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Scheuer CA, Barniak VL, Phatak NR, Rah MJ, Reindel W. Effect of Contact Lens Solutions in Stabilizing the Activity of Tear Lysozyme. CLINICAL OPTOMETRY 2023; 15:119-127. [PMID: 37205004 PMCID: PMC10187650 DOI: 10.2147/opto.s404261] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 04/17/2023] [Indexed: 05/21/2023]
Abstract
Purpose Interactions between tear proteins and the interfaces of contact lenses can be complex and can influence contact lens wear success. Tear proteins, including lysozyme, function to maintain the balance of ocular surface homeostasis, as evidenced by the effects of its conformation relative to stabilizing the tear film and its potential impact on corneal epithelial cells. Contact lens manufacturers include components in lens care and blister package solutions to help stabilize the tear film and preserve homeostasis. This in vitro study was performed to evaluate the ability of daily disposable contact lens package solutions to stabilize lysozyme and preserve its native conformation under denaturing conditions. Methods Lysozyme was added to contact lens solutions sampled from kalifilcon A, etafilcon A, senofilcon A, narafilcon A, nelfilcon A, verofilcon A, delefilcon A, somofilcon A, and stenfilcon A blister packages, then mixed with the protein denaturant sodium lauryl sulfate. Lysozyme activity was evaluated by adding test solutions to a suspension of Micrococcus luteus. Native lysozyme lyses the Micrococcus luteus cell wall, which decreases suspension turbidity. Stabilization of lysozyme activity was determined by comparing suspension turbidity before and after exposure to test solutions. Results Lysozyme stabilization was 90.7% for kalifilcon A solution, a statistically significant improvement (p < 0.05) compared to phosphate buffered saline (PBS, negative control). No significant improvement was observed with any other contact lens solution (all lysozyme stabilization < 5.00%). Conclusion The representative tear protein lysozyme was significantly more stable in the novel kalifilcon A contact lens solution containing multiple moisturizers and osmoprotectants than in PBS or other daily disposable contact lens solutions. The lysozyme activity assay provides mechanistic evidence that the kalifilcon A contact lens solution can stabilize proteins under conditions that typically denature proteins, which may contribute to maintaining ocular surface homeostasis.
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Affiliation(s)
| | | | - Nitasha R Phatak
- Vision Care, Bausch & Lomb Inc., Rochester, NY, USA
- Correspondence: Nitasha R Phatak, Vision Care, Bausch & Lomb Incorporated, Rochester, NY, USA, Tel +1 585 413-6397, Email
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Photoinduced electron transfer reactions in mixed micelles of a star block copolymer and surface active ionic liquids: Role of the anion. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Carpena-Torres C, Pastrana C, Rodríguez-Pomar C, Serramito M, Batres L, Carracedo G. Changes in visual quality with soft contact lenses after the instillation of hyaluronic acid eye drops. Cont Lens Anterior Eye 2021; 44:101471. [PMID: 34049809 DOI: 10.1016/j.clae.2021.101471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 03/26/2021] [Accepted: 05/22/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE To evaluate the changes in visual function and anterior surface aberrations during soft contact lens (SCL) wear after the instillation of hyaluronic acid (HA) eye drops with different viscosity. METHODS A prospective, randomized, and participant-masked study was performed. Twenty healthy participants (25.4 ± 2.6 years) were evaluated. Hydrogel (Ocufilcon D) and silicone-hydrogel (Somofilcon A) SCL were randomly assigned to both eyes of the same participant. Visual function in terms of high- and low-contrast corrected distance visual acuity (CDVA) and anterior contact lens surface aberrations (RMS HOA) were measured before and after the instillation, at different times, of different eye drops: saline (control) and 0.1%, 0.2%, and 0.3% HA. RESULTS Compared with the saline solution, during hydrogel SCL wear, there was an improvement (P < 0.05) in high-contrast CDVA after 3 and 10 min with 0.1% HA, and after 5 and 20 min with 0.2% HA. During silicone-hydrogel SCL wear, there was a deterioration (P < 0.05) in high-contrast CDVA after 1 and 30 min with 0.3% HA. Additionally, during silicone-hydrogel SCL wear, there was also a deterioration (P < 0.05) in low-contrast CDVA after 5 and 20 min with 0.3% HA. In terms of RMS HOA, there were no clinically relevant changes with both SCL. CONCLUSIONS The instillation of HA eye drops could have a different effect on visual quality depending on their concentration of HA, the contact lens material, its surface ionicity, or other physicochemical properties that should be studied in future studies.
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Affiliation(s)
- Carlos Carpena-Torres
- Ocupharm Research Group, Department of Optometry and Vision, Faculty of Optics and Optometry, Complutense University of Madrid, Madrid, Spain
| | - Cristina Pastrana
- Ocupharm Research Group, Department of Optometry and Vision, Faculty of Optics and Optometry, Complutense University of Madrid, Madrid, Spain
| | - Candela Rodríguez-Pomar
- Ocupharm Research Group, Department of Optometry and Vision, Faculty of Optics and Optometry, Complutense University of Madrid, Madrid, Spain
| | - María Serramito
- Ocupharm Research Group, Department of Optometry and Vision, Faculty of Optics and Optometry, Complutense University of Madrid, Madrid, Spain
| | - Laura Batres
- Ocupharm Research Group, Department of Optometry and Vision, Faculty of Optics and Optometry, Complutense University of Madrid, Madrid, Spain
| | - Gonzalo Carracedo
- Ocupharm Research Group, Department of Optometry and Vision, Faculty of Optics and Optometry, Complutense University of Madrid, Madrid, Spain.
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Evaluation of In Vitro Wettability of Soft Contact Lenses Using Tear Supplements. Eye Contact Lens 2021; 47:244-248. [PMID: 32443004 DOI: 10.1097/icl.0000000000000698] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2020] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To evaluate the interaction between tear supplements and soft contact lenses (SCLs), we measured the contact angles (CAs) on the SCLs using commercially available tear supplements. METHODS We used four daily disposable conventional hydrogel lenses (etafilcon A, etafilcon A+ polyvinylpyrrolidone, nelfilcon A, and omafilcon A containing 2-methacryloyloxyethyl phosphorylcholine [MPC]) and four silicone hydrogel lenses (narafilcon A, senofilcon A, delefilcon A, and stenfilcon A). The CAs on the SCLs were measured using a sessile drop technique and four different types of sessile drops, including saline, artificial tears, lubricants containing 2-MPC (MPC solution), and 0.1% hyaluronate acid (HA). RESULTS The CA values associated with the silicone hydrogel lenses were significantly (P<0.001) lower than those associated with the conventional hydrogel lenses with all four solutions. The mean CA of 0.1% HA was significantly (P<0.01) higher than that of saline. The mean CA of the MPC solution was significantly (P<0.01) lower than that of saline with the conventional hydrogel lenses but significantly (P<0.05) higher than that of saline with the silicone hydrogel lenses. CONCLUSIONS The CAs associated with the silicone hydrogel SCLs were higher with the use of the MPC solutions and HA in vitro. The measured CAs may depend on ingredient agents, surface treatment of the CLs, and components of the tear supplements.
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CLEAR - Contact lens complications. Cont Lens Anterior Eye 2021; 44:330-367. [DOI: 10.1016/j.clae.2021.02.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 02/01/2021] [Indexed: 12/20/2022]
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Badugu R, Szmacinski H, Reece EA, Jeng BH, Lakowicz JR. Fluorescent contact lens for continuous non-invasive measurements of sodium and chloride ion concentrations in tears. Anal Biochem 2020; 608:113902. [PMID: 32800702 DOI: 10.1016/j.ab.2020.113902] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/20/2020] [Accepted: 08/03/2020] [Indexed: 11/17/2022]
Abstract
Rapid and non-invasive measurement of hydration status is medically important because even mild levels of dehydration can have a significant impact on physical and cognitive performance. Despite the potential value of determining whole-body hydration based on the electrolytes found in tears, very few tests are available. An area of intense interest is the development of a contact lens which could measure ion concentrations in tears, specifically that of sodium (Na+) and chloride (Cl-) ions, the dominant electrolytes in blood plasma and tears. Here, we describe a method to make fluorescent contact lenses which allow determination of Na+ and Cl- ion concentrations in tears. Fluorophores known to be sensitive to Na+ and Cl- were derivatized to bind non-covalently to two commercially-available silicone hydrogel (SiHG) contact lenses-the Biofinity (Comfilcon A) or MyDay (Stenfilcon A) lenses. The sodium- and chloride-sensitive fluorophores displayed spectral changes in the physiological range for Na+ and Cl- ions in tears. The lenses for both Na+ and Cl- ions were completely reversible. The sodium responses were not sensitive to protein interference including human lysozyme, human serum albumin and mucin type 2. The chloride sensitivity was similar with both lenses, but the sodium-sensitive range was different in the Biofinity and MyDay lenses. We also fabricated a lens with both the Na+ and Cl- probes in a single MyDay lens resulting in a contact lens that independently measured Na+ and Cl- concentrations without physical separation of the fluorophores. Our findings indicated that a sodium and chloride-sensitive contact lens (NaCl-lens) could be used for rapid non-invasive detection of whole-body hydration, as well as associated diseases or other infections.
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Affiliation(s)
- Ramachandram Badugu
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 725 West Lombard St., Baltimore, MD, 21201, USA.
| | - Henryk Szmacinski
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 725 West Lombard St., Baltimore, MD, 21201, USA
| | - E Albert Reece
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Maryland School of Medicine, 655 W. Baltimore Street, Baltimore, MD, 21201, USA; Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 655 W. Baltimore Street, Baltimore, Md, 21201, USA; Department of Medicine, University of Maryland School of Medicine, 655 W. Baltimore Street, Baltimore, Md, 21201, USA
| | - Bennie H Jeng
- Department of Ophthalmology & Visual Sciences, University of Maryland School of Medicine, 419 W. Redwood Street, Baltimore, Md, 21201, USA
| | - Joseph R Lakowicz
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 725 West Lombard St., Baltimore, MD, 21201, USA.
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Pucker AD. A Review of the Compatibility of Topical Artificial Tears and Rewetting Drops with Contact Lenses. Cont Lens Anterior Eye 2020; 43:426-432. [DOI: 10.1016/j.clae.2020.04.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 04/21/2020] [Accepted: 04/22/2020] [Indexed: 11/27/2022]
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8
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Giant papillary conjunctivitis: A review. Ocul Surf 2020; 18:396-402. [DOI: 10.1016/j.jtos.2020.03.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 03/29/2020] [Indexed: 11/23/2022]
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Yu Y, Macoon R, Chauhan A. Improving wettability and lubricity of commercial contact lenses by polymerizing a thin film of dimethylacryamide. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2019.123974] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Uptake and Release of Polyvinyl Alcohol from Hydrogel Daily Disposable Contact Lenses. Optom Vis Sci 2019; 96:180-186. [DOI: 10.1097/opx.0000000000001351] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Comparison Between Viscous Teardrops and Saline Solution to Fill Orthokeratology Contact Lenses Before Overnight Wear. Eye Contact Lens 2018; 44 Suppl 1:S307-S311. [PMID: 28945652 DOI: 10.1097/icl.0000000000000416] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE To compare, in terms of efficacy, the differences between the use of saline solution and a viscous artificial tear to fill the lens during the first month of orthokeratology wear. METHODS A pilot, double-masked, crossed, randomized, and prospective study was conducted. In this study, 20 subjects (14 males and 6 females) with a mean age of 16.29±6.22 years (range, 10-26) were fitted with orthokeratology contact lenses. For the study, nonpreserved 0.9% NaCl commercial saline solution (Avizor, Madrid, Spain) and nonpreserved artificial teardrops with 0.3% of hyaluronic acid (Ocudry 0.3%; Avizor, Madrid, Spain) were used. Corneal staining, tear break up time (TBUT), topography, refraction, visual acuity, and subjective comfort and vision with the visual analog scale (score from 0 to 10, being 10 better comfort and vision) were evaluated at 1 day, 1 week, and 1 month of contact lens wear. RESULTS The corneal staining was statistically greater in the saline group than in the Ocudry group for the first day and during 1 week of wear (P<0.05). Comfort was found to be statistically better, with Ocudry 0.3% than saline solution, being 7.17±1.94 and 6.37±1.63, for the first day, and 8.78±0.43 and 8.15±0.62 for the day 28, respectively (P<0.05). However, no differences were found for subjective vision scores, TBUT, spherical equivalent, best-corrected visual acuity and uncorrected visual acuity, and mean keratometry between groups for any visit (P>0.05). CONCLUSION Viscous artificial tears improve the subjective comfort of patients and reduce the corneal staining, compared with saline solution during the orthokeratology lenses fitting process. However, no differences between solutions for the treatment efficacy, in vision and corneal topography, were found.
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McMonnies CW. An Amplifying Cascade of Contact Lens-Related End-of-Day Hyperaemia and Dryness Symptoms. Curr Eye Res 2018; 43:839-847. [PMID: 29630423 DOI: 10.1080/02713683.2018.1457163] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
End-of-day (EOD) symptoms of dryness are too often the cause of poor soft contact lens (SCL) tolerance and abandonment of wear. This review examines an amplifying cascade model for these symptoms, which involve thin tear layers on contact lens (CL) front surfaces being susceptible to evaporation-related short tear breakup (TBU) times. Susceptibility to faster tear loss by evaporation may be exacerbated by other forms of tear instability, such as lipid and mucin deficiencies as well as lens surface soiling. Bulbar and palpebral conjunctival hyperaemia and associated faster evaporation of warmer pre-conjunctival tears could also contribute to evaporative dry eye EOD symptoms. In CL wearers, a cascade of increasing hyperaemia toward the end of day, associated increasing tear temperature and evaporative loss, shortened TBU times (TBUTs) and increased osmolarity, all elevate the risk of higher symptom levels according to progressive amplification of this cascade. Chronic wound healing responses to SCL wear, perhaps related to limbal conjunctival trauma, stem cell deficiency and persistent epitheliopathy, as well as one or more immune responses, may contribute directly or indirectly to inflammation and the amplifying evaporative dryness cascade. A diurnal cycle that culminates in EOD symptoms appears to involve a process of recovery from causal mechanisms after lens removal, which allows lenses to be worn comfortably, at least initially the next day. Possible recovery processes are discussed in this review as are procedures that may help de-amplify an inflammatory, evaporative dryness cascade and alleviate EOD symptoms. Evidence of an accrual of adverse responses over long periods of more or less successful lens wear indicate an incremental failure to recover from EOD hyperaemia. Such incremental failure could help explain how SCL wear too often needs to be abandoned after many years of comfortable wear.
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Affiliation(s)
- Charles W McMonnies
- a School of Optometry and Vision Science , University of New South Wales , Kensington , Australia
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Lee JS, Park JM, Cho HK, Kim SJ, Huh HD, Park YM. Influence of Sodium Hyaluronate Concentration on Corneal Aberrations in Soft Contact Lens Wearers. KOREAN JOURNAL OF OPHTHALMOLOGY 2018; 32:89-94. [PMID: 29611370 PMCID: PMC5906407 DOI: 10.3341/kjo.2017.0099] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 08/29/2017] [Indexed: 12/11/2022] Open
Abstract
Purpose This study aimed to evaluate the influence of varying concentrations of sodium hyaluronate (SH) eye drops on corneal aberrations in normal individuals wearing silicone hydrogel contact lenses. Methods Normal individuals wearing silicone hydrogel contact lenses were enrolled in this study. Subjects were classified into two groups depending on the concentration of the preservative-free SH used (group 1, 0.1% SH; group 2, 0.3% SH). All subjects were asked to blink five times after instillation of the SH eye drop and before the Galilei measurements. Corneal aberrations were measured over the contact lenses before and after SH eye drop instillation. Visual acuity (VA) over the contact lenses was also measured both before instillation of the SH eye drop and after the subjects completed the five blinks. Results There was no change in VA after SH instillation in group 1; however, group 2's VA significantly deteriorated after SH instillation. Changes in VA after SH instillation compared to baseline were significantly higher in group 2 than in group 1. Similarly, the increase in corneal aberrations after SH instillation was significant in group 2 but not significant in group 1. Among the significantly increased corneal aberration parameters, defocus was the main type in group 2. Changes in corneal aberrations after SH instillation compared to baseline were significantly higher in group 2 than in group 1. Conclusions A 0.3%-concentration of SH increases corneal aberration and decreases VA in soft contact lens wearers. Defocus is the main type of aberration that increased in the 0.3% SH instillation group.
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Affiliation(s)
- Jong Soo Lee
- Department of Ophthalmology, Pusan National University Hospital, Pusan National University School of Medicine and Medical Research Institute, Yangsan, Korea
| | - Jong Moon Park
- Department of Ophthalmology, Gyeongsang National University Changwon Hospital, Gyeongsang National University School of Medicine, Changwon, Korea
| | - Hyun Kyung Cho
- Department of Ophthalmology, Gyeongsang National University Changwon Hospital, Gyeongsang National University School of Medicine, Changwon, Korea
| | - Su Jin Kim
- Department of Ophthalmology, Gyeongsang National University Changwon Hospital, Gyeongsang National University School of Medicine, Changwon, Korea
| | - Hyoun Do Huh
- Department of Ophthalmology, Gyeongsang National University Changwon Hospital, Gyeongsang National University School of Medicine, Changwon, Korea
| | - Young Min Park
- Department of Ophthalmology, Gyeongsang National University Changwon Hospital, Gyeongsang National University School of Medicine, Changwon, Korea.
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Vyas B, Pillai SA, Bahadur A, Bahadur P. A Comparative Study on Micellar and Solubilizing Behavior of Three EO-PO Based Star Block Copolymers Varying in Hydrophobicity and Their Application for the In Vitro Release of Anticancer Drugs. Polymers (Basel) 2018; 10:polym10010076. [PMID: 30966111 PMCID: PMC6414926 DOI: 10.3390/polym10010076] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 01/01/2018] [Accepted: 01/13/2018] [Indexed: 11/18/2022] Open
Abstract
The temperature and pH dependent self-assembly of three star shaped ethylene oxide-propylene oxide (EO-PO) block copolymers (Tetronics® 304, 904 and 908) with widely different hydrophobicity was examined in aqueous solutions. Physico-chemical methods viz. viscosity, cloud point, solubilization along with thermal, scattering and spectral techniques shows strongly temperature and salt dependent solution behavior. T304 possessing low molecular weight did not form micelles; moderately hydrophilic T904 remained as micelles at ambient temperature and showed micellar growth while very hydrophilic T908 formed micelles at elevated temperatures. The surface activity/micellization/solubilization power was favored in the presence of salt. The copolymers turn more hydrophilic in acidic pH due to protonation of central ethylene diamine moiety that hinders micelle formation. The solubilization of a model insoluble azo dye 1-(o-Tolylazo)-2-naphthol (Orange OT) and hydrophobic drugs (quercetin and curcumin) for copolymer solutions in aqueous and salt solutions are also reported. Among the three copolymers, T904 showed maximum solubility of dye and drugs, hence the in vitro release of drugs from T904 micelles was estimated and the effect on cytotoxicity of loading the drugs in T904 micelles was compared with the cytotoxicity of free drugs on the CHO-K1 cells. The results from the present work provide a better insight in selection of Tetronics® for their application in different therapeutic applications.
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Affiliation(s)
- Bijal Vyas
- Department of Chemistry, Veer Narmad South Gujarat University, Surat 395007, India.
| | - Sadafara A Pillai
- Department of Chemistry, Veer Narmad South Gujarat University, Surat 395007, India.
| | - Anita Bahadur
- Department of Zoology, PT Sarvajanik College of Science, Surat 395001, India.
| | - Pratap Bahadur
- Department of Chemistry, Veer Narmad South Gujarat University, Surat 395007, India.
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A Review of Techniques to Measure Protein Sorption to Soft Contact Lenses. Eye Contact Lens 2017; 43:276-286. [PMID: 28198731 DOI: 10.1097/icl.0000000000000366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To compare and critically evaluate a variety of techniques to measure the quantity and biological activity of protein sorption to contact lenses over short time periods. METHODS A literature review was undertaken investigating the major techniques to measure protein sorption to soft contact lens materials, with specific reference to measuring protein directly on lenses using in situ, ex situ, protein structural, and biological activity techniques. RESULTS The use of in situ techniques to measure protein quantity provides excellent sensitivity, but many are not directly applicable to contact lenses. Many ex situ techniques struggle to measure all sorbed proteins, and these measurements can have significant signal interference from the lens materials themselves. Techniques measuring the secondary and tertiary structures of sorbed proteins have exhibited only limited success. CONCLUSIONS There are a wide variety of techniques to measure both the amount of protein and the biological activity of protein sorbed to soft contact lens materials. To measure the mass of protein sorbed to soft contact lenses (not just thin films) over short time periods, the method of choice should be I radiolabeling. This technique is sensitive enough to measure small amounts of deposited protein, provided steps are taken to limit and measure any interaction of the iodine tracer with the materials. To measure the protein activity over short time periods, the method of choice should be to measure the biological function of sorbed proteins. This may require new methods or adaptations of existing ones.
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Asharlous A, Mirzajani A, Jafarzadehpur E, KhabazKhoob M, Ostadimoghaddam H. Objective and subjective assessing efficacy of a lubricating drop in eyes wearing silicone hydrogel contact lenses. J Curr Ophthalmol 2016; 28:69-74. [PMID: 27331150 PMCID: PMC4909696 DOI: 10.1016/j.joco.2016.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 03/30/2016] [Accepted: 03/31/2016] [Indexed: 11/17/2022] Open
Abstract
Purpose To investigate the effect of a lubricating drop on optical quality, tear film stability, and subjective symptoms in individuals wearing silicone hydrogel contact lens. Methods In this one-day, prospective single-center clinical study, Pre-lens Tear Deformation Time (PL-TDT), Root-Mean-Square (RMS) of Low Order Aberrations (LOA) and High Order Aberrations (HOA), individual twelve Zernike coefficients, and subjective symptoms were assessed in 43 volunteers (mean age 19.58 ± 1.63, 86 eyes) at 6 h after inserting the contact lens and then at 60 min after instilling a lubricating drop (Comfort drops, Avizor, Madrid-Spain). Results PL-TDT, LOA-RMS, and HOA-RMS values measured before drop instillation were not significantly different with those measured after drop. None of the Zernike coefficients were significantly different after instilling lubricating drop. Statistically significant decrement in both frequency and severity values in blurry vision, dryness, discomfort, burning, itching, foreign body sensation, excessive blinking, and lacrimation were seen after drop instillation (all P < 0.05). Conclusion Our results showed that although the lubricating drop did not improve the tear film stability and optical quality in the silicone hydrogel contact lens wearers, subjects experienced a subjective improvement.
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Affiliation(s)
- Amir Asharlous
- Optometry Department, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ali Mirzajani
- Optometry Department, Iran University of Medical Sciences, Tehran, Iran
| | | | - Mehdi KhabazKhoob
- Department of Medical Surgical Nursing, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hadi Ostadimoghaddam
- Refractive Errors Research Center, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
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Bahadur A, Cabana-Montenegro S, Aswal VK, Lage EV, Sandez-Macho I, Concheiro A, Alvarez-Lorenzo C, Bahadur P. NaCl-triggered self-assembly of hydrophilic poloxamine block copolymers. Int J Pharm 2015; 494:453-62. [PMID: 26315124 DOI: 10.1016/j.ijpharm.2015.08.058] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 08/18/2015] [Accepted: 08/20/2015] [Indexed: 12/22/2022]
Abstract
Tetronic 1307 (T1307) is a hydrophilic poloxamine (HLB>24) with a high molecular mass owing to its long PEO and PPO blocks. In spite of good biocompatibility, its use as a component of drug delivery systems is limited by its high critical micelle concentration (CMC) and temperature (CMT). The aim of this work was to elucidate whether the addition of NaCl or the combination of salts and temperature may bring T1307 micellization and gelling features into more practically useful values. Increasing NaCl concentration in the 0.154 M (isotonic) to 2M (hypertonic) range made the copolymer more hydrophobic and more prone to self-assemble into unimodal micelles, as observed by means of π-A isotherms, (1)H NMR, dynamic light scattering (DLS), small-angle neutron scattering (SANS), and pyrene fluorescence. The decrease in CMC and CMT observed for T1307 in 0.5 M NaCl medium (tolerable hypertonic solution), compared to water, notably favored the solubility of hydrophobic drugs such as curcumin and quercetin. Moreover, phase diagram, intrinsic viscosity and sol-to-gel transition were markedly affected by NaCl concentration. Overall, the strong dependence of T1307 self-assembly features on NaCl opens interesting possibilities for tuning the performance of T1307 as a component of nanocarriers and in situ gelling systems.
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Affiliation(s)
- Anita Bahadur
- Department of Zoology, PT Sarvajanik College of Science, Surat 395001 India
| | - Sonia Cabana-Montenegro
- Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Vinod Kumar Aswal
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - Emilio V Lage
- Departamento de Química Física, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Isabel Sandez-Macho
- Departamento de Química Física, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Angel Concheiro
- Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Carmen Alvarez-Lorenzo
- Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
| | - Pratap Bahadur
- Chemistry Department, Veer Narmad South Gujarat University, Surat 395001 India.
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Bengani LC, Scheiffele GW, Chauhan A. Incorporation of polymerizable surfactants in hydroxyethyl methacrylate lenses for improving wettability and lubricity. J Colloid Interface Sci 2015; 445:60-68. [DOI: 10.1016/j.jcis.2014.12.061] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 12/16/2014] [Accepted: 12/16/2014] [Indexed: 10/24/2022]
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Guan A, Li Z, Phillips KS. The effects of non-ionic polymeric surfactants on the cleaning of biofouled hydrogel materials. BIOFOULING 2015; 31:689-697. [PMID: 26469384 DOI: 10.1080/08927014.2015.1094690] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Block co-polymer surfactants have been used for cleaning hydrogel medical devices that contact the body (e.g., contact lenses) because of their biocompatibility. This work examined the relationship between concentration and detergency of two non-ionic polymeric surfactants (Pluronic F127 and Triton X-100) for cleaning protein soil, with anionic surfactants (sodium dodecyl sulfate and sodium laureth sulfate) as positive controls. Surface plasmon resonance was used to quantify removal of simulated tear soil from self-assembled monolayer surfaces, and a microplate format was used to study the removal of fluorescently labeled soil proteins from contact lenses. While detergency increased as a function of concentration for anionic surfactants, it decreased with concentration for the two polymeric surfactants. The fact that the protein detergency of some non-ionic polymeric surfactants did not increase with concentration above the critical micelle concentration could have implications for optimizing the tradeoff between detergency and biocompatibility.
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Affiliation(s)
- Allan Guan
- a Department of Biomedical Engineering , The George Washington University , Washington , DC , USA
| | - Zhenyu Li
- a Department of Biomedical Engineering , The George Washington University , Washington , DC , USA
| | - K Scott Phillips
- b Division of Biology, Chemistry and Materials Science , United States Food and Drug Administration, Office of Medical Products and Tobacco, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories , Silver Spring , MD , USA
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Contact lenses as drug reservoirs & delivery systems: the successes & challenges. Ther Deliv 2014; 5:1085-100. [DOI: 10.4155/tde.14.73] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Although conventional eye drops comprise over 90% of the marketed ocular dosage forms, they do have limitations, such as poor ocular drug bioavailability and systemic side effects; contact lenses are amongst the new delivery systems and devices that could overcome some of these problems. The most common approach to load drug molecules into contact lenses includes soaking in a drug solution. This approach had some success, but failed to achieve controlled/sustained drug release to the eye. On the other hand, nanoreservoir systems comprising nanoparticles, cyclodextrins, liposomes or surfactant aggregates being incorporated into the contact lenses could offer a plausible solution. This review highlights the status quo with contact lenses as ocular drug-delivery carriers and identifies possible future directions.
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Overview of factors that affect comfort with modern soft contact lenses. Cont Lens Anterior Eye 2014; 37:65-76. [DOI: 10.1016/j.clae.2013.08.154] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Revised: 07/31/2013] [Accepted: 08/13/2013] [Indexed: 11/21/2022]
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Ribeiro A, Sandez-Macho I, Casas M, Alvarez-Pérez S, Alvarez-Lorenzo C, Concheiro A. Poloxamine micellar solubilization of α-tocopherol for topical ocular treatment. Colloids Surf B Biointerfaces 2013; 103:550-7. [DOI: 10.1016/j.colsurfb.2012.10.055] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 10/04/2012] [Accepted: 10/18/2012] [Indexed: 10/27/2022]
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Effects of aqueous polymeric surfactants on silicone-hydrogel soft- contact-lens wettability and bacterial adhesion of Pseudomonas aeruginosa. Cont Lens Anterior Eye 2012; 35:155-62. [DOI: 10.1016/j.clae.2012.02.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 02/23/2012] [Accepted: 02/29/2012] [Indexed: 11/18/2022]
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Comparison of the effects of different lens-cleaning solutions on the protein profiles of human conjunctival cells. Graefes Arch Clin Exp Ophthalmol 2012; 250:1627-36. [PMID: 22820811 DOI: 10.1007/s00417-012-2100-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 06/03/2012] [Accepted: 06/22/2012] [Indexed: 10/28/2022] Open
Abstract
BACKGROUND Many contact lens wearers suffer from dry eye syndrome. Previous studies show significant changes in the protein composition of the tears depending on the lens-cleaning solution used. Therefore, the aim of this study was to detect the influence of different lens solutions on conjunctival cells, cells also involved in tear film composition. METHODS Conjunctival epithelium cells (HCjE; IOBA-NHC) were exposed to medium containing Complete® Multipurpose Solution Easy Rub® Formula (Complete) (AMO) or Opti-Free® Express Multipurpose Disinfecting Solution (Opti-Free) (Alcon) in different concentrations (0.1, 0.5, 1, 2.5 %) for 12 and 24 h. Apoptosis and necrosis using FACS and protein profiles of the cells using SELDI-TOF-MS and MALDI-TOF-MS were measured. Multivariate statistics were calculated to detect the most significant changes. RESULTS Complex protein profiles were measured with SELDI-TOF-MS and MALDI-TOF-MS. Significant differences of protein profiles between control and treatment cells were detected after 12 and 24 h, although cells incubated with Complete showed significantly fewer changes than cells incubated with Opti-Free, also showing concentration-dependent changes of some significantly changed proteins, e.g., protein at 6,736 Da (p > 0.002). Cells incubated with Complete showed significantly less apoptosis or necrosis in comparison to control cells (p < 0.05), whereas cells incubated with Opti-Free showed significantly more (p < 0.05). CONCLUSIONS We were able to demonstrate that Complete shows very little effect on the protein profiles of conjunctival cells in comparison to Opti-Free, where the cells showed very large protein profile changes, and apoptosis and necrosis of the cells was increased. These results are in concordance to clinical studies showing that the use of Complete solution made the tear film proteins similar to those of people not wearing contact lenses. Therefore, we believe that Complete is less aggressive and should provoke fewer side-effects, such as dry eye syndrome, for the users.
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Weeks A, Boone A, Luensmann D, Jones L, Sheardown H. The effects of hyaluronic acid incorporated as a wetting agent on lysozyme denaturation in model contact lens materials. J Biomater Appl 2012; 28:323-33. [PMID: 22561981 DOI: 10.1177/0885328212446936] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Conventional and silicone hydrogels as models for contact lenses were prepared to determine the effect of the presence of hyaluronic acid on lysozyme sorption and denaturation. Hyaluronic acid was loaded into poly(2-hydroxyethyl methacrylate) and poly(2-hydroxyethyl methacrylate)/TRIS--methacryloxypropyltris (trimethylsiloxy silane) hydrogels, which served as models for conventional and silicone hydrogel contact lens materials. The hyaluronic acid was cross-linked using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide in the presence of dendrimers. Active lysozyme was quantified using a Micrococcus lysodeikticus assay while total lysozyme was determined using 125-I radiolabeled protein. To examine the location of hyaluronic acid in the gels, 6-aminofluorescein labeled hyaluronic acid was incorporated into the gels using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide chemistry and the gels were examined using confocal laser scanning microscopy. Hyaluronic acid incorporation significantly reduced lysozyme sorption in poly(2-hydroxyethyl methacrylate) (p < 0.00001) and poly(2-hydroxyethyl methacrylate)/TRIS--methacryloxypropyltris (trimethylsiloxy silane) (p < 0.001) hydrogels, with the modified materials sorbing only 20% and 16% that of the control, respectively. More importantly, hyaluronic acid also decreased lysozyme denaturation in poly(2-hydroxyethyl methacrylate) (p < 0.005) and poly(2-hydroxyethyl methacrylate)/TRIS--methacryloxypropyltris (trimethylsiloxy silane) (p < 0.02) hydrogels. The confocal laser scanning microscopy results showed that the hyaluronic acid distribution was dependent on both the material type and the molecular weight of hyaluronic acid. This study demonstrates that hyaluronic acid incorporated as a wetting agent has the potential to reduce lysozyme sorption and denaturation in contact lens applications. The distribution of hyaluronic acid within hydrogels appears to affect denaturation, with more surface mobile, lower molecular weight hyaluronic acid being more effective in preventing denaturation.
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Affiliation(s)
- Andrea Weeks
- School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada
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Weeks A, Subbaraman LN, Jones L, Sheardown H. The Competing Effects of Hyaluronic and Methacrylic Acid in Model Contact Lenses. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 23:1021-38. [DOI: 10.1163/092050611x569060] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Andrea Weeks
- a School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada L8S 4L7
| | | | - Lyndon Jones
- c School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada L8S 4L7; Department of Chemical Engineering, McMaster University, Hamilton, ON, Canada L8S 4L7; Centre for Contact Lens Research, University of Waterloo, Waterloo, ON, Canada
| | - Heather Sheardown
- d School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada L8S 4L7; Department of Chemical Engineering, McMaster University, Hamilton, ON, Canada L8S 4L7; Centre for Contact Lens Research, University of Waterloo, Waterloo, ON, Canada.
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Chow LM, Subbaraman LN, Sheardown H, Jones L. Kinetics of in Vitro Lactoferrin Deposition on Silicone Hydrogel and FDA Group II and Group IV Hydrogel Contact Lens Materials. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 20:71-82. [PMID: 19105901 DOI: 10.1163/156856208x393509] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Lisa M. Chow
- a Centre for Contact Lens Research, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
| | - Lakshman N. Subbaraman
- b Centre for Contact Lens Research, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
| | - Heather Sheardown
- c Department of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8
| | - Lyndon Jones
- d Centre for Contact Lens Research, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
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Subbaraman LN, Jones L. Kinetics of Lysozyme Activity Recovered from Conventional and Silicone Hydrogel Contact Lens Materials. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 21:343-58. [DOI: 10.1163/156856209x415873] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Lakshman N. Subbaraman
- a Centre for Contact Lens Research, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Lyndon Jones
- b Centre for Contact Lens Research, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
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Weeks A, Luensmann D, Boone A, Jones L, Sheardown H. Hyaluronic acid as an internal wetting agent in model DMAA/TRIS contact lenses. J Biomater Appl 2011; 27:423-32. [DOI: 10.1177/0885328211410999] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Model silicone hydrogel contact lenses, comprised of N,N-dimethylacrylamide and methacryloxypropyltris (trimethylsiloxy) silane, were fabricated and hyaluronic acid (HA) was incorporated as an internal wetting agent using a dendrimer-based method. HA and dendrimers were loaded into the silicone hydrogels and cross-linked using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide chemistry. The presence and location of HA in the hydrogels was confirmed using X-ray photoelectron spectroscopy and confocal laser scanning microscopy, respectively. The effects of the presence of HA on the silicone hydrogels on hydrophilicity, swelling behavior, transparency, and lysozyme sorption and denaturation were evaluated. The results showed that HA increased the hydrophilicity and the equilibrium water content of the hydrogels without affecting transparency. HA also significantly decreased the amount of lysozyme sorption ( p < 0.002). HA had no effect on lysozyme denaturation in hydrogels containing 0% and 1.7% methacrylic acid (MAA) (by weight) but when the amount of MAA was increased to 5%, the level of lysozyme denaturation was significantly lower compared to control materials. These results suggest that HA has great potential to be used as a wetting agent in silicone hydrogel contact lenses to improve wettability and to decrease lysozyme sorption and denaturation.
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Affiliation(s)
- Andrea Weeks
- School of Biomedical Engineering, McMaster University, Hamilton ON Canada
| | | | - Adrienne Boone
- School of Optometry, University of Waterloo, Waterloo ON Canada
| | - Lyndon Jones
- School of Biomedical Engineering, McMaster University, Hamilton ON Canada
- School of Optometry, University of Waterloo, Waterloo ON Canada
- Department of Chemical Engineering, McMaster University, Hamilton ON Canada
| | - Heather Sheardown
- School of Biomedical Engineering, McMaster University, Hamilton ON Canada
- School of Optometry, University of Waterloo, Waterloo ON Canada
- Department of Chemical Engineering, McMaster University, Hamilton ON Canada
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Alvarez-Lorenzo C, Rey-Rico A, Brea J, Loza MI, Concheiro A, Sosnik A. Inhibition of P-glycoprotein pumps by PEO–PPO amphiphiles: branched versus linear derivatives. Nanomedicine (Lond) 2010; 5:1371-83. [DOI: 10.2217/nnm.10.53] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Inhibition of the activity of efflux transporters may relevantly improve the chemotherapy of cancer and infectious diseases. Aim: To explore the ability of poloxamines (Tetronic®, X-shaped structure with a central ethylendiamine group and four branches of poly[ethylene oxide]–poly[propylene oxide] [PEO–PPO]) to inhibit the activity of P-glycoprotein (P-gp) on Caco-2 cell monolayers and to elucidate the incidence of the molecular architecture of PEO–PPO block copolymers on the intracellular accumulation of a relevant substrate, doxorubicin, by comparison with poloxamers (Pluronic®, linear triblock copolymers), well-known inhibitors of this efflux transporter. Methods: Both pristine and N-methylated poloxamines displaying a wide range of molecular weights and EO/PO ratios were tested regarding cytocompatibility and accumulation of doxorubicin in Caco-2 monolayers. Verapamil was used as a control. Results: The most active anti-P-gp poloxamines (which enhanced two- to three-fold doxorubicin accumulation compared with verapamil) resulted to be pristine medium-to-high hydrophobic T304, T904, T1301, T901 and T150R1. A notable dependence of the anti-P-gp activity on the copolymer concentration was found. A joint diagram of the inhibitory activity of poloxamers and poloxamines as a function of the effective length of the PPO block is proposed. Conclusion: The anti-P-gp activity is maxima for block copolymers possessing a low-to-medium hydrophilic–lipophilic balance and an ‘effective number’ of PO units ranging from 30 to 50.
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Affiliation(s)
- Carmen Alvarez-Lorenzo
- Departamento de Farmacia y Tecnología Farmacéutica, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
- Instituto de Farmacia Industrial, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
| | - Ana Rey-Rico
- Departamento de Farmacia y Tecnología Farmacéutica, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
- Instituto de Farmacia Industrial, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
| | - Jose Brea
- Instituto de Farmacia Industrial, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
- Departamento de Farmacología, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
| | - Maria Isabel Loza
- Instituto de Farmacia Industrial, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
- Departamento de Farmacología, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
| | - Angel Concheiro
- Departamento de Farmacia y Tecnología Farmacéutica, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
- Instituto de Farmacia Industrial, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
| | - Alejandro Sosnik
- The Group of Biomaterials & Nanotechnologies for Improved Medicines (BIONIMED), Department of Pharmaceutical Technology, Faculty of Pharmacy & Biochemistry, University of Buenos Aires, Argentina; Department of Pharmaceutical Technology, Faculty of Pharmacy & Biochemistry, University of Buenos Aires, 956 Junín St., 6th Floor, Buenos Aires CP1113, Argentina
- National Science Research Council (CONICET), 1113-Buenos Aires, Argentina
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Role of hypo-osmotic saline drops in ocular comfort during contact lens wear. Cont Lens Anterior Eye 2010; 33:68-75. [DOI: 10.1016/j.clae.2010.01.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Revised: 12/21/2009] [Accepted: 01/04/2010] [Indexed: 11/17/2022]
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Chiappetta DA, Hocht C, Taira C, Sosnik A. Efavirenz-loaded polymeric micelles for pediatric anti-HIV pharmacotherapy with significantly higher oral bioavailability. Nanomedicine (Lond) 2010; 5:11-23. [DOI: 10.2217/nnm.09.90] [Citation(s) in RCA: 133] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Children constitute the most challenging population in anti-HIV/AIDS pharmacotherapy. Efavirenz (EFV; aqueous solubility 4 µg/ml, bioavailability 40–45%) is a first-line agent in the pediatric therapeutic cocktail. The liquid formulation of EFV is not available worldwide, preventing appropriate dose adjustment and more convenient administration. The bioavailability of liquid EFV is lower than that of the solid formulation. Improving the bioavailability of the drug would reduce the cost of treatment and enable less affluent patients to access this drug. Aim: To encapsulate EFV in polymeric micelles to improve the aqueous solubility and the the oral bioavailability of the drug. Methods: EFV was incorporated into the core of linear and branched poly(ethylene oxide)–poly(propylene oxide) block copolymer micelles. The size and size distribution of the drug-loaded aggregates were characterized by dynamic light scattering and the morphology by transmission electron microscopy. The bioavailability of the EFV-loaded micellar system (20 mg/ml) was assessed in male Wistar rats (40 mg/kg) and compared to that of a suspension prepared with the content of EFV capsules in 1.5% carboxymethylcellulose PBS solution (pH 5.0), and an EFV solution in a medium-chain triglyceride (Miglyol® 812). Results: This work demonstrates that the encapsulation of EFV, which is poorly water soluble, into polymeric micelles of different poly(ethylene oxide)–poly(propylene oxide) block copolymers significantly improves the oral bioavailability of the drug, and reduces the interindividual variability. Conclusion: This strategy appears a very promising one towards the development of a liquid aqueous EFV formulation for the improved pediatric HIV pharmacotherapy.
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Affiliation(s)
- Diego A Chiappetta
- The Group of Biomaterials & Nanotechnology for Improved Medicines (BIONIMED), Department of Pharmaceutical Technology, Faculty of Pharmacy & Biochemistry, University of Buenos Aires, 956 Junín St., 6th Floor, Buenos Aires CP1113, Argentina
- National Science Research Council (CONICET), Buenos Aires, Argentina
| | - Christian Hocht
- Department of Pharmacology, Faculty of Pharmacy & Biochemistry, University of Buenos Aires, 956 Junín St., Buenos Aires CP1113, Argentina
| | - Carlos Taira
- Department of Pharmacology, Faculty of Pharmacy & Biochemistry, University of Buenos Aires, 956 Junín St., Buenos Aires CP1113, Argentina
- National Science Research Council (CONICET), Buenos Aires, Argentina
| | - Alejandro Sosnik
- The Group of Biomaterials & Nanotechnology for Improved Medicines (BIONIMED), Department of Pharmaceutical Technology, Faculty of Pharmacy & Biochemistry, University of Buenos Aires, 956 Junín St., 6th Floor, Buenos Aires CP1113, Argentina
- National Science Research Council (CONICET), Buenos Aires, Argentina
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In Vitro Adsorption of Tear Proteins to Hydroxyethyl Methacrylate-Based Contact Lens Materials. Eye Contact Lens 2009; 35:320-8. [DOI: 10.1097/icl.0b013e3181becd3c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Subbaraman LN, Glasier MA, Senchyna M, Sheardown H, Jones L. Kinetics ofIn VitroLysozyme Deposition on Silicone Hydrogel, PMMA, and FDA Groups I, II, and IV Contact Lens Materials. Curr Eye Res 2009; 31:787-96. [PMID: 17050272 DOI: 10.1080/02713680600888799] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
We sought to compare the kinetics of in vitro lysozyme deposition on silicone hydrogel (SH), polymethyl methacrylate (PMMA), and FDA groups I, II, and IV contact lenses. Lenses were incubated in 125I-labeled lysozyme for time periods ranging from 1 hr to 28 days, and radioactive counts were determined. SH lenses and PMMA deposited less lysozyme than conventional hydrogel lenses (p < 0.05). Lysozyme accumulation on group IV lenses reached a maximum on the seventh day and then plateaued, whereas on groups I, II, and SH lenses, deposition continued to increase across all time periods, reiterating that kinetics of lysozyme deposition is highly material dependent.
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Affiliation(s)
- Lakshman N Subbaraman
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada.
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Glasier MA, Subbaraman LN, Senchyna M, Jones L. A Solid-Phase Assay for the Quantitation of Total Protein Eluted from Balafilcon, Lotrafilcon, and Etafilcon Contact Lenses. Curr Eye Res 2009; 33:631-40. [DOI: 10.1080/02713680802291537] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Mary-Ann Glasier
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada
| | - Lakshman N. Subbaraman
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada
| | | | - Lyndon Jones
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada
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Glasier MA, Keech A, Sheardown H, Subbaraman LN, Jones L. Conformational and Quantitative Characterization of Lysozyme Extracted from Galyfilcon and Senofilcon Silicone Hydrogel Contact Lenses. Curr Eye Res 2009; 33:1-11. [DOI: 10.1080/02713680701830278] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Sorbara L, Jones L, Williams-Lyn D. Contact lens induced papillary conjunctivitis with silicone hydrogel lenses. Cont Lens Anterior Eye 2009; 32:93-6. [DOI: 10.1016/j.clae.2008.07.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2008] [Revised: 07/22/2008] [Accepted: 07/28/2008] [Indexed: 11/16/2022]
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Toda I, Yoshida A, Sakai C, Hori-Komai Y, Tsubota K. Visual performance after reduced blinking in eyes with soft contact lenses or after LASIK. J Refract Surg 2009; 25:69-73. [PMID: 19244954 DOI: 10.3928/1081597x-20090101-09] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate visual performance during concentrated visual work in patients wearing soft contact lenses or after LASIK. METHODS Thirty-one eyes of 17 patients who had worn soft contact lenses before LASIK were examined by the following tests immediately and 10 seconds after eye opening: 1) functional visual acuity, which is defined as visual acuity measured after prolonged eye opening without blinking; 2) surface regularity index (SRI) and surface asymmetry index (SAI) in corneal topography; and 3) higher order aberration measured with NIDEK OPD-Scan. Results were compared in the same patients before (with soft contact lenses and no eye surgery) and 1 month after LASIK (without soft contact lenses). RESULTS Functional visual acuity was significantly decreased 10 seconds after eye opening compared with immediately after eye opening, both with soft contact lenses and after LASIK, and decreased to a greater extent with soft contact lenses. The SRI and SAI were significantly increased 10 seconds after eye opening compared with immediately after eye opening, both with soft contact lenses and after LASIK, and increased to a greater extent with soft contact lenses. Higher order aberration was increased 10 seconds after eye opening with soft contact lenses, but not after LASIK. CONCLUSIONS Our results suggest that prolonged eye opening induces a decreased quality of vision in eyes of soft contact lens wearers and after LASIK. Under conditions in which blinking is restricted due to concentrated visual work, such as visual display terminal work, reading, and driving, visual performance may be more compromised with soft contact lens wear than after LASIK.
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Efficacy of an Extraction Solvent Used to Quantify Albumin Deposition on Hydrogel Contact Lens Materials. Eye Contact Lens 2009; 35:76-80. [DOI: 10.1097/icl.0b013e318199aff6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Luensmann D, Glasier MA, Zhang F, Bantseev V, Simpson T, Jones L. Confocal Microscopy and Albumin Penetration into Contact Lenses. Optom Vis Sci 2007; 84:839-47. [PMID: 17873769 DOI: 10.1097/opx.0b013e3181559ea4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE To develop a novel in vitro method to detect the depth of penetration of the tear film protein albumin into contact lens materials using confocal laser scanning microscopy (CLSM). METHODS A poly-HEMA-based hydrogel (etafilcon A) and a silicone hydrogel material (lotrafilcon B) were examined. In vitro, bovine serum albumin (BSA) was labeled with 5-(4,6-dichloro-s-triazin-2-ylamino) fluorescein hydrochloride (DTAF). The lenses were incubated in this protein solution (0.5 mg/ml) at 37 degrees C. After 1 and 7 days incubation, the lenses were examined using CLSM (Zeiss 510, config. META 18) and the location of the fluorescently labeled BSA was identified. RESULTS BSA adsorption on the surface and penetration into the lens matrix occurred at a higher concentration for etafilcon compared to lotrafilcon (p < 0.001). For both materials, BSA was detected on the surface after 1 day of incubation. Significant levels of BSA were detected within the matrix of etafilcon after as little as 1 day (p < 0.001), but no BSA was detected in the matrix of lotrafilcon at any time (p > 0.05). CONCLUSION CLSM can be successfully used to examine the depth of penetration of fluorescently labeled proteins into various hydrogel polymers. Our results show that etafilcon lenses both adsorb BSA on the surface and absorb BSA within the matrix, whereas lotrafilcon B adsorbs small amounts of BSA on the surface only.
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Affiliation(s)
- Doerte Luensmann
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada.
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Subbaraman LN, Glasier MA, Senchyna M, Sheardown H, Jones L. Extraction Efficiency of an Extraction Buffer Used to Quantify Lysozyme Deposition on Conventional and Silicone Hydrogel Contact Lens Materials. Eye Contact Lens 2007; 33:169-73. [PMID: 17630622 DOI: 10.1097/01.icl.0000248155.23800.20] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Extracting lysozyme from Food and Drug Administration group IV etafilcon lenses by using 0.2% trifluoroacetic acid and acetonitrile (TFA/ACN) is a well-established procedure. TFA/ACN has been the extraction buffer of choice for extracting proteins from silicone hydrogel contact lenses. The purpose of this study was to determine the efficiency of TFA/ACN in extracting lysozyme from silicone hydrogel and etafilcon lenses by using an in vitro model. METHODS ACUVUE 2, Focus NIGHT & DAY, O2 Optix, PureVision, and ACUVUE Advance lenses were incubated in simple lysozyme solution and a complex artificial tear solution consisting of multiple tear components containing lysozyme labeled with iodine 125. All the silicone hydrogel lenses were incubated for 28 days, whereas the ACUVUE 2 lenses were incubated for 7 days at 37 degrees C with constant rotation. After the incubation period, radioactive counts were determined, and the lenses were placed in an appropriate volume of the buffer for 24 hours in darkness. The lenses were removed from the buffer, and radioactive counts were determined again. RESULTS Extraction efficiencies for lysozyme from the artificial tear solution were 97.2% +/- 1.2% for ACUVUE 2, 64.3% +/- 6.2% for Focus NIGHT & DAY, 62.5% +/- 5.6% for O2 Optix, 53.5% +/- 5.8% for PureVision, and 89.2% +/- 3.4% for ACUVUE Advance. Results were similar for the lysozyme extracted after incubating in the simple lysozyme solution. CONCLUSIONS TFA/ACN is extremely efficient at extracting lysozyme deposited on etafilcon lenses. However, it does not extract all the lysozyme deposited on silicone hydrogel lenses, and alternative extraction procedures should be sought.
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Affiliation(s)
- Lakshman N Subbaraman
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada.
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Suwala M, Glasier MA, Subbaraman LN, Jones L. Quantity and Conformation of Lysozyme Deposited on Conventional and Silicone Hydrogel Contact Lens Materials Using an In Vitro Model. Eye Contact Lens 2007; 33:138-43. [PMID: 17502748 DOI: 10.1097/01.icl.0000244155.87409.f6] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To determine the activity of hen egg lysozyme (HEL) deposited on conventional and silicone hydrogel contact lens materials by using an in vitro model. METHODS ACUVUE 2 (etafilcon A), PureVision (balafilcon A), ACUVUE Advance (galyfilcon A), Focus NIGHT & DAY (lotrafilcon A), O2 Optix (lotrafilcon B), Proclear (omafilcon A), and ACUVUE OASYS (senofilcon A) contact lenses were deposited in vitro in a phosphate-buffered solution (PBS) containing 2 mg/mL HEL. Lenses were briefly rinsed in PBS to remove unbound material and extracted in a mixture of acetonitrile and trifluoroacetic acid. After lyophilization, extracts were examined for lysozyme activity by micrococcal assay and total protein by Western blot. RESULTS In terms of total protein accumulation, ACUVUE 2 showed the most, with 1,800 microg per lens. Proclear was next, with 68 microg per lens, and Focus NIGHT & DAY showed the least, with 2 microg per lens. ACUVUE Advance, ACUVUE OASYS, and O2 Optix accumulated similar amounts of lysozyme, at approximately 6 microg per lens. Lysozyme deposited on ACUVUE 2 showed the greatest activity (91% +/- 5%), and this result was statistically different from all other lens types (P<0.001). Lysozyme deposited on Focus NIGHT & DAY (24% +/- 5%) and O2 Optix (23% +/- 11%) showed the lowest activity. Lysozyme deposits on other lens materials showed intermediate activity (ACUVUE Advance, 60% +/- 15%; ACUVUE OASYS, 51% +/- 9%; PureVision, 58% +/- 8%; and Proclear, 38% +/- 3%). CONCLUSIONS Silicone hydrogel lenses acquire less lysozyme deposit than conventional group II (Proclear) or group IV (ACUVUE 2) lenses do, and the levels of activity of the lysozyme are highly variable between materials.
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Affiliation(s)
- Maciej Suwala
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada
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