CN114917327A - Hydrogel micro-beads with core-shell structure and preparation method and application thereof - Google Patents

Hydrogel micro-beads with core-shell structure and preparation method and application thereof Download PDF

Info

Publication number
CN114917327A
CN114917327A CN202210686451.XA CN202210686451A CN114917327A CN 114917327 A CN114917327 A CN 114917327A CN 202210686451 A CN202210686451 A CN 202210686451A CN 114917327 A CN114917327 A CN 114917327A
Authority
CN
China
Prior art keywords
insulin
core
hydrogel
shell structure
chitosan
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210686451.XA
Other languages
Chinese (zh)
Inventor
李义
潘武黄江
坦比·萨瓦斯亚潘
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Jiaxing University
Original Assignee
Jiaxing University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Jiaxing University filed Critical Jiaxing University
Priority to CN202210686451.XA priority Critical patent/CN114917327A/en
Publication of CN114917327A publication Critical patent/CN114917327A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K38/00—Medicinal preparations containing peptides
    • A61K38/16—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
    • A61K38/17—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans
    • A61K38/22—Hormones
    • A61K38/28—Insulins
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
    • A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
    • A61K47/51—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent
    • A61K47/52—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being an inorganic compound, e.g. an inorganic ion that is complexed with the active ingredient
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
    • A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
    • A61K47/51—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent
    • A61K47/56—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being an organic macromolecular compound, e.g. an oligomeric, polymeric or dendrimeric molecule
    • A61K47/61—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being an organic macromolecular compound, e.g. an oligomeric, polymeric or dendrimeric molecule the organic macromolecular compound being a polysaccharide or a derivative thereof
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
    • A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
    • A61K47/69—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit
    • A61K47/6921—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P3/00—Drugs for disorders of the metabolism
    • A61P3/08—Drugs for disorders of the metabolism for glucose homeostasis
    • A61P3/10—Drugs for disorders of the metabolism for glucose homeostasis for hyperglycaemia, e.g. antidiabetics
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/54—Improvements relating to the production of bulk chemicals using solvents, e.g. supercritical solvents or ionic liquids

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Pharmacology & Pharmacy (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Animal Behavior & Ethology (AREA)
  • Engineering & Computer Science (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Epidemiology (AREA)
  • Diabetes (AREA)
  • Endocrinology (AREA)
  • Zoology (AREA)
  • Gastroenterology & Hepatology (AREA)
  • Immunology (AREA)
  • Proteomics, Peptides & Aminoacids (AREA)
  • Emergency Medicine (AREA)
  • Hematology (AREA)
  • Obesity (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Medicinal Preparation (AREA)
  • Medicines That Contain Protein Lipid Enzymes And Other Medicines (AREA)

Abstract

The invention relates to a hydrogel microbead with a core-shell structure and a preparation method and application thereof, belonging to the technical fields of biomedical materials, nano composite materials, insulin sustained release, oral insulin and the like. In particular to a hydrogel microbead with a core-shell structure and a preparation method thereof, wherein the hydrogel microbead is used for oral insulin and is coated with layered double hydroxides. The microbeads are prepared by combining the pH response characteristic of chitosan with the calcium response characteristic of sodium alginate, and insulin is loaded into the layered clay mineral in order to effectively control the release of insulin. The ions in the layered double hydroxide may effectively bind to insulin via hydrogen bonds to protect insulin from degradation. The product of the invention can be used for insulin slow release and oral insulin, can effectively inhibit the release of the insulin under the pH condition of gastric acid, and can realize the slow release of the insulin within 24 hours under the pH condition of intestinal tracts.

Description

Hydrogel micro-beads with core-shell structure and preparation method and application thereof
Technical Field
The invention belongs to the technical fields of biomedical materials, nano composite materials, insulin slow release, oral insulin and the like, and particularly relates to a core-shell structure hydrogel microbead coated with layered double hydroxides and used for oral insulin and a preparation method thereof.
Background
Diabetes is a chronic metabolic disorder characterized by high blood glucose levels in the body. Over the past few decades, researchers have developed many different sources of insulin variants for the treatment of diabetes. These exogenous insulin variants are formulated as fast, short, intermediate and long acting suspensions.
The most common method of insulin administration is subcutaneous injection, and this parenteral route often results in allergic reactions or poor compliance by the patient. In addition, the parenteral route of administration does not mimic endogenous insulin release, nor does it effectively control blood glucose levels in diabetic patients. Although portal delivery of insulin by enteral administration is similar to endogenous insulin, it is still associated with metabolic abnormalities. On the other hand, the development of a suitable oral insulin preparation improves the bioavailability of insulin and can effectively control the blood sugar level.
In addition, oral administration has received much attention because of its high patient acceptance. As an alternative, much research effort has focused on oral insulin delivery systems to replace traditional injection-based insulin infusion systems. However, a major obstacle to oral insulin delivery systems is that insulin is readily degraded in the strongly acidic environment of the stomach before it is targeted to the site of absorption (i.e., the intestinal tract). Therefore, coating or loading insulin with a suitable polymer is a necessary technique to protect insulin from the strong acidic environment of the stomach.
A hydrogel is a physically or chemically crosslinked three-dimensional semi-solid network composed of swellable hydrophilic or amphiphilic polymer chains. Hydrogels are widely used in biological applications due to their structural similarity to the extracellular matrix and natural soft tissue. In particular, hydrogels having pH responsiveness are biomaterials suitable for oral insulin because they can exhibit swelling and shrinking characteristics in response to changes in environmental pH. In these respects, hydrogels prepared using natural polymers are receiving much attention due to their biocompatibility, biodegradability and renewability.
However, since the macroporous structure of the sodium alginate hydrogel cannot effectively bind low molecular weight hydrophilic insulin, the sodium alginate hydrogel alone cannot retain insulin for a long time. In addition, sodium alginate hydrogel used alone shows a sudden release of insulin (burst release) at gastric acid pH. Therefore, it is very significant and necessary to develop a hydrogel material that can effectively inhibit insulin release at the pH of gastric acid and slowly release insulin by using the change of the surrounding pH when reaching the intestinal tract.
In addition, in order to overcome the problems associated with the conventional sodium alginate hydrogel beads, the stability of the sodium alginate hydrogel can be improved by combining the sodium alginate hydrogel with other polysaccharides. For example, sodium alginate microspheres reinforced with dextran sulfate show better insulin retention at gastric acid pH. However, the insulin release capacity of the composite hydrogel is not greatly increased due to the weak network structure strength.
Disclosure of Invention
In view of the above, the present invention provides a hydrogel microbead with a core-shell structure coated with a layered double hydroxide for oral administration of insulin and a preparation method thereof, in order to overcome the problems associated with the conventional sodium alginate hydrogel microbead.
It is noted that the product of the present invention can be used for sustained release of insulin and oral administration of insulin. The product is effective in inhibiting insulin release at gastric acid pH, and can achieve insulin release slowly over 24 hr at intestinal pH.
In order to achieve the above purpose, the invention provides the following technical scheme:
a preparation method of hydrogel microbeads with core-shell structures comprises the following steps:
(1) synthesizing LDHs nano particles:
adding magnesium salt and aluminum salt into a reaction container, adjusting the pH value to 8.0-10.0 by using an alkali solution, stirring for reaction, centrifuging the reaction mixture, repeatedly washing the reaction mixture by using deionized water for multiple times, and finally drying the reaction mixture in an oven to obtain pure white LDHs nano particles;
adding the mixture into a reaction container, adjusting the pH value to 8-10 by using an alkali solution, stirring for reaction, centrifuging the reaction mixture, repeatedly washing the reaction mixture by using deionized water for multiple times, and finally drying the reaction mixture in an oven to obtain pure white LDHs nano particles;
(2) preparing core-shell structure hydrogel microbeads:
1) dissolving chitosan in 1% acetic acid, and adding CaCl 2 Adjusting the pH value to 5.5-5.7 by using an alkali solution to obtain a chitosan solution for later use;
2) mixing insulin and the LDHs synthesized in the step (1) to form an ion complex, and then mixing the ion complex with the chitosan solution to obtain insulin/LDHs/chitosan/Ca 2+ A homogeneous solution of (a);
3) dissolving sodium alginate in deionized water, and then adjusting the pH to 8.5 by using an alkali solution to obtain a sodium alginate solution for later use;
4) mixing the insulin/LDHs/chitosan/Ca 2+ Dropwise adding the homogeneous solution into the sodium alginate solution under stirring to form hydrogel microbeads, soaking, separating, washing with deionized water, freeze-drying the collected core-shell hydrogel microbeads, and storing.
Preferably, in the step (1), the molar ratio of the magnesium salt to the aluminum salt is (0.5-2):1, and the magnesium salt is MgCl 2 ·6H 2 O, aluminium salt AlCl 3 ·6H 2 O; the alkali liquor is NaOH solution, and the molar concentration of the alkali liquor is 1 mol/L.
The molar ratio of magnesium salt to aluminum salt is 2:1,1:1,1:2, preferably 2: 1. When the molar ratio is 2:1, the surface charge of the obtained LDHs is +28mV, the ratio is reduced, and the surface charge is close to neutral; while a higher positive charge favors the adsorption of negatively charged insulin, so the preferred ratio of the two is 2: 1.
Further, the pH is adjusted to 8 to 10, preferably 9.0, with an alkali solution; when the pH value is 9.0, the obtained LDHs are hexagonal; while at pH 8 or 10, the shape of the resulting LDHs is a mixture of hexagonal and circular shapes.
Further, in the step (1), the reaction temperature is 80 ℃, and the reaction time is 24 hours; the centrifugal speed is 10000r/min, the centrifugal time is 10min, and the drying temperature is 60 ℃.
Preferably, in step (2), the insulin/LDHs/chitosan/Ca 2+ The final concentrations of chitosan, insulin, LDHs and calcium ions in the homogeneous solution of (1) were 3.0 wt%, 3.5mg/mL, 10mg/mL and 0.05-0.15M, respectively.
The calcium ion concentration is in the range of 0.05M to 0.15M, and preferably 0.1M. Under the optimal concentration, the microbeads with good appearance can be formed more quickly; at 0.05M, the formation rate of microbeads is slow; at 0.15M, the bead morphology was not perfectly spherical.
Further, the alkali liquor is NaOH solution, and the molar concentration of the alkali liquor is 1 mol/L; the soaking time is 5-60 min.
It is noted that in the process, the soaking time has a decisive influence on the shell thickness of the hydrogel microbeads with the core-shell structure; the pH value has a decisive influence on whether the chitosan can form gel, and the gel cannot be formed due to the excessively high or excessively low pH value;
similarly, the concentration of calcium ion has an important influence on the gelation of sodium alginate, too low a concentration of calcium ion may result in failure to gel, and too high a concentration of calcium ion is also disadvantageous for the formation of a uniform and stable gel.
In addition, the invention also claims a core-shell structure hydrogel microbead prepared by the method, wherein the hydrogel microbead has a core-shell structure of a layered double hydroxide coated with chitosan/sodium alginate on the surface.
The invention also provides application of the hydrogel micro-beads with the core-shell structure in the biomedical field.
According to the technical scheme, compared with the prior art, the core-shell structure hydrogel microbead and the preparation method thereof provided by the invention have the following excellent effects:
1) the preparation method disclosed by the invention is simple and quick, does not need to use an organic solvent, and is extremely environment-friendly;
2) the invention is prepared by combining the pH response characteristic of chitosan with the calcium response characteristic of sodium alginate, and in order to effectively control the release of insulin, the insulin is loaded into the layered clay mineral. And the ions in the layered double hydroxide can be effectively combined with the insulin through hydrogen bonds so as to protect the insulin from being degraded.
3) The product of the invention can be used for insulin slow release and oral insulin, can effectively inhibit the release of the insulin under the pH condition of gastric acid, and can realize the slow release of the insulin within 24 hours under the pH condition of intestinal tracts.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is a flow chart of LDHs preparation.
FIG. 2 is an appearance diagram of LDHs.
FIG. 3 is a graph showing the particle size and particle size distribution of LDHs.
FIG. 4 is a graph of the surface charge of LDHs and LDHs coated with insulin.
Fig. 5 is a flow chart of preparation of the core-shell structure hydrogel microbead coated with insulin.
Fig. 6 is an appearance view of the hydrogel microbead with core-shell structure coated with insulin.
FIG. 7 is a comparison of shell thicknesses of hydrogel microbeads with core-shell structures obtained at different preparation times. (the thickness of the shell can influence the release rate of insulin)
FIG. 8 is a graph showing the change of swelling ratio of hydrogel microbeads with time at different pH values and different calcium ion concentrations.
FIG. 9 is a photograph showing that hydrogel microbeads obtained without the concentration of calcium ions adhere to the surface of chicken small intestine.
FIG. 10 is a graph comparing the release rates of insulin/chitosan, insulin/chitosan/sodium alginate, insulin/LDHs/chitosan/sodium alginate hydrogel insulin in simulated gastric fluid (pH 1.2) and simulated intestinal fluid (pH 6.8).
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention and the accompanying drawings of the specification, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiment of the invention discloses a preparation method of a hydrogel microbead with a core-shell structure and a layered double hydroxide coating for oral insulin.
The present invention will be further specifically illustrated by the following examples for better understanding, but the present invention should not be construed as being limited thereto, and the insubstantial modifications and variations of the present invention as shown in the above-described summary of the invention are considered to fall within the scope of the invention by those skilled in the art.
The technical solution of the present invention will be further described with reference to the following specific examples.
Example 1
A preparation method of core-shell structure hydrogel microbeads specifically discloses:
1) synthesis of LDHs nanoparticles
6.82g of MgCl 2 .6H 2 O and 4.04gAlCl 3 .6H 2 O (Mg: Al ratio 2:1) was added to a round bottom flask containing 100mL of distilled water; the pH was adjusted to 9.0 with 1M NaOH solution and stirred at 80 ℃ for 24 hours to effect a reaction. Then subjecting the reaction mixture to dissociationRepeatedly washing the core (10000rpm, 10min) with deionized water for multiple times, and finally drying in an oven at 60 ℃ to obtain pure white LDHs nano particles;
2) preparation of core-shell structure hydrogel microbeads
First, chitosan was completely dissolved in 1% acetic acid (v/v) under vigorous stirring; then adding CaCl into the solution 2 And the pH of the chitosan solution was adjusted to pH 5.5-5.7 with 1M NaOH. Simultaneously, mixing insulin and LDHs at 4 ℃ to form an ionic complex; then, the complex solution is mixed with the chitosan solution to obtain insulin/LDHs/chitosan/Ca 2+ A homogeneous solution of (a); the final concentrations of chitosan, insulin, LDHs and calcium ions were 3.0 wt%, 3.5mg/mL, 10mg/mL and 0.1M, respectively.
Finally, sodium alginate was dissolved in deionized water (1 wt%) in a 100mL beaker, and the pH of the solution was then adjusted to pH 8.5 using 1M NaOH; mixing insulin/LDHs/chitosan/Ca 2+ Putting the solution into a 3mL syringe, and then dropwise adding the solution into the sodium alginate solution under stirring; about 20 hydrogel microbeads can be formed in 1mL of solution (about 0.05 mL/drop), and the formed hydrogel microbeads are soaked in the sodium alginate solution for 40 minutes so as to stabilize the core-shell structure of the hydrogel microbeads; then, hydrogel microbeads were separated and washed with deionized water, and then the collected core-shell structure hydrogel microbeads were freeze-dried and stored at 4 ℃ or lower.
Example 2
Based on the preparation process conditions disclosed in example 1, MgCl with unique different parameters 2 .6H 2 O and AlCl 3 .6H 2 The molar ratio of O is 1:1, and the rest process conditions are unchanged.
Example 3
Based on the preparation process conditions disclosed in example 1, only different parameters: MgCl 2 .6H 2 O and AlCl 3 .6H 2 The molar ratio of O is 1:2, and the rest process conditions are unchanged.
Example 4
Based on the preparation process conditions disclosed in example 1, only different parameters: the pH was adjusted to 8 with an alkaline solution, the remaining process conditions were unchanged.
Example 5
Based on the preparation process conditions disclosed in example 1, only different parameters: the pH was adjusted to 10 with an alkaline solution, the remaining process conditions were unchanged.
Example 6
Based on the preparation process conditions disclosed in example 1, only different parameters: CaCl 2 The concentration is 0.05M, and the rest process conditions are unchanged.
Example 7
Based on the preparation process conditions disclosed in example 1, only different parameters: CaCl 2 The concentration is 0.15M, and the rest process conditions are unchanged.
In addition, in order to further verify the superiority of the present application over the prior art, the inventors have also conducted the following experiments:
(1) synthesis and characterization of LDHs
As shown in fig. 2, LDHs are layered inorganic nanomaterials, which have been widely used in the biomedical field due to their special structural characteristics. In the present invention, we prepared Mg using a coprecipitation method 2 Al(OH) 6 NO 3 Based LDH nanoparticle suspensions, as shown in fig. 1, the prepared LDHs suspensions showed uniform dispersibility and typical layered structure.
And as shown by the particle size analysis of FIG. 3, the particle size distribution of LDHs is unimodal, and the average diameter of LDHs is about 120 nm. From the surface charge analysis of FIG. 4, it was shown that the zeta potential of LDHs was +28mV, indicating that the surface of LDHs is positively charged.
(2) Preparation and characterization of core-shell hydrogel microbeads
To prepare the core-shell hydrogel microbeads, we combined the stimulus response characteristics of chitosan and sodium alginate and prepared the chitosan-sodium alginate core-shell hydrogel microbeads by a one-pot method, as shown in fig. 5. By utilizing pH and temperature induced sol-gel transitions, polymers assemble into core-shell hydrogel microbeads, a relatively rare hydrogel morphology.
To prepare core-shell hydrogel beads, first we prepared chitosanAnd calcium chloride, and dripping the mixed solution into a sodium alginate solution; and the pH of the sodium alginate solution is maintained between 9 and 10 in order to form uniform microbeads and efficient gelation. Due to the pH response type sol-gel transition characteristic of chitosan, chitosan liquid drops in the sodium alginate solution are deprotonated at high pH to form stable cores; ca in the chitosan core, on the other hand 2+ Slowly diffuse on the surface and combine with sodium alginate molecules to form a shell. By increasing the incubation time, more calcium alginate gel surrounds the core, forming stable hydrogel microbeads.
After culturing for 40 minutes, the stable core-shell hydrogel microbeads can be obtained. The prepared chitosan-sodium alginate core-shell hydrogel has uniform bead shape and good stability. The chitosan core in the beads was opaque compared to the translucent sodium alginate shell, which clearly showed the boundary between the core and the shell. The cross-section of the microbeads clearly shows solid core shell microbeads with clear boundaries.
To further optimize the core shell microbeads, we prepared a variety of core shell microbeads with different shell thicknesses at different incubation times (5 min, 20 min and 40 min), as shown in fig. 7. From the light micrographs, it can be seen that the thickness of the shell increases with the incubation time. The pH of the reaction medium was adjusted to 8 or 10 except for the incubation time, and although beads could be obtained, the obtained beads were almost homogeneous and the core-shell boundaries could not be distinguished. Upon dissection, the microbeads showed a liquid core surrounded by a solid gel shell. This indicates that chitosan cannot undergo a pH-responsive transition in a low pH sodium alginate solution, and therefore chitosan is still present in the beads as a solution.
(3) Swelling behavior of core-shell hydrogel microbeads
The swelling behavior of hydrogels affects their diffusion, migration and surface properties and plays an important role in biological applications. In general, the swelling properties of hydrogels depend mainly on the medium, crosslink density and porosity of the hydrogel network. Therefore, we used Ca at different molar concentrations 2+ Cross-linkers (0.05M, 0.1M and 0.15M) investigated the swelling behavior of core-shell hydrogel microbeads, e.g.As shown in fig. 8.
All hydrogel microbeads exhibited swelling characteristics regardless of the calcium ion concentration. At a concentration of 0.05M, the hydrogel microbeads prepared had a swelling rate of over 200% after 15min and increased slowly over time. After 6 hours, hydrogel beads were prepared at 0.05M concentration at pH 1.2, pH 6.8 and pH 7.4 with swelling ratios of 600%, 550% and 1200%, respectively. It should be noted that the swelling properties of the hydrogel microbeads prepared at the concentrations of 0.1M and 0.15M were very high. Particularly, the swelling ratio of the hydrogel microspheres prepared under the calcium ion concentration of 0.15M reaches 600%, and after 6 hours, the swelling ratio reaches more than 1500%, which shows that the hydrogel microspheres have good swelling performance. These results show that the swelling ratio of the hydrogel beads is tunable by varying the calcium ion concentration.
(4) The biological adhesiveness of the core-shell hydrogel microspheres,
bioadhesive refers to the property of a material to adhere to the surface of living tissue. In general, bioadhesives are prepared using natural polymers (such as chitosan, gelatin and sodium alginate) or synthetic polymers (such as polyacrylamide and polyacrylic acid). These polymers exhibit adhesion to various substrates through hydrogen bonding or electrostatic interaction, etc.
To investigate the bioadhesive properties of core-shell hydrogel microbeads, we placed the microbeads on the surface of the chicken small intestine, as shown in fig. 9. After the continuous washing by the buffer solution, the hydrogel microspheres can still be effectively adhered to the chicken intestine mucus layer, which shows that the hydrogel microspheres have good biological adhesion.
(5) Effect of core-shell hydrogel microspheres on in-vitro release of insulin
At different pH corresponding to the gastrointestinal tract (GIT), pH 1.2 (simulated gastric fluid, SGF) and pH 6.8 (simulated intestinal fluid, SIF), we investigated the insulin release capacity of the core-shell hydrogel microbeads, as shown in fig. 10. The insulin/chitosan formulation undergoes a sudden release (complete release of insulin within 2 hours) in a simulated gastric medium (pH 1.2). Notably, the core shell hydrogel beads effectively inhibited burst release (pH 1.2). In particular, when insulin is co-loaded with LDHs, such sudden release is effectively inhibited. The formulation was then transferred to simulated intestinal fluid (SIF, pH 6.8) and sustained and gradual insulin release was observed.
The analysis proves that the chitosan-sodium alginate core-shell hydrogel microspheres are successfully prepared by a convenient one-pot instillation technology and are used for oral insulin. The prepared hydrogel microspheres show a core-shell structure, and clear boundaries exist among the core shells. The chitosan-sodium alginate micro-beads with solid cores or liquid cores can be prepared by adjusting the pH value of the sodium alginate solution.
In addition, Ca can be regulated 2+ The shell thickness of the microbeads. In order to improve the stability and the controlled release performance of the hydrogel microsphere oral insulin, insulin is loaded between LDHs layers. The core-shell hydrogel microbeads can be effectively adhered to chicken intestines. At a pH of 1.2, the core-shell hydrogel microbeads were able to retain insulin completely in SGF. In SIF with pH 6.8, insulin is gradually released within 24 hours, and when hydrogel microbeads are loaded with insulin/LDHs, the insulin release rate is more effectively controlled. Therefore, the chitosan-sodium alginate core-shell hydrogel microspheres prepared by the method have the potential of controlling the release of insulin after being orally taken.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (7)

1. The preparation method of the hydrogel microbeads with the core-shell structure is characterized by comprising the following steps:
(1) synthesizing LDHs nano particles:
adding magnesium salt and aluminum salt into a reaction container, adjusting the pH value to 8.0-10.0 by using an alkali solution, stirring for reaction, centrifuging the reaction mixture, repeatedly washing the reaction mixture by using deionized water for multiple times, and finally drying the reaction mixture in an oven to obtain pure white LDHs nano particles;
(2) preparing core-shell structure hydrogel microbeads:
1) dissolving chitosan in 1% acetic acid, and adding CaCl 2 Adjusting the pH value to 5.5-5.7 by using an alkali solution to obtain a chitosan solution for later use;
2) mixing insulin and the LDHs synthesized in the step (1) to form an ion complex, and then mixing the ion complex with the chitosan solution to obtain insulin/LDHs/chitosan/Ca 2+ The homogeneous solution of (a);
3) dissolving sodium alginate in deionized water, and then adjusting the pH to 8.5 by using an alkali solution to obtain a sodium alginate solution for later use;
4) mixing the insulin/LDHs/chitosan/Ca 2+ Dropwise adding the homogeneous solution into the sodium alginate solution under stirring to form hydrogel microbeads, soaking, separating, washing with deionized water, freeze-drying the collected core-shell hydrogel microbeads, and storing.
2. The method for preparing hydrogel microbeads with core-shell structure as claimed in claim 1, wherein in step (1), said magnesium salt and said aluminum salt are in a molar ratio of (0.5-2):1, and said magnesium salt is MgCl 2 ·6H 2 O, aluminium salt AlCl 3 ·6H 2 O; the alkali liquor is NaOH solution, and the molar concentration of the alkali liquor is 1 mol/L.
3. The preparation method of the hydrogel microbead with core-shell structure according to claim 1 or 2, wherein in the step (1), the reaction temperature is 80 ℃, and the reaction time is 24 hours; the centrifugation speed is 10000r/min, the centrifugation time is 10min, and the drying temperature is 60 ℃.
4. The method for preparing hydrogel microbeads with core-shell structure as recited in claim 1, wherein in step (2), said pancreas is replaced by said pancreasinsulin/LDHs/chitosan/Ca 2+ The final concentrations of chitosan, insulin, LDHs and calcium ions in the homogeneous solution of (1) were 3.0 wt%, 3.5mg/mL, 10mg/mL and 0.05-0.15M, respectively.
5. The preparation method of the hydrogel microbeads with the core-shell structure according to claim 1 or 4, wherein the alkali liquor is NaOH solution, and the molar concentration of the alkali liquor is 1 mol/L; the soaking time is 5-60 min.
6. The hydrogel microbead with core-shell structure prepared by the method as claimed in claim 1, wherein the hydrogel microbead has a core-shell structure with a surface of chitosan/sodium alginate-coated layered double hydroxide.
7. The application of the hydrogel microbeads with the core-shell structure prepared by the method according to claim 1 or the hydrogel microbeads with the core-shell structure according to claim 6 in the biomedical field.
CN202210686451.XA 2022-06-16 2022-06-16 Hydrogel micro-beads with core-shell structure and preparation method and application thereof Pending CN114917327A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210686451.XA CN114917327A (en) 2022-06-16 2022-06-16 Hydrogel micro-beads with core-shell structure and preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210686451.XA CN114917327A (en) 2022-06-16 2022-06-16 Hydrogel micro-beads with core-shell structure and preparation method and application thereof

Publications (1)

Publication Number Publication Date
CN114917327A true CN114917327A (en) 2022-08-19

Family

ID=82814905

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210686451.XA Pending CN114917327A (en) 2022-06-16 2022-06-16 Hydrogel micro-beads with core-shell structure and preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN114917327A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115323528A (en) * 2022-08-22 2022-11-11 东华大学 Artificial muscle fiber with calcium ion response and preparation method thereof

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115323528A (en) * 2022-08-22 2022-11-11 东华大学 Artificial muscle fiber with calcium ion response and preparation method thereof
CN115323528B (en) * 2022-08-22 2024-04-12 东华大学 Artificial muscle fiber with calcium ion response and preparation method thereof

Similar Documents

Publication Publication Date Title
Racoviţă et al. Polysaccharides based on micro-and nanoparticles obtained by ionic gelation and their applications as drug delivery systems
Sun et al. pH-sensitive ZnO/carboxymethyl cellulose/chitosan bio-nanocomposite beads for colon-specific release of 5-fluorouracil
Stanisz et al. Recent advances in the fabrication and application of biopolymer-based micro-and nanostructures: A comprehensive review
Huang et al. Advances in phenylboronic acid-based closed-loop smart drug delivery system for diabetic therapy
Liu et al. Synthesis of cellulose aerogels as promising carriers for drug delivery: a review
CN107375196B (en) Catechol-based natural polysaccharide composite hydrogel carrier and preparation method thereof
CN109289081B (en) Anti-adhesion polyvinyl alcohol embolism microsphere and preparation method and application thereof
CN110623918B (en) Carboxymethyl chitosan/sodium alginate nano hydrogel and preparation method and application thereof
Wu et al. Fabrication of core–shell microspheres using alginate and chitosan–polycaprolactone for controlled release of vascular endothelial growth factor
WO2012072012A1 (en) Microcapsule preparation of alginate-chitosan acyl derivatives, preparation and application thereof
CN114917327A (en) Hydrogel micro-beads with core-shell structure and preparation method and application thereof
CN115521627A (en) Structural protein/hyaluronic acid composite micro-nano particle, particle hydrogel material and application
CN113638078B (en) Polyelectrolyte complex hydrogel fiber and preparation method thereof
CN102688195A (en) Preparation method for doxorubicin hydrochloride-entrapped chitosan carboxymethyl chitosan nanometer controlled-release particle with pH sensibility
CN110180023B (en) Preparation method of high-strength biomass tissue engineering scaffold material
CN1679518A (en) Magnetic medicinal capsules and preparation thereof
Maiti et al. Cationic polyelectrolyte–biopolymer complex hydrogel particles for drug delivery
CN112225911A (en) Preparation method of composite hydrogel medical material
CN110408187B (en) Injectable chitosan-based hydrogel with self-repairing property and high mechanical strength, and preparation method and application thereof
CN101361976B (en) Hyaluronic acid modified polu-cyano acrylic acid alkyl ester nano granules and preparation method and use thereof
CN115337272B (en) Natural polysaccharide-based chemical-physical double-crosslinked hydrogel particles and preparation and application thereof
CN114748680B (en) Gelatin-alginate composite drug-loaded embolism microsphere and application thereof
CN115073768B (en) Preparation method of functional component loaded double-network hydrogel
WO2023123813A1 (en) Drug-loaded microspheres as well as preparation method therefor and use thereof
CN106727361B (en) A kind of gelatin-compounded microballoon of PLGA- and preparation method thereof carrying genistein

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination