A method for preparing a highly biocompatible phakic posterior chamber intraocular lens (ICL) material

Abstract

A method for preparing a highly biocompatible phakic posterior chamber intraocular lens (ICL) material, belonging to the field of polymer materials, includes the following steps: Hydroxyethyl methacrylate, ethylene glycol, bovine serum albumin solution, and initiator solution are stirred and mixed until the solution is clear, obtaining a mixture. The mixture is then degassed by ultrasonication. The degassed mixture is injected into a mold and transferred to an incubator for polymerization. After the reaction, the mold is removed and the sample is taken out. The obtained sample is dialyzed in a buffer solution to obtain the ICL material. This process has simple reaction steps, controllable reaction rate, and low energy consumption, reducing the production cost of ICL. The copolymer exhibits excellent optical and mechanical properties while demonstrating good biocompatibility, providing good visual effects and reducing eye irritation after implantation.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, and more particularly to a method for preparing a highly biocompatible phakic posterior chamber intraocular lens (ICL) material. Background Technology

[0002] A phakic posterior chamber intraocular lens (ICL) is an intraocular implantable lens, belonging to the category of posterior chamber refractive surgery. The concept of ICL was first proposed in the 1990s, and in recent years, with advancements in materials science and microsurgical techniques, it has become increasingly widely used for high myopia correction. Compared to traditional corneal laser surgery, ICL does not ablate the cornea, is reversible, and is suitable for a wider range of refractive errors. In terms of materials, the core material of ICL is Collamer—a collagen-acrylate copolymer. This material has excellent biocompatibility, oxygen permeability, and UV blocking capabilities. Because the ICL is located inside the eye and is in long-term contact with the aqueous humor, iris, lens, and other important tissues, the biocompatibility and stability of its material directly affect the safety and long-term effects of the surgery. The protein components in Collamer give it a hydrophilic surface, reducing protein deposition and inflammatory responses, while its high refractive index and high light transmittance help improve visual quality. Early intraocular lens materials such as polymethyl methacrylate (PMMA) had good mechanical properties but lacked flexibility and had low oxygen permeability; while silicone materials had high oxygen permeability but were prone to adhesion and inflammatory reactions. Therefore, to achieve safer, more stable, and more widely applicable ICL implantation, it is still necessary to continuously optimize material formulations, surface modification techniques, and implant structure design, and strengthen long-term biocompatibility and functional studies. Summary of the Invention

[0003] The purpose of this invention is to solve the above-mentioned problems in the prior art and provide a method for preparing a highly biocompatible phakic posterior chamber intraocular lens (ICL) material. By using a hydrophilic monomer ratio and a room temperature polymerization process, a phakic posterior chamber intraocular lens with excellent optical and structural properties, strong hydrophilicity, and high biocompatibility can be prepared.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A method for preparing a highly biocompatible phakic posterior chamber intraocular lens (ICL) material includes the following steps:

[0006] 1) Prepare bovine serum albumin (BSA) solution and initiator solution;

[0007] 2) Stir and mix hydroxyethyl methacrylate (HEMA), ethylene glycol, bovine serum albumin solution and initiator solution until the solution is clear to obtain a mixture;

[0008] 3) The mixture is ultrasonically degassed, the degassed mixture is injected into a mold, and then transferred to an incubator for polymerization reaction;

[0009] 4) After the polymerization reaction is completed, the mold is removed and the sample is taken out. The obtained sample is dialyzed in a buffer solution to obtain the substrate material, which is the posterior chamber type artificial lens material of the phakic eye.

[0010] The initiator includes one or more of ammonium persulfate (APS), sodium metabisulfite, sodium bisulfite, and tetramethylethylenediamine (TEMED).

[0011] The bovine serum albumin solution has a concentration of 0.1 to 1.5 mg / mL; the initiator solution has a mass percentage concentration of 2% to 22%.

[0012] Preferably, the concentration of bovine serum albumin in the bovine serum albumin solution is 0.5~0.8 mg / mL; and the mass percentage concentration of the initiator in the initiator solution is 5%~15%.

[0013] The mixture, by mass percentage, comprises 45%–65% hydroxyethyl methacrylate, 15%–25% ethylene glycol, 1%–12% initiator solution, and 5%–25% bovine serum albumin solution.

[0014] Preferably, the mixture comprises, by mass percentage, 50% to 60% hydroxyethyl methacrylate, 17% to 22% ethylene glycol, 5% to 10% initiator solution, and 10% to 20% bovine serum albumin solution.

[0015] The degassing time is 5-60 min, the polymerization temperature is 10-30℃, and the polymerization reaction time is 4-30 h; the dialysis temperature is 10-40℃, and the dialysis time is 15-30 h.

[0016] Preferably, the degassing time is 15-45 min, the polymerization temperature is 15-25℃, and the polymerization reaction time is 20-25 h; the dialysis temperature is 20-30℃, and the dialysis time is 20-25 h.

[0017] A highly biocompatible phakic posterior chamber intraocular lens (ICL) material was prepared using the above-described method.

[0018] Compared with the prior art, the beneficial effects achieved by the technical solution of this invention are:

[0019] This invention reduces production costs and energy consumption by employing inexpensive and readily available raw materials and a mild room-temperature polymerization process. The prepared copolymer material possesses excellent optical and mechanical properties, and due to its high hydrophilicity and good biocompatibility, it can effectively reduce protein deposition and inflammatory responses after intraocular implantation, thereby improving the material's safety and long-term stability. This material can be used to prepare phakic posterior chamber intraocular lenses, possessing broad clinical application value and market prospects.

[0020] The ICL material prepared by this invention has a tensile strength of 1.1644 MPa and a tensile strength at break of 349%, a transmittance of 98% for visible light, an Abbe refractive index of 1.466, a cell viability of 96%, and a protein adhesion amount of 0.00024 mg. Compared with the blank control group, the protein adhesion amount is reduced by about 14.29%, making it the ICL material with the best overall performance. Attached Figure Description

[0021] Figure 1 The test results for the optical and mechanical properties of Examples 1-5 are shown below. Figure 1 In the figure, 'a' represents the visible light transmittance test result. Figure 1 In the image, b represents the refractive index test result. Figure 1 In the figure, c represents the test results of tensile strength and tensile strength at break.

[0022] Figure 2 The results are the cytotoxicity test results for Examples 1-5.

[0023] Figure 3 The results are the protein adhesion test results for Examples 1-5, wherein... Figure 3 In the figure, 'a' represents the standard curve plotted from the prepared standard BSA sample. Figure 3 In the figure, b represents the quality of BSA obtained after elution following testing and calculated using a standard curve.

[0024] Figure 4 The following are the performance test results for Examples 6-11, in which... Figure 4 In the figure, 'a' represents the visible light transmittance test result. Figure 4 In the image, b represents the refractive index test result. Figure 4 In the figure, c represents the test results of tensile strength and elongation at break. Detailed Implementation

[0025] To make the technical problems, solutions, and beneficial effects of this invention clearer and more understandable, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. All reagents used in this invention can be purchased directly from the market or prepared by the methods described in the invention.

[0026] This invention uses bovine serum albumin (BSA) as a functional biomacromolecule and hydroxyethyl methacrylate (HEMA) as a polymerizing monomer to prepare phakic intraocular lens materials through polymerization under the action of an initiator. The substrate material is prepared by controlling the composition of the protein solution, polymerization conditions, and post-processing, and the performance of the obtained material is then tested.

[0027] Example 1:

[0028] (1) Prepare an aqueous solution with BSA content of 0.5 mg / mL and Tris-NaCl solvent. Mix the solution under stirring until the solution is homogeneous to obtain a protein solution.

[0029] (2) Prepare an aqueous solution of APS with a mass fraction of 12 wt% and an aqueous solution of sodium metabisulfite with a mass fraction of 12 wt% to obtain an initiator solution.

[0030] (3) Weigh 2.651 g of hydroxyethyl methacrylate, 1.07 g of ethylene glycol, 0.8 g of the protein solution obtained in step (1) and 200 mg of the initiator solution obtained in step (2), add them to a beaker, mix them under stirring until clear, and obtain a mixture.

[0031] (4) The mixture was placed in an ultrasonic machine for degassing for 20 min, and then the degassed mixture was injected into a mold and transferred to a 25 ℃ incubator for polymerization reaction for 25 h.

[0032] (5) After the polymerization reaction is completed, the mold is removed and the sample is taken out. The obtained sample is placed in Tris-NaCl buffer and dialyzed at 28 °C for 22 h to obtain the substrate material, namely the posterior chamber type artificial lens material of the phakic eye.

[0033] Example 2: The BSA content of the protein solution prepared in step (1) of Example 1 was changed to 1.0 mg / mL, and the rest of the treatment was the same as in Example 1.

[0034] Example 3: The BSA content of the protein solution prepared in step (1) of Example 1 was changed to 1.5 mg / mL, and the rest of the treatment was the same as in Example 1.

[0035] Example 4: The BSA content of the protein solution prepared in step (1) of Example 1 was changed to 2.0 mg / mL, and the rest of the treatment was the same as in Example 1.

[0036] Example 5: The protein solution prepared in step (1) of Example 1 was not treated with BSA, and the rest was the same as in Example 1.

[0037] Example 6: The initiator solution prepared in step (2) of Example 1 was modified to contain only TEMED, while the rest of the treatment remained the same as in Example 1.

[0038] Example 7: The initiator solution prepared in step (2) of Example 1 was changed to contain only APS, and the rest of the treatment was the same as in Example 1.

[0039] Example 8: The initiator solution prepared in step (2) of Example 1 was changed to contain only sodium metabisulfite, and the rest of the treatment was the same as in Example 1.

[0040] Example 9: The drug in the initiator solution prepared in step (2) of Example 1 was changed to sodium bisulfite, and the rest of the treatment was the same as in Example 1.

[0041] Example 10: The initiator solution prepared in step (2) of Example 1 was changed to contain APS and sodium bisulfite, and the rest of the treatment was the same as in Example 1.

[0042] Example 11: The types of drugs in the initiator solution prepared in step (2) of Example 1 were changed to sodium metabisulfite and sodium bisulfite, and the rest of the treatment was the same as in Example 1.

[0043] Table 1 Formulation parameters for each embodiment

[0044]

[0045] Performance testing:

[0046] 1. Visible light transmittance test:

[0047] The transmittance of the prepared ICL material was tested using a UV-Vis spectrophotometer. The sample was prepared into a thin slice measuring 1 cm × 3 cm × 0.04 cm, and the slice was placed in a cuvette containing physiological saline to completely immerse the sample. The transmittance of the sample was obtained by transillumination within a wavelength range of 200–800 nm.

[0048] 2. Refractive index test:

[0049] The refractive index of the prepared ICL material was determined using an Abbe refractometer. The sample was placed on the test platform of the refractive index testing device, and the refractive index was measured under isothermal conditions. Multiple parallel samples were tested separately, and the measurement was repeated multiple times for each sample. The average value of the multiple measurements was taken as the refractive index result of the material.

[0050] 3. Tensile strength and elongation at break:

[0051] The compressive strength and compressive strain of the ICL mirror were determined using a universal testing machine. A cubic specimen with dimensions of 5×5×0.3 cm was used, which was placed securely on a horizontal testing platform and measured using a fixture. The data were recorded and the average value was taken.

[0052] 4. Cytotoxicity test:

[0053] The cytotoxicity evaluation experiment of ICL material based on the CCK-8 assay was performed using mouse subcutaneous loose connective tissue (L929 fibroblasts) according to standard procedures, as follows:

[0054] (1) Establishment of cell culture system: L929 cells were cultured at a concentration of 1×10⁻⁶ cells / mL. 5 Cells / mL were seeded in MEM medium containing 10% fetal bovine serum and cultured in a constant temperature incubator at 5% CO2, 95% relative humidity, and 37°C until a dense monolayer was formed.

[0055] (2) Preparation of cell suspension: Cell monolayers with confluence >90% were digested at 37℃ using 0.25% trypsin-0.02% EDTA digestion solution. The cell pellet was collected by centrifugation at 1000×g for 5 min, and then resuspended in 2 mL of complete culture medium. The cell concentration was calibrated to 1×10⁻⁶ cells / mL using a hemocytometer. 5 cells / mL.

[0056] (3) Mix 150 μL of single-cell suspension with 10 mL of MEM medium to prepare cell inoculation solution. Add 200 μL of inoculation solution to each well of a 96-well plate and incubate at 5% CO2 and 37℃ for 24 h.

[0057] (4) The ICL material was processed into 6 circular samples with a diameter of 5 mm and placed in a 96-well plate containing cells for co-culture for 24 h.

[0058] (5) Discard the original culture medium, wash twice with PBS buffer, add 100 μL of fresh MEM culture medium containing 10% fetal bovine serum to each well, and add 10 μL of CCK-8 solution. Use an ELISA reader to measure the absorbance of each well at a wavelength of 450 nm.

[0059] 5. Protein adsorption assay

[0060] The experiment for determining the amount of protein adsorbed on the material surface based on the Bicinchoninic Acid Assay was conducted according to industry standards, and the specific operation is as follows:

[0061] (1) Preparation of standard protein solution: Dissolve bovine serum albumin in phosphate buffer to prepare a standard working solution of 1.00 mg / mL.

[0062] (2) Sample pretreatment: Cut the ICL mirror material into standard sample pieces of 1.0 cm × 1.0 cm.

[0063] (3) In vitro protein adsorption simulation: 2 mL of protein working solution was injected into each well and cultured in a constant temperature shaking incubator (37℃) for 24 h.

[0064] (4) Surface washing: Transfer the sample to a 50 mL centrifuge tube, vortex three times with 10 mL fresh PBS buffer, and collect the supernatant by centrifugation as a blank control. Preparation and structural design study of highly biocompatible ICLs.

[0065] (5) Protein desorption: Prepare a 1.00 wt% sodium dodecyl sulfate solution, take 4.00±0.05 mL and inject it into a centrifuge tube, and desorb by shaking in a 60℃ water bath for 4 h.

[0066] (6) BCA quantitative analysis: Following the standard procedure of the BCA kit, 50 μL of elution buffer was mixed with 200 μL of working solution and reacted at 37℃ for 30 min. Immediately afterward, the absorbance at 562 nm was measured using an ELISA reader. The amount of surface protein adsorbed (μg / cm²) was calculated based on the standard curve.

[0067] The performance of the material in Example 1 was measured according to the method described above.

[0068] (1) In the measurement of optical performance, by Figure 1 As shown in a and b, the light transmittance of the prepared material decreases with increasing BSA content. When the BSA content exceeds 1.0 mg / mL, the light transmittance of the material decreases significantly, failing to meet the requirements for use as an intraocular lens material.

[0069] (2) Among tensile strength and elongation at break, the latter is determined by… Figure 1 As can be seen from c, the mechanical properties of the material show a trend of first increasing and then decreasing with the change of bovine serum albumin addition. The tensile strength at break of Example 1 is 349%, which is 9% higher than that of Example 5.

[0070] (3) In cytotoxicity tests, such as Figure 2The cell compatibility assessment of the material showed that when the BSA addition was below 1.5 mg / mL, the cell viability remained above 95%, indicating that the material met the high biocompatibility requirements. Further increasing the BSA addition resulted in a decrease in cell viability. This phenomenon may be related to the mechanism of free radical polymerization during material preparation: the free radicals generated by the initiator not only initiate the polymerization of HEMA monomers but also react with the active groups on the BSA molecules, leading to incomplete monomer polymerization. In a preferred embodiment of the invention, to ensure high cell compatibility of the material, the BSA addition is controlled to be no higher than 1.5 mg / mL.

[0071] (4) In protein adhesion tests, such as Figure 3 As shown, with the increase of BSA addition in the material system, the amount of protein adsorption on the material surface gradually decreases. The protein adhesion of ICL-bsa-0.5 is 0.00024 mg, while that of ICL-blank is 0.00028 mg, which is a decrease of about 14.29%. This indicates that the pre-introduced BSA can form a bioinert layer on the material surface and effectively inhibit the non-specific adsorption of proteins by occupying adsorption sites.

[0072] (5) When using different initiators to prepare materials, such as Figure 4 The ICL-temed, ICL-aps, ICL-j, and ICL-y samples failed to form due to excessively fast reaction rates and insufficient free radical generation. ICL-bsa-0.5 and ICL-aps-y showed that the test results for ICL-bsa-0.5 met the requirements for ICL materials in various performance tests.

[0073] The above embodiments are merely preferred embodiments of the present invention and should not be considered as limiting the scope of the present invention. All equivalent variations and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A method for preparing a highly biocompatible phakic posterior chamber intraocular lens (ICL) material, characterized in that, Includes the following steps: 1) Prepare bovine serum albumin solution and initiator solution; 2) Stir and mix hydroxyethyl methacrylate, ethylene glycol, bovine serum albumin solution and initiator solution until the solution is clear to obtain a mixture; 3) The mixture is ultrasonically degassed, the degassed mixture is injected into a mold, and then transferred to an incubator for polymerization reaction; 4) After the polymerization reaction is completed, the mold is removed and the sample is taken out. The obtained sample is dialyzed in a buffer solution to obtain the substrate material, which is the posterior chamber type artificial lens material of the phakic eye.

2. The preparation method according to claim 1, characterized in that: The initiator includes one or more of ammonium persulfate, sodium metabisulfite, sodium bisulfite, and tetramethylethylenediamine.

3. The preparation method according to claim 1, characterized in that: The bovine serum albumin solution has a concentration of 0.1 to 1.5 mg / mL; the initiator solution has a mass percentage concentration of 2% to 22%.

4. The preparation method according to claim 3, characterized in that: The bovine serum albumin solution has a concentration of 0.5-0.8 mg / mL; the initiator solution has a mass percentage concentration of 5%-15%.

5. The preparation method according to claim 1, characterized in that: The mixture, by mass percentage, comprises 45%–65% hydroxyethyl methacrylate, 15%–25% ethylene glycol, 1%–12% initiator solution, and 5%–25% bovine serum albumin solution.

6. The preparation method according to claim 5, characterized in that: The mixture, by mass percentage, comprises 50%–60% hydroxyethyl methacrylate, 17%–22% ethylene glycol, 5%–10% initiator solution, and 10%–20% bovine serum albumin solution.

7. The preparation method according to claim 1, characterized in that: The degassing time is 5-60 min, the polymerization temperature is 10-30℃, and the polymerization reaction time is 4-30 h; the dialysis temperature is 10-40℃, and the dialysis time is 15-30 h.

8. The preparation method according to claim 7, characterized in that: The degassing time is 15-45 min, the polymerization temperature is 15-25℃, and the polymerization reaction time is 20-25 h; the dialysis temperature is 20-30℃, and the dialysis time is 20-25 h.

9. A highly biocompatible phakic posterior chamber intraocular lens (ICL) material, characterized in that: It is prepared by any one of the preparation methods of claims 1 to 8.

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