Disclosure of Invention
The invention aims to provide a diatomite modified antibacterial dressing and a preparation method thereof, which solve the following technical problems:
(1) Solves the problem that the injection of antibiotics in the wound healing process is easy to cause bacteria to generate drug resistance and cause wound infection.
(2) Solves the problem of easy scar generation after wound healing.
The aim of the invention can be achieved by the following technical scheme:
the diatomite modified antibacterial dressing is prepared from the following raw materials in parts by weight: 1-2 parts of modified diatomite, 30-40 parts of cationic cyclodextrin, 50-60 parts of chitosan and 0.2-0.6 part of lithospermum oil;
the modified diatomite is prepared by acid etching and calcining diatomite and then carrying out surface modification by using a surfactant;
the cationic cyclodextrin is prepared by introducing epoxy groups into the structure of the cationic cyclodextrin and then modifying halogen-free quaternary ammonium salt.
Further, the preparation method of the modified diatomite comprises the following steps:
step one: dispersing diatomite in nitric acid, stirring for 4-8 hours at the temperature of 70-75 ℃, discharging, washing with pure water to be neutral, transferring the materials into a tube furnace, raising the temperature of the tube furnace to 400-500 ℃, calcining for 1-2 hours under the protection of nitrogen, and sieving to obtain diatomite pretreatment materials;
step two: pouring the diatomite pretreatment material into pure water for uniform dispersion, adding sodium dodecyl benzene sulfonate, regulating the pH of the system to 1-2 by using hydrochloric acid, stirring for 2-6 hours at room temperature, standing for precipitation, collecting solid materials, washing, and drying in vacuum to obtain the modified diatomite.
Through the technical scheme, after the diatomite is subjected to acid etching, the purity of the diatomite is greatly improved, the porosity of the diatomite is increased, the pore structure of the diatomite is promoted to be optimized, the pore volume and the pore diameter of the pore structure of the diatomite are further increased through high-temperature calcination, the diatomite pretreatment material with rich pore structures is formed, and the diatomite is further subjected to surface modification by using the surfactant sodium dodecyl benzene sulfonate, so that the modified diatomite is obtained.
Further, in the first step, the concentration of the nitric acid is 2-4mol/L.
Further, in the first step, the mesh number of the sieving is 300-500 mesh.
Further, in the second step, the concentration of the hydrochloric acid is 0.1-0.2mol/L.
Further, the preparation method of the cationic cyclodextrin comprises the following steps:
the first step: dissolving beta-cyclodextrin in pure water, adding sodium hydroxide solution, mixing, continuously adding epichlorohydrin into the system, stirring at constant temperature of 40-45 ℃ for 2-3h, discharging, washing to neutrality, and drying to obtain modified cyclodextrin;
and a second step of: mixing the modified cyclodextrin, alkylamine and pure water, stirring uniformly, raising the temperature of the system to 60-70 ℃, keeping the temperature, stirring for 4-12 hours, naturally cooling the materials, and discharging to obtain the cationic cyclodextrin.
Further, in the first step, the concentration of the sodium hydroxide is 0.05-0.1mol/L.
Further, in the first step, the alkylamine is any one of N, N-dimethyl-N-octylamine or N, N-dimethyl-dodecylamine.
Through the technical scheme, under the action of sodium hydroxide, epoxy chloropropane reacts with beta-cyclodextrin, epoxy groups are introduced into the beta-cyclodextrin structure to form epoxy modified beta-cyclodextrin, and under a high-temperature environment, the epoxy groups in the structure can further undergo ring opening reaction with tertiary amine groups in an alkylamine structure to form halogen-free quaternary ammonium salt cationic cyclodextrin.
A method for preparing a diatomite modified antibacterial dressing, comprising the following steps:
s1: dissolving cationic cyclodextrin in pure water, uniformly mixing, adding modified diatomite, oscillating for 4-6 hours at room temperature, and centrifuging to separate solid materials to obtain a diatomite-cyclodextrin compound;
s2: dispersing the diatomite-cyclodextrin compound in pure water, adding a sodium periodate solution, stirring for 1-2 hours at room temperature, discharging, washing, and drying in vacuum to obtain the diatomite-cyclodextrin oxide compound;
s3: dispersing the diatomite-cyclodextrin oxide compound in pure water to form a dispersion liquid with the mass fraction of 1-2%, adding chitosan into the dispersion liquid, stirring for 1-2 hours at room temperature, discharging, washing and drying to obtain the diatomite-cyclodextrin-chitosan ternary crosslinked compound;
s4: mixing the diatomite-cyclodextrin-chitosan ternary crosslinked compound with pure water to form a dispersion liquid, adding arnebia oil into the dispersion liquid, stirring for 2-4 hours at the temperature of 60-65 ℃, discharging, and freeze-drying to obtain the diatomite modified antibacterial dressing.
Further, in the step S2, the mass fraction of the sodium periodate solution is 10-15%, and the solid-to-liquid ratio of the diatomite-cyclodextrin complex to the sodium periodate solution is 1:5-10.
Through the technical scheme, after the modified diatomite is modified by sodium dodecyl benzene sulfonate, the surface is electronegative, cationic cyclodextrin can be adsorbed and combined through electrostatic action and a porous structure to form a diatomite-cyclodextrin compound, a large number of hydroxyl groups in a cyclodextrin molecular chain can be oxidized into aldehyde groups by sodium periodate to obtain the diatomite-cyclodextrin oxide compound, the chitosan structure contains rich amino groups and can react with the aldehyde groups in the diatomite-cyclodextrin oxide compound structure to form a diatomite-cyclodextrin-chitosan ternary crosslinked compound with a crosslinked structure, and finally, the inclusion of the lithospermum oil is carried out through the inclusion action of cyclodextrin to obtain the diatomite modified antibacterial dressing
The invention has the beneficial effects that:
(1) According to the invention, the cationic cyclodextrin is prepared and used as a matrix material of the dressing, so that the excellent antibacterial performance of quaternary ammonium salt cations can be utilized, a good antibacterial effect is given to the dressing, bacterial infection is avoided in the wound healing process, electrostatic adsorption can be generated between the cationic cyclodextrin and modified diatomite through positive electricity brought by the cations, the cationic cyclodextrin is embedded into the pore structure of the diatomite, and then the cationic cyclodextrin in the diatomite pores is crosslinked with the cationic cyclodextrin in the pores, so that the cationic diatomite in the diatomite pores is converted into a chitosan-diatomite three-dimensional network structure, the cationic cyclodextrin and chitosan are effectively prevented from falling off from the diatomite structure, a durable antibacterial effect is achieved, the modified diatomite is uniformly dispersed in the dressing, the coagulation factor in blood can be adsorbed by utilizing the adsorption effect of the diatomite, the concentration of the coagulation factor at the wound is improved, and the rapid hemostasis is realized.
(2) The antibacterial dressing prepared by the invention contains chitosan, has good biocompatibility, can promote metabolism, quicken the formation of wound granulation tissues and is beneficial to wound healing. The lithospermum oil included by the cyclodextrin has good anti-inflammatory effect, can promote epithelial proliferation and coverage, inhibit and control body fluid extravasation, inhibit excessive growth of granulation tissue, further play a role in inhibiting scar, and has stronger astringing effect, so that the lithospermum oil can control body fluid extravasation, reduce body fluid loss, promote epithelial growth, and further accelerate wound healing. In addition, under the inclusion effect of cyclodextrin, the controllable slow release of the lithospermum oil can be realized, so that a good effect can be achieved by adding a small amount of lithospermum oil into the formula. In conclusion, the antibacterial dressing prepared by the invention can provide a good environment for wound healing, has lasting antibacterial effect, realizes controllable drug loading, can slowly release the healing promoting substances, accelerates wound healing, and reduces the generation of skin problems such as scars.
Of course, it is not necessary for any one product to practice the invention to achieve all of the advantages set forth above at the same time.
Detailed Description
The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1
The diatomite modified antibacterial dressing is prepared from the following raw materials in parts by weight: 1.5 parts of modified diatomite, 35 parts of cationic cyclodextrin, 55 parts of chitosan and 0.5 part of lithospermum oil;
the preparation method of the antibacterial dressing comprises the following steps:
s1: dissolving cationic cyclodextrin in pure water, uniformly mixing, adding modified diatomite, oscillating for 5 hours at room temperature, and centrifuging to separate solid materials to obtain a diatomite-cyclodextrin compound;
s2: dispersing the diatomite-cyclodextrin compound in pure water, adding a sodium periodate solution with the mass fraction of 15%, stirring for 2 hours at room temperature, discharging, washing, and drying in vacuum to obtain the diatomite-cyclodextrin oxide compound, wherein the solid-to-liquid ratio of the diatomite-cyclodextrin compound to the sodium periodate solution is 1:8;
s3: dispersing the diatomite-cyclodextrin oxide compound in pure water to form a dispersion liquid with the mass fraction of 2%, adding chitosan into the dispersion liquid, stirring for 2 hours at room temperature, discharging, washing and drying to obtain the diatomite-cyclodextrin-chitosan ternary crosslinked compound;
s4: mixing the diatomite-cyclodextrin-chitosan ternary crosslinked compound with pure water to form a dispersion liquid, adding arnebia oil into the dispersion liquid, stirring for 3 hours at the temperature of 65 ℃, discharging, and freeze-drying to obtain the diatomite modified antibacterial dressing; the inclusion rate of the arnebia oil is calculated by using the mass (g) of the diatomite modified antibacterial dressing/(the mass (g) of the diatomite-cyclodextrin-chitosan ternary crosslinked complex and the arnebia oil) ]multipliedby 100 percent, and the calculated inclusion rate is 89.57 percent.
The preparation method of the modified diatomite comprises the following steps:
step one: dispersing 5g of diatomite in 3 mol/L nitric acid, stirring for 6 hours at 70 ℃, discharging, washing with pure water to neutrality, transferring the materials into a tube furnace, raising the temperature of the tube furnace to 450 ℃, calcining for 2 hours under the protection of nitrogen, and sieving with a 500-mesh sieve to obtain a diatomite pretreatment material;
step two: pouring 2g of diatomite pretreatment material into pure water for uniform dispersion, adding 3.5g of sodium dodecyl benzene sulfonate, regulating the pH value of the system to be 1 by using hydrochloric acid with the concentration of 0.1mol/L, stirring for 4 hours at room temperature, standing for precipitation, collecting solid materials, washing and drying in vacuum to obtain the modified diatomite.
The preparation method of the cationic cyclodextrin comprises the following steps:
the first step: dissolving 10g of beta-cyclodextrin in pure water, adding 4mL of sodium hydroxide solution with the concentration of 0.1mol/L, uniformly mixing, continuously adding 2.5g of epichlorohydrin into the system, stirring at the constant temperature of 40 ℃ for 2 hours, discharging, washing to be neutral, and drying to obtain modified cyclodextrin;
and a second step of: mixing 4g of modified cyclodextrin, 1.2g of N, N-dimethyl N-octylamine and pure water, uniformly stirring, raising the temperature of the system to 70 ℃, preserving heat and stirring for 9 hours, and discharging after the materials are naturally cooled to obtain cationic cyclodextrin; a5 mg sample of cationic cyclodextrin was weighed and subjected to elemental analysis using an XKCHN-700 type elemental analyzer, and the cationic cyclodextrin sample was tested to have a nitrogen content of 6.25% and, as analyzed, the nitrogen was derived from a quaternary ammonium cationic group.
Example 2
The diatomite modified antibacterial dressing is prepared from the following raw materials in parts by weight: 1 part of modified diatomite, 30 parts of cationic cyclodextrin, 50 parts of chitosan and 0.2 part of lithospermum oil;
the preparation method of the antibacterial dressing comprises the following steps:
s1: dissolving cationic cyclodextrin in pure water, uniformly mixing, adding modified diatomite, oscillating for 4 hours at room temperature, and centrifuging to separate solid materials to obtain a diatomite-cyclodextrin compound;
s2: dispersing the diatomite-cyclodextrin compound in pure water, adding a sodium periodate solution with the mass fraction of 10%, stirring for 1h at room temperature, discharging, washing, and vacuum drying to obtain the diatomite-cyclodextrin oxide compound, wherein the solid-to-liquid ratio of the diatomite-cyclodextrin compound to the sodium periodate solution is 1:5;
s3: dispersing the diatomite-cyclodextrin oxide compound in pure water to form a dispersion liquid with the mass fraction of 1%, adding chitosan into the dispersion liquid, stirring for 1h at room temperature, discharging, washing and drying to obtain the diatomite-cyclodextrin-chitosan ternary crosslinked compound;
s4: mixing the diatomite-cyclodextrin-chitosan ternary crosslinked compound with pure water to form a dispersion liquid, adding arnebia oil into the dispersion liquid, stirring for 2 hours at the temperature of 60 ℃, discharging, and freeze-drying to obtain the diatomite modified antibacterial dressing.
Wherein the modified diatomaceous earth and cationic cyclodextrin were prepared in the same manner as in example 1.
Example 3
The diatomite modified antibacterial dressing is prepared from the following raw materials in parts by weight: 2 parts of modified diatomite, 40 parts of cationic cyclodextrin, 60 parts of chitosan and 0.6 part of lithospermum oil;
the preparation method of the antibacterial dressing comprises the following steps:
s1: dissolving cationic cyclodextrin in pure water, uniformly mixing, adding modified diatomite, oscillating at room temperature for 6 hours, and centrifuging to separate solid materials to obtain a diatomite-cyclodextrin compound;
s2: dispersing the diatomite-cyclodextrin compound in pure water, adding a sodium periodate solution with the mass fraction of 15%, stirring for 2 hours at room temperature, discharging, washing, and drying in vacuum to obtain the diatomite-cyclodextrin oxide compound, wherein the solid-to-liquid ratio of the diatomite-cyclodextrin compound to the sodium periodate solution is 1:10;
s3: dispersing the diatomite-cyclodextrin oxide compound in pure water to form a dispersion liquid with the mass fraction of 2%, adding chitosan into the dispersion liquid, stirring for 2 hours at room temperature, discharging, washing and drying to obtain the diatomite-cyclodextrin-chitosan ternary crosslinked compound;
s4: mixing the diatomite-cyclodextrin-chitosan ternary crosslinked compound with pure water to form a dispersion liquid, adding arnebia oil into the dispersion liquid, stirring for 4 hours at the temperature of 65 ℃, discharging, and freeze-drying to obtain the diatomite modified antibacterial dressing.
Wherein the modified diatomaceous earth and cationic cyclodextrin were prepared in the same manner as in example 1.
Comparative example 1
The diatomite modified antibacterial dressing is prepared from the following raw materials in parts by weight: 1.5 parts of modified diatomite, 35 parts of beta-cyclodextrin, 55 parts of chitosan and 0.5 part of lithospermum oil;
the preparation method of the antibacterial dressing comprises the following steps:
s1: dissolving beta-cyclodextrin in pure water, uniformly mixing, adding modified diatomite, oscillating for 5 hours at room temperature, and centrifuging to separate solid materials to obtain a diatomite-cyclodextrin compound;
s2: dispersing the diatomite-cyclodextrin compound in pure water, adding a sodium periodate solution with the mass fraction of 15%, stirring for 2 hours at room temperature, discharging, washing, and drying in vacuum to obtain the diatomite-cyclodextrin oxide compound, wherein the solid-to-liquid ratio of the diatomite-cyclodextrin compound to the sodium periodate solution is 1:8;
s3: dispersing the diatomite-cyclodextrin oxide compound in pure water to form a dispersion liquid with the mass fraction of 2%, adding chitosan into the dispersion liquid, stirring for 2 hours at room temperature, discharging, washing and drying to obtain the diatomite-cyclodextrin-chitosan ternary crosslinked compound;
s4: mixing the diatomite-cyclodextrin-chitosan ternary crosslinked compound with pure water to form a dispersion liquid, adding arnebia oil into the dispersion liquid, stirring for 3 hours at the temperature of 65 ℃, discharging, and freeze-drying to obtain the diatomite modified antibacterial dressing.
Wherein the preparation method of the modified diatomaceous earth is the same as in example 1.
Comparative example 2
The diatomite modified antibacterial dressing is prepared from the following raw materials in parts by weight: 1.5 parts of diatomite, 35 parts of cationic cyclodextrin, 55 parts of chitosan and 0.5 part of lithospermum oil;
the preparation method of the antibacterial dressing comprises the following steps:
s1: dissolving cationic cyclodextrin in pure water, uniformly mixing, adding modified diatomite, oscillating for 5 hours at room temperature, and centrifuging to separate solid materials to obtain a diatomite-cyclodextrin compound;
s2: dispersing the diatomite-cyclodextrin compound in pure water, adding a sodium periodate solution with the mass fraction of 15%, stirring for 2 hours at room temperature, discharging, washing, and drying in vacuum to obtain the diatomite-cyclodextrin oxide compound, wherein the solid-to-liquid ratio of the diatomite-cyclodextrin compound to the sodium periodate solution is 1:8;
s3: dispersing the diatomite-cyclodextrin oxide compound in pure water to form a dispersion liquid with the mass fraction of 2%, adding chitosan into the dispersion liquid, stirring for 2 hours at room temperature, discharging, washing and drying to obtain the diatomite-cyclodextrin-chitosan ternary crosslinked compound;
s4: mixing the diatomite-cyclodextrin-chitosan ternary crosslinked compound with pure water to form a dispersion liquid, adding arnebia oil into the dispersion liquid, stirring for 3 hours at the temperature of 65 ℃, discharging, and freeze-drying to obtain the diatomite modified antibacterial dressing.
Wherein the cationic cyclodextrin was prepared in the same manner as in example 1.
Comparative example 3
The diatomite modified antibacterial dressing is prepared from the following raw materials in parts by weight: 1.5 parts of modified diatomite, 35 parts of cationic cyclodextrin and 55 parts of chitosan;
the preparation method of the antibacterial dressing comprises the following steps:
s1: dissolving cationic cyclodextrin in pure water, uniformly mixing, adding modified diatomite, oscillating for 5 hours at room temperature, and centrifuging to separate solid materials to obtain a diatomite-cyclodextrin compound;
s2: dispersing the diatomite-cyclodextrin compound in pure water, adding a sodium periodate solution with the mass fraction of 15%, stirring for 1-2 hours at room temperature, discharging, washing, and vacuum drying to obtain the diatomite-cyclodextrin oxide compound, wherein the solid-to-liquid ratio of the diatomite-cyclodextrin compound to the sodium periodate solution is 1:8;
s3: dispersing the diatomite-cyclodextrin oxide compound in pure water to form a dispersion liquid with the mass fraction of 2%, adding chitosan into the dispersion liquid, stirring for 2 hours at room temperature, discharging, washing and drying to obtain the diatomite modified antibacterial dressing.
Wherein the modified diatomaceous earth and cationic cyclodextrin were prepared in the same manner as in example 1.
Performance detection
a. The antibacterial dressings prepared in examples 1 to 3 and comparative examples 1 to 3 of the present invention were co-cultured with E.coli in an environment of 37℃for 12 hours with reference to appendix C4 of GB 15979-2002 hygienic Standard for Disposable sanitary products, the antibacterial rates of which were tested, and the test results are shown in the following Table:
as can be seen from the above table, the antibacterial dressing prepared in the examples 1-3 of the invention has a bacteriostasis rate of over 99%, has a good antibacterial effect, and can effectively inhibit bacterial infection of wounds, and the antibacterial dressing prepared in the comparative example 1 uses cyclodextrin without quaternary ammonium salt cations as a dressing substrate, so that the antibacterial performance is poor, and only weak antibacterial performance of chitosan can be utilized for antibacterial. The antibacterial dressing prepared in comparative example 2 was not surface-modified with diatomaceous earth, and only a small amount of cationic cyclodextrin was adsorbed by adsorption, so that the antibacterial performance was general. The antibacterial dressing prepared in the comparative example 3 has a good antibacterial rate which reaches more than 90%.
b. Randomly selecting 70 healthy rats with equivalent body weight, and equally dividing the rats into an example 1-an example 3, a comparative example 1-a comparative example 3 and a blank group, wherein 10 rats in each group are scraped, the back hair of the rats is scanned at the same position on the backs of the rats by using laser until a wound surface of 2cm multiplied by 2cm is formed, under the same culture condition, each group of rats is externally applied by using an antibacterial dressing prepared by the corresponding group, once daily, each time of external application is carried out for 2 hours, the blank group of rats is not treated, and the wound healing condition of the mice is observed and recorded, and the results are shown in the following table:
from the above table, the antibacterial dressing prepared in the examples 1-3 of the invention can rapidly stop bleeding, and the wound can be basically healed in about 7 days, and no obvious scar is found at the wound. The antibacterial dressing prepared in comparative example 1 also can achieve rapid hemostasis, but because of the poor antibacterial property of the dressing, wound infection occurs in about 3 days, red swelling is caused, the healing process is slow, and the wound is still not completely healed at about 15 days. The dressing prepared in comparative example 2 showed general antimicrobial properties, so that a few infections occurred at 3 days, resulting in a slow recovery rate. The dressing prepared in the comparative example 3 has better antibacterial performance, but no arnebia oil is added, granulation tissue grows slowly, healing speed is slower, and scar at the wound after healing is obvious.
The foregoing is merely illustrative and explanatory of the principles of the invention, as various modifications and additions may be made to the specific embodiments described, or similar thereto, by those skilled in the art, without departing from the principles of the invention or beyond the scope of the appended claims.