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Sanjanwala D, Londhe V, Trivedi R, Bonde S, Sawarkar S, Kale V, Patravale V. Polysaccharide-based hydrogels for medical devices, implants and tissue engineering: A review. Int J Biol Macromol 2024; 256:128488. [PMID: 38043653 DOI: 10.1016/j.ijbiomac.2023.128488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 11/10/2023] [Accepted: 11/27/2023] [Indexed: 12/05/2023]
Abstract
Hydrogels are highly biocompatible biomaterials composed of crosslinked three-dimensional networks of hydrophilic polymers. Owing to their natural origin, polysaccharide-based hydrogels (PBHs) possess low toxicity, high biocompatibility and demonstrate in vivo biodegradability, making them great candidates for use in various biomedical devices, implants, and tissue engineering. In addition, many polysaccharides also show additional biological activities such as antimicrobial, anticoagulant, antioxidant, immunomodulatory, hemostatic, and anti-inflammatory, which can provide additional therapeutic benefits. The porous nature of PBHs allows for the immobilization of antibodies, aptamers, enzymes and other molecules on their surface, or within their matrix, potentiating their use in biosensor devices. Specific polysaccharides can be used to produce transparent hydrogels, which have been used widely to fabricate ocular implants. The ability of PBHs to encapsulate drugs and other actives has been utilized for making neural implants and coatings for cardiovascular devices (stents, pacemakers and venous catheters) and urinary catheters. Their high water-absorption capacity has been exploited to make superabsorbent diapers and sanitary napkins. The barrier property and mechanical strength of PBHs has been used to develop gels and films as anti-adhesive formulations for the prevention of post-operative adhesion. Finally, by virtue of their ability to mimic various body tissues, they have been explored as scaffolds and bio-inks for tissue engineering of a wide variety of organs. These applications have been described in detail, in this review.
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Affiliation(s)
- Dhruv Sanjanwala
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Nathalal Parekh Marg, Matunga (E), Mumbai 400019, Maharashtra, India; Department of Pharmaceutical Sciences, College of Pharmacy, 428 Church Street, University of Michigan, Ann Arbor, MI 48109, United States.
| | - Vaishali Londhe
- SVKM's NMIMS, Shobhaben Pratapbhai College of Pharmacy and Technology Management, V.L. Mehta Road, Vile Parle (W), Mumbai 400056, Maharashtra, India
| | - Rashmi Trivedi
- Smt. Kishoritai Bhoyar College of Pharmacy, Kamptee, Nagpur 441002, Maharashtra, India
| | - Smita Bonde
- SVKM's NMIMS, School of Pharmacy and Technology Management, Shirpur Campus, Maharashtra, India
| | - Sujata Sawarkar
- Department of Pharmaceutics, SVKM's Dr. Bhanuben Nanavati College of Pharmacy, University of Mumbai, Mumbai 400056, Maharashtra, India
| | - Vinita Kale
- Department of Pharmaceutics, Gurunanak College of Pharmacy, Kamptee Road, Nagpur 440026, Maharashtra, India
| | - Vandana Patravale
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Nathalal Parekh Marg, Matunga (E), Mumbai 400019, Maharashtra, India.
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2
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Costa D, De Matteis V, Treso F, Montani G, Martino M, Rinaldi R, Corrado M, Cascione M. Impact of the physical properties of contact lens materials on the discomfort: role of the coefficient of friction. Colloids Surf B Biointerfaces 2024; 233:113630. [PMID: 37956592 DOI: 10.1016/j.colsurfb.2023.113630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/31/2023] [Accepted: 11/01/2023] [Indexed: 11/15/2023]
Abstract
Contact Lens Discomfort (CLD) is the main cause in contact lens (CLs) discontinuation, referred in literature as drop-out phenomenon. Despite such evidence was reported in several clinical studies, a relationship between physico-chemical properties of CLs and CLD is not still totally understood. In this regard, the friction of CLs surfaces seems to be related to discomfort feeling events, probably due to an alteration of the lubricate function of the tear film after the CL placement inside the ocular environment. In the last years, many studies have been finalized to the friction measurements of CLs surface, finding conflicting data due to a lack in standardized protocol. The aim of this review is primarily to show evident relationships between CLs surface properties (i.e. wettability, tear evaporation, tear film quality, etc.) and the coefficient of friction (CoF), resulting therefore the most relevant physical quantity in the CLs characterization. In addition, we reported the most recent studies in CLs tribology, which highlight that the introduction of a standard protocol in CoF measurements is necessary to obtain reproducible results, considering the aim to evaluate in a more precise way the relationship between this material surface property and comfort in CLs users.
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Affiliation(s)
- D Costa
- Department of Mathematics and Physics "Ennio De Giorgi", University of Salento, Via Arnesano, Lecce 73100, Italy
| | - V De Matteis
- Department of Mathematics and Physics "Ennio De Giorgi", University of Salento, Via Arnesano, Lecce 73100, Italy; Institute for Microelectronics and Microsystems (IMM), CNR, Via Monteroni, Lecce 73100, Italy.
| | - F Treso
- Department of Mathematics and Physics "Ennio De Giorgi", University of Salento, Via Arnesano, Lecce 73100, Italy; Centro di Ricerca in Contattologia Avanzata, Via Arnesano, Lecce 73100, Italy
| | - G Montani
- Department of Mathematics and Physics "Ennio De Giorgi", University of Salento, Via Arnesano, Lecce 73100, Italy; Centro di Ricerca in Contattologia Avanzata, Via Arnesano, Lecce 73100, Italy
| | - M Martino
- Department of Mathematics and Physics "Ennio De Giorgi", University of Salento, Via Arnesano, Lecce 73100, Italy; Centro di Ricerca in Contattologia Avanzata, Via Arnesano, Lecce 73100, Italy
| | - R Rinaldi
- Department of Mathematics and Physics "Ennio De Giorgi", University of Salento, Via Arnesano, Lecce 73100, Italy; Institute for Microelectronics and Microsystems (IMM), CNR, Via Monteroni, Lecce 73100, Italy
| | - M Corrado
- Department of Mathematics and Physics "Ennio De Giorgi", University of Salento, Via Arnesano, Lecce 73100, Italy
| | - M Cascione
- Department of Mathematics and Physics "Ennio De Giorgi", University of Salento, Via Arnesano, Lecce 73100, Italy; Institute for Microelectronics and Microsystems (IMM), CNR, Via Monteroni, Lecce 73100, Italy; Centro di Ricerca in Contattologia Avanzata, Via Arnesano, Lecce 73100, Italy.
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3
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Kim TY, Lee GH, Mun J, Cheong S, Choi I, Kim H, Hahn SK. Smart Contact Lens Systems for Ocular Drug Delivery and Therapy. Adv Drug Deliv Rev 2023; 196:114817. [PMID: 37004938 DOI: 10.1016/j.addr.2023.114817] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 03/27/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023]
Abstract
Ocular drug delivery and therapy systems have been extensively investigated with various methods including direct injections, eye drops and contact lenses. Nowadays, smart contact lens systems are attracting a lot of attention for ocular drug delivery and therapy due to their minimally invasive or non-invasive characteristics, highly enhanced drug permeation, high bioavailability, and on-demand drug delivery. Furthermore, smart contact lens systems can be used for direct light delivery into the eyes for biophotonic therapy replacing the use of drugs. Here, we review smart contact lens systems which can be classified into two groups of drug-eluting contact lens and ocular device contact lens. More specifically, this review covers smart contact lens systems with nanocomposite-laden systems, polymeric film-incorporated systems, micro and nanostructure systems, iontophoretic systems, electrochemical systems, and phototherapy systems for ocular drug delivery and therapy. After that, we discuss the future opportunities, challenges and perspectives of smart contact lens systems for ocular drug delivery and therapy.
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Affiliation(s)
- Tae Yeon Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Geon-Hui Lee
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Jonghwan Mun
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Sunah Cheong
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Inhoo Choi
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Hyemin Kim
- Department of Cosmetics Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
| | - Sei Kwang Hahn
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea; PHI BIOMED Co., 168 Yeoksam-ro, Gangnamgu, Seoul 06248, Republic of Korea.
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Influence of Selected Ophthalmic Fluids on the Wettability and Hydration of Hydrogel and Silicone Hydrogel Contact Lenses—In Vitro Study. MATERIALS 2022; 15:ma15030930. [PMID: 35160876 PMCID: PMC8839750 DOI: 10.3390/ma15030930] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 01/11/2022] [Accepted: 01/20/2022] [Indexed: 11/16/2022]
Abstract
This study attempts to evaluate the effect of incubation in selected ophthalmic fluids on contact lenses (Etafilcon A, Omafilcon A, Narafilcon A, Senofilcon A). Four research groups differing in the incubation environment were created: (1) initial state, (2) contact lens solution (CLS), (3) contact lens solution and eye drops (ED) and (4) eye drops. Dehydration by gravimetric method and the contact angle (CA) by the sessile drop method were tested. The surface free energy (SFE) was also calculated with the use of several methods: Owens–Wendt, Wu, Neumann, and Neumann–Kwok. The greatest changes in the dehydration profile were observed for contact lenses incubated in ED. The most noticeable changes in CA values were observed for contact lenses incubated in ED, in which it was not possible to settle water drop after incubation. On the basis of SFE analysis, higher values were found for hydrogel contact lenses, e.g., according to the Owens–Wendt method, they ranged from 54.45 ± 6.56 mJ/m2 to 58.09 ± 4.86 mJ/m2, while in the case of silicone-hydrogel contact lenses, they ranged from 32.86 ± 3.47 mJ/m2 to 35.33 ± 6.56 mJ/m2. Incubation in all tested environments decreased the SFE values, but the differences were in most cases statistically insignificant. Calculating the SFE may be a useful method as it can be used to estimate the possibility of bacteria adhering to contact lens surfaces.
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5
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Lodhi APS, Kumar D. Natural emulsifier assisted lubricity of the colloidal system: Effect of natural emulsifier concentration. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116900] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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6
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Zhu D, Liu Y, Gilbert JL. Micromechanical measurement of adhesion of dehydrating silicone hydrogel contact lenses to corneal tissue. Acta Biomater 2021; 127:242-251. [PMID: 33812075 DOI: 10.1016/j.actbio.2021.03.053] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 03/19/2021] [Accepted: 03/23/2021] [Indexed: 10/21/2022]
Abstract
Adhesion properties, which can vary with multiple factors, of silicone hydrogel contact lenses are important to their performance and comfort in the eye. In this study, we developed and used a simple, representative testing system and method to study the adhesive interactions of different silicone contact lenses (balafilcon A and senofilcon A) on polished titanium alloy and porcine whole eye cornea under dehydrating conditions. Adhesive interactions for senofilcon A varied by hydration state for both corneal and titanium adhesion, starting low, rising to a maximum and falling with dehydration time and dehydration state. Balafilcon A showed a rise and fall against titanium, but retained a relatively constant adhesive interaction with corneal tissue over dehydration time. Senofilcon A reached the highest adhesion forces (400 mN) within 5 to 10 min of testing against cornea, then dropped with time after that. Johnson-Kendall-Roberts (JKR) theory was applied to determine the surface energy of the lenses, and work of adhesion (WOA) was also determined for both lenses. Similar trends as observed with the force-hydration curves were seen with surface energy and work of adhesion as well (peak surface energy of 8 N/m and work of adhesion of 80 µJ for senofilcon A). Video imaging of the adhesive interactions showed significant corneal deformation taking place during testing, and post-test analysis shows damage to the corneal tissue. This method could be used to assess pre-clinical performance of long-lasting contact lenses and the role of hydration state. STATEMENT OF SIGNIFICANCE: Adhesion properties of contact lenses play significant roles in their performance and comfort in the eye. Adhesion is influenced by polymer chemistry, counterface materials and hydration state of the contact lenses. However, no test method has been developed to directly study the adhesion properties between contact lenses and corneal tissue during the dehydration process. Our work aims to fill this gap by developing testing and analysis methods for evaluating the adhesive interactions in vitro between contact lenses of different chemistries and properties and different counter surfaces under dehydrating conditions over time. Our study shows that adhesive interactions of contact lenses are highly dependent on polymer type, surface treatment, counterface material and hydration state.
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Franco P, De Marco I. Contact Lenses as Ophthalmic Drug Delivery Systems: A Review. Polymers (Basel) 2021; 13:1102. [PMID: 33808363 PMCID: PMC8037676 DOI: 10.3390/polym13071102] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/27/2021] [Accepted: 03/29/2021] [Indexed: 12/25/2022] Open
Abstract
Ophthalmic drugs used for the treatment of various ocular diseases are commonly administered by eye drops. However, due to anatomical and physiological factors, there is a low bioavailability of the active principle. In order to increase the drug residence time on the cornea to adequate levels, therapeutic contact lenses have recently been proposed. The polymeric support that constitutes the contact lens is loaded with the drug; in this way, there is a direct and effective pharmacological action on the target organ, promoting a prolonged release of the active principle. The incorporation of ophthalmic drugs into contact lenses can be performed by different techniques; nowadays, the soaking method is mainly employed. To improve the therapeutic performance of drug-loaded contact lenses, innovative methods have recently been proposed, including the impregnation with supercritical carbon dioxide. This updated review of therapeutic contact lenses production and application provides useful information on the most effective preparation methodologies, recent achievements and future perspectives.
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Affiliation(s)
- Paola Franco
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy;
| | - Iolanda De Marco
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy;
- Research Centre for Biomaterials BIONAM, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy
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8
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Lodhi APS, Kumar D. Natural ingredients based environmental friendly metalworking fluid with superior lubricity. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2020.126071] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Karayilan M, Clamen L, Becker ML. Polymeric Materials for Eye Surface and Intraocular Applications. Biomacromolecules 2021; 22:223-261. [PMID: 33405900 DOI: 10.1021/acs.biomac.0c01525] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Ocular applications of polymeric materials have been widely investigated for medical diagnostics, treatment, and vision improvement. The human eye is a vital organ that connects us to the outside world so when the eye is injured, infected, or impaired, it needs immediate medical treatment to maintain clear vision and quality of life. Moreover, several essential parts of the eye lose their functions upon aging, causing diminished vision. Modern polymer science and polymeric materials offer various alternatives, such as corneal and scleral implants, artificial ocular lenses, and vitreous substitutes, to replace the damaged parts of the eye. In addition to the use of polymers for medical treatment, polymeric contact lenses can provide not only vision correction, but they can also be used as wearable electronics. In this Review, we highlight the evolution of polymeric materials for specific ocular applications such as intraocular lenses and current state-of-the-art polymeric systems with unique properties for contact lens, corneal, scleral, and vitreous body applications. We organize this Review paper by following the path of light as it travels through the eye. Starting from the outside of the eye (contact lenses), we move onto the eye's surface (cornea and sclera) and conclude with intraocular applications (intraocular lens and vitreous body) of mostly synthetic polymers and several biopolymers. Initially, we briefly describe the anatomy and physiology of the eye as a reminder of the eye parts and their functions. The rest of the Review provides an overview of recent advancements in next-generation contact lenses and contact lens sensors, corneal and scleral implants, solid and injectable intraocular lenses, and artificial vitreous body. Current limitations for future improvements are also briefly discussed.
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Affiliation(s)
- Metin Karayilan
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Liane Clamen
- Adaptilens, LLC, Boston, Massachusetts 02467, United States
| | - Matthew L Becker
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States.,Mechanical Engineering and Materials Science, Orthopaedic Surgery, and Biomedical Engineering, Duke University, Durham, North Carolina 27708, United States
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Wei Y, Hu Y, Shen X, Zhang X, Guan J, Mao S. Design of circular-ring film embedded contact lens for improved compatibility and sustained ocular drug delivery. Eur J Pharm Biopharm 2020; 157:28-37. [DOI: 10.1016/j.ejpb.2020.09.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 09/17/2020] [Accepted: 09/21/2020] [Indexed: 12/14/2022]
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Zhu Y, Sheng Y. RETRACTED: Sustained delivery of epalrestat to the retina using PEGylated solid lipid nanoparticles laden contact lens. Int J Pharm 2020; 587:119688. [PMID: 32717281 DOI: 10.1016/j.ijpharm.2020.119688] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 07/04/2020] [Accepted: 07/21/2020] [Indexed: 12/21/2022]
Abstract
This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Significant similarities were noticed post-publication between this article and an article submitted to the Journal of Drug Delivery Science and Technology on the same day, by an apparently unrelated research group: Tong Zhang, Tianhui Zhu, Fanyin Wang, Ling Peng and Mingying Lai 60 (2020) 101949 https://doi.org/10.1016/j.jddst.2020.101949 Moreover, the authors did not respond to the journal request to comment on these similarities and to provide the raw data, and the Editor-in-Chief decided to retract the article. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and genuine. As such this article represents a severe abuse of the scientific publishing system.
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Affiliation(s)
- Yanni Zhu
- Department of Ophthalmology, The Second Affiliated Hospital of Xi'an Medical University, No. 167, Fangdong Street, Baqiao District, Xi'an, Shaanxi 710038, China
| | - Yanjuan Sheng
- Department of Ophthalmology, The Second People's Hospital of Jinan, Jinan, Shandong 250001, China.
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Lanier OL, Christopher KG, Macoon RM, Yu Y, Sekar P, Chauhan A. Commercialization challenges for drug eluting contact lenses. Expert Opin Drug Deliv 2020; 17:1133-1149. [DOI: 10.1080/17425247.2020.1787983] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Olivia L. Lanier
- Chemical and Biological Engineering, Colorado School of Mines, Golden, CO, USA
| | | | - Russell M. Macoon
- Department of Chemical Engineering, University of Florida, Gainesville, FL, USA
| | - Yifan Yu
- Department of Chemical Engineering, University of Florida, Gainesville, FL, USA
| | - Poorvajan Sekar
- Department of Chemical Engineering, University of Florida, Gainesville, FL, USA
| | - Anuj Chauhan
- Chemical and Biological Engineering, Colorado School of Mines, Golden, CO, USA
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Yu Y, Hsu KH, Gharami S, Butler JE, Hazra S, Chauhan A. Interfacial polymerization of a thin film on contact lenses for improving lubricity. J Colloid Interface Sci 2020; 571:356-367. [PMID: 32213354 DOI: 10.1016/j.jcis.2020.03.060] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 02/07/2020] [Accepted: 03/16/2020] [Indexed: 11/17/2022]
Abstract
HYPOTHESIS A large number of contact lens wearers drop out each year due to end of day discomfort, which could possibly be reduced by designing lenses with highly lubricious surfaces. We hypothesize that polymerizing a thin film of dimethyl acrylamide (DMA) on the surface of the lenses will improve lubricity. EXPERIMENTS The thin film is polymerized by loading a commercial contact lens (1-DAY ACUVUE® TruEye®) with N,N,N',N'-Tetramethylethane-1,2-diamine (TEMED) and soaking it in a solution of DMA and ammonium per sulfate (APS). The two components of the redox couple (APS and TEMED) mix near the surface of the lens due to diffusion and react rapidly to form free radicals. The free radicals lead the polymerization of the DMA monomer near the surface resulting in the formation of the thin hydrogel layer that is attached to the lens matrix through activation of unreacted vinyl groups or possibly through formation of entanglements with the lens polymer. FINDINGS The thickness of the layer is controlled by the polymerization time which is limited to 30 s to create a layer of DMA only at the surface. The presence of the DMA layer is confirmed through measurements of Fourier-transform infrared spectroscopy (FTIR) spectra in total internal reflection mode. The layer is determined to be about 3-5 µm thick with a water content of about 285%. The presence of the layer significantly improves lubricity as is evident through the qualitative rubbing test and quantitative measurement of the friction coefficient. A preliminary one-week safety study in rabbits show that lens wear does not cause any toxicity.
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Affiliation(s)
- Yifan Yu
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, United States
| | - Kuan-Hui Hsu
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, United States
| | - Sumana Gharami
- Department of Veterinary Surgery & Radiology, West Bengal University of Animal & Fishery Sciences, Kolkata 700 037, India
| | - Jason E Butler
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, United States
| | - Sarbani Hazra
- Department of Veterinary Surgery & Radiology, West Bengal University of Animal & Fishery Sciences, Kolkata 700 037, India
| | - Anuj Chauhan
- Chemical and Biological Engineering, Colorado School of Mines, Golden, CO 80401, United States.
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