fluid finally pass through the channel 13 and the reaction channel 14, and the prepared poly The liquid core hydrogel microcapsules flow out from the fluid outlet 15 and are collected.

The chip laminar flow channel has a width of 400 μm and a height of 360 cm; the main channel has a width of 400 μm and a height of 360 cm, the core and shell channels have a width of 50 μm and a height of 300 μm, and the continuous phase channel has a width of 320 μm and a height of 360 cm. As shown in Figure 1.

Example 2

A three-liquid core hydrogel microcapsule chip based on two aqueous phases.

The chip is formed by bonding three layers of PDMS chips (upper layer, middle layer, lower layer).

Mainly consists of upper continuous phase inlet 1, shell fluid inlet 2, nuclear fluid inlet 3, core fluid split port 4, shell fluid split port 5; intermediate layer continuous phase inlet 6, intermediate layer shell fluid inlet 7, shell channel 8, intermediate layer The nuclear fluid inlet 9, the nuclear channel 10, the continuous phase channel 11, the laminar flow channel 12, the main channel 13, the reaction channel 14, and the fluid outlet 15 are composed;

The core fluid enters the core fluid inlet 9 from the core fluid inlet 3 through the core fluid shunt 4 respectively, and flows into the laminar flow channel 12 through the core channel 10; the shell fluid flows from the shell fluid inlet 2 through the shell fluid shunt 5, and flows through the shell channel 8. Laminar flow channel 12; continuous flow flows from the continuous phase inlet 1 through the continuous phase inlet 6 of the intermediate layer and flows into the main channel 13 through the continuous phase channel 11; the core fluid, the shell fluid, and the continuous fluid finally pass through the channel 13 and the reaction channel 14, and the prepared poly The liquid core hydrogel microcapsules flow out from the fluid outlet 15 and are collected.

The laminar flow channel of the chip is 300μm wide and 300cm high; the main channel is 300μm wide and 300cm high, the core and shell channels are 70μm wide and 100μm high, and the continuous phase channel is 300μm wide and 300cm high, as shown in Figure 2.

Example 3

A four-liquid core hydrogel microcapsule chip based on two aqueous phases.

The chip is formed by bonding three layers of PDMS chips (upper layer, middle layer, lower layer).

Mainly consists of upper continuous phase inlet 1, shell fluid inlet 2, nuclear fluid inlet 3, core fluid split port 4, shell fluid split port 5; intermediate layer continuous phase inlet 6, intermediate layer shell fluid inlet 7, shell channel 8, intermediate layer The nuclear fluid inlet 9, the nuclear channel 10, the continuous phase channel 11, the laminar flow channel 12, the main channel 13, the reaction channel 14, and the fluid outlet 15 are composed;

The core fluid enters the core fluid inlet 9 from the core fluid inlet 3 through the core fluid shunt 4 respectively, and flows into the laminar flow channel 12 through the core channel 10; the shell fluid flows from the shell fluid inlet 2 through the shell fluid shunt 5, and flows through the shell channel 8. Laminar flow channel 12; continuous flow flows from the continuous phase inlet 1 through the continuous phase inlet 6 of the intermediate layer and flows into the main channel 13 through the continuous phase channel 11; the core fluid, the shell fluid, and the continuous fluid finally pass through the channel 13 and the reaction channel 14, and the prepared poly The liquid core hydrogel microcapsules flow out from the fluid outlet 15 and are collected.

The laminar flow channel of the chip is 400μm wide and 400cm high; the main channel is 300μm wide and 400cm high, the core and shell channels are 70μm wide and 200μm high, and the continuous phase channel is 400μm wide and 300cm high, as shown in Figure 3.

Example 4

An application of a two-liquid core hydrogel microcapsule chip based on two aqueous phases.

Utilize a kind of two-liquid core hydrogel microcapsule chip based on two aqueous phases in Example 1 to prepare two-liquid core hydrogel microcapsules, the core fluid component is Dex, and the shell fluid is PEG, sodium alginate (NaA) and calcium disodium ethylenediaminetetraacetate (Ca-EDTA), the continuous phase is a mixture of mineral oil, acetic acid (HAc) and Span 80.

The PEG molecular weight: 20kDa, concentration: 17%; Dex molecular weight: 50kDa, concentration: 15%; NaA concentration: 1%, viscosity 55cps, Ca-EDTA concentration: 1%, HAc concentration 0.15%, Span 80 concentration 2%.

The core, shell, and continuous phase fluids were respectively introduced into the microfluidic chip from the core, shell, and continuous phase fluid inlets. The core flow rate: 0.6 μL/min, the shell flow rate: 4 μL/min, and the continuous phase flow rate: 30 μL/min. The bright-field image of the dual-core hydrogel microcapsules prepared based on the above conditions is shown in Figure 4.

Example 5

A three-liquid core hydrogel microcapsule chip application based on two aqueous phases.

Utilize a kind of two-phase-based three-liquid core hydrogel microcapsule chip in Example 2 to prepare two-liquid core hydrogel microcapsules, the core fluid component is Dex, and the shell fluid is PEG, sodium alginate (NaA) and calcium disodium ethylenediaminetetraacetate (Ca-EDTA), the continuous phase is a mixture of mineral oil, acetic acid (HAc) and Span 80.

The PEG molecular weight: 20kDa, concentration: 17%; Dex molecular weight: 50kDa, concentration: 15%; NaA concentration: 1%, viscosity 55cps, Ca-EDTA concentration: 1%, HAc concentration 0.10%, Span 80 concentration 2%.

The core, shell, and continuous phase fluids were respectively introduced into the microfluidic chip from the core, shell, and continuous phase fluid inlets. The core flow rate: 0.3 μL/min, the shell flow rate: 9 μL/min, and the continuous phase flow rate: 20 μL/min. The bright field image of the three-liquid core hydrogel microcapsules prepared based on the above conditions is shown in Figure 5.

Claims (5)

1. A multiliquid core hydrogel microcapsule chip based on double aqueous phases is characterized in that: the chip is manufactured by a conventional soft lithography method, and is a three-layer PDMS chip formed by bonding an upper chip layer, a middle chip layer and a lower chip layer, wherein the upper chip layer adopts a shunting design;

the upper layer of the chip mainly comprises a core fluid inlet (3), a shell fluid inlet (2), a continuous phase inlet (1), a core fluid shunting port (4) and a shell fluid shunting port (5); the chip middle layer mainly comprises a continuous phase inlet (6), a continuous phase channel (11), a core fluid inlet (9), a shell fluid inlet (7), a core channel (10), a shell channel (8), a laminar flow channel (12), a main channel (13), a reaction channel (14) and a fluid outlet (15); the lower layer of the chip is a white board without a structure;

the nuclear fluid shunting port (4) on the upper layer of the chip is communicated with the nuclear fluid inlet (9) on the middle layer of the chip; the nuclear fluid inlet of the chip middle layer is communicated with the nuclear channel;

the shell fluid shunting port (5) on the upper layer of the chip is communicated with the shell fluid inlet (7) on the middle layer of the chip; a shell fluid inlet of the chip intermediate layer is communicated with the shell channel;

the continuous phase inlet (1) of the upper layer of the chip is communicated with the continuous phase inlet (6) of the middle layer of the chip; a branch fluid inlet of a shell fluid inlet (2) on the upper layer of the chip is a shell fluid shunting port (5), and a branch fluid inlet of a core fluid inlet (3) on the upper layer of the chip is a core fluid shunting port (4); the shell fluid shunting port, the shell fluid inlet of the chip middle layer and the shell channel are correspondingly equal in number; the number of the nuclear fluid shunt ports, the number of the nuclear fluid inlets in the chip middle layer and the number of the nuclear channels are correspondingly equal; the number of the core channels (10) is 2, 3 or 4, and the number of the shell channels (8) is 3, 4 or 5 correspondingly; realizing the multi-liquid-core hydrogel microcapsule.

2. The aqueous two-phase based multi-liquid-core hydrogel microencapsulation chip of claim 1, wherein: nuclear fluid enters a nuclear fluid inlet (9) of the chip middle layer from a nuclear fluid inlet (3) of the chip upper layer through a nuclear fluid diversion port (4) and flows into a laminar flow channel (12) through a nuclear channel (10); the shell fluid flows into the laminar flow channel (12) from the shell fluid inlet (2) on the upper layer of the chip through the shell fluid shunting port (5), passes through the shell fluid inlet (7) on the middle layer of the chip and flows into the shell channel (8); a continuous flow flows into a main channel (13) from a continuous phase inlet (1) on the upper layer of the chip through a continuous phase inlet (6) on the middle layer and through a continuous phase channel (11); the core fluid, the shell fluid and the continuous fluid finally pass through the main channel (13) and the reaction channel (14), and the prepared multi-liquid-core hydrogel microcapsule flows out from the fluid outlet (15) and is collected.

3. The aqueous two-phase based multi-liquid-core hydrogel microencapsulation chip of claim 1, wherein: the laminar flow channel (12) has a width of 100-600 μm and a height of 100-500cm; the width of the main channel (13) is 100-500 mu m, and the height is 50-500cm; the width of the core channel (10) and the shell channel (8) is 20-200 μm, and the height is 20-200 μm; the width of the continuous phase channel (11) is 100-400 μm, and the height is 50-300cm.

4. The aqueous two-phase based multi-liquid-core hydrogel microencapsulation chip of claim 1, wherein: the number of liquid cores of the microcapsule is more than or equal to 1.

5. The aqueous two-phase based multi-liquid-core hydrogel microencapsulation chip of claim 1, wherein: the core of the formed multi-liquid-core hydrogel microcapsule is aqueous solution, and the shell is hydrogel.

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