Antibacterial cellulose hydrogel dressing and preparation method thereof

Abstract

The invention belongs to the field of medical supplies, and particularly discloses an antibacterial cellulose hydrogel dressing and a preparation method thereof. The antibacterial cellulose hydrogel dressing is prepared from the following raw materials: carboxymethyl cellulose and amino hyperbranched polysiloxane modified porous silicon loaded with carboxyl-containing antibiotics. The amino hyperbranched polysiloxane modified porous silicon is used as an antibiotic carrier to be applied to the CMC hydrogel dressing, the drug loading capacity and the mechanical strength of the cellulose-based hydrogel dressing are greatly improved, and the prepared hydrogel dressing has good biocompatibility and a long-acting antibacterial effect.

Description

Technical Field

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

[0002] Cellulose, as a raw material for natural hydrogels, is the most abundant renewable resource in nature. It has the characteristics of biodegradability, regeneration and recycling, and can meet the society's demand for environmental friendliness. Compared with other hydrogel dressings, cellulose-based hydrogel dressings have suitable porosity and good cell compatibility, can provide the required wettability for the wound surface, and can also carry out gas exchange and exudate absorption. Carboxymethyl cellulose (CMC) is based on cellulose, and carboxymethyl (-CH 2 After the side groups of COOH) are added, carboxymethyl cellulose is formed. Due to this structural change, CMC has better water solubility. CMC hydrogel can be easily trimmed into any shape, easy to fully contact with the wound site, convenient for wrapping and filling the wound, thereby improving the self-healing effect. In addition, the CMC molecular structure contains a large number of carboxyl groups, which can combine with the iron ions of hemoglobin in the blood, thereby activating coagulation factors to promote coagulation, and at the same time promote the adhesion of platelets in the blood, enhancing 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 and copper ions, may be added to give it antibacterial properties; although the added nano-antibacterial metal ions have the characteristics of strong antibacterial spectrum and strong antibacterial performance, they are easy to accumulate in the human body and cause harm; and high concentrations of metal ions may have toxic effects on surrounding healthy tissues, thereby adversely affecting wound healing and tissue repair. In addition, some individuals may be sensitive to metal ions, leading to allergic reactions or skin irritation. On the other hand, the poor interface between metal ions and CMC dressings will cause a serious decrease in the mechanical strength of cellulose dressings. Adding antibiotics to cellulose hydrogel dressings is another means to give dressings antibacterial properties; but due to the weak binding ability of cellulose with small molecule antibiotics, cellulose dressings often have the disadvantages of low drug loading and fast drug release. 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 modified porous silicon is amino hyperbranched polysiloxane modified porous silicon; the antibiotic contains a carboxyl group.

[0005] The present invention firstly proposes to use amino-hyperbranched polysiloxane-modified porous silicon as a carrier of antibiotics in CMC-based hydrogel dressings. The internal pores of porous silicon can meet the demand for higher drug loading, thereby solving the technical problem that cellulose and small molecule antibiotics have weak binding force. At the same time, the present invention modifies porous silicon with amino-hyperbranched polysiloxane so that the dendritic hyperbranched polysiloxane is coated on the surface of porous silicon, effectively reducing the aggregation of porous silicon in the cellulose matrix, and enabling a large number of amino groups to exist on the surface of the carrier, which can generate hydrogen bonding with antibiotics containing carboxyl groups (the carboxyl oxygen atom in the carboxyl group carries a partial negative charge, while the amino group has a negative charge). The hydrogen atoms in the amino group carry partial positive charge), thereby achieving the effect of sustained release of antibiotics, solving the technical problem of too fast drug release in conventional cellulose dressings, helping to reduce the number of dressing changes required for wounds and protecting granulation tissue from further infection; and due to the presence of hydrogen bonds, the drug loading capacity of the modified porous silicon is higher; on the other hand, the large number of amino groups on the surface of the carrier can also produce hydrogen bonds with the large number of carboxyl groups contained in CMC, thereby improving the interfacial force between the carrier and the CMC matrix, solving the technical problem of weak binding force between multiple components in the composite dressing, and cooperating with 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] The mass ratio of carboxymethyl cellulose to the modified porous silicon loaded with antibiotics is 100:(5-30). The antibiotics may be clindamycin hydrochloride, ciprofloxacin hydrochloride, or the like.

[0007] The second aspect of the present invention provides a method for preparing the above-mentioned antibacterial cellulose hydrogel dressing, comprising the following steps: mixing modified porous silicon loaded with antibiotics with 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 antibiotic contains a carboxyl group. Subsequently, the above-mentioned antibacterial cellulose hydrogel dressing can also be poured into a PTFE mold and dried at 50°C for 12 hours.

[0008] Among them, the preparation process of the above-mentioned carboxymethyl cellulose hydrogel includes the following steps: citric acid, glycerol and carboxymethyl cellulose are mixed 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 and thus help wound recovery. The preparation process can be specifically: dissolve citric acid and glycerol in water, then add CMC, and stir evenly to obtain the above-mentioned carboxymethyl cellulose hydrogel; the mass ratio of citric acid, glycerol and CMC is 0.5g:0.5g:1g.

[0009] Among them, the preparation process of the modified porous silicon loaded with antibiotics includes the following steps: dispersing the modified porous silicon into an antibiotic solution so that the antibiotic solution penetrates into the pores of the modified porous silicon, separating the modified porous silicon loaded with antibiotics by centrifugal precipitation, and obtaining the result after drying.

[0010] The preparation process of the modified porous silicon (i.e. amino-hyperbranched polysiloxane modified porous silicon) comprises 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), condensing and refluxing at 60°C-95°C (the time can be 4 hours), and obtaining the modified porous silicon after the reaction is completed. After the reaction is completed, the unreacted amino-hyperbranched polysiloxane can be washed with alcohol and water twice, and then centrifuged to obtain a precipitate, which is dried at 60°C for 12 hours. The ratio of porous silicon to the amino-hyperbranched polysiloxane is 1g: (0.05-1) mL. By controlling the ratio of the amino-hyperbranched polysiloxane to the porous silicon, the amount of surface grafting modification can be controlled, thereby controlling the number of amino groups on the surface, thereby controlling the rate of sustained release of the antibiotic.

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

[0012] The above-mentioned aminosilane is at least one of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, aminoethylaminopropyltrimethoxysilane, aminoethylaminopropyltriethoxysilane, aminoethylaminopropylmethyldimethoxysilane, aminoethylaminomethyltriethoxysilane, diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropyltriethoxysilane, diethylenetriaminopropylmethyldimethoxysilane and diethylenetriaminomethyldiethoxysilane.

[0013] Among them, the preparation process of the above-mentioned porous silicon includes the following steps: dissolving the surfactant in water and adjusting the pH to 9-12, then adding the silicon source and mixing, and then hydrothermally reacting at 60℃-120℃ for 12h-48h, centrifuging to obtain a precipitate, and then calcining at 500℃-800℃ for 1h-4h to obtain the above-mentioned porous silicon.

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

[0015] The pore size of the porous silicon can be controlled by controlling the type and amount of surfactant (if two or more surfactants are used, the pore size will be smaller), pH value, temperature and time of the hydrothermal reaction; the larger the pore size, the greater the drug loading capacity, but if the pore size is too large, the macromolecules of the aminohyperbranched polysiloxane will be able to enter the pores for modification and occupy the space inside the pores, which will cause the final drug loading capacity to decrease.

[0016] Therefore, it is necessary to comprehensively consider the control of the pore size of porous silicon and the molecular weight of the amino hyperbranched polysiloxane to achieve the maximum drug loading. In this case, the preparation process of porous silicon can be specifically as follows: dissolve CTAB in water, adjust the pH to 10.5, then add tetraethoxysilane, stir evenly, hydrothermally react 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 amino hyperbranched polysiloxane can be specifically as follows: disperse aminosilane in a methanol / water system, adjust the pH to 10, react for 6h under a nitrogen atmosphere and 60°C, and obtain the above amino hyperbranched polysiloxane after removing methanol and water by rotary evaporation; the molar ratio of aminosilane, methanol and water is 1mol:1.3mol:1.3mol.

[0017] The beneficial effects of the present invention are as follows: the present invention utilizes amino-hyperbranched polysiloxane-modified porous silicon as an antibiotic carrier applied to a 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-lasting antibacterial effect. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0019] Figure 2 Shown is a transmission electron microscope image 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 a schematic diagram of the synthesis of amino hyperbranched polysiloxane in Example 1;

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

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

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

[0026] Fig. 9 Shown is a transmission electron microscope image of amino hyperbranched polysiloxane modified porous silicon in Example 1 and a corresponding EDX element distribution map;

[0027] Fig.10 Shown are thermogravimetric curves of the modified porous silicon synthesized in the process of Example 1 and the porous silicon synthesized in the process of Comparative Example 1 after loading antibiotics;

[0028] Fig.11 Shown are Zeta potential diagrams of modified porous silicon or porous silicon synthesized in the processes of Examples 1-5 and Comparative Examples 1-2;

[0029] Fig.12 Shown are the tensile properties of the hydrogel dressings prepared in Examples 1-4 and Comparative Examples 1-2;

[0030] Fig.13Shown is a digital photo of the antibacterial cellulose hydrogel dressing prepared in Example 1. DETAILED DESCRIPTION

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

[0032] Example 1

[0033] An antibacterial cellulose hydrogel dressing, the preparation method of which comprises the following steps:

[0034] (1) Synthesis of porous silicon: First, 0.6 g of CTAB (surfactant) was dissolved in 100 mL of water, and then NaOH was added to adjust the pH value to 10.5, and then 4 mL of tetraethoxysilane (TEOS) was added. After being fully stirred for 2 hours, the mixture was transferred to a PTFE-lined hydrothermal reactor and reacted at 100°C for 24 hours. Then, a white precipitate was obtained by centrifugation at 10,000 rpm for 15 minutes. The obtained white precipitate was placed in a tubular furnace and calcined at 600°C for 2 hours in an air atmosphere to obtain porous silicon. The scanning electron microscope image is shown in FIG. Figure 1 Its transmission electron microscope image is shown in Figure 2 As shown, it contains an ordered pore structure; its XRD pattern is shown Figure 3 As shown, the crystal form of porous silicon is confirmed. Figure 4 The FTIR data comprehensively proves 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 shown in Figure 4 As shown;

[0035] (2) Synthesis of amino hyperbranched polysiloxane: 1 mol of 3-aminoethylaminopropyltrimethoxysilane, 1.3 mol of methanol and 1.3 mol of water were uniformly mixed in a flask, and then ammonia water was added to adjust the pH to 10. The mixture was reacted at 60° C. in a nitrogen atmosphere for 6 hours. The reactants were transferred to a rotary evaporator, and the alcohol and water were evaporated to obtain amino hyperbranched polysiloxane. The synthesis schematic diagram is shown in FIG. Figure 5 As shown, its GPC diagram is as follows Figure 6 As shown;

[0036] (3) Preparation of modified porous silicon: 1 g of porous silicon prepared in step (1) was dispersed in a mixture of 90 ml of methanol and 10 ml of water, and ultrasonicated for 5 minutes. 0.5 ml of aminohyperbranched polysiloxane prepared in step (2) was added, and condensed and refluxed at 70° C. for 4 hours. After the reaction was completed, the mixture was rinsed twice with alcohol and water respectively to clean the unreacted hyperbranched polysiloxane, and then centrifuged at 10000 rpm for 10 minutes to obtain a white precipitate. The mixture was placed in a vacuum oven at 60° C. and dried for 12 hours. Modified porous silicon, i.e., aminohyperbranched polysiloxane modified porous silicon, was obtained. The transmission electron microscopy image of aminohyperbranched polysiloxane modified porous silicon and the corresponding EDX element distribution map are shown in FIG. Fig. 9 As shown, porous silicon itself does not carry nitrogen, and the nitrogen comes from amino hyperbranched polysiloxane. As shown in the figure, the nitrogen is evenly distributed on the surface of porous silicon, indicating that amino hyperbranched polysiloxane is evenly modified on the surface of porous silicon;

[0037] (4) Synthesis of modified porous silicon loaded with clindamycin: The modified porous silicon prepared in step (3) was dispersed in a clindamycin hydrochloride aqueous solution (50 mg / mL; 50 mg / mL is the maximum solubility of clindamycin hydrochloride in aqueous solution) at a concentration of 10 mg / mL; ultrasonic dispersion was performed for 10 min, and vigorous stirring was performed for 24 hours to allow the clindamycin hydrochloride aqueous solution to penetrate into the internal pores of the modified porous silicon; then high-speed centrifugation was performed at 10,000 rpm for 10 min to obtain a white precipitate; then the white precipitate was placed in a vacuum oven at 50° C. and dried continuously for 12 hours; thus, the modified porous silicon loaded with clindamycin was obtained;

[0038] (5) Synthesis of antibacterial cellulose hydrogel dressing: First, 0.5 g of lemon and 0.5 g of glycerol were dissolved in 100 mL of water, and then 1 g of CMC was added and stirred thoroughly to obtain a uniform CMC hydrogel; 0.1 g of the modified porous silicon loaded with clindamycin obtained in step (4) was added and stirred thoroughly to obtain a uniform cellulose / drug-loaded modified porous silicon mixed hydrogel, i.e., the antibacterial cellulose hydrogel; the above hydrogel was poured into a PTFE mold, vacuumed to remove bubbles, and dried at 50° C. for 10 hours to obtain the antibacterial cellulose hydrogel dressing; a photo of the same is shown in FIG. Fig.13 shown.

[0039] Example 2

[0040] An antibacterial cellulose hydrogel dressing, the preparation steps of which are different from those of Example 1 in that "ciprofloxacin hydrochloride" is used instead of "clindamycin"; the rest are the same as those of Example 1.

[0041] Example 3

[0042] An antibacterial cellulose hydrogel dressing, the preparation steps of which are different from those of Example 1 in that "0.8 g CTAB" is used instead of "0.6 g CTAB"; the rest are the same as those of Example 1.

[0043] Since more surfactant is added in Example 3 than in Example 1, smaller internal pores are generated during the preparation of porous silicon, and less antibiotic-containing drugs enter the pores. Therefore, after removing the antibiotic solvent, less antibiotics remain in the pores.

[0044] Example 4

[0045] An antibacterial cellulose hydrogel dressing, the preparation steps of which are different from those of Example 1 in that: "diethylenetriaminopropyltrimethoxysilane" is used instead of "3-aminoethylaminopropyltrimethoxysilane"; "reacting for 2 hours" is used instead of "reacting for 6 hours" in step (2); and the rest are the same as those of Example 1.

[0046] In this embodiment, the GPC chart of the amino hyperbranched polysiloxane synthesized in the process is as follows: Figure 7 shown.

[0047] Example 5

[0048] An antibacterial cellulose hydrogel dressing, the preparation steps of which are different from those of Example 1 in that: "1.2 mol 3-aminopropyltrimethoxysilane" is used instead of "1 mol 3-aminoethylaminopropyltrimethoxysilane"; "reacting at 75°C in a nitrogen atmosphere for 6 hours" is used instead of "reacting at 60°C in a nitrogen atmosphere for 6 hours" in step (2); and the rest are the same as those of Example 1.

[0049] In this embodiment, the GPC chart of the amino hyperbranched polysiloxane synthesized in the process is as follows: Figure 8 As shown, Mw (equivalent to MW) represents the weight average molecular weight, which is Figure 6 , Figure 7 and Figure 8 It can be seen that the molecular weight of the amino hyperbranched polysiloxane synthesized in Example 1, Example 4 and Example 5 is much higher than that of the silane monomer, indicating that the amino hyperbranched polysiloxane obtained by polymerization of different amino silane monomers was successfully prepared. On the other hand, just because the molecular weight of the amino hyperbranched polysiloxane is much higher, Figure 5 As shown, it presents a dendrite-like molecular structure. By adjusting the pore size of porous silicon, amino hyperbranched polysiloxane is not easy to enter the pores of porous silicon.

[0050] Comparative Example 1

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

[0052] (1) Synthesis of porous silicon: First, 0.6 g of CTAB (surfactant) was dissolved in 100 mL of water, and then NaOH was added to adjust the pH value to 10.5, and then 4 mL of tetraethoxysilane (TEOS) was added. After being fully stirred for 2 hours, the mixture was transferred to a PTFE-lined hydrothermal reactor and reacted at 100°C for 24 hours. Then, a white precipitate was obtained by centrifugation at 10,000 rpm for 15 minutes. The obtained white precipitate was placed in a tubular furnace and calcined at 600°C for 2 hours in an air atmosphere to obtain porous silicon.

[0053] (2) Synthesis of porous silicon loaded with clindamycin: The porous silicon prepared in step (1) was dispersed in a clindamycin hydrochloride aqueous solution (50 mg / mL) to a concentration of 10 mg / mL; ultrasonic dispersion was performed for 10 min and vigorous stirring was performed for 24 hours to allow the clindamycin hydrochloride aqueous solution to penetrate into the internal pores of the porous silicon; then high-speed centrifugation was performed at 10,000 rpm for 10 min to obtain a precipitate; then the white precipitate was placed in a vacuum oven at 50° C. and dried continuously for 12 hours to obtain porous silicon loaded with clindamycin;

[0054] (3) Synthesis of hydrogel dressing: First, 0.5 g of lemon and 0.5 g of glycerol were dissolved in 100 mL of water, and then 1 g of CMC was added and stirred thoroughly to obtain a uniform CMC hydrogel; 0.1 g of the porous silicon loaded with clindamycin obtained in step (2) was added and stirred thoroughly to obtain a uniform cellulose / drug-loaded porous silicon mixed hydrogel; the above hydrogel was poured into a PTFE mold, vacuumed to remove bubbles, and dried at 50° C. for 10 hours to obtain the hydrogel dressing.

[0055] Comparative Example 2

[0056] A hydrogel dressing, compared with Example 1, uses non-hyperbranched conventional aminosilane (3-glycidyloxypropyltrimethoxysilane) to modify porous silicon; that is, step (2) and step (3) in Example 1 are replaced by: 1g of porous silicon prepared in step (1) is dispersed in a mixture of 90ml methanol / 10ml water, ultrasonicated for 5 minutes, 0.5ml 3-glycidyloxypropyltrimethoxysilane is added, and condensed and refluxed at 70°C for 4 hours; after the reaction is completed, rinsed twice with alcohol and water respectively, and then centrifuged at 10000rpm for 10 minutes to obtain a precipitate; and placed in a vacuum oven at 60°C for 12 hours.

[0057] The performance tests of the hydrogel dressings prepared in the examples and comparative examples were performed as follows:

[0058] 1. Tensile performance test: The samples of the hydrogel dressings prepared in Examples 1-5 and Comparative Examples 1-2 were 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 with 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 sample was 40 mm, and the tensile speed was 15 mm / min. Each group of samples was tested at least 5 times, and the data obtained was the average of 5 groups of valid data.

[0059] 2. Drug loading test: The modified porous silicon synthesized in Examples 1-5, the porous silicon (unmodified) synthesized in Comparative Example 1, and the non-hyperbranched modified porous silicon synthesized in Comparative Example 2 were respectively placed in an oven at 60° C. for 24 hours, and then the same mass (recorded as m 0 ) The dried modified porous silicon, porous silicon, and non-hyperbranched modified porous silicon were immersed in an aqueous solution of clindamycin (50 mg / mL), ultrasonicated for 30 min, and then stirred continuously for 12 hours. The sample was centrifuged and then transferred to an oven and dried at 60°C for 24 hours. The weight was recorded as m t . Calculate the drug loading according to the following formula: drug loading rate = ((m t -m 0 ) / m 0 )*100%.

[0060] The results of its mechanical properties and drug loading performance are shown in Table 1; the tensile properties of the dressing are shown in Fig.12 As shown, it is shown that the porous silicon modified with amino hyperbranched polysiloxane contains a large number of amino groups, which can form hydrogen bonds with the carboxylmethyl groups on cellulose, thereby having better compatibility with the cellulose matrix and 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 a pH of 7.4, then dissolve clindamycin in the PBS buffer solution to obtain a 1 mg / mL antibiotic solution, and then dilute with different amounts of PBS buffer to obtain solutions of different concentrations. Take the above antibiotic solutions of different concentrations for high performance liquid chromatography to determine the concentration, and fit to obtain a standard curve.

[0066] The hydrogel dressings prepared in Example 1, Examples 3-5 and Comparative Examples 1-2 were cut into 20 mm × 20 mm squares, immersed in 50 mL of PBS buffer, 0.01 mL of release solution was extracted at a specified time, and 0.01 mL of fresh PBS buffer was added at the same time. The concentration of antibiotics was determined by high performance liquid chromatography, 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 of Example 1 and the porous silicon of Comparative Example 1 after loading antibiotics are as follows: Fig.10 As shown by Fig.10 It can be seen that hyperbranched modification can load more antibiotics, so the weight loss is greater. However, porous silicon itself is silicon, which is stable in nature and will not lose weight during the heating process. Antibiotics are small molecules and will decompose when heated.

[0071] The Zeta potential diagrams of the modified porous silicon or porous silicon synthesized in the process of Examples 1-5 and Comparative Examples 1-2 are as follows: Fig.11 As shown, it is shown that modifying amino-hyperbranched polysiloxane can effectively change the surface electronegativity of porous silicon.

[0072] The above is only a preferred embodiment of the present invention. The present invention is not limited to the above implementation. As long as the technical effect of the present invention is achieved by the same means, it should belong to the protection scope of the present invention. Within the protection scope of the present invention, its technical scheme and / or implementation method can have various 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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