1
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Naik K, du Toit LC, Ally N, Choonara YE. In vivo evaluation of a Nano-enabled therapeutic vitreous substitute for the precise delivery of triamcinolone to the posterior segment of the eye. Drug Deliv Transl Res 2024:10.1007/s13346-024-01566-1. [PMID: 38519828 DOI: 10.1007/s13346-024-01566-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/26/2024] [Indexed: 03/25/2024]
Abstract
This study focused on the design of a thermoresponsive, nano-enabled vitreous substitute for the treatment of retinal diseases. Synthesis of a hydrogel composed of hyaluronic acid and a poloxamer blend was undertaken. Poly(D,L-lactide-co-glycolide) acid nanoparticles encapsulating triamcinolone acetonide (TA) were synthesised with a spherical morphology and mean diameter of ~ 153 nm. Hydrogel fabrication and nanoparticle loading within the hydrogel was confirmed via physicochemical analysis. Gelation studies indicated that hydrogels formed in nine minutes and 10 min for the unloaded and nanoparticle-loaded hydrogels, respectively. The hydrogels displayed in situ gel formation properties, and rheometric viscoelastic studies indicated the unloaded and loaded hydrogels to have modulus values similar to those of the natural vitreous at 37 °C. Administration of the hydrogels was possible via 26G needles allowing for clinical application and drug release of triamcinolone acetonide from the nanoparticle-loaded hydrogel, which provided sustained in vitro drug release over nine weeks. The hydrogels displayed minimal swelling, reaching equilibrium swelling within 12 h for the unloaded hydrogel, and eight hours for the nanoparticle-loaded hydrogel. Biodegradation in simulated vitreous humour with lysozyme showed < 20% degradation within nine weeks. Biocompatibility of both unloaded and loaded hydrogels was shown with mouse fibroblast and human retinal pigment epithelium cell lines. Lastly, a pilot in vivo study in a New Zealand White rabbit model displayed minimal toxicity with precise, localised drug release behaviour, and ocular TA levels maintained within the therapeutic window for the 28-day investigation period, which supports the potential applicability of the unloaded and nanoparticle-loaded hydrogels as vitreous substitutes that function as drug delivery systems following vitrectomy surgery.
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Affiliation(s)
- Kruti Naik
- Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Johannesburg, Parktown, 2193, South Africa
| | - Lisa Claire du Toit
- Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Johannesburg, Parktown, 2193, South Africa
| | - Naseer Ally
- Division of Ophthalmology, Department of Neurosciences, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Johannesburg, Parktown, 2193, South Africa
| | - Yahya Essop Choonara
- Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Johannesburg, Parktown, 2193, South Africa.
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2
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Naik K, Du Toit LC, Ally N, Choonara YE. Advances in Polysaccharide- and Synthetic Polymer-Based Vitreous Substitutes. Pharmaceutics 2023; 15:pharmaceutics15020566. [PMID: 36839888 PMCID: PMC9961338 DOI: 10.3390/pharmaceutics15020566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/01/2023] [Accepted: 02/05/2023] [Indexed: 02/11/2023] Open
Abstract
The vitreous humour is a gel-like structure that composes the majority of each eye. It functions to provide passage of light, be a viscoelastic dampener, and hold the retina in place. Vitreous liquefaction causes retinal detachment and retinal tears requiring pars plana vitrectomy for vitreous substitution. An ideal vitreous substitute should display similar mechanical, chemical, and rheological properties to the natural vitreous. Currently used vitreous substitutes such as silicone oil, perfluorocarbon liquids, and gases cannot be used long-term due to adverse effects such as poor retention time, cytotoxicity, and cataract formation. Long-term, experimental vitreous substitutes composed of natural, modified and synthetic polymers are currently being studied. This review discusses current long- and short-term vitreous substitutes and the disadvantages of these that have highlighted the need for an ideal vitreous substitute. The review subsequently focuses specifically on currently used polysaccharide- and synthetic polymer-based vitreous substitutes, which may be modified or functionalised, or employed as the derivative, and discusses experimental vitreous substitutes in these classes. The advantages and challenges associated with the use of polymeric substitutes are discussed. Innovative approaches to vitreous substitution, namely a novel foldable capsular vitreous body, are presented, as well as future perspectives related to the advancement of this field.
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Affiliation(s)
- Kruti Naik
- Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa
| | - Lisa C. Du Toit
- Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa
| | - Naseer Ally
- Division of Ophthalmology, Department of Neurosciences, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa
| | - Yahya E. Choonara
- Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa
- Correspondence: ; Tel.: +27-11-717-2052
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3
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Pandey DK, Kuddushi M, Kumar A, Singh DK. Iron Oxide Nanoparticles Loaded Smart Hybrid Hydrogel for Anti-Inflammatory Drug Delivery: Preparation and Characterizations. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.129631] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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4
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Alshaikh RA, Waeber C, Ryan KB. Polymer based sustained drug delivery to the ocular posterior segment: barriers and future opportunities for the treatment of neovascular pathologies. Adv Drug Deliv Rev 2022; 187:114342. [PMID: 35569559 DOI: 10.1016/j.addr.2022.114342] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 04/28/2022] [Accepted: 05/09/2022] [Indexed: 12/12/2022]
Abstract
There is an increasing momentum in research and pharmaceutical industry communities to design sustained, non-invasive delivery systems to treat chronic neovascular ocular diseases that affect the posterior segment of the eye including age-related macular degeneration and diabetic retinopathy. Current treatments include VEGF blockers, which have revolutionized the standard of care for patients, but their maximum therapeutic benefit is hampered by the need for recurrent and invasive administration procedures. Currently approved delivery systems intended to address these limitations exploit polymer technology to regulate drug release in a sustained manner. Here, we critically review sustained drug delivery approaches for the treatment of chronic neovascular diseases affecting the ocular posterior segment, with a special emphasis on novel and polymeric technologies spanning the spectrum of preclinical and clinical investigation, and those approved for treatment. The mechanism by which each formulation imparts sustained release, the impact of formulation characteristics on release and foreign body reaction, and special considerations related to the translation of these systems are discussed.
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Affiliation(s)
| | - Christian Waeber
- School of Pharmacy, University College Cork, Cork, Ireland; Department of Pharmacology and Therapeutics, University College Cork, Cork, Ireland
| | - Katie B Ryan
- School of Pharmacy, University College Cork, Cork, Ireland; SSPC The SFI Research Centre for Pharmaceuticals, School of Pharmacy, University College Cork, Ireland.
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5
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Wang T, Ran R, Ma Y, Zhang M. Polymeric hydrogel as a vitreous substitute: current research, challenges, and future directions. Biomed Mater 2021; 16. [PMID: 34038870 DOI: 10.1088/1748-605x/ac058e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 05/26/2021] [Indexed: 02/08/2023]
Abstract
Vitreoretinal surgery is an essential approach to treat proliferative diabetic vitreopathy, retinal detachment, retinal tear, ocular trauma, and macular holes. The removal of the natural vitreous and the replacement with substitutes are critical steps for retina reattachment. Vitreous substitutes including silicone oil (SiO), air, sulfur hexafluoride (SF6), and perfluoropropane (C3F8), have been widely applied in clinical practice. However, these substitutes are reported to cause complications such as emulsification, high intraocular pressure, and lens opacification. Polymeric hydrogels are a kind of material with favorable physical, mechanical properties, and adaptable biocompatibility, thus being highly expected to be ideal vitreous substitutes. Despite years of research, very few polymeric hydrogels can be applied practically in the vitreous cavity. In this review, we focus on the development of polymeric natural-based hydrogels and synthetic hydrogels. Particularly, we pay attention to recent advances in the novel stimuli-response and self-assembly supramolecular hydrogels. Characterized by easy injectability and long residence time, this kind of hydrogel becomes the potentially promising candidates for ideal vitreous substitutes. Finally, we evaluate the current challenges and provide the future directions of vitreous substitutes.
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Affiliation(s)
- Ting Wang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, People's Republic of China.,West China School of Medicine, West China Hospital, Sichuan University, Chengdu 610041, People's Republic of China
| | - Ruijin Ran
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, People's Republic of China.,Minda Hospital of Hubei Minzu University, Enshi, People's Republic of China
| | - Yan Ma
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, People's Republic of China
| | - Ming Zhang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, People's Republic of China
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6
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Mondelo-García C, Bandín-Vilar E, García-Quintanilla L, Castro-Balado A, Del Amo EM, Gil-Martínez M, Blanco-Teijeiro MJ, González-Barcia M, Zarra-Ferro I, Fernández-Ferreiro A, Otero-Espinar FJ. Current Situation and Challenges in Vitreous Substitutes. Macromol Biosci 2021; 21:e2100066. [PMID: 33987966 DOI: 10.1002/mabi.202100066] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/23/2021] [Indexed: 12/11/2022]
Abstract
Vitreo-retinal disorders constitute a significant portion of treatable ocular diseases. These pathologies often require vitreo-retinal surgery and, as a consequence, the use of vitreous substitutes. Nowadays, the vitreous substitutes that are used in clinical practice are mainly divided into gases (air, SF6 , C2 F6 , C3 F8 ) and liquids (perfluorocarbon liquids, silicone oils, and heavy silicone oils). There are specific advantages and drawbacks to each of these, which determine their clinical indications. However, developing the ideal biomaterial for vitreous substitution continues to be one of the most important challenges in ophthalmology, and a multidisciplinary approach is required. In this sense, recent research has focused on the development of biocompatible, biodegradable, and injectable hydrogels (natural, synthetic, and smart), which also act as medium and long-term internal tamponade agents. This comprehensive review aims to cover the main characteristics and indications for use of the extensive range of vitreous substitutes that are currently used in clinical practice, before going on to describe the hydrogels that have been developed recently and which have emerged as promising biomaterials for vitreous substitution.
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Affiliation(s)
- Cristina Mondelo-García
- Pharmacy Department, University Clinical Hospital of Santiago de Compostela (SERGAS), Santiago de Compostela, 15706, Spain.,Pharmacology Group, Health Research Institute of Santiago de Compostela (FIDIS), Santiago de Compostela, 15706, Spain
| | - Enrique Bandín-Vilar
- Pharmacy Department, University Clinical Hospital of Santiago de Compostela (SERGAS), Santiago de Compostela, 15706, Spain.,Pharmacology Group, Health Research Institute of Santiago de Compostela (FIDIS), Santiago de Compostela, 15706, Spain
| | - Laura García-Quintanilla
- Pharmacy Department, University Clinical Hospital of Santiago de Compostela (SERGAS), Santiago de Compostela, 15706, Spain.,Pharmacology Group, Health Research Institute of Santiago de Compostela (FIDIS), Santiago de Compostela, 15706, Spain
| | - Ana Castro-Balado
- Pharmacy Department, University Clinical Hospital of Santiago de Compostela (SERGAS), Santiago de Compostela, 15706, Spain.,Pharmacology Group, Health Research Institute of Santiago de Compostela (FIDIS), Santiago de Compostela, 15706, Spain
| | - Eva M Del Amo
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio, 70211, Finland
| | - María Gil-Martínez
- Ophthalmology Department, University Clinical Hospital of Santiago de Compostela (SERGAS), Santiago de Compostela, 15706, Spain
| | - María José Blanco-Teijeiro
- Ophthalmology Department, University Clinical Hospital of Santiago de Compostela (SERGAS), Santiago de Compostela, 15706, Spain
| | - Miguel González-Barcia
- Pharmacy Department, University Clinical Hospital of Santiago de Compostela (SERGAS), Santiago de Compostela, 15706, Spain.,Pharmacology Group, Health Research Institute of Santiago de Compostela (FIDIS), Santiago de Compostela, 15706, Spain
| | - Irene Zarra-Ferro
- Pharmacy Department, University Clinical Hospital of Santiago de Compostela (SERGAS), Santiago de Compostela, 15706, Spain.,Pharmacology Group, Health Research Institute of Santiago de Compostela (FIDIS), Santiago de Compostela, 15706, Spain
| | - Anxo Fernández-Ferreiro
- Pharmacy Department, University Clinical Hospital of Santiago de Compostela (SERGAS), Santiago de Compostela, 15706, Spain.,Pharmacology Group, Health Research Institute of Santiago de Compostela (FIDIS), Santiago de Compostela, 15706, Spain
| | - Francisco J Otero-Espinar
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology Faculty of Pharmacy, University of Santiago de Compostela (USC), Santiago de Compostela, 15782, Spain
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7
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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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8
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Thacker M, Tseng CL, Lin FH. Substitutes and Colloidal System for Vitreous Replacement and Drug Delivery: Recent Progress and Future Prospective. Polymers (Basel) 2020; 13:E121. [PMID: 33396863 PMCID: PMC7796247 DOI: 10.3390/polym13010121] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/18/2020] [Accepted: 12/19/2020] [Indexed: 01/10/2023] Open
Abstract
Vitreoretinal surgeries for ocular diseases such as complicated retinal detachment, diabetic retinopathy, macular holes and ocular trauma has led to the development of various tamponades over the years in search for an ideal vitreous substitute. Current clinically used tamponade agents such as air, perfluorocarbons, silicone oil and expansile gases serve only as a short-term solution and harbors various disadvantages. However, an ideal long-term substitute is yet to be discovered and recent research emphasizes on the potential of polymeric hydrogels as an ideal vitreous substitute. This review highlights the recent progress in the field of vitreous substitution. Suitability and adverse effects of various tamponade agents in present day clinical use and biomaterials in the experimental phase have been outlined and discussed. In addition, we introduced the anatomy and functions of the native vitreous body and the pathological conditions which require vitreous replacement.
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Affiliation(s)
- Minal Thacker
- Graduate Institute of Biomedical Engineering, National Taiwan University, Daan District, Taipei 10051, Taiwan;
| | - Ching-Li Tseng
- Graduate Institute of Biomedical Materials and Tissue Engineering, Taipei Medical University, Taipei 11031, Taiwan
| | - Feng-Huei Lin
- Graduate Institute of Biomedical Engineering, National Taiwan University, Daan District, Taipei 10051, Taiwan;
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Miaoli County 35053, Taiwan
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9
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Yadav I, Purohit SD, Singh H, Bhushan S, Yadav MK, Velpandian T, Chawla R, Hazra S, Mishra NC. Vitreous substitutes: An overview of the properties, importance, and development. J Biomed Mater Res B Appl Biomater 2020; 109:1156-1176. [PMID: 33319466 DOI: 10.1002/jbm.b.34778] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 10/27/2020] [Accepted: 11/28/2020] [Indexed: 11/12/2022]
Abstract
Vitreous or vitreous humor is a complex transparent gel that fills the space between the lens and retina of an eye and acts as a transparent medium that allows light to pass through it to reach the photoreceptor layer (retina) of the eye. The vitreous humor is removed in ocular surgery (vitrectomy) for pathologies like retinal detachment, macular hole, diabetes-related vitreous hemorrhage detachment, and ocular trauma. Since the vitreous is not actively regenerated or replenished, there is a need for a vitreous substitute to fill the vitreous cavity to provide a temporary or permanent tamponade to the retina following some vitreoretinal surgeries. An ideal vitreous substitute could probably be left inside the eye forever. The vitreous humor is transparent, biocompatible, viscoelastic and highly hydrophilic; polymeric hydrogels with these properties can be a potential candidate to be used as vitreous substitutes. To meet the tremendous demand for the vitreous substitute, many scientists all over the world have developed various kinds of vitreous substitutes or tamponade agent. Vitreous substitutes, whatsoever developed till date, are associated with several advantages and disadvantages, and there is no ideal vitreous substitute available till date. This review highlights the polymer-based vitreous substitutes developed so far, along with their advantages and limitations. The gas-based and oil-based substitutes have also been discussed but very briefly.
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Affiliation(s)
- Indu Yadav
- Department of Polymer and Process Engineering, Indian Institute of Technology Roorkee, Roorkee, India
| | - Shiv Dutt Purohit
- Department of Polymer and Process Engineering, Indian Institute of Technology Roorkee, Roorkee, India
| | - Hemant Singh
- Department of Polymer and Process Engineering, Indian Institute of Technology Roorkee, Roorkee, India
| | - Sakchi Bhushan
- Department of Polymer and Process Engineering, Indian Institute of Technology Roorkee, Roorkee, India
| | - Manoj Kumar Yadav
- School of Computing and Electrical Engineering, Indian Institute of Technology Mandi, Mandi, India
| | - Thirumurthy Velpandian
- Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Rohan Chawla
- Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Saugata Hazra
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, India
| | - Narayan Chandra Mishra
- Department of Polymer and Process Engineering, Indian Institute of Technology Roorkee, Roorkee, India
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10
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Xue K, Liu Z, Lin Q, Lim JYC, Tang KY, Wong SL, Parikh BH, Su X, Loh XJ. PCL-Based Thermogelling Polymer: Molecular Weight Effects on Its Suitability as Vitreous Tamponade. ACS APPLIED BIO MATERIALS 2020; 3:9043-9053. [DOI: 10.1021/acsabm.0c01266] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Kun Xue
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, #08-03 Innovis, 138634 Singapore
| | - Zengping Liu
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, NUHS Tower Block, Level 7, 119228 Singapore
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive Proteos, 138673 Singapore
| | - Qianyu Lin
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, #08-03 Innovis, 138634 Singapore
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117575 Singapore
| | - Jason Y. C. Lim
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, #08-03 Innovis, 138634 Singapore
| | - Karen Yuanting Tang
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, #08-03 Innovis, 138634 Singapore
| | - Soo Lin Wong
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, NUHS Tower Block, Level 7, 119228 Singapore
| | - Bhav Harshad Parikh
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, NUHS Tower Block, Level 7, 119228 Singapore
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive Proteos, 138673 Singapore
| | - Xinyi Su
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, NUHS Tower Block, Level 7, 119228 Singapore
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive Proteos, 138673 Singapore
- Singapore Eye Research Institute, 11 Third Hospital Avenue, 168751 Singapore
| | - Xian Jun Loh
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, #08-03 Innovis, 138634 Singapore
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117575 Singapore
- Singapore Eye Research Institute, 11 Third Hospital Avenue, 168751 Singapore
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11
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Kuddushi M, Ray D, Aswal V, Hoskins C, Malek N. Poly(vinyl alcohol) and Functionalized Ionic Liquid-Based Smart Hydrogels for Doxorubicin Release. ACS APPLIED BIO MATERIALS 2020; 3:4883-4894. [PMID: 35021732 DOI: 10.1021/acsabm.0c00393] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Limitations associated with the traditional cancer therapies prompt the scientific community to develop effective, safer, smarter, and targeted drug carriers that improve the efficiency of the drug carrier, reduce the adverse effects of the drug on the healthy cells, and help in preventing the cancer recurrences. This research aims to design a stimuli-responsive, self-healable, adhesive, and injectable polymeric hydrogel with an ester-functionalized ionic liquid as one of the additives to improve the efficiency of the anticancer drug in encapsulation and localized delivery. The designed polymeric hydrogel responds to intracellular biological stimuli (e.g., acidic pH of cancerous cells and temperature), changes the morphology through changing the shape and size of the gelator within the hydrogel matrix, and releases encapsulated doxorubicin (DOX) at the tumor site efficiently. Molecular interactions, gel morphology, and mechanical strength of the hydrogel were characterized through various analytical techniques, including small-angle neutron scattering. Adhesive properties of the polymeric hydrogel were measured by lap-shear strength tests and the biocompatibility and cellular drug uptake study on human breast cancer (MCF-7) and human cervical carcinoma cells (HeLa). The in vitro cytotoxicity and drug release study showed that the hybrid hydrogel is more effective at killing the cancerous cells, and the targeted release of DOX occurred at intracellular acidic pH. The polymeric hydrogel provides an efficient therapeutic approach for the encapsulation and release of the drug. Overall, the study offers a proof of concept to test the feasibility of the hydrogel system whether the hydrogel formulation helped or hindered the total cellular DOX trafficking.
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Affiliation(s)
- Muzammil Kuddushi
- Applied Chemistry Department, S.V. National Institute of Technology, Surat 395007, Gujarat, India.,Department of Pure & Applied Chemistry, University of Strathclyde, 99 George Street, Glasgow G1 1XQ, U.K
| | - Debes Ray
- Solid State Physics Division, Bhabha Atomic Research Center Trombay, Mumbai 400085, India
| | - Vinod Aswal
- Solid State Physics Division, Bhabha Atomic Research Center Trombay, Mumbai 400085, India
| | - Clare Hoskins
- Department of Pure & Applied Chemistry, University of Strathclyde, 99 George Street, Glasgow G1 1XQ, U.K
| | - Naved Malek
- Applied Chemistry Department, S.V. National Institute of Technology, Surat 395007, Gujarat, India
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12
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Laradji A, Shui YB, Karakocak BB, Evans L, Hamilton P, Ravi N. Bioinspired Thermosensitive Hydrogel as a Vitreous Substitute: Synthesis, Properties, and Progress of Animal Studies. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E1337. [PMID: 32183465 PMCID: PMC7143394 DOI: 10.3390/ma13061337] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Revised: 02/26/2020] [Accepted: 03/13/2020] [Indexed: 11/16/2022]
Abstract
In many vitreal diseases, the surgeon removes the natural vitreous and replaces it with silicone oils, gases, or balanced salt solutions to fill the eyeball and hold the retina in position. However, these materials are often associated with complications and have properties that differ from natural vitreous. Herein, we report an extension of our previous work on the synthesis of a biomimetic hydrogel that is composed of thiolated gellan as an analogue of type II collagen and poly(methacrylamide-co-methacrylate-co-bis(methacryloyl)cystamine), a polyelectrolyte, as an analogue of hyaluronic acid. This thermosensitive hydrogel can be injected into the eye as a viscous solution at 45 °C. It then forms a physical gel in situ when it reaches body temperature, and later forms disulfide covalent crosslinks. In this article, we evaluated two different formulations of the biomimetic hydrogels for their physical, mechanical, and optical properties, and we determined their biocompatibility with several cell lines. Finally, we report on the progress of the four-month preclinical evaluation of our bio-inspired vitreous substitute in comparison to silicone oil or a balanced salt solution. We assessed the eyes with a slit-lamp examination, intraocular pressure measurements, electroretinography, and optical coherence tomography. Preliminary results are very encouraging for the continuing evaluation of our bio-inspired hydrogel in clinical trials.
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Affiliation(s)
- Amine Laradji
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; (A.L.); (Y.-B.S.); (B.B.K.); (L.E.); (P.H.)
- Department of Veterans Affairs, St. Louis Medical Center, St. Louis, MO 63106, USA
| | - Ying-Bo Shui
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; (A.L.); (Y.-B.S.); (B.B.K.); (L.E.); (P.H.)
| | - Bedia Begum Karakocak
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; (A.L.); (Y.-B.S.); (B.B.K.); (L.E.); (P.H.)
- Department of Veterans Affairs, St. Louis Medical Center, St. Louis, MO 63106, USA
| | - Lynn Evans
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; (A.L.); (Y.-B.S.); (B.B.K.); (L.E.); (P.H.)
| | - Paul Hamilton
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; (A.L.); (Y.-B.S.); (B.B.K.); (L.E.); (P.H.)
| | - Nathan Ravi
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; (A.L.); (Y.-B.S.); (B.B.K.); (L.E.); (P.H.)
- Department of Veterans Affairs, St. Louis Medical Center, St. Louis, MO 63106, USA
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63110, USA
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13
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Preliminary study of the safety and efficacy of medium-chain triglycerides for use as an intraocular tamponading agent in minipigs. Graefes Arch Clin Exp Ophthalmol 2017; 255:1593-1604. [DOI: 10.1007/s00417-017-3695-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 04/24/2017] [Accepted: 05/09/2017] [Indexed: 11/27/2022] Open
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14
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Stryjewski TP, Stefater JA, Eliott D. Emerging Applications for Polymers in Ophthalmology. Clin Ophthalmol 2017; 57:137-149. [DOI: 10.1097/iio.0000000000000196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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15
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Abstract
Hydrogel delivery systems can leverage therapeutically beneficial outcomes of drug delivery and have found clinical use. Hydrogels can provide spatial and temporal control over the release of various therapeutic agents, including small-molecule drugs, macromolecular drugs and cells. Owing to their tunable physical properties, controllable degradability and capability to protect labile drugs from degradation, hydrogels serve as a platform in which various physiochemical interactions with the encapsulated drugs control their release. In this Review, we cover multiscale mechanisms underlying the design of hydrogel drug delivery systems, focusing on physical and chemical properties of the hydrogel network and the hydrogel-drug interactions across the network, mesh, and molecular (or atomistic) scales. We discuss how different mechanisms interact and can be integrated to exert fine control in time and space over the drug presentation. We also collect experimental release data from the literature, review clinical translation to date of these systems, and present quantitative comparisons between different systems to provide guidelines for the rational design of hydrogel delivery systems.
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Affiliation(s)
- Jianyu Li
- John A. Paulson School of Engineering and Applied Sciences, and the Wyss Institute for biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts 02138, USA
| | - David J Mooney
- John A. Paulson School of Engineering and Applied Sciences, and the Wyss Institute for biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts 02138, USA
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16
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Su X, Tan MJ, Li Z, Wong M, Rajamani L, Lingam G, Loh XJ. Recent Progress in Using Biomaterials as Vitreous Substitutes. Biomacromolecules 2015; 16:3093-102. [PMID: 26366887 DOI: 10.1021/acs.biomac.5b01091] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Vitreous substitutes are crucial adjuncts during vitreo-retinal surgery for retinal diseases such as complicated retinal detachment, macular holes, complications of diabetic retinopathy, and ocular trauma involving posterior segment. In retinal detachment surgery, an internal tamponade agent is required to provide internal pressure for reattachment of the detached neurosensory retina. Current available options serve only as a temporary surgical adduct or short-term solution and are associated with inherent problems. Despite many years of intensive research, an ideal vitreous substitute remains elusive. Indeed, the development of an ideal vitreous substitute requires the concerted efforts of synthetic chemists and biomaterial engineers, as well as ophthalmic surgeons. In this review, we propose that polymeric hydrogels present the future of artificial vitreous substitutes due to its high water composition, optical transparency, and rheological properties that closely mimic the natural vitreous. In particular, thermosensitive smart hydrogels, with reversible sol to gel change, have emerged as the material class with the most potential to succeed as ideal vitreous substitutes, facilitating easy implementation during surgery. Importantly, these smart hydrogels also display potential as efficacious drug delivery systems.
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Affiliation(s)
- Xinyi Su
- Department of Ophthalmology, National University Hospital , 1E Kent Ridge Road, NUHS Tower Block, Level 7, Singapore 119228, Singapore.,Singapore Eye Research Institute , 11 Third Hospital Avenue, Singapore 168751, Singapore
| | - Mein Jin Tan
- Institute of Materials Research and Engineering (IMRE), A*STAR , 3 Research Link, Singapore 117602, Singapore
| | - Zibiao Li
- Institute of Materials Research and Engineering (IMRE), A*STAR , 3 Research Link, Singapore 117602, Singapore
| | - Meihua Wong
- Department of Ophthalmology, National University Hospital , 1E Kent Ridge Road, NUHS Tower Block, Level 7, Singapore 119228, Singapore
| | | | - Gopal Lingam
- Department of Ophthalmology, National University Hospital , 1E Kent Ridge Road, NUHS Tower Block, Level 7, Singapore 119228, Singapore
| | - Xian Jun Loh
- Institute of Materials Research and Engineering (IMRE), A*STAR , 3 Research Link, Singapore 117602, Singapore.,Department of Materials Science and Engineering, National University of Singapore , 9 Engineering Drive 1, Singapore 117576, Singapore.,Singapore Eye Research Institute , 11 Third Hospital Avenue, Singapore 168751, Singapore
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17
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Hydrogels in ophthalmic applications. Eur J Pharm Biopharm 2015; 95:227-38. [DOI: 10.1016/j.ejpb.2015.05.016] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 05/05/2015] [Accepted: 05/21/2015] [Indexed: 12/20/2022]
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18
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Donati S, Caprani SM, Airaghi G, Vinciguerra R, Bartalena L, Testa F, Mariotti C, Porta G, Simonelli F, Azzolini C. Vitreous substitutes: the present and the future. BIOMED RESEARCH INTERNATIONAL 2014; 2014:351804. [PMID: 24877085 PMCID: PMC4024399 DOI: 10.1155/2014/351804] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 04/15/2014] [Accepted: 04/16/2014] [Indexed: 02/05/2023]
Abstract
Vitreoretinal surgery has advanced in numerous directions during recent years. The removal of the vitreous body is one of the main characteristics of this surgical procedure. Several molecules have been tested in the past to fill the vitreous cavity and to mimic its functions. We here review the currently available vitreous substitutes, focusing on their molecular properties and functions, together with their adverse effects. Afterwards we describe the characteristics of the ideal vitreous substitute. The challenges facing every ophthalmology researcher are to reach a long-term intraocular permanence of vitreous substitute with total inertness of the molecule injected and the control of inflammatory reactions. We report new polymers with gelification characteristics and smart hydrogels representing the future of vitreoretinal surgery. Finally, we describe the current studies on vitreous regeneration and cell cultures to create new intraocular gels with optimal biocompatibility and rheological properties.
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Affiliation(s)
- Simone Donati
- Department of Surgical and Morphological Sciences, Section of Ophthalmology, School of Medicine, University of Insubria, Via Guicciardini 9, 21100 Varese, Italy
| | - Simona Maria Caprani
- Department of Surgical and Morphological Sciences, Section of Ophthalmology, School of Medicine, University of Insubria, Via Guicciardini 9, 21100 Varese, Italy
| | - Giulia Airaghi
- Department of Surgical and Morphological Sciences, Section of Ophthalmology, School of Medicine, University of Insubria, Via Guicciardini 9, 21100 Varese, Italy
| | - Riccardo Vinciguerra
- Department of Surgical and Morphological Sciences, Section of Ophthalmology, School of Medicine, University of Insubria, Via Guicciardini 9, 21100 Varese, Italy
| | - Luigi Bartalena
- Endocrine Unit, Department of Clinical and Experimental Medicine, School of Medicine, University of Insubria, 21100 Varese, Italy
| | - Francesco Testa
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Second University of Naples, 80121 Naples, Italy
| | - Cesare Mariotti
- Department of Ophthalmology, Polytechnic University of Ancona, 60121 Ancona, Italy
| | - Giovanni Porta
- Genetic Laboratory, Department of Surgical and Morphological Sciences, School of Medicine, University of Insubria, 21100 Varese, Italy
| | - Francesca Simonelli
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Second University of Naples, 80121 Naples, Italy
| | - Claudio Azzolini
- Department of Surgical and Morphological Sciences, Section of Ophthalmology, School of Medicine, University of Insubria, Via Guicciardini 9, 21100 Varese, Italy
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19
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20
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Study in vivo intraocular biocompatibility of in situ gelation hydrogels: poly(2-ethyl oxazoline)-block-poly(ε-caprolactone)-block-poly(2-ethyl oxazoline) copolymer, matrigel and pluronic F127. PLoS One 2013; 8:e67495. [PMID: 23840873 PMCID: PMC3698124 DOI: 10.1371/journal.pone.0067495] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Accepted: 05/20/2013] [Indexed: 11/19/2022] Open
Abstract
The long term in vivo biocompatibility is an essential feature for the design and development of sustained drug release carriers. In the recent intraocular drug delivery studies, hydrogels were suggested as sustained release carriers. The biocompatibility test for these hydrogels, however, was commonly performed only through in vitro cell culture examination, which is insufficient before the clinical applications. We compared three thermosensitive hydrogels that have been suggested as the carriers for drugs by their gel-solution phase-change properties. A new block terpolymer (PEOz-PCL-PEOz, ECE) and two commercial products (Matrigel® and Pluronic F127) were studied. The results demonstrated that the ocular media remained translucent for ECE and Pluronic F127 in the first 2 weeks, but cataract formation for Matrigel occurred in 2 weeks and for Pluronic F127 in 1 month, while turbid media was observed for both Matrigel and Pluronic F127 in 2 months. The electrophysiology examinations showed significant neuroretinal toxicity of Matrigel and Pluronic F127 but good biocompatibility of ECE. The neuroretinal toxicity of Matrigel and Pluronic F127 and superior biocompatibility of ECE hydrogel suggests ECE as more appropriate biomaterial for use in research and potentially in intraocular application.
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21
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The synthesis and characterization of a thermally responsive hyaluronic acid/Pluronic copolymer and an evaluation of its potential as an artificial vitreous substitute. J BIOACT COMPAT POL 2013. [DOI: 10.1177/0883911513491181] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A smart in situ polymerizable artificial vitreous substitute was synthesized via the copolymerization of hyaluronic acid and Pluronic® F-127. This copolymer has a unique sol–gel transition at different temperatures. The liquid was injected into a vitreous cavity at room temperature and forms a hydrogel at physiological temperatures. The chemical, rheological, and optical properties and the biodegradability and biocompatibility were studied to determine the optimum formulation for the hydrogel. The H1F20 hydrogel optical properties were similar to those of the vitreous humor. Biodegradability studies indicate that the H1F20 hydrogel maintains 60% of the mass in 10,000 U mL−1 of lysozyme solution, after 7 days. The H1F20 hydrogel had the highest human retinal pigment epithelial cell (ARPE-19) viability, which was significantly higher than that of the control ( p < 0.01). In summary, H1F20 appears to be a suitable artificial vitreous substitute.
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22
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23
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Affiliation(s)
- Tina Vermonden
- Department of Pharmaceutics, Utrecht University, P.O. Box 80082, 3508 TB Utrecht, The Netherlands.
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24
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A gelatin-g-poly(N-isopropylacrylamide) biodegradable in situ gelling delivery system for the intracameral administration of pilocarpine. Biomaterials 2011; 33:2372-87. [PMID: 22182746 DOI: 10.1016/j.biomaterials.2011.11.085] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Accepted: 11/28/2011] [Indexed: 12/22/2022]
Abstract
In this study, the aminated gelatin was grafted with carboxylic end-capped poly(N-isopropylacrylamide) (PN) via a carbodiimide-mediated coupling reaction to fabricate biodegradable in situ forming delivery systems for intracameral administration of antiglaucoma medications. The chemical structure of the graft copolymers (GN) was confirmed by Fourier transform infrared (FTIR) spectroscopy. When the feed molar ratio of NH(2)/COOH was 0.36, the grafting ratio, efficiency and degree of grafting, and weight ratio of PN to aminated gelatin was 25.6, 18.6%, 52.6%, and 1.9, respectively. As compared to PN, the GN samples possessed better thermal gelation ability and adherence, indicating remarkable phase transition properties. Under gelatinase degradation, the remaining weight of GN was significantly lower than those of PN at each time point from 8 h to 4 weeks. Cytocompatibility studies showed that the culture of anterior segment cells with both in situ forming gels does not affect proliferation and has little effect on inflammation. Higher encapsulation efficiency (~62%) and cumulative release (~95%) were achieved for GN vehicles, which was attributed to initial fast temperature triggered capture of pilocarpine and subsequent progressive degradation of gelatin network. In a rabbit glaucoma model, the performance of delivery carriers was evaluated by biomicroscopy, intraocular pressure (IOP), and pupil size change. Intracameral administration of pilocarpine using GN was found to be more effective than other methods such as instillation of eye drop and injection of free drug or PN containing drug in improving ocular bioavailability and extending the pharmacological responses (i.e., miosis and IOP lowering effect and preservation of corneal endothelial cell density).
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25
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Abashzadeh S, Dinarvand R, Sharifzadeh M, Hassanzadeh G, Amini M, Atyabi F. Formulation and evaluation of an in situ gel forming system for controlled delivery of triptorelin acetate. Eur J Pharm Sci 2011; 44:514-21. [DOI: 10.1016/j.ejps.2011.09.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2011] [Revised: 08/20/2011] [Accepted: 09/12/2011] [Indexed: 11/16/2022]
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26
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Annaka M, Mortensen K, Vigild ME, Matsuura T, Tsuji S, Ueda T, Tsujinaka H. Design of an Injectable in Situ Gelation Biomaterials for Vitreous Substitute. Biomacromolecules 2011; 12:4011-21. [DOI: 10.1021/bm201012f] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Masahiko Annaka
- Department
of Chemistry, Kyushu University, Fukuoka
812-8581, Japan
- International
Research Center
for Molecular Systems, Kyushu University, Fukuoka 819-0395, Japan
| | - Kell Mortensen
- Department of Natural Sciences, University of Copenhagen, Thorvaldsensvej 40, DK1871
Frederiksberg C, Denmark
| | - Martin E. Vigild
- Danish Polymer Center and Department
of Chemical Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Toyoaki Matsuura
- Department of Ophthalmology, Nara Medical University, Kashihara, Nara 634-8522,
Japan
| | - Souichiro Tsuji
- Department
of Chemistry, Kyushu University, Fukuoka
812-8581, Japan
| | - Tetsuo Ueda
- Department of Ophthalmology, Nara Medical University, Kashihara, Nara 634-8522,
Japan
| | - Hiroki Tsujinaka
- Department of Ophthalmology, Nara Medical University, Kashihara, Nara 634-8522,
Japan
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Baino F. Towards an ideal biomaterial for vitreous replacement: Historical overview and future trends. Acta Biomater 2011; 7:921-35. [PMID: 21050899 DOI: 10.1016/j.actbio.2010.10.030] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 10/22/2010] [Accepted: 10/27/2010] [Indexed: 02/03/2023]
Abstract
Removal of the natural vitreous body from the eye and its substitution with a tamponade agent may be necessary in cases of complicated retinal detachment. Many materials have been variously proposed and tested over the years in an attempt to find an ideal vitreous substitute. This review highlights the evolution of research in the field of vitreous replacement and chronicles the main advances that have been made in such a context. The suitability and limitations of vitreous tamponade agents and substitutes in current clinical use are examined, and the future promise of experimentally tested biomaterials are described and discussed. Future trends in research are also considered and, specifically, the great potential of polymeric hydrogels is emphasized, as they seem to be very effective in closely mimicking the features of the natural vitreous and they could successfully act as long-term vitreous substitutes without inducing clinical complications in the patient's eye.
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Affiliation(s)
- Francesco Baino
- Materials Science and Chemical Engineering Department, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy.
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28
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The Use of Polymers in the Treatment of Retinal Detachment: Current Trends and Future Perspectives. Polymers (Basel) 2010. [DOI: 10.3390/polym2030286] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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29
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Safety Assessment of Poloxamers 101, 105, 108, 122, 123, 124, 181, 182, 183, 184, 185, 188, 212, 215, 217, 231, 234, 235, 237, 238, 282, 284, 288, 331, 333, 334, 335, 338, 401, 402, 403, and 407, Poloxamer 105 Benzoate, and Poloxamer 182 Dibenzoate as Used in Cosmetics. Int J Toxicol 2008; 27 Suppl 2:93-128. [DOI: 10.1080/10915810802244595] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Poloxamers are polyoxyethlyene, polyoxypropylene block polymers. The impurities of commercial grade Poloxamer 188, as an example, include low-molecular-weight substances (aldehydes and both formic and acetic acids), as well as 1,4-dioxane and residual ethylene oxide and propylene oxide. Most Poloxamers function in cosmetics as surfactants, emulsifying agents, cleansing agents, and/or solubilizing agents, and are used in 141 cosmetic products at concentrations from 0.005% to 20%. Poloxamers injected intravenously in animals are rapidly excreted in the urine, with some accumulation in lung, liver, brain, and kidney tissue. In humans, the plasma concentration of Poloxamer 188 (given intravenously) reached a maximum at 1 h, then reached a steady state. Poloxamers generally were ineffective in wound healing, but were effective in reducing postsurgical adhesions in several test systems. Poloxamers can cause hypercholesterolemia and hypertriglyceridemia in animals, but overall, they are relatively nontoxic to animals, with LD50 values reported from 5 to 34.6 g/kg. Short-term intravenous doses up to 4 g/kg of Poloxamer 108 produced no change in body weights, but did result in diffuse hepatocellular vacuolization, renal tubular dilation in kidneys, and dose-dependent vacuolization of epithelial cells in the proximal convoluted tubules. A short-term inhalation toxicity study of Poloxamer 101 at 97 mg/m3 identified slight alveolitis after 2 weeks of exposure, which subsided in the 2-week postexposure observation period. A short-term dermal tox-icity study of Poloxamer 184 in rabbits at doses up to 1000 mg/kg produced slight erythema and slight intradermal inflammatory response on histological examination, but no dose-dependent body weight, hematology, blood chemistry, ororgan weight changes. A6-month feeding study in rats and dogs of Poloxamer 188 at exposures up to 5% in the diet produced no adverse effects. Likewise, Poloxamer 331 (tested up to 0.5 g/kg day-1), Poloxamer 235 (tested up to 1.0 g/kg day-1), and Poloxamer 338 (at 0.2 or 1.0 g/kg day-1) produced no adverse effects in dogs. Poloxamer 338 (at 5.0 g/kg day-1) produced slight transient diarrhea in dogs. Poloxamer 188 at levels up to 7.5% in diet given to rats in a 2-year feeding study produced diarrhea at 5% and 7.5% levels, a small decrease in growth at the 7.5% level, but no change in survival. Doses up to 0.5 mg/kg day-1 for 2 years using rats produced yellow discoloration of the serum, high serum alkaline phosphatase activity, and elevated serum glutamicpyruvic transaminase and glutamic-oxalacetic transaminase activities. Poloxamers are minimal ocular irritants, but are not dermal irritants or sensitizers in animals. Data on reproductive and developmental toxicity of Poloxamers were not found. An Ames test did not identify any mutagenic activity of Poloxamer 407, with or without metabolic activation. Several studies have suggested anti-carcinogenic effects of Poloxamers. Poloxamers appear to increase the sensitivity to anticancer drugs of multidrug-resistant cancer cells. In clinical testing, Poloxamer 188 increased the hydration of feces when used in combination with a bulk laxative treatment. Compared to controls, one study of angioplasty patients receiving Poloxamer 188 found a reduced myocardial infarct size and a reduced incidence of reinfarction, with no evidence of toxicity, but two other studies found no effect. Poloxamer 188 given to patients suffering from sickle cell disease had decreased pain and decreased hospitilization, compared to controls. Clinical tests of dermal irritation and sensitization were uniformly negative. The Cosmetic Ingredient Review (CIR) Expert Panel stressed that the cosmetic industry should continue to use the necessary purification procedures to keep the levels below established limits for ethylene oxide, propylene oxide, and 1,4-dioxane. The Panel did note the absence of reproductive and developmental toxicity data, but, based on molecular weight and solubility, there should be little skin penetration and any penetration of the skin should be slow. Also, the available data demonstrate that Poloxamers that are introduced into the body via routes other than dermal exposure have a rapid clearance from the body, suggesting that there would be no risk of reproductive and/or developmental toxicity. Overall, the available data do not suggest any concern about carcinogenesis. Although there are gaps in knowledge about product use, the overall information available on the types of products in which these ingredients are used, and at what concentration, indicates a pattern of use. Based on these safety test data and the information that the manufacturing process can be controlled to limit unwanted impurities, the Panel concluded that these Poloxamers are safe as used.
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Kabanov A, Zhu J, Alakhov V. Pluronic Block Copolymers for Gene Delivery. NON-VIRAL VECTORS FOR GENE THERAPY, SECOND EDITION: PART 1 2005; 53PA:231-261. [PMID: 16243066 DOI: 10.1016/s0065-2660(05)53009-8] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Amphiphilic block copolymers of poly(ethylene oxide) and poly(propylene oxide) called Pluronic or poloxamer are commercially available pharmaceutical excipients. They recently attracted considerable attention in gene delivery applications. First, they were shown to increase the transfection with adenovirus and lentivirus vectors. Second, they were shown to increase expression of genes delivered into cells using non-viral vectors. Third, the conjugates of Pluronic with polycations, were used as DNA-condensing agents to form polyplexes. Finally, it was demonstrated that they can increase regional expression of the naked DNA after its injection in the skeletal and cardiac muscles or tumor. Therefore, there is substantial evidence that Pluronic block copolymers can improve gene expression with different delivery routes and different types of vectors, including naked DNA. These results and possible mechanisms of Pluronic effects are discussed. At least in some cases, Pluronic can act as biological adjuvants by activating selected signaling pathways, such as NF-kappaB, and upregulating the transcription of the genes.
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Affiliation(s)
- Alexander Kabanov
- Department of Pharmaceutical Sciences and Center for Drug Delivery and Nanomedicine, College of Pharmacy, University of Nebraska Medical Center Omaha, Nebraska 68198
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31
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Abstract
Aqueous polymer solutions that are transformed into gels by changes in environmental conditions, such as temperature and pH, thus resulting in in situ hydrogel formation, have recently attracted the attention of many investigators for scientific interest and for practical biomedical or pharmaceutical applications. When the hydrogel is formed under physiological conditions and maintains its integrity for a desired period of time, the process may provide various advantages over conventional hydrogels. Because of the simplicity of pharmaceutical formulation by solution mixing, biocompatibility with biological systems, and convenient administration, the pharmaceutical and biomedical uses of the water-based sol-gel transition include solubilization of low-molecular-weight hydrophobic drugs, controlled release, labile biomacromolecule delivery, such as proteins and genes, cell immobilization, and tissue engineering. When the formed gel is proven to be biocompatible and biodegradable, producing non-toxic degradation products, it will provide further benefits for in vivo applications where degradation is desired. It is timely to summarize the polymeric systems that undergo sol-gel transitions, particularly due to temperature, with emphasis on the underlying transition mechanisms and potential delivery aspects. This review stresses the polymeric systems of natural or modified natural polymers, N-isopropylacrylamide copolymers, poly(ethylene oxide)/poly(propylene oxide) block copolymers, and poly(ethylene glycol)/poly(D,L-lactide-co-glycolide) block copolymers.
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Affiliation(s)
- Byeongmoon Jeong
- Pacific Northwest National Laboratory (PNNL), 902 Battelle Blvd. P.O. Box 999, K2-44, Richland, WA 99352, USA
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