CN114381083B - Antibacterial and antioxidant hydrogel for corneal contact lens and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of polymer hydrogel, and particularly relates to an antibacterial antioxidant hydrogel for a contact lens and a preparation method thereof, wherein the antibacterial antioxidant hydrogel comprises the following components in percentage by weight: 15 to 20 percent of acrylamide monomer, 1 to 1.5 percent of quaternized chitosan, 0.01 to 0.05 percent of cross-linking agent, 0.01 to 0.05 percent of initiator, 0.03 to 0.08 percent of accelerator and the balance of water. The antibacterial and antioxidant hydrogel disclosed by the invention has good light transmittance, mechanical property, antibacterial and antioxidant capacity and biocompatibility, and can be used as a hydrogel contact lens material for treating bacterial keratitis.

Description

Antibacterial and antioxidant hydrogel for corneal contact lens and preparation method thereof

technical field

The invention belongs to the technical field of polymer hydrogel, and in particular relates to an antibacterial and anti-oxidation hydrogel for corneal contact lenses and a preparation method thereof.

Background technique

Bacterial keratitis is an ocular disorder caused by bacterial infection of the cornea after injury or contact lens wear, leading to complications such as corneal perforation and stromal damage. At present, eye drops containing broad-spectrum antibiotics are generally used clinically to treat bacterial keratitis. However, limited by the way of administration, the drug utilization rate of antibiotic eye drops is low, and less than 5% of the drug can actually reach the infected area. Furthermore, bacterial infection is often accompanied by inflammation of the immune system and oxidative stress damage via reactive oxygen species. Excess ROS can lead to impairment of normal cell function and even induce cell death.

Antimicrobial polymers exhibit remarkable selectivity for bacteria compared with other antimicrobial agents and are considered as next-generation bactericides. Antibacterial polymers can be divided into two categories according to their antibacterial mechanism: contact-active polymers and polymers that release bactericides. The former usually have cationic charges and directly inhibit bacterial growth by interacting with negatively charged bacterial membranes; the latter release Bactericides to inactivate bacteria, such as antibiotics or other substances with strong antimicrobial activity (such as metal nanoparticles).

Hydrogel is a soft material composed of cross-linked hydrophilic polymers. Because of its high water content, adjustable mechanical properties, and good biocompatibility, it is widely used in tissue engineering and medical fields, such as artificial joints, Contact lenses, medical dressings, etc. Hydrogel can be used as an antibacterial polymer carrier to load antibiotics or nanoparticles, and then inhibit bacterial infection by contacting or releasing bactericides, for example, the drug slow-release hydrogel contact lens disclosed in the patent document CN102316832B. However, the sustained drug release of antibiotics in hydrogels still cannot solve the problem of drug-resistant bacteria, and metal and metal oxide nanoparticles are highly cytotoxic to mammalian cells. Therefore, antimicrobial materials that can inactivate bacteria only by contact rather than releasing drugs or nanoparticles would be safer and more reliable.

Contents of the invention

Based on the above-mentioned shortcomings and deficiencies in the prior art, one of the purposes of the present invention is to at least solve one or more of the above-mentioned problems in the prior art. In other words, one of the purposes of the present invention is to provide a One or more antibacterial and antioxidant hydrogels for corneal contact lenses and a preparation method thereof.

In order to achieve the above object of the invention, the present invention adopts the following technical solutions:

An antibacterial and antioxidant hydrogel for contact lenses, by weight percentage, comprising the following components:

15-20% of acrylamide monomer, 1-1.5% of quaternized chitosan, 0.01-0.05% of cross-linking agent, 0.01-0.05% of initiator, 0.03-0.08% of accelerator, and the balance is water.

As a preferred solution, the antibacterial and antioxidant hydrogel further includes the following components in weight percentage: 0.001-1.5% tannic acid.

The antibacterial and antioxidant hydrogel for contact lenses of the present invention uses polyacrylamide hydrogel as a matrix, and forms a new polyacrylamide hydrogel network by introducing quaternized chitosan and tannic acid into the polyacrylamide hydrogel network. Physically cross-link bonds (hydrogen bonds, π-π interactions, cation-π interactions) to form semi-interpenetrating networks for enhanced mechanical strength. Quaternized chitosan mainly provides antibacterial properties, and tannic acid mainly provides antioxidant properties, and the two are synergistic; by adjusting the content of each component in the system, a series of antibacterial and antioxidant properties can be used to treat bacterial infections. Hydrogel contact lenses for keratitis.

As a preferred solution, the acrylamide monomer is acrylamide, N-isopropylacrylamide or N,N-bismethacrylamide.

As a preferred version, the structural formula of the quaternized chitosan is:

Wherein, x/(x+y) is the quaternization ratio, which is controlled at 40-70%.

As a preferred version, the crosslinking agent is N,N-methylenebisacrylamide, the initiator is potassium persulfate or ammonium persulfate, and the accelerator is N,N,N',N'-tetra Methylethylenediamine.

The present invention also provides the preparation method of the antibacterial and antioxidant hydrogel as described in the above scheme, comprising the following steps:

(1) Add quaternized chitosan and acrylamide monomers into water, stir until completely dissolved; then add initiator, crosslinking agent, accelerator in turn, stir to form a reaction mixture;

(2) Transfer the reaction mixture to a mold for free radical polymerization. After the reaction, take the product out of the mold and transfer it to water to make the gel reach a swelling balance to obtain an antibacterial and antioxidant hydrogel.

The present invention also provides the preparation method of the antibacterial and antioxidant hydrogel as described in the above scheme, comprising the following steps:

(1) Add quaternized chitosan and acrylamide monomers into water, stir until completely dissolved; then add initiator, crosslinking agent, accelerator in turn, stir to form a reaction mixture;

(2) Transfer the reaction mixture to a mold for free radical polymerization, and after the reaction, take the product out of the mold and freeze-dry it to obtain a freeze-dried gel;

(3) immerse the lyophilized gel in an aqueous tannic acid solution with a pH of 2 to 3, adjust the pH of the aqueous tannic acid solution to neutral after the immersion, and then transfer the gel to water to allow the gel to reach a swelling equilibrium, An antibacterial and antioxidant hydrogel was obtained.

As a preferred solution, the temperature of the radical polymerization reaction is 20-35° C., and the time is 12-36 hours.

As a preferred solution, in the step (3), the soaking temperature is 60-75° C., and the soaking time is 10-24 hours.

As a preferred solution, in the step (3), hydrochloric acid is used to adjust the pH of the tannic acid aqueous solution to 2-3, and sodium hydroxide is used to adjust the pH of the tannic acid aqueous solution to neutral.

The present invention compares with prior art, beneficial effect is:

(1) The antibacterial and antioxidant hydrogel of the present invention has high light transmittance and soft and tough mechanical properties, and can be used as a contact lens material to meet the comfort and safety requirements of the wearer;

(2) The antibacterial and antioxidant hydrogel of the present invention has excellent antibacterial and antioxidant activities, and the two have synergistic effects;

(3) The antibacterial and antioxidant hydrogel of the present invention, the quaternized chitosan and tannic acid used in it all belong to natural biological compounds, and the raw materials are cheap and easy to get, which can greatly reduce the cost of hydrogel preparation;

(4) The antibacterial and antioxidant hydrogel of the present invention does not contain drugs such as antibiotics, and has no problem of drug resistance;

(5) The antibacterial and antioxidant hydrogel of the present invention has good biocompatibility;

(6) The antibacterial and antioxidative hydrogel of the present invention can adjust its antibacterial and antioxidative properties by changing the content of each component, and the preparation process is simple and easy to control.

Description of drawings

Fig. 1 is the synthetic principle roadmap of the antibacterial and antioxidant hydrogel of the embodiment of the present invention;

Fig. 2 is the comparative figure of light transmittance curve of the antibacterial antioxidation hydrogel of the embodiment of the present invention 1-5;

Fig. 3 is the comparison chart of the tensile stress-strain curve of the antibacterial and antioxidative hydrogel of the embodiment of the present invention 1-5;

Fig. 4 is the comparative figure of the antioxidant performance of the antibacterial and antioxidant hydrogels of Examples 1-5 and Comparative Examples 1-5 of the present invention;

Fig. 5 is the comparison chart of the antibacterial properties of the antibacterial and antioxidant hydrogels of Examples 1-5 and Comparative Examples 1-5 of the present invention;

Fig. 6 is a comparison chart of the cytotoxicity of the antibacterial and antioxidant hydrogels of Examples 1-5 of the present invention.

Detailed ways

The technical solutions of the present invention will be further explained below through specific examples.

The preparation method of the antibacterial and antioxidant hydrogel of the embodiment of the present invention comprises the following steps:

(1) Add 1 to 1.5 wt% of quaternized chitosan and 15 to 20 wt% of acrylamide monomer into water, stir until completely dissolved; then add 0.01 to 0.05 wt% of initiator and 0.01 to 0.05 wt% of crosslinking agent in sequence wt%, accelerator 0.03-0.08wt%, stirring evenly to form a reaction mixture;

(2) Transfer the reaction mixture to a mold, and carry out free radical polymerization reaction at 20-35° C., the reaction time is 12-36 hours, and the product is taken out from the mold after the reaction;

(3) The product taken out in step (2) is subjected to freeze-drying treatment to obtain a freeze-dried gel; then the freeze-dried gel is soaked in tannic acid ( TA) in an aqueous solution, heated in a water bath at 60-75°C for 10-24 hours;

(4) After the water-bath heating finishes, the pH value of the tannic acid solution is adjusted to neutrality with sodium hydroxide;

(5) taking out the gel after step (4) treatment, soaking in water for 3 days, to remove unreacted acrylamide monomer, quaternized chitosan, initiator, accelerator and tannic acid, And make the gel reach the swelling equilibrium, and obtain the hydrogel with antibacterial and antioxidative properties. For details, please refer to the synthesis principle of the antibacterial and antioxidant hydrogel shown in Fig. 1 .

Specifically, the structural formula of quaternized chitosan (QCS) is:

Wherein, x/(x+y) is the quaternization ratio, which is controlled at 40-70%.

The acrylamide monomer is acrylamide, N-isopropylacrylamide or N,N-bismethacrylamide, the crosslinking agent is N,N-methylenebisacrylamide, and the initiator is potassium persulfate (KPS ) or ammonium persulfate (APS), the accelerator is N,N,N',N'-tetramethylethylenediamine; the amount of water used is 6mL.

The differences between Examples 1-9 and Comparative Examples 1-5 are compared and listed below through the list of ingredients and the table of preparation parameters. The specific preparation process can refer to the preparation method of the antibacterial and antioxidant hydrogel of the above-mentioned embodiment of the present invention, such as Table 1 and Table 2 are shown. In addition, it should be noted that if the antibacterial and antioxidant hydrogel does not contain tannic acid, the above steps (3) to (4) are omitted, and the product of step (2) is directly processed in step (5) to obtain water gel.

The batching table of table 1 embodiment 1～9 and comparative example 1～5

Wherein, the acrylamide monomer in Examples 1-7 and Comparative Examples 1-5 adopts acrylamide; the acrylamide monomer in Example 8 is N-isopropylacrylamide; the acrylamide in Example 9 The analogue monomer is N,N-bismethacrylamide.

The preparation parameter table of table 2 embodiment 1～9 and comparative example 1～5

The performance test of the hydrogels of Examples 1-5 and Comparative Examples 1-5 is as follows:

1. Light transmittance test: measure the light transmittance of the contact lens with an ultraviolet-visible spectrophotometer in the wavelength range of 450-800nm.

2. Mechanical properties test: At room temperature and 50% humidity, cut the hydrogel into a dumbbell shape (length 16mm, width 4mm), use a universal testing machine to fix the tensile rate at 100mm/min, test the hydrogel contact The tensile mechanical properties of the mirror.

3. Antioxidant test: Add 10 mg of hydrogel sample to 30 mL of freshly prepared 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH ^· ) or 2,2'-azino-bis -(3-Ethylbenzodihydrothiazoline-6-sulfonic acid) (ABTS ^·+ ) free radical solution, and respectively keep the mixture in the dark for 1h or 40min, and then use the UV-Vis spectrophotometer to measure the Absorbance at 517nm (DPPH ^· ) or 752nm (ABTS ^·+ ).

The free radical scavenging rate S was calculated as follows:

S=[1-A _i /A _c ]*100%

Wherein, A _i and A _c are the absorbance at 517nm or 752nm of the radical solution mixed with the hydrogel sample and the radical solution of the blank group, respectively.

4. Antibacterial performance test: the samples were sterilized and placed in a 48-well plate, and then 200 μL of bacterial suspension (1×10 ⁵ CFU/mL) was added to each well. The bacteria selected are Escherichia coli (E.coli) or Staphylococcus aureus (S.aureus). After incubation in a shaker at 37° C. for 8 h, the bacteria were inoculated on Luria-Bertani (LB) agar plates, and the bacterial concentration was counted after 10-fold serial dilution. Finally, relative bacterial survival was calculated based on the number of colonies before and after incubation.

5. In vitro cytotoxicity test: human corneal epithelial cells (HCECs) were placed in Ham's F12 complete medium (containing 10% FBS) for proliferation and culture for 2 to ³ days, and then transferred to the in a 96-well plate. After continuing to culture for 24 h, the cell adhesion was observed. When the growth density of HCECs reached 90%, the hydrogel with a diameter of 4 mm was incubated with the cells for 10 h. After removing the hydrogel, add the Cell Counting Kit-8 (CCK-8) reagent into the well plate, and incubate for another 1-4 hours. Finally, by measuring the optical density (OD) value at a wavelength of 450nm with a microplate reader, the number of viable cells can be indirectly quantified and reflect the viability of the cells.

As shown in FIG. 2 , the light transmittances of the hydrogels of Examples 1-5 in the visible light wavelength range are all greater than 80%, which proves that the hydrogels of Examples 1-5 have good light transmittance.

As shown in Figure 3, the hydrogels of Examples 1-5 all have good elongation at break and moderate tensile strength.

As shown in FIG. 4 , the hydrogels of Examples 1-5 and Comparative Examples 1-5 all have certain oxidation resistance, and the oxidation resistance is enhanced with the increase of tannic acid content.

As shown in Figure 5, the hydrogels of Examples 1-5 have good antibacterial ability to Staphylococcus aureus (S.aureus) and Escherichia coli (E.coli), while the water gels of Comparative Examples 1-5 Gels without quaternized chitosan exhibited poor antibacterial efficacy.

As shown in FIG. 6 , the hydrogels of Examples 1-5 all have certain biocompatibility, and the survival rates of human corneal epithelial cells are 99%, 95%, 100%, 82%, and 74%, respectively.

The above experimental results show that the antibacterial and antioxidant hydrogels of the various embodiments of the present invention, especially the hydrogel of Example 3, have good light transmittance, certain mechanical properties, high antibacterial and antioxidant capabilities and excellent biocompatibility and can be used as a hydrogel contact lens material for the treatment of bacterial keratitis.

Due to the large number of embodiments of the present invention, the experimental data of each embodiment is huge and numerous, so it is not suitable to list and describe them one by one here, but the content to be verified and the final conclusion obtained by each embodiment are close. Therefore, the verification content of each embodiment will not be described one by one here, and only embodiments 1-5 are used as representatives to illustrate the advantages of the application of the present invention.

The above is only a detailed description of the preferred embodiments and principles of the present invention. For those of ordinary skill in the art, according to the ideas provided by the present invention, there will be changes in the specific implementation, and these changes should also be It is regarded as the protection scope of the present invention.

Claims (9)

1. an antibacterial and antioxidant hydrogel for contact lenses, characterized in that, by weight percentage, comprising the following components: Acrylamide monomer 15-20%, quaternized chitosan 1-1.5%, cross-linking agent 0.01-0.05%, initiator 0.01-0.05%, accelerator 0.03-0.08%, and the balance is water. 2. an antibacterial and antioxidant hydrogel for contact lenses, characterized in that, by weight percentage, it comprises the following components: Acrylamide monomer 15-20%, quaternized chitosan 1-1.5%, cross-linking agent 0.01-0.05%, initiator 0.01-0.05%, accelerator 0.03-0.08%, tannic acid 0.001-1.5% , the balance is water; The preparation method of antibacterial and antioxidant hydrogel comprises the following steps: (1) Add quaternized chitosan and acrylamide monomers into water, stir until completely dissolved; then add initiator, crosslinking agent, and accelerator in sequence, and stir evenly to form a reaction mixture; (2) Transfer the reaction mixture to a mold for free radical polymerization. After the reaction, take the product out of the mold and freeze-dry it to obtain a freeze-dried gel; (3) Immerse the freeze-dried gel in an aqueous tannic acid solution with a pH of 2 to 3, adjust the pH of the aqueous tannic acid solution to neutral after soaking, and then transfer the gel to water to make the gel reach a swelling equilibrium, An antibacterial and antioxidant hydrogel was obtained. 3 . The antibacterial and antioxidant hydrogel for contact lenses according to claim 2 , wherein in the step (3), the soaking temperature is 60-75° C. and the soaking time is 10-24 hours. 4 . 4. The antibacterial and antioxidant hydrogel for contact lenses according to claim 2, characterized in that in the step (3), hydrochloric acid is used to adjust the pH of the tannic acid aqueous solution to 2-3, and hydrogen Sodium oxide adjusts the pH of the aqueous tannic acid solution to neutral. 5. The antibacterial and antioxidant hydrogel for contact lenses according to claim 1 or 2, wherein the acrylamide monomer is acrylamide, N-isopropylacrylamide or N,N - Bismethacrylamide. 6. The antibacterial and antioxidant hydrogel for contact lenses according to claim 1 or 2, wherein the quaternization ratio of the quaternized chitosan is controlled at 40-70%. 7. The antibacterial and antioxidant hydrogel for a kind of contact lens according to claim 1 or 2, wherein the crosslinking agent is N, N-methylenebisacrylamide, and the initiator is Potassium persulfate or ammonium persulfate, and the accelerator is N, N, N', N'-tetramethylethylenediamine. 8. The preparation method of antibacterial and antioxidant hydrogel as claimed in claim 1, is characterized in that, comprises the following steps: (1) Add quaternized chitosan and acrylamide monomers into water, stir until completely dissolved; then add initiator, crosslinking agent, and accelerator in sequence, and stir evenly to form a reaction mixture; (2) Transfer the reaction mixture to a mold for free radical polymerization. After the reaction, take the product out of the mold and transfer it to water to make the gel reach swelling equilibrium to obtain an antibacterial and antioxidant hydrogel. 9. The preparation method according to claim 8, characterized in that the temperature of the radical polymerization reaction is 20-35° C., and the time is 12-36 hours.

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