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Cheung LTY, Manthey AL, Lai JSM, Chiu K. Targeted Delivery of Mitochondrial Calcium Channel Regulators: The Future of Glaucoma Treatment? Front Neurosci 2017; 11:648. [PMID: 29213227 PMCID: PMC5702640 DOI: 10.3389/fnins.2017.00648] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/07/2017] [Indexed: 11/18/2022] Open
Affiliation(s)
- Leanne T Y Cheung
- Department of Ophthalmology, University of Hong Kong, Hong Kong, China
| | - Abby L Manthey
- Department of Ophthalmology, University of Hong Kong, Hong Kong, China
| | - Jimmy S M Lai
- Department of Ophthalmology, University of Hong Kong, Hong Kong, China
| | - Kin Chiu
- Department of Ophthalmology, University of Hong Kong, Hong Kong, China
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A novel nanoparticles impregnated ocular insert for enhanced bioavailability to posterior segment of eye: In vitro, in vivo and stability studies. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 71:529-540. [PMID: 27987741 DOI: 10.1016/j.msec.2016.10.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 09/30/2016] [Accepted: 10/13/2016] [Indexed: 12/24/2022]
Abstract
The present investigation was carried out to demonstrate with the help of in vitro and in vivo studies that nanoparticles impregnated ocular inserts effectively delivers significant concentration of drug to the posterior segment of eye after topical administration for treatment of glaucoma. Drug loaded Nanoparticles and their ocular insert have been reported to reduce side effects of orally administered Acetazolamide. Eudragit NPs were prepared by the solvent diffusion nanoprecipitation technique. The prepared NPs were evaluated for various parameters such as particle size, zeta potential, % entrapment efficiency, % drug loading, DSC, FTIR, TEM and stability studies. Ocular inserts of NPs were prepared by solvent casting method. The prepared ocular inserts were evaluated for thickness, content uniformity, folding endurance, disintegration time, morphology and stability study. The NPs and ocular inserts were evaluated for in-vitro drug diffusion study, ex-vivo trans-corneal permeability study, in-vivo ocular tolerability and intra ocular pressure (IOP) reduction study. The optimized batch was stable for a period of 3months in lyophilized form. The optimized formulations had size range of 367nm±8nm, zeta potential around +7mV±1.3mV and 51.61%±3.84% entrapment efficiency with 19%±1.40% drug loading. The ex-vivo trans-corneal study showed higher cumulative corneal permeation, flux across corneal tissue (2.460±0.028μg/ml) and apparent corneal permeability (3.926×10-6cm2/s & 3.863×10-6cm2/s) from drug loaded Eudragit NPs and Ocular inserts as compared to drug solution (0.671±0.020μg/ml & 3.166×10-6cm2/s). In-vivo study showed the Eudragit NPs and ocular insert produced significant (P<0.001) lowering in intra ocular pressure compared with the solution of free drug after 3h of topical ocular administration. Plain Eudragit NPs caused no inflammation and/or discomfort in rabbit eyes and neither affected the intra ocular pressure establishing their safety and non irritancy.
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Abstract
Glaucoma is a progressive optic neuropathy that causes characteristic changes of the optic nerve and visual field in relation to intraocular pressure (IOP). It is now known that glaucoma can occur at statistically normal IOPs and prevalence studies have shown that normal tension glaucoma (NTG) is more common than previously thought. While IOP is believed to be the predominant risk factor in primary open angle glaucoma (POAG), IOP-independent risk factors, such as vascular dysregulation, are believed to play an important part in the pathogenesis of NTG. Though certain distinguishing phenotypic features of NTG have been reported, such as an increased frequency of disc hemorrhages, acquired pits of the optic nerve and characteristic patterns of disc cupping and visual field loss, there is much overlap of the clinical findings in NTG with POAG, suggesting that NTG is likely part of a continuum of open angle glaucomas. However, IOP modification is still the mainstay of treatment in NTG. As in traditional POAG, reduction of IOP can be achieved with the use of medications, laser trabeculoplasty or surgery. Studies now show that the choice of medication may also be important in determining the outcomes of these patients. Though it is likely that future treatment of NTG will involve modification of both IOP and IOP-independent risk factors, current efforts to develop IOP-independent neuroprotective treatments have not yet proven to be effective in humans.
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Affiliation(s)
| | - Joseph Caprioli
- Jules Stein Eye Institute, Department of Ophthalmology, University of California, Los Angeles, USA
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Quill B, Irnaten M, Docherty NG, McElnea EM, Wallace DM, Clark AF, O'Brien CJ. Calcium channel blockade reduces mechanical strain-induced extracellular matrix gene response in lamina cribrosa cells. Br J Ophthalmol 2015; 99:1009-14. [PMID: 25795916 DOI: 10.1136/bjophthalmol-2014-306093] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 02/18/2015] [Indexed: 11/04/2022]
Abstract
PURPOSE This study examines the effect of the L-type calcium channel blocker verapamil on mechanical strain-induced extracellular matrix genes in optic nerve head lamina cribrosa (LC) cells. METHODS Changes in LC cell intracellular calcium [Ca(2+)]i following hypotonic cell membrane stretch were measured with the fluorescent probe fura-2/AM. Fluorescence intensity was measured, after labelling, by calcium (Ca2+) imaging confocal microscopy. Confluent human LC cell cultures were serum starved for 24 h prior to exposure to cyclical mechanical strain (1 Hz, 15%) for 24 h in the presence or absence of verapamil (10 mm). Transforming growth factor-β 1 (TGF-β1), collagen 6A3 (COL6A3) and chondroitin sulfate proteoglycan 2 (CSPG2) mRNA expression levels were assessed by quantitative RT-PCR. RESULTS Hypotonic cell membrane stretch of LC cells from normal donors significantly increased [Ca2+]i (p<0.05). Exposure to cyclical mechanical strain (15% strain) produced a statistically significant increase in the three matrix genes that were examined (TGF-β1, COL6A3 and CSPG2). This response in both cyclical and mechanical stretch was significantly reduced by pretreating LC cells with the L-type calcium channel blocker verapamil (p<0.05). CONCLUSIONS This study provides evidence of a novel mechanotransduction pathway linking mechanical strain, cation channel function and the induction of LC cell matrix gene transcription. This highlights the potential involvement of calcium influx in the activation of matrix remodelling responses in the optic nerve head and supports the rationale that calcium channel blockers may attenuate disease progression in glaucoma.
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Affiliation(s)
- B Quill
- Institute of Ophthalmology, Mater Misericordiae University Hospital, Dublin, Ireland Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland University College Dublin School of Medicine and Health Sciences, University College Dublin, Dublin, Ireland
| | - M Irnaten
- Institute of Ophthalmology, Mater Misericordiae University Hospital, Dublin, Ireland Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - N G Docherty
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland University College Dublin School of Medicine and Health Sciences, University College Dublin, Dublin, Ireland
| | - E M McElnea
- Institute of Ophthalmology, Mater Misericordiae University Hospital, Dublin, Ireland Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland University College Dublin School of Medicine and Health Sciences, University College Dublin, Dublin, Ireland
| | - D M Wallace
- Institute of Ophthalmology, Mater Misericordiae University Hospital, Dublin, Ireland Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland University College Dublin School of Medicine and Health Sciences, University College Dublin, Dublin, Ireland
| | - A F Clark
- University College Dublin School of Medicine and Health Sciences, University College Dublin, Dublin, Ireland
| | - C J O'Brien
- Institute of Ophthalmology, Mater Misericordiae University Hospital, Dublin, Ireland Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland University College Dublin School of Medicine and Health Sciences, University College Dublin, Dublin, Ireland
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Yu S, Wang QM, Wang X, Liu D, Zhang W, Ye T, Yang X, Pan W. Liposome incorporated ion sensitive in situ gels for opthalmic delivery of timolol maleate. Int J Pharm 2015; 480:128-36. [PMID: 25615987 DOI: 10.1016/j.ijpharm.2015.01.032] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 12/31/2014] [Accepted: 01/18/2015] [Indexed: 12/30/2022]
Abstract
This study was aimed to design a liposomal based ion-sensitive in situ ophthalmic delivery system of timolol maleate (TM). The TM liposome was produced by the reverse evaporation technique coupled with pH-gradients method (REVPR), and then was incorporated into deacetylated gellan gum gels. The TM liposome was demonstrated to be a round and uniform shape in TEM pictures. Compared with the TM eye drops, the TM liposome produced a 1.93 folds increase in apparent permeability coefficients (Papp), resulting in a significant increase of the corneal penetration. The TM-loaded liposome incorporated ion sensitive in situ gels (TM L-ISG) showed longer retention time on corneal surface compared with the eye drops using gamma scintigraphy technology. Draize testing showed that TM L-ISG was non-irritant for ocular tissues. The biggest efficacy of TM L-ISG occurred 30 min after eye drops administration, and efficacy disappeared after 240min. Then, compared with the eye drops, the optimal TM L-ISG could quickly reduce the intraocular pressure and the effective time was significantly longer (P≤0.05). These results indicate that liposome incorporated ion sensitive in situ gels have a potential ability for the opthalmic delivery.
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Affiliation(s)
- Shihui Yu
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang 110016, China
| | - Qi-Ming Wang
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, PR China; Department of Pharmaceutics, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, PR China
| | - Xin Wang
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang 110016, China
| | - Dandan Liu
- School of Biomedical & Chemical Engineering, Liaoning Institute of Science and Technology, Benxi 117004, PR China
| | - Wenji Zhang
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang 110016, China
| | - Tiantian Ye
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang 110016, China
| | - Xinggang Yang
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang 110016, China.
| | - Weisan Pan
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang 110016, China.
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Mayama C. Calcium channels and their blockers in intraocular pressure and glaucoma. Eur J Pharmacol 2013; 739:96-105. [PMID: 24291107 DOI: 10.1016/j.ejphar.2013.10.073] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 10/17/2013] [Accepted: 10/17/2013] [Indexed: 10/25/2022]
Abstract
Several factors besides high intraocular pressure assumed to be associated with the development and progression of glaucoma, and calcium channel blockers (CCBs) have been an anticipated option for glaucoma treatment by improving ocular perfusion and/or exerting neuroprotective effects on retinal ganglion cells with safety established in wide and long-term usage. Decrease in IOP has been reported after topical application of CCBs, however, the effect is much smaller and almost negligible after systemic application. Various CCBs have been reported to increase posterior ocular blood flow in vivo and to exert direct neuroprotection in neurons in vitro. Distribution of the drug at a pharmacologically active concentration in the posterior ocular tissues across the blood-brain barrier or blood-retina barrier, especially in the optic nerve head and retina where the ganglion cells mainly suffer from glaucomatous damage, is essential for clinical treatment of glaucoma. Improved visual functions such as sensitivity in the visual field test have been reported after administration of CCBs, but evidences from the randomized studies have been limited and effects of CCBs on blood flow and direct neuroprotection are hardly distinguished from each other.
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Affiliation(s)
- Chihiro Mayama
- Department of Ophthalmology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan.
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In vitro and in vivo efficacy of SYL040012, a novel siRNA compound for treatment of glaucoma. Mol Ther 2013; 22:81-91. [PMID: 24025749 DOI: 10.1038/mt.2013.216] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 09/03/2013] [Indexed: 12/30/2022] Open
Abstract
Glaucoma is a progressive ocular syndrome characterized by degeneration of the optic nerve and irreversible visual field loss. Elevated intraocular pressure (IOP) is the main risk factor for glaucoma. Increased IOP is the result of an imbalance between synthesis and outflow of aqueous humor (AH). Blocking β2 adrenergic receptor (ADRB2) has shown to reduce IOP by decreasing production of AH at the ciliary body (CB). SYL040012 is a siRNA designed to specifically silence ADRB2 currently under development for glaucoma treatment. Here, we show that SYL040012 specifically reduces ADRB2 expression in cell cultures and eye tissues. The compound enters the eye shortly after administration in eye drops and is rapidly distributed among structures of the anterior segment of the eye. In addition, SYL040012 is actively taken up by cells of the CB but not by cells of systemic organs such as the lungs, where inhibition of ADRB2 could cause undesirable side effects. Moreover, SYL040012 reduces IOP in normotensive and hypertensive animal models and the effect appears to be long lasting and extremely well tolerated both locally and systemically.
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Fukunaga T, Ikesugi K, Nishio M, Sugimoto M, Sasoh M, Hidaka H, Uji Y. The effect of the Rho-associated protein kinase inhibitor, HA-1077, in the rabbit ocular hypertension model induced by water loading. Curr Eye Res 2009; 34:42-7. [PMID: 19172469 DOI: 10.1080/02713680802531353] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
PURPOSE The aim of this study was to investigate the intraocular pressure (IOP)-lowering effect of a new anti-glaucoma drug, the Rho-associated protein kinase (ROCK) inhibitor, HA-1077, in a rabbit ocular hypertension model. METHODS Experiments were carried out in 18 male New Zealand white rabbits, with ocular hypertension induced by water loading. Animals were divided into three groups followed by topical administration of 1 mM, 2 mM, and 3 mM HA-1077 in the left eye. As a control, phosphate buffered saline was administered in the opposite eye. RESULTS After administration of HA-1077 eye drops, there was a significant time- and dose-dependent decrease of the IOP. While minor conjunctival injection was seen in a few cases, no abnormalities of the anterior chamber or fundus were observed. CONCLUSIONS This is the first report of the effect of the ROCK inhibitor, HA-1077, on the IOP in an ocular hypertension model. Study results indicated that HA-1077 has a strong IOP-lowering effect.
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Affiliation(s)
- Takaki Fukunaga
- Department of Ophthalmology, Graduate School of Medicine, Mie University, Tsu, Mie, Japan
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