Hyaluronic acid contact lens nano-composite coating and preparation method thereof
By preparing a nanocomposite coating of hyaluronic acid, nanocellulose, and polydopamine on contact lenses, the problems of easy drying, protein deposition, and unsustainable wettability of contact lenses are solved, achieving long-lasting moisturizing and anti-fouling properties, and improving wearing comfort and service life.
Patent Information
- Application Number
- CN202510943491.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-09
- Publication Date
- 2025-10-28
AI Technical Summary
Existing contact lenses are prone to drying out, protein and lipid deposition, and unsustainable wettability after long-term wear, affecting wearing comfort and service life.
The lens employs a nanocomposite coating of hyaluronic acid, nanocellulose, and polydopamine. Through oxygen plasma treatment and cross-linking curing, a dual mechanism of covalent cross-linking and physical adsorption is formed, which enhances the lens's moisturizing and anti-fouling properties and achieves long-lasting wettability.
It significantly improves the lens's wettability and resistance to protein deposits, maintains long-lasting moisture retention and abrasion resistance, and enhances wearing comfort and lifespan.
Smart Images
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Figure BDA0005490266130000061
Abstract
Description
Technical Field
[0001] This invention relates to the field of contact lens technology, and more particularly to a hyaluronic acid nanocomposite coating for contact lenses and its preparation method. Background Technology
[0002] The wetting properties of contact lenses directly affect wearing comfort and eye health, but currently available contact lenses still generally suffer from problems such as dryness, protein deposition, and limited wearing time. The limitations of existing wetting contact lenses are: (1) High water content hydrogel lenses enhance hydration by increasing the water content of the lens (e.g., above 56%), reducing the feeling of dryness in the eyes. However, high water content lenses are prone to water loss in dry environments (e.g., air-conditioned rooms), causing the lenses to harden and rub against the cornea; when the ambient humidity is low, the lenses may absorb water from the tears, exacerbating dry eye symptoms. (2) Silicone hydrogel lenses have high oxygen permeability (DK / t value increased by 4-6 times), reducing corneal hypoxia, but have poor wetting properties. Silicone material is highly hydrophobic, making it difficult for tears to spread evenly, resulting in dry spots easily forming on the lens surface, requiring external wetting agents. (3) Surface hydrophilic coating technology, plasma treatment: temporarily improves surface hydrophilicity, but the effect is not lasting; PVP or hyaluronic acid (HA) coating: improves initial wettability, but is easily rubbed off by blinking or tear washing, and has poor durability: most coatings degrade within a few hours and cannot support all-day wear.
[0003] In summary, current moisturizing contact lenses have the following problems: 1) Easily dry: Traditional contact lens materials (such as silicone hydrogel) are prone to water loss after prolonged wear, leading to dry eyes and discomfort from friction. 2) Protein and lipid deposition: Proteins and lipids in tears are easily adsorbed onto the lens surface, reducing oxygen permeability and causing eye inflammation. 3) Unsustainable wettability: Existing hydrophilic coatings (such as polyvinylpyrrolidone, PVP) lose wettability after repeated blinking or prolonged exposure to air. Summary of the Invention
[0004] The purpose of this invention is to provide a hyaluronic acid nanocomposite coating for contact lenses and its preparation method. This nanocomposite coating can achieve long-lasting moisturizing, anti-fouling and re-wetting properties for contact lenses, thereby improving the wearing comfort and service life of contact lenses.
[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:
[0006] This invention provides a method for preparing a hyaluronic acid nanocomposite coating for contact lenses, comprising the following steps:
[0007] The contact lens substrate is subjected to oxygen plasma treatment to obtain a pretreated substrate;
[0008] Hyaluronic acid, nanocellulose, polydopamine and buffer solution were mixed and homogenized by ultrasound to obtain a composite solution.
[0009] After the composite liquid is coated onto the pretreated substrate to form a coating film, it is cross-linked and cured in a cross-linking agent solution to obtain a hyaluronic acid contact lens nanocomposite coating.
[0010] Preferably, the contact lens substrate is silicone hydrogel or poly(hydroxyethyl methacrylate).
[0011] Preferably, the oxygen plasma treatment has a power of 50-300W, an oxygen flow rate of 10-100 sccm, a pressure of 0.1-10 Pa, and a time of 0.5-5 min.
[0012] Preferably, the molecular weight of the hyaluronic acid is 10 to 1000 kDa.
[0013] Preferably, the mass ratio of hyaluronic acid, nanocellulose and polydopamine is 3-6:1-3:0.5-2.
[0014] Preferably, the buffer solution is a PBS buffer solution with a pH of 7.4.
[0015] Preferably, the thickness of the coating is 1 to 5 μm.
[0016] Preferably, the crosslinking agent in the crosslinking agent solution includes genipin or an EDC-NHS mixture; the molar ratio of EDC to NHS is 1:0.5 to 2, and the concentration of the crosslinking agent solution is 1 to 10 mg / mL.
[0017] Preferably, the cross-linking curing temperature is 35-38°C and the time is 1-3 hours.
[0018] This invention provides a hyaluronic acid nanocomposite coating for contact lenses prepared by the preparation method described above.
[0019] This invention provides a method for preparing a hyaluronic acid nanocomposite coating for contact lenses. This composite coating is based on hyaluronic acid and nanocomposite materials, utilizing a dual mechanism of covalent cross-linking and physical adsorption. Hyaluronic acid provides continuous hydration, preventing lens dryness; hyaluronic acid and nanocellulose synergistically lock in water, achieving long-lasting moisturization. PDA nanoparticles reorganize after wetting, restoring hydrophilicity and improving wettability. The nanocomposite layer forms a physical barrier, reducing tear protein adsorption and improving anti-protein deposition effects, thus exhibiting anti-fouling properties. This coating has self-healing capabilities, restoring hydrophilicity after blinking or wetting with eye drops, providing reusable wetting. The composite coating of this invention is suitable for daily and monthly disposable soft contact lenses.
[0020] The results of the examples show that the initial contact angle of the coated lens of the present invention is 32°, and the water contact angle remains <40° after simulated tear flushing; the BSA adsorption capacity of the coated lens is only 0.8 μg / cm2, while the BSA adsorption capacity of the uncoated lens is 3.5 μg / cm2. 2 The amount of BSA adsorption is reduced by more than 70%; the water contact angle of the lens after coating is reduced from ~80° to ~30°, and the wettability is significantly improved; the moisture content is maintained at >50% for up to 12 hours in a dry environment (humidity 30%), and the moisturizing performance is excellent; after a simulated blink test (100,000 cycles), the coating retention rate is >90%, and the abrasion resistance is excellent. Detailed Implementation
[0021] Unless otherwise specified, all raw materials or reagents used in this invention are commercially available products well known in the art.
[0022] This invention provides a method for preparing a hyaluronic acid nanocomposite coating for contact lenses, comprising the following steps:
[0023] The contact lens substrate is subjected to oxygen plasma treatment to obtain a pretreated substrate;
[0024] Hyaluronic acid, nanocellulose, polydopamine and buffer solution were mixed and homogenized by ultrasound to obtain a composite solution.
[0025] After the composite liquid is coated onto the pretreated substrate to form a coating film, it is cross-linked and cured in a cross-linking agent solution to obtain a hyaluronic acid contact lens nanocomposite coating.
[0026] In this invention, the contact lens substrate is preferably silicone hydrogel or polyhydroxyethyl methacrylate (HEMA).
[0027] In this invention, the preferred power of the oxygen plasma treatment is 50–300 W, the preferred oxygen flow rate is 10–100 sccm, the preferred pressure is 0.1–10 Pa, and the preferred time is 0.5–5 min. This invention introduces hydroxyl (-OH) or carboxyl (-COOH) groups onto the lens surface through oxygen plasma treatment, thereby enhancing coating adhesion.
[0028] In this invention, the molecular weight of the hyaluronic acid (HA) is preferably 10-1000 kDa, which can improve the viscoelasticity, moisturizing properties and long-lasting lubrication of contact lenses.
[0029] In this invention, the diameter of the nanocellulose (CNF) is preferably 5-50 nm, and the particle size of the polydopamine (PDA) is preferably 20-100 nm.
[0030] In this invention, the preferred mass ratio of hyaluronic acid, nanocellulose, and polydopamine is 3–6:1–3:0.5–2, more preferably 5:2:1. In this invention, nanocellulose (CNF) enhances mechanical strength and provides a porous structure for water retention; polydopamine (PDA) improves adhesion and stain resistance.
[0031] In this invention, the buffer solution is preferably a PBS buffer solution with a pH of 7.4.
[0032] The present invention does not specifically limit the process of ultrasonic homogenization; the material can be ultrasonically homogenized according to a process known in the art.
[0033] In this invention, the coating method is preferably dip-coating or spin coating; this invention does not have any special limitations on the specific process of dip-coating or spin coating, and the desired coating thickness can be obtained by following methods well known in the art.
[0034] In this invention, the thickness of the coating is preferably 1 to 5 μm.
[0035] In this invention, the crosslinking agent in the crosslinking agent solution preferably includes genipin or an EDC-NHS mixture; the molar ratio of EDC to NHS is preferably 1:0.5 to 2; the concentration of the crosslinking agent solution is 1 to 10 mg / mL, more preferably 5 mg / mL; and the solvent used for the crosslinking agent solution is preferably PBS buffer (pH 7.4).
[0036] In this invention, the crosslinking and curing temperature is preferably 35–38°C, more preferably 36–37°C, and the time is preferably 1–3 hours, more preferably 2 hours. This invention covalently fixes HA with a crosslinking agent to form a stable network structure.
[0037] After the crosslinking is completed, the present invention preferably rinses the obtained contact lens coating with PBS (pH 7.4) to obtain a hyaluronic acid contact lens nanocomposite coating.
[0038] This invention provides a hyaluronic acid nanocomposite coating for contact lenses prepared by the preparation method described above.
[0039] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods.
[0040] Unless otherwise specified, the experimental and testing methods described below are conventional methods; unless otherwise specified, the reagents and raw materials described below are commercially available.
[0041] Example 1
[0042] Silicone hydrogel contact lens substrate is taken and treated with oxygen plasma. The preferred power is 100W, the oxygen flow rate is 50sccm, the pressure is 5Pa, and the treatment time is 5min to obtain the pretreated substrate.
[0043] Hyaluronic acid, nanocellulose, and polydopamine were dispersed in PBS buffer (pH 7.4) with mass fractions of 2% hyaluronic acid (500 kDa), 0.8% nanocellulose, and 0.4% polydopamine, respectively, and then ultrasonically mixed to obtain a composite solution.
[0044] The pretreated substrate was immersed in the composite solution at a lifting speed of 1 mm / s and dried at room temperature for 10 minutes to form a coating with a thickness of 2 μm. The resulting film was then immersed in a 5 mg / mL genipin solution (PBS buffer with pH 7.4) and crosslinked at 37°C for 2 h. The resulting product was then rinsed three times with PBS buffer (pH 7.4) to obtain a hyaluronic acid contact lens nanocomposite coating.
[0045] Example 2
[0046] The only difference from Example 1 is that the mass fraction is 3% hyaluronic acid (500kDa), 1.2% nanocellulose and 0.6% polydopamine.
[0047] Example 3
[0048] The only difference from Example 1 is that the mass fraction is 3% hyaluronic acid (500kDa), 1.5% nanocellulose and 1% polydopamine.
[0049] Comparative Example 1
[0050] The only difference from Example 1 is that no nanocellulose is added.
[0051] Comparative Example 2
[0052] The only difference from Example 1 is that polydopamine is not added.
[0053] Comparative Example 3
[0054] The only difference from Example 1 is that nanocellulose and polydopamine are not added.
[0055] Comparative Example 4
[0056] The only difference from Example 1 is that a composite liquid is not used for coating.
[0057] Performance testing
[0058] Wettability (water contact angle): Measured by a dynamic contact angle meter;
[0059] Moisture retention: The coating was tested for the duration it maintained a moisture content >50% in a dry environment (30% humidity).
[0060] Anti-protein adsorption: Lenses with different coatings were immersed in a 1 mg / mL BSA solution for 24 h, and the amount of BSA adsorbed was tested;
[0061] Abrasion resistance: Coating retention rate was tested after a simulated blink test (100,000 cycles).
[0062] Table 1. Performance of contact lenses with different coatings in Examples 1-3 and Comparative Examples 1-4
[0063]
[0064]
[0065] As shown in Table 1, the initial contact angle of the coated lens prepared by this invention is 32°, and the water contact angle remains <40° after simulated tear flushing; the BSA adsorption capacity of the coated lens is only 0.8 μg / cm³. 2 The BSA adsorption amount of the uncoated lens is 3.5 μg / cm2, which is more than 70% less than the original amount. The water contact angle of the coated lens is reduced from ~80° to ~30°, which significantly improves wettability. It maintains a moisture content of >50% for up to 12 hours in a dry environment (humidity 30%), which is excellent. After a simulated blink test (100,000 cycles), the coating retention rate is >90%, which is excellent.
[0066] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing a hyaluronic acid nanocomposite coating for contact lenses, characterized in that, Includes the following steps: The contact lens substrate is subjected to oxygen plasma treatment to obtain a pretreated substrate; Hyaluronic acid, nanocellulose, polydopamine and buffer solution were mixed and homogenized by ultrasound to obtain a composite solution. After the composite liquid is coated onto the pretreated substrate to form a coating film, it is cross-linked and cured in a cross-linking agent solution to obtain a hyaluronic acid contact lens nanocomposite coating.
2. The preparation method according to claim 1, characterized in that, The contact lens substrate is silicone hydrogel or poly(hydroxyethyl methacrylate).
3. The preparation method according to claim 1 or 2, characterized in that, The oxygen plasma treatment has a power of 50–300 W, an oxygen flow rate of 10–100 sccm, a pressure of 0.1–10 Pa, and a time of 0.5–5 min.
4. The preparation method according to claim 1, characterized in that, The molecular weight of the hyaluronic acid is 10-1000 kDa.
5. The preparation method according to claim 1 or 4, characterized in that, The mass ratio of hyaluronic acid, nanocellulose, and polydopamine is 3-6:1-3:0.5-2.
6. The preparation method according to claim 1, characterized in that, The buffer solution is PBS buffer, and the pH value of the PBS buffer is 7.
4.
7. The preparation method according to claim 1 or 6, characterized in that, The thickness of the coating is 1–5 μm.
8. The preparation method according to claim 1, characterized in that, The crosslinking agent in the crosslinking agent solution includes genipin or an EDC-NHS mixture; the molar ratio of EDC to NHS is 1:0.5 to 2, and the concentration of the crosslinking agent solution is 1 to 10 mg / mL.
9. The preparation method according to claim 8, characterized in that, The cross-linking curing temperature is 35–38°C, and the time is 1–3 hours.
10. The hyaluronic acid nanocomposite coating for contact lenses prepared by the preparation method according to any one of claims 1 to 9.