CN113842846A

CN113842846A - A kind of preparation method of β-cyclodextrin/polyvinyl alcohol nano-microcapsule

Info

Publication number: CN113842846A
Application number: CN202111141557.3A
Authority: CN
Inventors: 吴述平; 马俊杰; 张侃; 朱脉勇; 丁福源
Original assignee: Jiangsu University
Current assignee: Jiangsu University
Priority date: 2021-09-28
Filing date: 2021-09-28
Publication date: 2021-12-28

Abstract

The invention belongs to the technical field of nanotechnology and microcapsules, and particularly relates to a preparation method of beta-cyclodextrin/polyvinyl alcohol nano-microcapsules. The beta-cyclodextrin/polyvinyl alcohol nano microcapsule prepared by the invention has the advantages of nano-scale size, good biocompatibility and biodegradability, no organic solvent is used in the preparation process, the influence on the environment is reduced, and the beta-cyclodextrin/polyvinyl alcohol nano microcapsule has wide application market in the fields of food, medicine, pesticide and the like.

Description

Preparation method of beta-cyclodextrin/polyvinyl alcohol nano microcapsule

Technical Field

The invention belongs to the technical field of nanotechnology and microcapsules, and particularly relates to a preparation method of a beta-cyclodextrin/polyvinyl alcohol nano microcapsule.

Background

At present, the preparation technology of microcapsules is mature, but most microcapsules prepared by a physical or chemical method stay at the micron level, so that the encapsulated medicine cannot effectively play a role, for example, in the aspect of pesticides, the usage amount of the pesticides in China is as high as more than 200 million tons every year, but the traditional method has the defects of small pesticide action area, easy falling and the like due to the large size of medicine particles, so that a large amount of pesticide residues in soil or water are caused, and the environment is seriously damaged.

Nanotechnology has become the leading subject field of the leading edge of modern science and technology, and is a subject with strong crossability. The nano material can realize special functions which are not possessed by the traditional material by combining with other fields through special properties such as special small-size effect, quantum effect, material localization, surface interface effect and the like. The research field of preparing the nano-grade drug-carrying microcapsule is formed by organically combining the nano technology and the microcapsule preparation technology. The nano microcapsule overcomes some defects of the traditional microcapsule, can effectively improve the embedding rate and the slow release effect of the medicine, enables the medicine to act on a target more efficiently due to the unique small-size effect, and improves the use efficiency of the medicine.

Beta-cyclodextrin is a cyclic polysaccharide, has the advantages of no toxicity, good biocompatibility, capability of preventing the oxidative decomposition of drugs and the like, is easy to dissolve in water, is easy to form stable hydrate, has a truncated cone-shaped structure, regular spatial structure, hydrophobicity in a cavity and hydrophilicity on the outer layer, is easy to form an inclusion compound with polar hydrophobic drug molecules, and is very suitable for preparing drug-loaded microcapsules. At present, research on preparing microcapsules by using beta-cyclodextrin is more, but the size of the prepared microcapsules is basically in the range of several micrometers to dozens of micrometers, so that the utilization rate of a medicament is low, and the preparation also uses organic solvents such as an emulsifier, a dispersing agent and the like, so that the preparation not only influences the characteristics of the microcapsules, but also pollutes the environment.

Disclosure of Invention

The invention aims to overcome the defects of the existing preparation method, and adopts a novel method for preparing the microcapsule, namely a high-voltage electrostatic spraying method for preparing the nano microcapsule, takes nontoxic and environment-friendly water as a solvent, respectively heats and stirs beta-cyclodextrin and polyvinyl alcohol to prepare transparent solutions, uniformly mixes the two solutions according to a certain proportion, puts the transparent solutions into an injector, and applies high voltage to ensure that liquid drops in the solutions form the nano microcapsule. The method avoids the use of organic solvent, adopts degradable biomass material as the capsule wall material, reduces the harm to the environment, meets the requirement of sustainable development, has simple operation and high yield, and has good application prospect.

In order to achieve the purpose, the technical scheme of the invention is as follows:

the invention provides a preparation method of beta-cyclodextrin/polyvinyl alcohol nano microcapsules, which comprises the following specific steps:

(1) respectively mixing two capsule wall materials of beta-cyclodextrin and polyvinyl alcohol with water to prepare a wall material solution with a certain mass fraction, stirring and heating to completely dissolve the capsule wall materials, then mixing the two capsule wall material solutions according to a certain proportion, and stirring to uniformly disperse the two capsule wall materials to form a spray solution;

(2) placing the spraying solution obtained in the step (1) into a flat-head needle injector, placing the injector on a high-voltage electrostatic spraying device, connecting a high-voltage live wire at the needle head, grounding at a receiving device, placing a heating device between the needle head and the receiving device, starting spraying after adjusting the injection speed, the receiving distance, the temperature of the heating device and voltage parameters, and obtaining a layer of thick film, namely a nano microcapsule film, on the receiving device after spraying for a period of time;

(3) and (3) grinding the nano microcapsule membrane obtained in the step (2) into powder to obtain nano microcapsule powder, or dissolving the nano microcapsule powder in water to form a nano microcapsule solution.

In the step (1), the mass percentage concentration of the beta-cyclodextrin wall material solution is 2-4%, and the mass percentage concentration of the polyvinyl alcohol wall material solution is 4-5%;

in the step (1), the stirring and heating are carried out by adopting water bath stirring and heating, the temperature of beta-cyclodextrin is 30-50 ℃, the temperature of polyvinyl alcohol is 90-95 ℃, the stirring speed is 200-400 r/min, and the time is 1-1.5 h;

in the step (1), the mass ratio of the beta-cyclodextrin wall material solution to the polyvinyl alcohol wall material solution is 1: 1.5-1: 4;

in the step (1), the stirring speed of the spraying solution is 100-200 r/min;

in the step (2), the size of a needle head of the flat-head needle injector is 23-27G;

in the step (2), the receiving device adopts tinfoil for receiving;

in the step (2), the heating device is heated by an infrared lamp at the temperature of 75-80 ℃;

in the step (2), the injection speed is 2-8 mul/min, the receiving distance is 6-11 cm, and the voltage is 10-15 kv; the spraying time is 2-3 h.

The beta-cyclodextrin/polyvinyl alcohol nano microcapsule prepared by the invention is applied to the fields of food, medicine, environmental protection, pesticide and the like.

The advantages and the characterization effects of the invention are as follows:

(1) the biological nanometer microcapsule membrane provided by the invention has the particle size of 200-700 nm under the observation of a scanning electron microscope, wherein the particle size is mainly distributed between 350-550 nm, the distribution is concentrated, the powder is pure white, the solution dissolved in water is clear and transparent, and the solution is still clear and transparent after being placed for months at room temperature, and the property is stable.

(2) The solvent used in the invention is water, the raw materials are green and environment-friendly and degradable, and no emulsifier or dispersant is used, so that the use of organic solvent is avoided, the environmental pollution is reduced, and the sustainable development requirement is met.

(3) The invention reduces the micro-capsule prepared by beta-cyclodextrin from micro-scale to nano-scale by the novel nano-microcapsule preparation method, which not only improves the effective action area of the microcapsule, but also enhances the adhesion of the microcapsule on a target body.

Drawings

FIG. 1 is SEM image of β -cyclodextrin/PVA nanocapsules of example 1;

FIG. 2 is a distribution diagram of the particle size of the nano-microcapsules obtained by combining the SEM image of the beta-cyclodextrin/polyvinyl alcohol nano-microcapsules of FIG. 1.

Detailed Description

The invention is further illustrated below with reference to specific embodiments and the accompanying drawings.

Example 1

(1) Weighing 0.5g of beta-cyclodextrin and 1.25g of polyvinyl alcohol according to a formula, respectively adding water to the total weight of 20g and 25g, fully stirring by using a magnetic heating stirrer to completely dissolve the beta-cyclodextrin and the polyvinyl alcohol, wherein the temperature for heating the beta-cyclodextrin is 30 ℃, the temperature for heating the polyvinyl alcohol is 90 ℃, the stirring speed is 300r/min, and the stirring and heating time is 1h to obtain a wall material solution;

(2) two wall material solutions were prepared according to the ratio of beta-cyclodextrin: polyvinyl alcohol ═ 3: 7, mixing the mixture into 5g of solution, and fully mixing the solution by using a magnetic stirrer, wherein the stirring speed is 150r/min, and the stirring time is 10min to obtain a spray solution;

(3) sucking enough spraying solution by a flat-head needle injector, placing on a high-voltage electrostatic spraying device, wherein the flat-head needle is 25G in type, a layer of tin foil is laid on a receiving device, a high-voltage live wire and a ground wire are respectively connected with the needle head and the receiving device at the electric connection part, the receiving distance is adjusted to 10cm, the injection rate is 4 mul/min, the voltage is 11.25kv, and the temperature of an infrared heating device is adjusted to 75 ℃. Starting injection, continuously adjusting voltage until the liquid drop at the needle head changes from a spherical shape to a stable conical shape, namely a Taylor cone, continuously spraying vaporous liquid drop to the receiving device, and spraying for 3h to obtain a nano microcapsule film on the tin foil;

(4) the nano microcapsule membrane on the tin foil is slowly torn off and is continuously ground in a mortar to form powder, namely nano microcapsule powder, and the nano microcapsule powder can also be directly dissolved in water to form nano microcapsule solution.

Example 2

(1) Weighing 0.6g of beta-cyclodextrin and 1.25g of polyvinyl alcohol according to a formula, respectively adding water to the total weight of 20g and 25g, fully stirring by using a magnetic heating stirrer to completely dissolve the beta-cyclodextrin and the polyvinyl alcohol, wherein the temperature for heating the beta-cyclodextrin is 40 ℃, the temperature for heating the polyvinyl alcohol is 90 ℃, the stirring speed is 300r/min, and the stirring and heating time is 1h to obtain a wall material solution;

(2) mixing two wall material solutions according to the proportion of beta-cyclodextrin: polyvinyl alcohol ═ 2: 8, mixing the mixture into 5g of solution, and fully mixing the solution by using a magnetic stirrer, wherein the stirring speed is 150r/min, and the stirring time is 10min to obtain a spray solution;

(3) sucking enough spraying solution by a flat-head needle injector, placing on a high-voltage electrostatic spraying device, wherein the flat-head needle is 25G in type, a layer of tin foil is laid on a receiving device, a high-voltage live wire and a ground wire are respectively connected with the needle head and the receiving device at the electric connection part, the receiving distance is adjusted to 11cm, the injection rate is 7 mul/min, the voltage is 13.90kv, and the temperature of an infrared heating device is 75 ℃. Starting injection, continuously adjusting voltage until the liquid drop at the needle head changes from a spherical shape to a stable conical shape, namely a Taylor cone, continuously spraying vaporous liquid drop to the receiving device, and spraying for 3h to obtain a nano microcapsule film on the tin foil;

Example 3

(2) mixing two wall material solutions according to the proportion of beta-cyclodextrin: polyvinyl alcohol ═ 3: 7, mixing the mixture into 5g of solution, and fully mixing the solution by using a magnetic stirrer, wherein the stirring speed is 150r/min, and the stirring time is 10min to obtain a spray solution;

(3) sucking enough spraying solution by a flat-head needle injector, placing on a high-voltage electrostatic spraying device, wherein the flat-head needle is 25G in type, a layer of tin foil is laid on a receiving device, a high-voltage live wire and a ground wire are respectively connected with the needle head and the receiving device at the electric connection part, the receiving distance is adjusted to 10cm, the injection rate is 7 mul/min, the voltage is 14.39kv, and the temperature of an infrared heating device is 75 ℃. Starting injection, continuously adjusting voltage until the liquid drop at the needle head changes from a spherical shape to a stable conical shape, namely a Taylor cone, continuously spraying vaporous liquid drop to the receiving device, and spraying for 3h to obtain a nano microcapsule film on the tin foil;

Example 4

(1) Weighing 0.5g of beta-cyclodextrin and 1.25g of polyvinyl alcohol according to a formula, respectively adding water to the total weight of 20g and 25g, fully stirring by using a magnetic heating stirrer to completely dissolve the beta-cyclodextrin and the polyvinyl alcohol, wherein the temperature for heating the beta-cyclodextrin is 40 ℃, the temperature for heating the polyvinyl alcohol is 90 ℃, the stirring speed is 300r/min, and the stirring and heating time is 1h to obtain a wall material solution;

(3) sucking enough spraying solution by a flat-head needle injector, placing on a high-voltage electrostatic spraying device, wherein the flat-head needle is 25G in type, a layer of tinfoil is laid on a receiving device, a high-voltage live wire and a ground wire are respectively connected with the needle head and the receiving device at the electric connection part, the receiving distance is adjusted to 8cm, the injection rate is 5 mul/min, the voltage is 12.44kv, and the temperature of an infrared heating device is 75 ℃. Starting injection, continuously adjusting voltage until the liquid drop at the needle head changes from a spherical shape to a stable conical shape, namely a Taylor cone, continuously spraying vaporous liquid drop to the receiving device, and spraying for 3h to obtain a nano microcapsule film on the tin foil;

FIG. 1 is SEM image of β -cyclodextrin/PVA nanocapsules of example 1; FIG. 2 is a distribution diagram of the particle size of the nano-microcapsules obtained by combining the SEM image of the beta-cyclodextrin/polyvinyl alcohol nano-microcapsules of FIG. 1; as can be seen from FIGS. 1 and 2, the particle size is 200-700 nm, wherein the particle size is mainly distributed between 350-550 nm, and the distribution is concentrated.

Claims

1. a preparation method of β-cyclodextrin/polyvinyl alcohol nano-microcapsule, is characterized in that, comprises the steps:

(1) Two kinds of capsule wall materials, β-cyclodextrin and polyvinyl alcohol, are mixed with water to form a wall material solution with a certain mass fraction, and the capsule wall material is completely dissolved by stirring and heating, and then the two capsule wall material solutions are mixed. Mix according to a certain proportion, stir to disperse evenly, and form a spray solution;

(2) The spray solution in step (1) is placed in a flat needle syringe, the syringe is placed on a high-voltage electrostatic spray device, a high-voltage electric live wire is connected at the needle, a ground wire is placed at the receiving device, and the needle and the receiving device are connected. A heating device is placed between the devices, and the injection speed, receiving distance, temperature and voltage parameters of the heating device are adjusted, and the spraying is started. After spraying for a period of time, a thick film, that is, a nano-microcapsule film, is obtained on the receiving device;

(3) grinding the nano-microcapsule film obtained in step (2) into powder to obtain nano-microcapsule powder, or dissolving it in water to form a nano-microcapsule solution.

2. The preparation method according to claim 1, wherein in step (1), the mass percentage concentration of the β-cyclodextrin wall material solution is 2% to 4%, and the quality of the polyvinyl alcohol wall material solution is 2% to 4%. The percentage concentration is 4% to 5%.

3. preparation method as claimed in claim 1 is characterized in that, in step (1), described stirring heating adopts water bath stirring heating, for β-cyclodextrin temperature, take 30～50 ℃, for polyvinyl alcohol temperature take 30～50 ℃ 90～95℃, stirring speed is 200～400r/min, time is 1～1.5h.

4 . The preparation method according to claim 1 , wherein, in step (1), the mass ratio of the β-cyclodextrin wall material solution to the polyvinyl alcohol wall material solution is 1:1.5˜1:4. 5 .

5 . The preparation method according to claim 1 , wherein, in step (1), the stirring rate of the spray solution is 100-200 r/min. 6 .

6 . The preparation method according to claim 1 , wherein in step (2), the size of the needle of the flat needle syringe is 23-27G. 7 .

7. The preparation method according to claim 1, wherein in step (2), the receiving device adopts tin foil to receive.

8 . The preparation method according to claim 1 , wherein in step (2), the heating device is heated by an infrared lamp, and the temperature is 75-80° C. 9 .

9. The preparation method according to claim 1, wherein in step (2), the injection speed is 2～8 μl/min, the receiving distance is 6～11cm, the voltage is 10～15kv; the spraying time is 2 -3h.