Calcium alginate hydrogel with high light transmittance and its rapid electro-controlled forming method

Abstract

The present invention provides a calcium alginate hydrogel with high light transmittance and a rapid electro-control forming method thereof, comprising the following steps: S1. Sodium alginate and calcium disodium ethylene diamine tetraacetate are added to deionized water to obtain a viscous liquid; S2. A cathode and an anode are placed in the viscous liquid, and an electrolytic water reaction is carried out by energization, so that calcium ions released by sodium alginate and calcium disodium ethylene diamine tetraacetate are crosslinked and deposited at the anode to obtain a calcium alginate hydrogel with high light transmittance. By selecting EDTANa2Ca as the calcium ion source, the present invention utilizes hydrogen ions generated by the electrode reaction to promote the release of calcium ions, thereby crosslinking with alginic acid near the electrode and gradually depositing on the electrode, obtaining a calcium alginate hydrogel with higher transparency and more uniform structure, and significantly improving the preparation efficiency. When used as a wound dressing, it is convenient to observe the wound condition.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogel preparation, and particularly to a calcium alginate hydrogel with high light transmittance and a rapid electro-controlled forming method thereof. Background Art

[0002] Natural polysaccharide hydrogel materials are widely used in the biomedical field. Among them, alginate hydrogel materials can usually be chelated with calcium ions to rapidly gelate and form calcium alginate hydrogels. In the prior art, an initial gel matrix is generally obtained by freeze-drying or casting a casting solution to scrape a film, and then cross-linked with a soluble calcium salt to obtain a calcium alginate hydrogel.

[0003] For example, Patent CN114437404A discloses a preparation method of a calcium alginate porous hydrogel. The sodium alginate aqueous solution is freeze-dried to obtain a porous dry gel, and then cross-linked in a calcium chloride solution to obtain a calcium alginate porous organic gel. Patent CN110743398A discloses a preparation method of a rare earth ion-doped calcium alginate / carbon nanotube hydrogel antibacterial filter membrane. Carboxylated carbon nanotubes and sodium alginate are dissolved in water together to obtain a casting solution. The casting solution is scraped into a film and immersed in a soluble calcium salt aqueous solution for sufficient cross-linking to obtain a calcium alginate hydrogel membrane containing carboxylated carbon nanotubes. However, both of these methods cannot achieve fine regulation of the initial gel matrix, and only calcium ion cross-linking is realized after impregnation treatment. The cross-linking structure of the gel is relatively single, and both the strength and transparency are not good, which limits its expansion and application.

[0004] In view of this, it is necessary to design an improved calcium alginate hydrogel with high light transmittance and a rapid electro-controlled forming method thereof to solve the above problems. Summary of the Invention

[0005] In order to overcome the above-mentioned deficiencies of the prior art, the purpose of the present invention is to provide a calcium alginate hydrogel with high light transmittance and a rapid electro-controlled forming method thereof. By using an EDTANa2Ca molecule to electrolytically release calcium ions to promote cross-linking and gradually deposit on the electrode, a calcium alginate hydrogel with higher transparency and more uniform structure is obtained, and the preparation efficiency is significantly improved. When used as a wound dressing, it is convenient to observe the wound condition.

[0006] To achieve the above-mentioned invention purpose, the present invention provides a rapid electro-controlled forming method of a calcium alginate hydrogel dressing, including the following steps:

[0007] S1. Sodium alginate and calcium disodium ethylene diamine tetraacetate are added to deionized water to obtain a viscous liquid;

[0008] S2. Place the cathode and anode in the viscous liquid, and apply an electric current to carry out the electrolytic water reaction, so that the calcium ions released by sodium alginate and calcium disodium ethylene diamine tetraacetate crosslink and deposit at the anode to obtain a high light transmittance calcium alginate hydrogel.

[0009] As a further improvement of the present invention, the high light transmittance calcium alginate hydrogel obtained in step S2 is impregnated and crosslinked in a CaCl2 solution, and the unreacted ethylenediaminetetraacetic acid and sodium ions are washed away to obtain an enhanced high light transmittance calcium alginate hydrogel.

[0010] As a further improvement of the present invention, in step S1, the mass ratio of sodium alginate to calcium disodium ethylene diamine tetraacetate is (1-2):1, and the mass concentration of calcium disodium ethylene diamine tetraacetate is 1-5 g / L.

[0011] As a further improvement of the present invention, in step S2, the voltage of the electrolytic water reaction is 1-10 V, and the deposition time is 0.1-20 min.

[0012] As a further improvement of the present invention, in step S2, the thickness of the high light transmittance calcium alginate hydrogel is 0.01-1 cm, and the visible light transmittance reaches 70%-90%.

[0013] As a further improvement of the present invention, the voltage of the electrolytic water reaction is 5 V, and the deposition time is 0.8-1.5 min to obtain a high light transmittance calcium alginate hydrogel with a thickness of 0.1-0.3 cm and a visible light transmittance of 80%-90%;

[0014] Or, the voltage of the electrolytic water reaction is 9 V, and the deposition time is 0.5-1.5 min to obtain a high light transmittance calcium alginate hydrogel with a thickness of 0.2-0.4 cm and a visible light transmittance of 70%-85%.

[0015] As a further improvement of the present invention, in step S2, the cathode and anode are platinum electrodes.

[0016] As a further improvement of the present invention, in step S1, other polysaccharide matrices are also added to the deionized water, and the other polysaccharide matrices include one or more of hyaluronic acid, carboxymethyl chitosan, and cellulose.

[0017] As a further improvement of the present invention, the mass ratio of the other polysaccharide matrix to the sodium alginate is (0.1-2):1.

[0018] A high light transmittance calcium alginate hydrogel is prepared by using the rapid electro-control forming method described in any one of the above.

[0019] The beneficial effects of the present invention are:

[0020] 1. The rapid electrocontrolled forming method of the high light transmittance calcium alginate hydrogel dressing provided by the present invention uses EDTANa2Ca as the calcium source. By means of electrodeposition, the hydrogen ions generated by the electrode reaction promote the release of calcium ions, so as to crosslink with alginic acid near the electrode and gradually deposit on the electrode. Since no gas is generated when EDTANa2Ca releases calcium ions, which will not affect the forming of the gel, a calcium alginate hydrogel with higher transparency and more uniform structure can be obtained. The present invention can not only achieve the precise control of the ultra-thin calcium alginate hydrogel through the electrolysis intensity and time, but also obtain a calcium alginate hydrogel with higher transparency and strength. When used as a wound dressing, it is convenient to observe the wound condition, and the electrolysis preparation efficiency is significantly improved. Since no additional additives are needed to promote the release of calcium ions, the hydrogel has higher purity and will not have a negative impact on its functionality.

[0021] 2. The calcium ion source EDTANa2Ca selected by the present invention can be uniformly mixed with alginic acid and has a relatively sensitive pH responsiveness, which can significantly improve the efficiency and transparency of the gel formed by electrodeposition, and solve the problems that calcium carbonate nanoparticles have uneven mixed distribution, and CO2 gas is generated during their dissolution process, which has a great impact on the uniformity of the internal structure of the formed gel, and the optical fiber refraction and scattering phenomena caused by internal cavities or defect structures, so that the gel shows a semi-transparent state and has poor mechanical properties.

[0022] 3. The present invention first releases calcium ions by electrolysis to obtain a preliminarily formed calcium alginate hydrogel, and then impregnates it with a calcium chloride solution to strengthen the crosslinking. By such operation, the initial crosslinked structure can be regulated. Finally, the strength after impregnation and crosslinking is significantly increased and the structure is more uniform, which is convenient for application.

[0023] 4. The method of the present invention is simple and easy to operate, environmentally friendly, with mild reaction, little damage to sodium alginate and disodium ethylenediaminetetraacetate. The prepared gel can be made into a gel material with a specific shape by controlling the shape of the working electrode, the thickness is precisely controllable, and it has high transparency and good biocompatibility, and is expected to be used in materials such as wound dressings. Description of the Drawings

[0024] Figure 1 It is the schematic diagram of the preparation of a highly transparent calcium alginate gel controlled by an electrical signal.

[0025] Figure 2 It is the optical growth photos of the calcium alginate hydrogel under different deposition voltages and deposition times.

[0026] Figure 3 It is the curve of the thickness of the calcium alginate hydrogel changing with time under different constant voltage deposition conditions.

[0027] Figure 4The transmittance curves of calcium alginate hydrogels prepared under different deposition conditions were measured using an ultraviolet spectrophotometer.

[0028] Figure 5 Among them, the optical photos of Example 1 and Example 2 are shown from left to right in sequence.

[0029] Figure 6 On the left in the figure is the SEM image of the calcium alginate hydrogel prepared in Example 1, and on the right is the SEM image of the two-component calcium alginate hydrogel prepared in Example 2.

[0030] Figure 7 They are the compression performance curves of the calcium alginate-based hydrogels prepared in Example 1 and Example 2. Detailed implementation manners

[0031] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in detail below with reference to specific embodiments.

[0032] Here, it should also be noted that in order to avoid obscuring the present invention due to unnecessary details, only the structures and / or processing steps closely related to the solution of the present invention are shown in the specific embodiments, while other details less related to the present invention are omitted.

[0033] In addition, it should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0034] Please refer to Figure 1 As shown, a rapid electro-controlled forming method for a high-transmittance calcium alginate hydrogel dressing provided by the present invention includes the following steps:

[0035] S1. Sodium alginate and calcium disodium ethylene diamine tetraacetate (EDTANa2Ca) are added to deionized water to obtain a viscous liquid;

[0036] S2. A cathode and an anode are placed in the viscous liquid, and an electrolytic water reaction is carried out by energization, so that calcium ions released by sodium alginate and calcium disodium ethylene diamine tetraacetate are cross-linked and deposited at the anode to obtain a high-transmittance calcium alginate hydrogel.

[0037] By operating in this way, using EDTANa2Ca as the calcium source, the calcium ions exist in a complex state in water. During electrolysis, hydrogen ions are generated at the anode, promoting the release of the complexed calcium ions, which then crosslink with alginic acid near the electrode and gradually deposit on the electrode. Since no gas is generated when EDTANa2Ca releases calcium ions, it does not affect the formation of the gel, and thus a calcium alginate hydrogel with higher transparency and a more uniform structure is obtained. Through the electrolysis method of the present invention, not only can the precise control of the ultra-thin calcium alginate hydrogel be achieved through the electrolysis intensity and time, but also a calcium alginate hydrogel with higher transparency can be obtained. When used as a wound dressing, it is convenient to observe the wound condition, and the electrolysis preparation efficiency is significantly improved. The present invention does not require the addition of extra additives to promote the release of calcium ions, so the hydrogel has a higher purity and will not have a negative impact on its functionality.

[0038] Specifically, the high-transparency calcium alginate hydrogel obtained in step S2 is impregnated and crosslinked in a CaCl2 solution, and the unreacted ethylenediaminetetraacetic acid and sodium ions are washed away to obtain an enhanced high-transparency calcium alginate hydrogel. By operating in this way, calcium ions are slowly released through electrolysis to obtain a preliminarily formed calcium alginate hydrogel. Compared with the prior art methods such as freeze-drying or scraping film, on the one hand, the preparation controllability is higher, and a gel with better thickness and transparency can be obtained; on the other hand, the present invention can overcome the problem that due to excessive free calcium ions, the direct crosslinking with the sodium alginate solution is uncontrollable, and it is necessary to first solidify and then impregnate and crosslink. This allows the calcium ions to participate in the crosslinking first, regulate the initial crosslinked structure, and finally the strength is significantly increased after impregnation and crosslinking, and the structure is more uniform, which is convenient for application.

[0039] In step S1, the mass ratio of sodium alginate to calcium disodium ethylenediaminetetraacetate is (1 - 2):1, and the mass concentration of calcium disodium ethylenediaminetetraacetate is 1 - 5 g / L.

[0040] In step S2, the voltage of the electrolyzed water reaction is 1 - 10 V, and the deposition time is 0.1 - 20 min.

[0041] In step S2, the thickness of the high-transparency calcium alginate hydrogel is 0.01 - 1 cm, and the visible light transmittance reaches 70% - 90%. The present invention can obtain a highly uniform ultra-thin calcium alginate hydrogel.

[0042] In some embodiments, the voltage of the electrolyzed water reaction is 5 V, and the deposition time is 0.8 - 1.5 min, and a high-transparency calcium alginate hydrogel with a thickness of 0.1 - 0.3 cm and a visible light transmittance of 80% - 90% can be obtained; the deposition efficiency can reach an average of 0.6 - 0.2 cm / min, and the preparation efficiency is high.

[0043] Alternatively, the voltage of the electrolyzed water reaction is 9V, and the deposition time is 0.5 - 1.5 min, to obtain a high light transmittance calcium alginate hydrogel with a thickness of 0.2 - 0.4 cm and a visible light transmittance of 70% - 85%.

[0044] Alternatively, the voltage of the electrolyzed water reaction is 3V, and the deposition time is 0.5 - 2 min, to obtain a high light transmittance calcium alginate hydrogel with a thickness of 0.05 - 0.15 cm and a visible light transmittance of 80% - 90%.

[0045] Preferably, in step S2, the cathode and anode are platinum electrodes. The electrodes are rod-shaped, sheet-shaped or polyhedral. By changing the electrode shape, calcium alginate hydrogels with different deposition structures can be obtained, with high controllability.

[0046] In step S1, other polysaccharide matrices are added to the deionized water. The other polysaccharide matrices include one or more of hyaluronic acid, carboxymethyl chitosan, and cellulose, preferably carboxymethyl chitosan. The mass ratio of the other polysaccharide matrix to sodium alginate is (0.1 - 2):1. By adding other polysaccharide matrices, multifunctional composite hydrogels can be obtained, expanding the application of hydrogels.

[0047] Example 1

[0048] A rapid electro-controlled forming method for a high light transmittance calcium alginate hydrogel dressing, comprising the following steps:

[0049] S1. Sodium alginate and calcium disodium ethylenediaminetetraacetate are added to deionized water at a mass ratio of 1:1 to obtain a viscous liquid; the concentration of sodium alginate is 0.3 g / L;

[0050] S2. The cathode and anode are placed in the viscous liquid, and an electrolyzed water reaction is carried out by applying an electric current (voltage 3 - 9V) for 60 - 300 s, so that the calcium ions released by sodium alginate and calcium disodium ethylenediaminetetraacetate crosslink and deposit at the anode. By controlling the working voltage and deposition time, high light transmittance calcium alginate hydrogels with different thicknesses and transparencies are obtained.

[0051] As Figure 2 shown, it can be seen that at different voltages, with the extension of the electrolysis time, the deposition amount of the hydrogel gradually increases, and it can be seen that the hydrogel has good transparency and the electrodes wrapped by it can be observed.

[0052] As Figure 3 shown, it can be seen that at the beginning of electrolysis, the hydrogel thickness increases rapidly, and as the reaction proceeds, the thickness increase gradually slows down because the reactant concentration in the solution gradually decreases. The raw materials can be continuously supplemented to maintain a uniform and high production rate.

[0053] Combined with Figure 3and 4 It can be seen that when the voltage is 5V and the electrolysis time is 60s, the thickness is 0.2cm, and the light transmittance of 400 - 600nm can reach about 88%. The infrared transmittance is also relatively high, and the ultraviolet transmittance is about 70%. With the increase of the thickness, the visible light transmittance decreases slightly. When the thickness is 0.4cm, the visible light transmittance is about 75%, and the ultraviolet transmittance is about 40%. It can be seen that through the selection of the thickness, the present invention can obtain a hydrogel with high visible light and infrared transmittance and low ultraviolet transmittance. When used as a wound dressing, it is convenient to observe the wound condition, prevent the influence of ultraviolet radiation on the wound, and regulate the wound environment through the infrared thermal radiation effect to promote wound healing.

[0054] In the present invention, through electrodeposition, the fixed-point release of calcium ions promotes cross-linking deposition. Compared with adding acid to promote the release of calcium ions in the solution, the uniformity and controllability are significantly improved.

[0055] Furthermore, the obtained hydrogel can be immersed in a 0.1mol / L CaCl2 solution for curing, so that the alginate molecules are fully cross-linked with calcium ions, and the EDTA and Na ions therein are washed away to obtain a calcium alginate hydrogel with higher strength and purity.

[0056] Example 2

[0057] A rapid electro-controlled forming method for a high light transmittance calcium alginate hydrogel dressing. Compared with Example 1, the difference is that in step S1, carboxymethyl chitosan is further added, and the mass ratio of it to sodium alginate is 1:1.

[0058] On the original basis, carboxymethyl chitosan (CMC) with an equal proportion of mass fraction was added to the deposition precursor solution, and the mass ratio was 1:1, and its optical photo, SEM photo and compression performance test curve were obtained. From Figure 5 It can be seen that the transparency of the calcium alginate-based hydrogel prepared by the present invention is good. From Figure 6 It can be seen that both the single-component or two-component calcium alginate-based hydrogels have a uniform pore structure. From Figure 7 It can be seen that the compression strength of the single-component calcium alginate-based hydrogel is lower than that of the two-component one, but the elongation at break is higher, indicating that its toughness is relatively better, while the strength of the two-component one is better.

[0059] In summary, for the rapid electro-controlled forming method of the high light transmittance calcium alginate hydrogel dressing provided by the present invention, EDTANa2Ca is used as the calcium source, and the method of electrodeposition is adopted. The hydrogen ions generated by the electrode reaction promote the release of calcium ions, so as to crosslink with alginic acid near the electrode and gradually deposit on the electrode. Since no gas is generated when EDTANa2Ca releases calcium ions, which will not affect the forming of the gel, a calcium alginate hydrogel with higher transparency and more uniform structure can be obtained. The present invention can not only achieve the precise control of the ultra-thin calcium alginate hydrogel through the electrolysis intensity and time, but also obtain a calcium alginate hydrogel with higher transparency and strength. When used as a wound dressing, it is convenient to observe the wound condition, and the electrolysis preparation efficiency is significantly improved. Since no additional additives are required to promote the release of calcium ions, the hydrogel has higher purity and will not have a negative impact on its functionality.

[0060] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A rapid electro-controlled forming method for a calcium alginate hydrogel dressing with high light transmittance, characterized in that, It includes the following steps: S1. Add sodium alginate and calcium disodium edetate to deionized water to obtain a viscous liquid; S2. Place the cathode and anode in the viscous liquid, and conduct electrolytic water reaction by applying electricity, so that the calcium ions released by sodium alginate and calcium disodium edetate are cross-linked and deposited at the anode to obtain a calcium alginate hydrogel with high light transmittance; the voltage of the electrolytic water reaction is 1-10V, and the deposition time is 0.1-20min; the thickness of the calcium alginate hydrogel with high light transmittance is 0.01-1cm, and the visible light transmittance reaches 70%-90%.

2. The rapid electro-controlled forming method of the high light transmittance calcium alginate hydrogel dressing according to claim 1, characterized in that Immerse and cross-link the calcium alginate hydrogel with high light transmittance obtained in step S2 in a CaCl2 solution, and wash away the unreacted ethylenediaminetetraacetic acid and sodium ions to obtain an enhanced calcium alginate hydrogel with high light transmittance.

3. The rapid electro-controlled forming method of the high light transmittance calcium alginate hydrogel dressing according to claim 1, characterized in that, In step S1, the mass ratio of sodium alginate to calcium disodium edetate is (1-2):1, and the mass concentration of calcium disodium edetate is 1-5g / L.

4. The rapid electro-controlled forming method of the high light transmittance calcium alginate hydrogel dressing according to claim 1, characterized in that The voltage of the electrolytic water reaction is 5V, and the deposition time is 0.8-1.5min to obtain a calcium alginate hydrogel with high light transmittance having a thickness of 0.1-0.3cm and a visible light transmittance of 80%-90%; Alternatively, the voltage of the electrolytic water reaction is 9V, and the deposition time is 0.5-1.5min to obtain a calcium alginate hydrogel with high light transmittance having a thickness of 0.2-0.4cm and a visible light transmittance of 70%-85%.

5. The rapid electro-controlled forming method of the high light transmittance calcium alginate hydrogel dressing according to claim 1, characterized in that, In step S2, the cathode and anode are platinum electrodes.

6. The rapid electro-controlled forming method of the high light transmittance calcium alginate hydrogel dressing according to any one of claims 1 to 5, characterized in that, In step S1, other polysaccharide matrices are further added to the deionized water, and the other polysaccharide matrices include one or more of hyaluronic acid, carboxymethyl chitosan, and cellulose.

7. The rapid electro-controlled forming method of the high light transmittance calcium alginate hydrogel dressing according to claim 6, characterized in that, The mass ratio of the other polysaccharide matrix to the sodium alginate is (0.1-2):

1.

8. A calcium alginate hydrogel with high light transmittance, characterized in that, It is prepared by using the rapid electro-controlled forming method described in any one of claims 1 to 7.

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