POLYSACCHARIDE COMPOSITION AND METHOD FOR REDUCING PROTEIN ADSORPTION

Abstract

Provided are a polysaccharide composition and method capable of reducing, whether during pre-wear immersion or during post-wear cleaning, the amount of protein adsorbed on hard contact lenses and orthokeratology lenses. The polysaccharide composition and method reduce the amount of protein adsorbed on hard contact lenses and thereby prevent corneal abrasions and inflammations of the conjunctiva and cornea.

Claims

1. A polysaccharide composition for reducing protein adsorption, essentially comprising alginic acid, carrageenan and buffer solution.

2. The composition of claim 1, further comprising γ-polyglutamic acid (γ-PGA).

3. The composition of claim 1, wherein a ratio of the alginic acid to the carrageenan is 1:1.

4. The composition of claim 1, wherein both the alginic acid and the carrageenan have a concentration of 1˜10 mg/ml.

5. The composition of claim 1, wherein both the alginic acid and the carrageenan have a concentration of 2.25˜9 mg/ml.

6. The composition of claim 1, wherein the buffer solution has a pH of 6.5˜7.5.

7. The composition of claim 1, which is a hard contact lens cleaning solution or multipurpose solution.

8. A method of using the composition of claim 1 to manufacture a reagent for reducing protein adsorption.

9. The method of claim 8, wherein the reagent is a hard contact lens cleaning solution or multipurpose solution.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above description and the description below can be better understood by referring to the accompanying drawings. For the sake of illustration, the accompanying drawings depict the preferred, specific embodiments of the present disclosure.

[0018] The Accompanying Drawings

[0019] FIG. 1 is a bar chart of the amount of protein adsorbed on contact lenses when alginic acid and carrageenan multipurpose solutions of different concentrations and commercially-available multipurpose solutions are in use. They are compared with 2.25 mg/ml of alginic acid and carrageenan multipurpose solutions, using t-test, *P<0.05 or ***P<0.001.

[0020] FIG. 2 is a bar chart of the amount of protein adsorbed on contact lenses when polysaccharide multipurpose solution which contains γ-polyglutamic acid (γ-PGA), alginic acid and carrageenan multipurpose solution which does not contain γ-PGA, and commercially-available multipurpose solutions are in use. They are compared with polysaccharide multipurpose solution which contains γ-PGA, using t-test and *P<0.05.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] Technical features, including specific features, are disclosed in the appended claims. The technical features of the present disclosure are illustrated by embodiments, depicted by accompanying drawings, and described below.

[0022] Unless otherwise defined, all technical and scientific terms used herein and in the appended claims are comprehensible to persons skilled in the art. Unless otherwise specified, expressions descriptive of an odd number, such as “a,” “one” and “the,” and the like, may indicate one or more objects. Unless otherwise specified, the conjunctions “and” and “or” may also mean “and/or.” Furthermore, the terms “comprise” and “include” are open-ended and do not indicate limitation. The aforesaid definitions refer to term definition and shall not be interpreted as restrictive of the scope of the present invention.

[0023] The term “hard contact lens” used herein means a hard contact lens or an orthokeratology lens.

[0024] The present disclosure provides a polysaccharide composition for reducing protein adsorption, essentially comprising alginic acid, carrageenan and buffer solution.

[0025] In an embodiment, the alginic acid has a molecular weight of about 120,000˜190,000 g/mol, and the carrageenan has a molecular weight of about 560.5˜580.5 g/mol.

[0026] In an embodiment, the composition further comprises γ-polyglutamic acid (γ-PGA).

[0027] In an embodiment, the γ-PGA has a molecular weight of about 1,024, 000 g/mol.

[0028] In another embodiment, the composition further comprises: an antiseptic, for example, polyhexamethylene biguanide hydrochloride (PHMB); and a non-ionic surfactant, for example, Poloxamer-407.

[0029] In a preferred embodiment, the concentration of γ-PGA is 1.5% (v/v).

[0030] In an embodiment, a ratio of the alginic acid to the carrageenan is 1:1.

[0031] In an embodiment, both the alginic acid and the carrageenan have a concentration of 1˜10 mg/ml.

[0032] In a preferred embodiment, both the alginic acid and the carrageenan have a concentration of 2.25˜9 mg/ml.

[0033] In a preferred embodiment, the buffer solution has a pH of 6.5˜7.5.

[0034] In a preferred embodiment, the buffer solution comprises ethylenediaminetetraacetic acid disodium (EDTA.Math.2Na), calcium chloride (CaCl.sub.2), potassium chloride (KCl), sodium chloride (NaCl), and sodium hydrogen phosphate (Na.sub.2HPO.sub.4).

[0035] In an embodiment, the composition of the present disclosure is a hard contact lens cleaning solution or multipurpose solution.

[0036] The present disclosure further provides a method of using the composition of the present disclosure to manufacture a reagent for reducing protein adsorption.

[0037] In an embodiment, the reagent is a hard contact lens cleaning solution or multipurpose solution.

[0038] In some embodiments, the solution provided by the present disclosure and intended to handle hard contact lenses is a solution for preserving hard contact lenses (i.e., contact lens preserving solution) or a solution for cleaning hard contact lenses (i.e., contact lens cleaning solution). In some embodiments, the solution provided by the present disclosure and intended to handle hard contact lenses selectively comprises a surfactant and/or a moisturizer.

Embodiment 1

[0039] Method of Preparing Multipurpose Solution

[0040] The preparation of 100 ml of multipurpose solution involves adding 0.2 g of EDTA.Math.2Na, 0.015 g of CaCl.sub.2, 0.15 g of KCl, 0.45 g of NaCl and 1.8 g of Na.sub.2HPO.sub.4 to 100 ml of secondary water to form a buffer solution, adding 1.5 g of γ-PGA and 0.75 g of Poloxamer-407 to the buffer solution, and filtering the resultant buffer solution with a filtering membrane with pores of a diameter of 0.22 μm before its preservation begins. Then, the preparation process requires adding alginic acid (0.225˜0.9 g), carrageenan (0.225˜0.9 g) and 0.5 μl antiseptic (polyhexamethylene biguanide hydrochloride, PHMB) to the buffer solution. The multipurpose solution is measured with a pH meter to ensure that the pH of the buffer solution falls within the range of 6.5˜7.5.

[0041] Ongoing Adsorption of Protein and Cholesterol on Contact Lens and Cleaning Step

[0042] A contact lens is immersed in bionic tears at 37° C. for 8 hours before being taken out and moved to the multipurpose solution of the present disclosure or a commercially-available multipurpose solution and then immersed therein at 37° C. for 16 hours before being taken out and rubbed. The rubbing step entails placing the contact lens at the center of the palm, washing the contact lens from the center and outward, and then rubbing the concave surface of the lens (from the center and outward) for 20 seconds, placing the contact lens in new bionic tears, and repeating the immersion and rubbing steps three times. Three contact lenses (N=3) are used in each experiment.

[0043] The bionic tears (Table 1) [13] prepared to include the same ingredients as the human tears comprise salts, lipids, and proteins (albumin 0.2 mg/mL and lysozyme 2 mg/mL).

TABLE-US-00001 TABLE 1 Ingredients of artificial tears concentration ingredient (mg/ml) NaCl 5.26 KCl 1.19 Na.sub.2CO.sub.3 1.27 KHCO.sub.3 0.30 CaCl.sub.2 0.07 HCl 0.94 Na.sub.2HPO.sub.4 3.41 ProClin 300 200 μl/L Na.sub.3C.sub.6H.sub.5O.sub.7 0.44 Urea 0.072 Glucose 0.036 Oleic acid 0.0018 Oleic acid 0.012 methyl ester Phosphatidylcholine 0.0005 Triolein 0.016 Cholesterol 0.0018 Cholesteryl oleate 0.024 Lysozyme 2 Albumin 0.2

[0044] Protein Measurement Procedure

[0045] Plotting Standard Curve

[0046] Protein Reagent A and Protein Reagent S are mixed at a proportion of 50:1 to form Protein Reagent A′, using Bio-Rad DC protein quantitative analysis reagent. With solvents comprising different single protein artificial tears, 100 μl of standard protein solution is consecutively transferred from eight standard protein solutions of concentrations of 0, 0.05, 0.1, 0.2, 0.4, 0.8, 1.6, 3.2 mg/ml to 15 ml centrifuge tubes, respectively. Then, 500 μl of Protein Reagent A′ is added to the 15 ml centrifuge tubes, and the mixtures therein undergo vortex mixing for 10 seconds. After that, 4000 μl of Protein Reagent B is added to the 15 ml centrifuge tubes, and the mixtures therein undergo vortex mixing for 10 seconds. Next, the 15 ml centrifuge tubes stand still for 15 minutes. Finally, absorbance (with wavelength being set to 750 nm and the test being finished in 1 hour) of the mixtures in the 15 ml centrifuge tubes is measured with an ELISA (enzyme-linked immunosorbent assay) reader.

[0047] Protein Orthokeratology Lens Test Procedure

[0048] Initial protein solution concentration is tested. The orthokeratology lenses are immersed in a lens residual protein solution, multipurpose solution post-rinsing solution, and multipurpose solution post-immersion solution.fwdarw.concentration of the proteins adsorbed on the orthokeratology lenses is calculated. Protein Reagent A and Protein Reagent S are mixed at a proportion of 50:1 to form Protein Reagent A′. 100 μl of a sample is transferred to a 15 ml centrifuge tube. Then, 500 μl of Protein Reagent A′ is added to the 15 ml centrifuge tube, and the mixture therein undergoes vortex mixing for 10 seconds. After that, 4000 μl of Protein Reagent B is added to the 15 ml centrifuge tube, and the mixture therein undergoes vortex mixing for 10 seconds. Next, the 15 ml centrifuge tube stands still for 15 minutes. Finally, absorbance (with wavelength being set to 750 nm and the test being finished in 1 hour) of the mixture in the 15 ml centrifuge tube is measured with an ELISA (enzyme-linked immunosorbent assay) reader.

[0049] Experimental Results

[0050] The multipurpose solutions contain 2.25, 4.5, and 9 mg/ml of alginic acid and carrageenan, respectively. The contact lenses are immersed in bionic tears for three days and then rinsed. As shown in FIG. 1, the amount of proteins adsorbed on the contact lenses rinsed with the multipurpose solutions which contain alginic acid and carrageenan is much less than the amount of proteins adsorbed on the contact lenses rinsed with commercially-available Progent® multipurpose solution and Bausch+Lomb® multipurpose solution.

[0051] The amount of proteins adsorbed on contact lenses rinsed with 4.5 mg/ml of alginic acid and carrageenan multipurpose solution which contains 1.5% γ-PGA is not only less than the amount of proteins adsorbed on contact lenses rinsed with 4.5 mg/ml of alginic acid and carrageenan multipurpose solution which does not contain γ-PGA but also much less than the amount of proteins adsorbed on contact lenses rinsed with the commercially-available multipurpose solutions (FIG. 2).

[0052] The present disclosure is illustrated by embodiments. Persons skilled in the art easily understand that the embodiments are illustrative rather than restrictive. Persons skilled in the art may make changes and replacements to the embodiments without departing from technical features disclosed herein. As indicated by the embodiments of the present disclosure, changes can be made to the present disclosure without affecting the implementation thereof. The teachings embodied in the embodiments may be combined as long as the combination is not contradictory. The scope of the present disclosure shall be defined by the appended claims and shall cover the aforesaid method and structure as well as equivalents thereof.

REFERENCE

[0053] [1] Chang D C, Grant G B. Multistate outbreak of fusarium keratitis associated with use of a contact lens solution. American Journal of Ophthalmology. 2006; 142(5): 896-897. [0054] [2] Nichols J J, Chalmers R L. The case for using hydrogen peroxide contact lens care solutions: A review. Eye Contact Lens. 2019; 45(2):69-82. [0055] [3] Koffler B H, Karpecki P M. Positive aspects of the use of multipurpose disinfection solutions. Arch Ophthalmol. 2009; 127:1540-1543. [0056] [4] Kilvington S, Huang L, Kao E, Powell C H. Development of a new contact lens multipurpose solution: comparative analysis of microbiological, biological and clinical performance. J Optom. 2010; 3(3):134-142. [0057] [5] Barniak V L, Burke S E, Venkatesh S. Comparative evaluation of multi-purpose solutions in the stabilization of tear lysozyme. Cont Lens Anterior Eye. 2010; 33S:S7-S11. [0058] [6] Luensmann D, Jones L. Deposition on contact lenses: the past, the present, and the future. Cont Lens Anterior Eye. 2012 April; 35(2):53-64. [0059] [7] Green-Church K B, Nichols K K., Kleinholz N M., Zhang L., Nichols J J. Investigation of the human tear film proteome using multiple proteomic approaches. Mol Vis. 2008; 14:456-470. [0060] [8] Omila N B, Subbaraman L N, Coles-Brennan C, Fadli Z, Jones L W. Biological and clinical implications of lysozyme deposition on soft contact lenses. Optom Vis Sci. 2015 July; 92(7):750-7. [0061] [9] Bajpai A K, Mishra D D. Adsorption of a blood protein on to hydrophilic sponges based on poly(2-hydroxyethyl methacrylate). J Mater Sci Mater Med. 2004; 15:583-592. [0062] [10] Stapleton F, Willcox M D, Morris C A, Sweeney D F. Tear changes in contact lens wearers following overnight eye closure. Curr Eye Res. 1998; 17:183-188. [0063] [11] Skotnitsky C C, Naduvilath T J, Sweeney D F, Sankaridurg P R. Two presentations of contact lens-induced papillary conjunctivitis (CLCP) in hydrogel lens wear: local and general. Optom Vis Sci. 2006; 83(1):27-36. [0064] [12] Bontempo A R, Rapp J. Protein-lipid interaction on the surface of a rigid gas-permeable contact lens in vitro. Curr Eye Res. 1997; 16(12):1258-1262. [0065] [13] Omali N B, Subbaraman L N. Surface versus bulk activity of lysozyme deposited on hydrogel contact lens materials in vitro. Cont Lens Anterior Eye. 2018; 41(4): 329-334.