An antibacterial cellulose hydrogel dressing and its preparation method

Abstract

The present invention belongs to the field of medical supplies, and specifically discloses an antibacterial cellulose hydrogel dressing and a preparation method thereof. The raw materials of the antibacterial cellulose hydrogel dressing include carboxymethyl cellulose and amino hyperbranched polysiloxane-modified porous silicon loaded with carboxyl-containing antibiotics. The present invention uses amino hyperbranched polysiloxane-modified porous silicon as an antibiotic carrier and applies it to the CMC hydrogel dressing, greatly improving the drug loading amount and mechanical strength of the cellulose-based hydrogel dressing, and the prepared hydrogel dressing has good biocompatibility and long-term antibacterial effect.

Description

Technical Field

[0001] The present invention belongs to the field of medical supplies, and particularly relates to an antibacterial cellulose hydrogel dressing and a preparation method thereof. Background Art

[0002] As a raw material for natural hydrogels, cellulose is the most abundant renewable resource in nature, with characteristics such as biodegradability, regeneration, and recyclability, which can meet the social demand for environmental friendliness. Compared with other hydrogel dressings, cellulose-based hydrogel dressings have appropriate porosity and good cell compatibility, can provide the required wettability for the wound surface, and can also perform gas exchange and exudate absorption. Carboxymethyl cellulose (CMC) is formed by introducing carboxymethyl (-CH2COOH) side groups through chemical reactions on the basis of cellulose. Due to this structural change, CMC has better water solubility. CMC hydrogels can be easily trimmed into any shape, are easy to come into full contact with the wound site, and are convenient for wrapping and filling the wound, thereby improving the self-healing effect. In addition, a large number of carboxyl groups are contained in the CMC molecular structure, which can combine with hemoglobin iron ions in the blood, and then activate coagulation factors to promote blood coagulation. At the same time, it can promote the adhesion of platelets in the blood and enhance the hemostatic effect.

[0003] However, usually, single carboxymethyl cellulose itself has no antibacterial activity to prevent wound infection. Therefore, in general, nano metal ions with antibacterial activity, such as silver ions, copper ions, etc., may be added to endow it with antibacterial properties; although the added nano antibacterial metal ions have characteristics such as a broad antibacterial spectrum and strong antibacterial performance, they are easy to accumulate in the human body and cause harm; moreover, high concentrations of metal ions may have a toxic effect on the surrounding healthy tissues, thus having an adverse impact on wound healing and tissue repair. In addition, some individuals may be sensitive to metal ions, resulting in allergic reactions or skin irritation. On the other hand, the interfacial interaction between metal ions and CMC dressings is poor, which will lead to a serious decline in the mechanical strength of cellulose dressings. Adding antibiotics to cellulose hydrogel dressings is another means to endow the dressings with antibacterial properties; however, due to the weak binding ability between cellulose and small molecule antibiotic drugs, cellulose dressings often have the disadvantages of low drug loading and fast drug release rate. Summary of the Invention

[0004] The purpose of the present invention is to solve the deficiencies of the prior art. Based on this, the first aspect of the present invention provides an antibacterial cellulose hydrogel dressing, the raw materials of which include carboxymethyl cellulose and modified porous silicon loaded with antibiotics; the above-mentioned modified porous silicon is amino hyperbranched polysiloxane modified porous silicon; the above-mentioned antibiotics contain carboxyl groups.

[0005] The present invention first proposes to use amino hyperbranched polysiloxane-modified porous silicon as the carrier of antibiotics in the CMC-based hydrogel dressing. The internal pores of the porous silicon can meet the requirement of higher drug loading capacity, thus solving the technical problem that the binding force between cellulose and small molecule antibiotic drugs is not strong. At the same time, in the present invention, by modifying the porous silicon with amino hyperbranched polysiloxane, the dendritic hyperbranched polysiloxane is coated on the surface of the porous silicon, effectively reducing the aggregation of the porous silicon in the cellulose matrix, and enabling a large number of amino groups to exist on the surface of the carrier. On the one hand, it can form hydrogen bond interactions with antibiotics containing carboxyl groups (the carboxyl oxygen atom in the carboxyl group has partial negative charge, while the hydrogen atom in the amino group has partial positive charge), thereby achieving the effect of sustained release of antibiotics and solving the technical problem of too fast drug release of conventional cellulose dressings, which helps to reduce the number of dressing changes required for the wound and protect the granulation tissue from further infection. Moreover, due to the existence of hydrogen bonds, the drug loading capacity of the modified porous silicon is higher. On the other hand, a large number of amino groups existing on the surface of the carrier can also form hydrogen bond interactions with a large number of carboxyl groups contained in CMC, thereby improving the interfacial interaction force between the carrier and the CMC matrix, solving the technical problem of weak binding force between various components in the composite dressing, and synergistically with the porous silicon as an inorganic rigid material to further improve the mechanical properties of the dressing. In addition, the main components of the porous silicon in the present invention are Si and O, and the main components of the hyperbranched polysiloxane are Si, O and C, both of which have good biocompatibility and no cytotoxicity.

[0006] Among them, the mass ratio of carboxymethyl cellulose to the above-mentioned modified porous silicon loaded with antibiotics is 100:(5 - 30). The antibiotics can be clindamycin hydrochloride, ciprofloxacin hydrochloride, etc.

[0007] The second aspect of the present invention provides a preparation method of the above-mentioned antibacterial cellulose hydrogel dressing, which includes the following steps: mixing the modified porous silicon loaded with antibiotics with the carboxymethyl cellulose hydrogel to obtain the above-mentioned antibacterial cellulose hydrogel dressing; the above-mentioned modified porous silicon is amino hyperbranched polysiloxane-modified porous silicon; the above-mentioned antibiotics contain carboxyl groups. Subsequently, the above-mentioned antibacterial cellulose hydrogel dressing can be poured into a PTFE mold and dried at 50 °C for 12 h.

[0008] Among them, the preparation process of the above-mentioned carboxymethyl cellulose hydrogel includes the following steps: mixing citric acid, glycerol and carboxymethyl cellulose in water to obtain the above-mentioned carboxymethyl cellulose hydrogel. The added citric acid can be used as a cross-linking agent to cross-link CMC, thereby improving the mechanical strength of the cellulose dressing; the added glycerol can make the cellulose dressing softer and also help to retain moisture, thus contributing to wound recovery. The specific preparation process can be: dissolving citric acid and glycerol in water, and then adding CMC, and stirring evenly to obtain the above-mentioned carboxymethyl cellulose hydrogel; the mass ratio of citric acid, glycerol and CMC is 0.5 g:0.5 g:1 g.

[0009] Among them, the preparation process of the above-mentioned antibiotic-loaded modified porous silicon includes the following steps: dispersing the above-mentioned modified porous silicon into an antibiotic solution so that the antibiotic solution infiltrates into the pores of the above-mentioned modified porous silicon, and separating the antibiotic-loaded modified porous silicon by centrifugal precipitation, and obtaining it after drying.

[0010] Among them, the preparation process of the above-mentioned modified porous silicon (i.e., amino hyperbranched polysiloxane-modified porous silicon) includes the following steps: mixing porous silicon and amino hyperbranched polysiloxane in an alcohol / water system (the alcohol can be one of methanol, ethanol, and isopropanol; the volume ratio of alcohol to water can be 90 mL:10 mL), carrying out condensation reflux under the condition of 60°C - 95°C (the time can be 4 h), and obtaining the above-mentioned modified porous silicon after the reaction ends. After the reaction ends, it can also be rinsed twice with alcohol and water respectively to wash away the unreacted amino hyperbranched polysiloxane, then centrifuged to obtain a precipitate, and dried at 60°C for 12 h. The ratio of porous silicon to the above-mentioned amino hyperbranched polysiloxane is 1 g:(0.05 - 1) mL. By controlling the ratio of the above-mentioned amino hyperbranched polysiloxane to porous silicon, the amount of surface graft modification can be controlled, thereby controlling the number of amino groups on the surface, and thus controlling the rate of the above-mentioned antibiotic sustained release.

[0011] Among them, the preparation process of the above-mentioned amino hyperbranched polysiloxane includes the following steps: dispersing amino silane in an alcohol / water system (the alcohol can be one of methanol, ethanol, and isopropanol; the ratio of amino silane, methanol, and water is (1 - 1.2) mol:1.3 mol:1.3 mol), adjusting the pH to 8 - 11, and reacting for 4 h - 12 h under a nitrogen atmosphere and the condition of 60°C - 95°C to obtain the above-mentioned amino hyperbranched polysiloxane. Amino silane undergoes hydrolysis and further condensation under alkaline and aqueous conditions to form Si - O - Si bonds, thereby obtaining a dendritic hyperbranched structure; by controlling the pH, the hydrolysis rate of amino silane can be controlled, thereby affecting the molecular weight of the synthesized hyperbranched polysiloxane; in addition, by controlling the reaction time, reaction temperature, and type of amino silane, the molecular weight of the synthesized amino hyperbranched polysiloxane can also be affected; the larger the molecular weight, it means the larger the volume of the amino hyperbranched polysiloxane, the more the number of polymerized silane monomers, and it also means the more the number of amino groups on the surface of the modified porous silicon and the more the positive charges carried.

[0012] The above amino-silanes are at least one of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, aminoethylaminopropyltrimethoxysilane, aminoethylaminopropyltriethoxysilane, aminoethylaminopropylmethyldimethoxysilane, aminoethylaminomethyltriethoxysilane, diethylenetriaminepropyltrimethoxysilane, diethylenetriaminepropyltriethoxysilane, diethylenetriaminepropylmethyldimethoxysilane, and diethylenetriaminomethyldiethoxysilane.

[0013] Among them, the preparation process of the above porous silicon includes the following steps: Dissolve the surfactant in water, adjust the pH to 9-12, then add the silicon source and mix evenly, and then carry out hydrothermal reaction at 60°C - 120°C for 12h - 48h, centrifuge to obtain a precipitate, and then calcine at 500°C - 800°C for 1h - 4h to obtain the above porous silicon.

[0014] Among them, the ratio of the above surfactant to the above silicon source is (0.3g - 0.8g) : 4mL; the above surfactant is at least one of cetyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium bromide (DTAB), polyether P123, polyether F127, and sodium dodecyl sulfate (SDS); the above silicon source is tetraethoxysilane (TEOS) or tetramethoxysilane.

[0015] By controlling the type and dosage of the surfactant (if two or more surfactants are selected, the resulting pore size will be smaller), pH value, temperature and time of the hydrothermal reaction, the pore size of the prepared porous silicon can be controlled; the larger the pore size, the greater the drug loading capacity, but if the pore size is too large, the macromolecules of the amino hyperbranched polysiloxane can also enter the pore interior for modification, occupying the space inside the pores, which will instead cause a decrease in the final drug loading capacity.

[0016] Therefore, it is necessary to comprehensively consider controlling the pore size of the porous silicon and the molecular weight of the above amino hyperbranched polysiloxane to achieve the maximum drug loading capacity. In this case, the preparation process of the porous silicon can be specifically: Dissolve CTAB in water, adjust the pH to 10.5, then add tetraethoxysilane, stir evenly, and carry out hydrothermal reaction at 100°C for 24h, centrifuge (10000rpm, 15min) to obtain a precipitate, and then calcine at 600°C for 2h to obtain the above porous silicon; the ratio of CTAB to tetraethoxysilane is 0.6g : 4mL. The preparation process of the amino hyperbranched polysiloxane can be specifically: Disperse the amino-silane in the methanol / water system, adjust the pH to 10, react at 60°C under a nitrogen atmosphere for 6h, and obtain the above amino hyperbranched polysiloxane after rotary evaporation to remove methanol and water; the molar ratio of amino-silane, methanol, and water is 1mol : 1.3mol : 1.3mol.

[0017] The beneficial effects of the present invention are as follows: The present invention uses amino hyperbranched polysiloxane modified porous silicon as an antibiotic carrier and applies it to the CMC hydrogel dressing, which greatly improves the drug loading capacity and mechanical strength of the cellulose-based hydrogel dressing, and the prepared hydrogel dressing has good biocompatibility and long-term antibacterial effect. Description of the Drawings

[0018] Figure 1 Shown is the scanning electron micrograph of the porous silicon synthesized in Example 1;

[0019] Figure 2 Shown is the transmission electron micrograph of the porous silicon synthesized in Example 1;

[0020] Figure 3 Shown is the XRD pattern of the porous silicon synthesized in Example 1;

[0021] Figure 4 Shown is the infrared spectrum of the porous silicon synthesized in Example 1;

[0022] Figure 5 Shown is the synthesis schematic diagram of amino hyperbranched polysiloxane in Example 1;

[0023] Figure 6 Shown is the GPC pattern of amino hyperbranched polysiloxane in Example 1;

[0024] Figure 7 Shown is the GPC pattern of amino hyperbranched polysiloxane in Example 4;

[0025] Figure 8 Shown is the GPC pattern of amino hyperbranched polysiloxane in Example 5;

[0026] Figure 9 Shown is the transmission electron micrograph and the corresponding EDX elemental distribution map of amino hyperbranched polysiloxane modified porous silicon in Example 1;

[0027] Figure 10 Shown is the thermogravimetric curve of the modified porous silicon synthesized during the process of Example 1 and the porous silicon synthesized during the process of Comparative Example 1 after loading antibiotics;

[0028] Figure 11 Shown is the Zeta potential diagram of the modified porous silicon or porous silicon synthesized during the processes of Examples 1-5 and Comparative Examples 1-2;

[0029] Figure 12 Shown is the tensile property diagram of the hydrogel dressings prepared in Examples 1-4 and Comparative Examples 1-2;

[0030] Figure 13The digital photo of the antibacterial cellulose hydrogel dressing prepared in Example 1 is shown as follows. Detailed implementation manners

[0031] The concept of the present invention and the technical effects generated will be clearly and completely described below in conjunction with the embodiments and the drawings, so as to fully understand the purpose, solution and effects of the present invention. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0032] Example 1

[0033] An antibacterial cellulose hydrogel dressing, and its preparation method includes the following steps:

[0034] (1) Synthesis of porous silicon: First, dissolve 0.6 g of CTAB (surfactant) in 100 mL of water, then add NaOH to adjust the pH value to 10.5, and then add 4 mL of tetraethoxysilane (TEOS). After stirring evenly for 2 hours, transfer it to a hydrothermal reaction kettle lined with PTFE and react at 100 °C for 24 hours. Then, through centrifugation at 10,000 rpm for 15 min, a white precipitate is obtained; place the obtained white precipitate in a tube furnace and calcine it at 600 °C in an air atmosphere for 2 hours to obtain porous silicon; its scanning electron microscope image is as shown in Figure 1 shown; its transmission electron microscope image is as shown in Figure 2 shown, indicating that it contains an ordered pore structure; its XRD pattern is as shown in Figure 3 shown, to confirm the crystal form of the porous silicon. Combined with the FTIR data of Figure 4 , it is proved that the synthesized porous silicon has a stable structure, mainly Si-O bonds, and this material is harmless to the human body; its infrared spectrum is as shown in Figure 4 shown;

[0035] (2) Synthesis of amino hyperbranched polysiloxane: Uniformly mix 1 mol of 3-aminoethylaminopropyltrimethoxysilane with 1.3 mol of methanol and 1.3 mol of water in a flask, then add ammonia water to adjust the pH to 10, and react at 60 °C under a nitrogen atmosphere for 6 hours; transfer the reactant to a rotary evaporator to distill off the alcohol and water to obtain amino hyperbranched polysiloxane; its synthesis schematic diagram is as shown in Figure 5 shown, and its GPC pattern is as shown in Figure 6 shown;

[0036] (3) Preparation of modified porous silicon: Disperse 1 g of the porous silicon prepared in step (1) in a mixed solution of 90 mL of methanol / 10 mL of water, sonicate for 5 minutes, add 0.5 mL of the amino hyperbranched polysiloxane prepared in step (2), and carry out condensation reflux at 70 °C for 4 hours; after the reaction is completed, rinse twice with alcohol and water respectively to wash away the unreacted hyperbranched polysiloxane, and then centrifuge at 10000 rpm for 10 min to obtain a white precipitate; place it in a vacuum oven at 60 °C and dry for 12 hours; the modified porous silicon is prepared, that is, amino hyperbranched polysiloxane modified porous silicon; the transmission electron microscope image and the corresponding EDX elemental distribution map of the amino hyperbranched polysiloxane modified porous silicon are as Figure 9 shown. The porous silicon itself does not contain nitrogen element, and the nitrogen element comes from the amino hyperbranched polysiloxane. As shown in the figure, the nitrogen element is evenly distributed on the surface of the porous silicon, indicating that the amino hyperbranched polysiloxane is evenly modified on the surface of the porous silicon;

[0037] (4) Synthesis of clindamycin-loaded modified porous silicon: Disperse the modified porous silicon prepared in step (3) into an aqueous solution of clindamycin hydrochloride (50 mg / mL; 50 mg / mL is the maximum solubility of clindamycin hydrochloride in aqueous solution), and the concentration of the modified porous silicon is 10 mg / mL; sonicate for 10 min and stir vigorously for 24 hours to allow the aqueous solution of clindamycin hydrochloride to penetrate into the internal pores of the modified porous silicon; then centrifuge at 10000 rpm for 10 min to obtain a white precipitate; then place the white precipitate in a vacuum oven at 50 °C and dry continuously for 12 hours; the clindamycin-loaded modified porous silicon is obtained;

[0038] (5) Synthesis of antibacterial cellulose hydrogel dressing: First dissolve 0.5 g of lemon and 0.5 g of glycerol in 100 mL of water, then add 1 g of CMC, and stir well to obtain a uniform CMC hydrogel; add 0.1 g of the clindamycin-loaded modified porous silicon prepared in step (4), and stir well to obtain a uniform cellulose / drug-loaded modified porous silicon mixed hydrogel; that is, the antibacterial cellulose hydrogel; pour the above hydrogel into a PTFE mold, evacuate to remove air bubbles, and dry at 50 °C for 10 hours to obtain the antibacterial cellulose hydrogel dressing; its photo is as Figure 13 shown.

[0039] Example 2

[0040] An antibacterial cellulose hydrogel dressing, the difference in its preparation steps from Example 1 is that: "ciprofloxacin hydrochloride" is used instead of "clindamycin"; others are the same as Example 1.

[0041] Example 3

[0042] An antibacterial cellulose hydrogel dressing, the difference in its preparation steps from Example 1 lies in: using "0.8 g CTAB" instead of "0.6 g CTAB"; others are the same as in Example 1.

[0043] Since Example 3 adds more surfactant compared to Example 1, during the preparation of porous silicon, the internal pore size generated is smaller, and less of the drug containing antibiotics enters the pores. Therefore, after removing the solvent of the antibiotics, less antibiotics remain in the pores.

[0044] Example 4

[0045] An antibacterial cellulose hydrogel dressing, the difference in its preparation steps from Example 1 lies in: using "diethylenetriaminepropyltrimethoxysilane" instead of "3 - aminoethylaminopropyltrimethoxysilane"; using "react for 2 hours" instead of "react for 6 hours" in step (2); others are the same as in Example 1.

[0046] In this example, the GPC graph of the amino - hyperbranched polysiloxane synthesized during the process is as Figure 7 shown.

[0047] Example 5

[0048] An antibacterial cellulose hydrogel dressing, the difference in its preparation steps from Example 1 lies in: using "1.2 mol 3 - aminopropyltrimethoxysilane" instead of "1 mol 3 - aminoethylaminopropyltrimethoxysilane"; using "react for 6 hours under the condition of 75 °C in a nitrogen atmosphere" instead of "react for 6 hours under the condition of 60 °C in a nitrogen atmosphere" in step (2); others are the same as in Example 1.

[0049] In this example, the GPC graph of the amino - hyperbranched polysiloxane synthesized during the process is as Figure 8 shown, where Mw (equivalent to MW) represents the weight - average molecular weight. As can be seen from Figure 6 , Figure 7 and Figure 8 it can be seen that the molecular weights of the amino - hyperbranched polysiloxanes synthesized in Example 1, Example 4, and Example 5 are much higher than those of the silane monomers, indicating that the amino - hyperbranched polysiloxanes polymerized from different amino - silane monomers are successfully prepared. On the other hand, precisely because the molecular weight of the amino - hyperbranched polysiloxane is much higher, as shown in Figure 5 it presents a dendritic - like molecular structure, and through the pore size adjustment of the porous silicon, the amino - hyperbranched polysiloxane is not easily able to enter the interior of the pores of the porous silicon.

[0050] Comparative Example 1

[0051] A hydrogel dressing, compared with Example 1 where the porous silicon was not modified and directly loaded with antibiotics, the specific preparation process is as follows:

[0052] (1) Synthesis of porous silicon: First, dissolve 0.6 g of CTAB (surfactant) in 100 mL of water, then add NaOH to adjust the pH value to 10.5, and then add 4 mL of tetraethoxysilane (TEOS). After stirring evenly for 2 hours, transfer it to a hydrothermal reaction kettle lined with PTFE and react at 100 °C for 24 hours. Then, through centrifugation at 10,000 rpm for 15 minutes, a white precipitate is obtained; place the obtained white precipitate in a tube furnace and calcine it at 600 °C in an air atmosphere for 2 hours to obtain porous silicon;

[0053] (2) Synthesis of porous silicon loaded with clindamycin: Disperse the porous silicon prepared in step (1) into an aqueous solution of clindamycin hydrochloride (50 mg / mL), and the concentration of the porous silicon is 10 mg / mL; ultrasonically disperse for 10 minutes and stir vigorously for 24 hours to allow the aqueous solution of clindamycin hydrochloride to penetrate into the internal pores of the porous silicon; then centrifuge at a high speed of 10,000 rpm for 10 minutes to obtain a precipitate; then place the white precipitate in a vacuum oven at 50 °C and dry it continuously for 12 hours; that is, porous silicon loaded with clindamycin is obtained;

[0054] (3) Synthesis of hydrogel dressing: First, dissolve 0.5 g of lemon and 0.5 g of glycerol in 100 mL of water, then add 1 g of CMC and stir well to obtain a uniform CMC hydrogel; add 0.1 g of the porous silicon loaded with clindamycin prepared in step (2) and stir well to obtain a uniform cellulose / drug-loaded porous silicon mixed hydrogel; pour the above hydrogel into a PTFE mold, evacuate to remove air bubbles, and dry it at 50 °C for 10 hours to obtain the hydrogel dressing.

[0055] Comparative Example 2

[0056] A hydrogel dressing, compared with Example 1, uses a non-hyperbranched conventional aminosilane (3-glycidoxypropyltrimethoxysilane) to modify the porous silicon; that is, steps (2) and (3) in Example 1 are replaced with: Disperse 1 g of the porous silicon prepared in step (1) in a mixture of 90 mL of methanol / 10 mL of water, ultrasonically for 5 minutes, add 0.5 mL of 3-glycidoxypropyltrimethoxysilane, and condense and reflux at 70 °C for 4 hours; after the reaction is completed, rinse twice with alcohol and water respectively, and then centrifuge at a high speed of 10,000 rpm for 10 minutes to obtain a precipitate; place it in a vacuum oven at 60 °C and bake for 12 hours.

[0057] Perform performance tests on the hydrogel dressings prepared in the examples and comparative examples, as follows:

[0058] 1. Tensile property test: Samples of the hydrogel dressings prepared in Examples 1-5 and Comparative Examples 1-2 were respectively cut into rectangles of 80 mm * 10 mm, and the thickness was measured with a thickness gauge. The tensile strength of the samples was tested using a universal electronic testing machine. The samples were placed in an environment with a relative humidity of 70% and a temperature of 23 °C, saturated for 24 hours, and then tested. The clamping distance of the samples was 40 mm, and the tensile speed was 15 mm / min. Each group of samples was tested at least 5 times, and the obtained data was the average value of 5 groups of valid data.

[0059] 2. Drug loading test: Samples of the modified porous silicon synthesized in the process of Examples 1-5, the porous silicon (unmodified) synthesized in the process of Comparative Example 1, and the non-hyperbranched modified porous silicon synthesized in the process of Comparative Example 2 were respectively placed in an oven at 60 °C and dried continuously for 24 hours. Then, the same mass (recorded as m0) of the dried modified porous silicon, porous silicon, and non-hyperbranched modified porous silicon was weighed and immersed in an aqueous solution of clindamycin (50 mg / mL), ultrasonicated for 30 min, and then continuously stirred for 12 hours. The samples were centrifuged out, then transferred to an oven at 60 °C and dried continuously for 24 hours, and the mass was weighed and recorded as m t . According to the following formula, the drug loading was calculated: Drug loading rate = ((m t - m0) / m0) * 100%.

[0060] The results of its mechanical properties and drug loading properties are shown in Table 1; the tensile property diagram of the dressing is as Figure 12 shown, indicating that the porous silicon modified with amino hyperbranched polysiloxane contains a large amount of amino groups, can form hydrogen bonds with the carboxymethyl groups on cellulose, and thus has better compatibility with the cellulose matrix, showing better tensile properties.

[0061] Table 1

[0062]

[0063]

[0064] 3. In vitro drug release experiment:

[0065] Drug standard curve equation: Prepare a PBS buffer solution with pH = 7.4, then dissolve clindamycin in the PBS buffer solution to obtain an antibiotic solution with a concentration of 1 mg / mL, and then dilute it with different amounts of PBS buffer solution to obtain solutions with different concentrations. Take the above different concentrations of antibiotic solutions for high performance liquid chromatography to determine the concentration, and fit to obtain the standard curve.

[0066] The hydrogel dressings prepared in Example 1, Examples 3-5 and Comparative Examples 1-2 were respectively cut into squares of 20 mm×20 mm, immersed in 50 mL of PBS buffer solution, 0.01 mL of the release solution was extracted at the specified time, and at the same time 0.01 mL of fresh PBS buffer solution was added. High performance liquid chromatography was used to determine the concentration of the antibiotic, and the similar release amount of the drug was calculated. Three parallel samples were set for each group of samples. The results are shown in Table 2.

[0067] Table 2

[0068] Cumulative release rate of clindamycin (%) Comparative Example 1 Comparative Example 2 Example 1 Example 3 Example 4 Example 5 0 0 0 0 0 0 0 2 hours 40.9 30.3 15.8 20.4 17.7 18.3 4 hours 55.7 45.3 24.7 27.3 26.5 28.0 8 hours 62.1 56.7 39.6 37.4 36.0 37.5 12 hours 65.7 61.4 53.2 51.8 48.9 50.4 24 hours 67.8 64.4 59.5 61.1 60.6 58.9 48 hours 67.7 64.7 68.4 69.4 68.7 66.2 72 hours 68.1 64.9 77.9 75.3 73.2 72.6 96 hours 68.3 65.4 85.3 81.7 79.8 77.5

[0069] 4. Other tests:

[0070] The thermogravimetric curves of the amino hyperbranched polysiloxane-modified porous silicon in Example 1 and the porous silicon in Comparative Example 1 after loading antibiotics are as Figure 10 shown. It can be seen from Figure 10 that hyperbranched modification can load more antibiotics, so more weight loss occurs. Porous silicon itself is silicon and has stable properties, and will not lose weight during heating. Antibiotics are small molecules and decompose when heated.

[0071] The Zeta potential diagrams of the modified porous silicon or porous silicon synthesized in the processes of Examples 1-5 and Comparative Examples 1-2 are as Figure 11 shown, indicating that modifying amino hyperbranched polysiloxane can effectively change the surface electronegativity of porous silicon.

[0072] As mentioned above, it is only the preferred embodiment of the present invention. The present invention is not limited to the above-mentioned embodiments. As long as it achieves the technical effects of the present invention by the same means, it should fall within the protection scope of the present invention. Within the protection scope of the present invention, its technical solutions and / or embodiments can have various different modifications and changes.

Claims

1. An antibacterial cellulose hydrogel dressing, characterized in that: The raw materials include carboxymethyl cellulose and modified porous silicon loaded with antibiotics; the modified porous silicon is amino hyperbranched polysiloxane modified porous silicon; and the antibiotics contain carboxyl groups.

2. The antibacterial cellulose hydrogel dressing according to claim 1, characterized in that: The mass ratio of carboxymethyl cellulose to the modified porous silicon loaded with antibiotics is 100:(5-30).

3. A method for preparing an antibacterial cellulose hydrogel dressing, characterized in that: The following steps are involved: Mixing the modified porous silicon loaded with antibiotics with the carboxymethyl cellulose hydrogel to obtain the antibacterial cellulose hydrogel dressing; The modified porous silicon is amino-hyperbranched polysiloxane-modified porous silicon; The antibiotic contains a carboxyl group.

4. The preparation method according to claim 3, characterized in that: The preparation process of the modified porous silicon comprises the following steps: mixing porous silicon and amino hyperbranched polysiloxane in an alcohol / water system, condensing and refluxing at 60° C.-95° C., and obtaining the modified porous silicon after the reaction is completed.

5. The preparation method according to claim 4, characterized in that: The ratio of the porous silicon to the amino-hyperbranched polysiloxane is 1 g: (0.05-1) mL.

6. The preparation method according to claim 4, characterized in that: The preparation process of the amino hyperbranched polysiloxane comprises the following steps: dispersing aminosilane in an alcohol / water system, adjusting the pH to 8-11, and reacting for 4h-12h under a nitrogen atmosphere and a temperature of 60°C-95°C to obtain the amino hyperbranched polysiloxane.

7. The preparation method according to claim 6, characterized in that: The aminosilane is at least one of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, aminoethylaminopropyltrimethoxysilane, aminoethylaminopropyltriethoxysilane, aminoethylaminopropylmethyldimethoxysilane, aminoethylaminomethyltriethoxysilane, diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropyltriethoxysilane, diethylenetriaminopropylmethyldimethoxysilane and diethylenetriaminomethyldiethoxysilane.

8. The preparation method according to claim 4, characterized in that: The preparation process of the porous silicon includes the following steps: dissolving a surfactant in water and adjusting the pH to 9-12, then adding a silicon source and mixing, and then hydrothermally reacting at 60°C-120°C for 12h-48h, centrifuging to obtain a precipitate, and then calcining at 500°C-800°C for 1h-4h to obtain the porous silicon.

9. The preparation method according to claim 8, characterized in that: The ratio of the surfactant to the silicon source is (0.3g-0.8g):4mL; and / or the surfactant is at least one of n-hexadecyltrimethylammonium bromide, dodecyltrimethylammonium bromide, polyether P123, polyether F127 and sodium dodecyl sulfate; and / or the silicon source is tetraethoxysilane or tetramethoxysilane.

10. The preparation method according to claim 3, characterized in that: The preparation process of the carboxymethyl cellulose hydrogel comprises the following steps: mixing citric acid, glycerol and carboxymethyl cellulose in water to obtain the carboxymethyl cellulose hydrogel.

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