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Sheets KG, Jun B, Zhou Y, Zhu M, Petasis NA, Gordon WC, Bazan NG. Microglial ramification and redistribution concomitant with the attenuation of choroidal neovascularization by neuroprotectin D1. Mol Vis 2013; 19:1747-59. [PMID: 23922492 PMCID: PMC3733904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 07/31/2013] [Indexed: 11/26/2022] Open
Abstract
PURPOSE Neuroprotectin D1 (NPD1) attenuates laser-induced choroidal neovascularization (CNV) when administered intraperitoneally. Due to its lipophilicity and low molecular weight, NPD1 is well suited for topical delivery; thus, we investigated the efficacy of topically applied NPD1 in attenuating CNV. We also examined the effect of NPD1 on the recruitment and activation of microglia surrounding CNV lesions. METHODS Mice were given laser-induced CNV and treated with NPD1 eye drops. CNV was evaluated by fluorescein leakage using a novel image analysis method and by isolectin B4 immunofluorescence of neovasculature. Microglia; recruitment was assessed by quantification. Using form factor, solidity, convexity, and fractal dimension, microglial activation was quantitatively assessed by two-dimensional, and for the first time, three-dimensional morphology. An ImageJ plugin, 3D Shape, was developed to enable this analysis. RESULTS NPD1 attenuated leakage and neovascularization. The proximity of microglia to CNV lesions was significantly closer with NPD1. Consistent with the cellular ramification, microglia in NPD1-treated eyes were larger and exhibited a lower form factor and higher fractal dimension. CONCLUSIONS Our data show that NPD1 signaling induces a ramified, non-injury-inducing microglial phenotype coincident with attenuation of CNV. Since microglia are crucial participants in neurodegenerative diseases, the discovery that microglia are potential targets of NPD1 signaling warrants further investigation.
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Affiliation(s)
- Kristopher G. Sheets
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, School of Medicine, New Orleans, LA
| | - Bokkyoo Jun
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, School of Medicine, New Orleans, LA
| | - Yongdong Zhou
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, School of Medicine, New Orleans, LA
| | - Min Zhu
- Department of Chemistry and Loker Hydrocarbon Research Institute, University of Southern California, Los Angeles, CA
| | - Nicos A. Petasis
- Department of Chemistry and Loker Hydrocarbon Research Institute, University of Southern California, Los Angeles, CA
| | - William C. Gordon
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, School of Medicine, New Orleans, LA
| | - Nicolas G. Bazan
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, School of Medicine, New Orleans, LA
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152
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Chaplot SP, Rupenthal ID. Dendrimers for gene delivery – a potential approach for ocular therapy? J Pharm Pharmacol 2013; 66:542-56. [DOI: 10.1111/jphp.12104] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Accepted: 06/15/2013] [Indexed: 12/12/2022]
Abstract
Abstract
Objectives
A vast number of blinding diseases have genetic aetiologies and may be treated by molecular based therapies such as antisense oligonucleotides or short interfering RNA. However, treatment success of ocular gene therapy is highly dependent on efficient delivery of such molecules.
Key findings
The majority of clinical studies for ocular gene therapy utilize viral vectors. While these have proven highly efficient, they show limited loading capacity and pose significant safety risks owing to their oncogenic and immunogenic effects. Non-viral gene carriers have emerged as a promising alternative with dendrimers providing great potential for gene therapy because of their size, shape and high density of modifiable surface groups. However, while dendrimers have been used extensively for drug and gene delivery to other organs, only a few studies have been reported on the eye.
Summary
This review focuses on the development of dendrimers for gene delivery with special emphasis on ocular gene therapy. Different synthesis approaches and types of dendrimers are discussed. Ocular gene therapy targets are highlighted with an overview of current clinical studies. The use of dendrimers in ocular gene delivery in comparison to liposomes and nanoparticles is also discussed. Finally, future prospects of tailored multifunctional dendrimers for ocular gene therapy are highlighted.
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Affiliation(s)
- Sahil P Chaplot
- Drug Delivery Research Unit, School of Pharmacy, The University of Auckland, Auckland, New Zealand
| | - Ilva D Rupenthal
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
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153
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Abarca EM, Salmon JH, Gilger BC. Effect of choroidal perfusion on ocular tissue distribution after intravitreal or suprachoroidal injection in an arterially perfused ex vivo pig eye model. J Ocul Pharmacol Ther 2013; 29:715-22. [PMID: 23822159 DOI: 10.1089/jop.2013.0063] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To compare tissue distribution of dye-drug surrogates after intravitreal (IVT) and suprachoroidal (SCS) delivery to determine the influence of drug lipophilicity and choroidal circulation. METHODS Thirty-two pig eyes were collected immediately after euthanasia. Sixteen eyes were perfused for 30 min through one long posterior ciliary artery with nondye containing nutrient media. An IVT or SCS injection was performed with either a 100 μL balanced salt solution (BSS, n=8), 1% sodium fluorescein (NaF, n=12) or 0.12% lipophilic carbocyanine dye (DiI, n=12). Globes were maintained at 37°C for 15 min, and then snap-frozen and dissected. Aqueous extraction and measurement of NaF or DiI concentration was performed using spectrophotometry and spectrofluorometry, respectively. RESULTS After SCS delivery of NaF scleral, iris-ciliary body, choroidal and vitreous dye levels were higher in nonperfused eyes compared to perfused eyes. After DiI SCS or IVT delivery, no significant differences were found in dye tissue concentrations in perfused eyes compared to nonperfused eyes. Following perfusion, a better and even drug distribution was found in the retinal pigmented epithelium (RPE)-choroid following IVT and SCS delivery of the hydrophilic drug and after IVT injection of the lipophilic drug compared to nonperfused eyes. CONCLUSIONS Choroidal circulation reduces the tissue drug concentration of the hydrophilic drug suggesting an early clearance mechanism after SCS delivery. SCS injections of lipid and hydrophilic drugs allowed direct drug delivery to the retina and RPE-choroid with limited exposition to the anterior segment.
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Affiliation(s)
- Eva M Abarca
- Department of Clinical Sciences, North Carolina State University , Raleigh, North Carolina
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154
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Intraocular Pressure Monitoring Post Intravitreal Steroids: A Systematic Review. Surv Ophthalmol 2013; 58:291-310. [DOI: 10.1016/j.survophthal.2012.08.003] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 08/04/2012] [Accepted: 08/07/2012] [Indexed: 12/29/2022]
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155
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Abstract
The eye is a highly protected organ, and designing an effective therapy is often considered a challenging task. The anatomical and physiological barriers result in low ocular bioavailability of drugs. Due to these constraints, less than 5% of the administered dose is absorbed from the conventional ophthalmic dosage forms. Further, physicochemical properties such as lipophilicity, molecular weight and charge modulate the permeability of drug molecules. Vision-threatening diseases such as glaucoma, diabetic macular edema, cataract, wet and dry age-related macular degeneration, proliferative vitreoretinopathy, uveitis, and cytomegalovirus retinitis alter the pathophysiological and molecular mechanisms. Understanding these mechanisms may result in the development of novel treatment modalities. Recently, transporter/receptor targeted prodrug approach has generated significant interest in ocular drug delivery. These transporters and receptors are involved in the transport of essential nutrients, vitamins, and xenobiotics across biological membranes. Several influx transporters (peptides, amino acids, glucose, lactate and nucleosides/nucleobases) and receptors (folate and biotin) have been identified on conjunctiva, cornea, and retina. Structural and functional delineation of these transporters will enable more drugs targeting the posterior segment to be successfully delivered topically. Prodrug derivatization targeting transporters and receptors expressed on ocular tissues has been the subject of intense research. Several prodrugs have been designed to target these transporters and enhance the absorption of poorly permeating parent drug. Moreover, this approach might be used in gene delivery to modify cellular function and membrane receptors. This review provides comprehensive information on ocular drug delivery, with special emphasis on the use of transporters and receptors to improve drug bioavailability.
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156
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Kambhampati SP, Kannan RM. Dendrimer nanoparticles for ocular drug delivery. J Ocul Pharmacol Ther 2013; 29:151-65. [PMID: 23410062 DOI: 10.1089/jop.2012.0232] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Eye is a unique organ of perfection and complexity, and is a microcosm of the body in many ways. It represents a great opportunity for nanomedicine, since it is readily accessible-allowing for direct drug/gene delivery to maximize the therapeutic effect and minimize side effects. The development of appropriate delivery systems that can sustain and deliver therapeutics to the target tissues is a key challenge that can be addressed by nanotechnology. Dendrimers are tree-like, nanostructured polymers that have received significant attention as ocular drug delivery systems, due to their well-defined size, tailorable structure, and potentially favorable ocular biodistribution. In this review, we highlight recent developments in dendrimer-based ocular therapies for both anterior and posterior segment diseases.
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Affiliation(s)
- Siva P Kambhampati
- Department of Ophthalmology, Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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157
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Bernards DA, Bhisitkul RB, Wynn P, Steedman MR, Lee OT, Wong F, Thoongsuwan S, Desai TA. Ocular biocompatibility and structural integrity of micro- and nanostructured poly(caprolactone) films. J Ocul Pharmacol Ther 2013; 29:249-57. [PMID: 23391326 DOI: 10.1089/jop.2012.0152] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The identification of biomaterials that are well tolerated in the eye is important for the development of new ocular drug delivery devices and implants, and the application of micro- and nanoengineered devices to biomedical treatments is predicated on the long-term preservation within the target organ or tissue of the very small functional design elements. This study assesses the ocular tolerance and durability of micro- and nanostructured biopolymer thin films injected or implanted into the rabbit eye. Structured poly(caprolactone) (PCL) thin films were placed in adult rabbit eyes for survival studies, with serial ophthalmic examinations over 6 months. Morphologic abnormalities and device/tissue reactions were evaluated by histologic studies, and scanning electron microscopy (SEM) of films was used to determine the structural integrity. Structured PCL thin films (20- to 40-μm thick) were constructed to design specifications with 50-μm linear microgrooves or arrays of nanopores with ~30-nm diameters. After up to 9 months of ocular residency, SEM on devices retrieved from the eye showed preservation of micro- and nanostructural features. In ocular safety evaluations carried out over 6 months, serial examinations in 18 implanted eyes showed no evidence of chronic inflammation, cataractogenesis, or retinal toxicity. Postoperative ocular inflammation was seen in 67% of eyes for 1 week, and persistent corneal edema occurred in 1 eye. Histology revealed no ocular inflammation or morphologic abnormalities of ocular tissues. Thin-film/tissue responses such as cellular reaction, fibrosis, or surface biodeposits were not seen. Micro- and nanostructured PCL thin films exhibited acceptable ocular tolerance and maintained the structural integrity of design features while residing in the eye. Thin-film micro- and nanostructured PCL appears to be a feasible biomaterial for intraocular therapeutic applications.
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Affiliation(s)
- Daniel A Bernards
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA 94158, USA
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158
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Eperon S, Balaskas K, Vaudaux J, Guex-Crosier Y. Experimental uveitis can be maintained in rabbits for a period of six weeks after a safe sensitization method. Curr Eye Res 2013; 38:405-12. [PMID: 23294112 DOI: 10.3109/02713683.2012.747616] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE New treatments against long-lasting uveitis need to be tested. Our aim was to develop a six-week model of uveitis in rabbits. METHODS Rabbits were presensitized with an s.c. injection of Mycobacterium tuberculosis H37RA emulsified with TiterMax Gold adjuvant. Uveitis was induced at day 28 and 50, by intravitreal challenges of antigen suspension. Ocular inflammation was assessed till euthanasia at day 71 after s.c. injection of M. tuberculosis H37RA by: (a) the number of inflammatory cells in aqueous humor (AH); (b) the protein concentration in AH; (c) the clinical score (mean of conjunctival hyperaemia, conjunctival chemosis, oedema and secretion); (d) the microscopical score (mean presence of fibrin and synechiae, aqueous cell density and aqueous flare grade, as scored by slit lamp). RESULTS At the sites of presensitization injection, rabbits presented flat nodules which progressively vanished. The first challenge induced a significant increase in the four parameters (p < 0.05 the Wilcoxon/Kruskal-Wallis test). The AH contained 764 ± 82 cells/µl and 32 ± 0.77 mg protein/ml. During the following days, inflammatory parameters decreased slightly. The second intravitreal challenge increased inflammation (3564 ± 228 cells/µl AH and 31 ± 1 mg protein/ml), which remained at a high level for a longer period of time. CONCLUSION We developed a model of long-term uveitis, which could be maintained in rabbits for at least six weeks. Such a model could be used to test the efficacy of either new drugs or various drug delivery systems intended to deliver active agents during a few months.
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Affiliation(s)
- S Eperon
- Jules Gonin Eye Hospital, Lausanne University, Lausanne, Switzerland.
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159
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Sustained protection against photoreceptor degeneration in tubby mice by intravitreal injection of nanoceria. Biomaterials 2012; 33:8771-81. [PMID: 22959465 DOI: 10.1016/j.biomaterials.2012.08.030] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 08/13/2012] [Indexed: 02/05/2023]
Abstract
We previously reported that nanoceria can slow retinal degeneration in the tubby mouse for two weeks by multiple systemic injections. However, the long-term protection of retinal structure and function by directly deliver of nanoceria to the eye had not been explored. In this study, 172 ng of nanoceria in 1 μl saline (1 mm) were intravitreally injected into tubby P7 pups and assays were performed at P28, P49, P80 and P120. The expression of antioxidant associated genes and photoreceptor-specific genes was significantly up regulated, the mislocalization of rod and cone opsins was decreased, and retinal structure and function were protected. These findings demonstrate that nanoceria can function as catalytic antioxidants in vivo and may be broad spectrum therapeutic agents for multiple types of ocular diseases.
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160
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Cai X, Sezate SA, Seal S, McGinnis JF. WITHDRAWN: Sustained protection against photoreceptor degeneration in tubby mice by intravitreal injection of nanoceria. Biomaterials 2012:S0142-9612(12)00767-3. [PMID: 22871422 DOI: 10.1016/j.biomaterials.2012.06.102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 06/30/2012] [Indexed: 11/21/2022]
Abstract
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Xue Cai
- Department of Ophthalmology, Dean A. McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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161
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Thakur A, Fitzpatrick S, Zaman A, Kugathasan K, Muirhead B, Hortelano G, Sheardown H. Strategies for ocular siRNA delivery: Potential and limitations of non-viral nanocarriers. J Biol Eng 2012; 6:7. [PMID: 22686441 PMCID: PMC3533807 DOI: 10.1186/1754-1611-6-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Accepted: 04/26/2012] [Indexed: 02/07/2023] Open
Abstract
Controlling gene expression via small interfering RNA (siRNA) has opened the doors to a plethora of therapeutic possibilities, with many currently in the pipelines of drug development for various ocular diseases. Despite the potential of siRNA technologies, barriers to intracellular delivery significantly limit their clinical efficacy. However, recent progress in the field of drug delivery strongly suggests that targeted manipulation of gene expression via siRNA delivered through nanocarriers can have an enormous impact on improving therapeutic outcomes for ophthalmic applications. Particularly, synthetic nanocarriers have demonstrated their suitability as a customizable multifunctional platform for the targeted intracellular delivery of siRNA and other hydrophilic and hydrophobic drugs in ocular applications. We predict that synthetic nanocarriers will simultaneously increase drug bioavailability, while reducing side effects and the need for repeated intraocular injections. This review will discuss the recent advances in ocular siRNA delivery via non-viral nanocarriers and the potential and limitations of various strategies for the development of a ‘universal’ siRNA delivery system for clinical applications.
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Affiliation(s)
- Ajit Thakur
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada.
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162
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Berezovsky DE, Patel SR, McCarey BE, Edelhauser HF. In vivo ocular fluorophotometry: delivery of fluoresceinated dextrans via transscleral diffusion in rabbits. Invest Ophthalmol Vis Sci 2011; 52:7038-45. [PMID: 21791594 DOI: 10.1167/iovs.11-7207] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To evaluate the transscleral delivery of fluoresceinated dextrans (FITC-D) with molecular mass up to 70 kDa to the rabbit posterior segment using sub-Tenon injections. METHODS Eighteen NZW rabbits received a unilateral 200-μL injection of 2 mg/mL sodium fluorescein (NaF), 25 mg/mL 40-kDa FITC-D, or 25 mg/mL 70-kDa FITC-D, with (n = 9) or without (n = 9) immediate euthanatization. In live animals, fluorescence was measured in the retina/choroid and mid-vitreous by fluorophotometry, immediately after injection and after 4, 24, 48, and 72 hours. Euthanatized animals were examined hourly through 5 or 6 hours. RESULTS In live animals, the average peak NaF concentration in the retina/choroid was 310.2 ng/mL, measured 3 hours after injection. Average 40- and 70-kDa FITC-D concentrations in the retina/choroid peaked at 5409.6 and 2375.6 ng/mL, respectively, 24 hours after injection. Fluorescence returned to baseline levels 6 hours after NaF injection, and 48 and 72 hours after 40- and 70-kDa FITC-D injections, respectively. Rabbits that received NaF followed by euthanatization exhibited a continuous increase in retina/choroid and mid-vitreous fluorescence, beginning 1 hour after injection, whereas FITC-D-injected eyes did not show elevated retina/choroid or mid-vitreous fluorescence through 6 hours. CONCLUSIONS FITC-D weighing up to 70-kDa, as well as NaF, reached the posterior retina/choroid after sub-Tenon injections in live rabbits. NaF and 40-kDa FITC-D reached higher peak concentrations and were cleared from the eye more rapidly than was 70-kDa FITC-D. There was minimal penetration of NaF and FITC-D into the mid-vitreous in the in vivo experiments.
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163
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Pirmoradi FN, Jackson JK, Burt HM, Chiao M. On-demand controlled release of docetaxel from a battery-less MEMS drug delivery device. LAB ON A CHIP 2011; 11:2744-52. [PMID: 21698338 DOI: 10.1039/c1lc20134d] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We report the development of a magnetically controlled MEMS device capable of on-demand release of defined quantities of an antiproliferative drug, docetaxel (DTX). Controlled release of DTX with a dosage suitable for the treatment of diabetic retinopathy has been achieved for 35 days. The device consists of a drug-loaded microreservoir (Ø6 mm ×∼550 μm), sealed by an elastic magnetic PDMS (polydimethylsiloxane) membrane (Ø6 mm × 40 μm) with a laser-drilled aperture (∼100 × 100 μm(2)). By applying a magnetic field, the magnetic PDMS membrane deforms, causing the discharge of the drug solution from the device. Controlled DTX release at a rate of 171 ± 16.7 ng per actuation interval has been achieved for 35 days using a 255 mT magnetic field. The background leakage of drug solution through the aperture was negligible at 0.053 ± 0.014 ng min(-1). The biological activity of the released drug was investigated using a cytotoxicity assay (cell apoptosis) for two cell lines, HUVEC (human umbilical vein endothelial cells) and PC3 (prostate cancer) cells. Reproducible release rates have been achieved and DTX within the PDMS MEMS reservoir maintains full pharmacological efficacy for more than two months. This device is a proof-of-concept development for targeted delivery of hydrophobic drugs such as DTX and other taxane-based agents that require accurate delivery in nanomolar concentrations.
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164
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Thakur A, Kadam RS, Kompella UB. Influence of drug solubility and lipophilicity on transscleral retinal delivery of six corticosteroids. Drug Metab Dispos 2011; 39:771-81. [PMID: 21346004 PMCID: PMC3082374 DOI: 10.1124/dmd.110.037408] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 02/23/2011] [Indexed: 11/22/2022] Open
Abstract
The influence of drug properties including solubility, lipophilicity, tissue partition coefficients, and in vitro transscleral permeability on ex vivo and in vivo transscleral delivery from corticosteroid suspensions was determined. Solubility, tissue/buffer partition coefficients for bovine sclera and choroid-retinal pigment epithelium (CRPE), and in vitro bovine sclera and sclera-choroid-retinal pigment epithelium (SCRPE) transscleral transport were determined at pH 7.4 for triamcinolone, prednisolone, dexamethasone, fluocinolone acetonide, triamcinolone acetonide, and budesonide in solution. Ex vivo and in vivo transscleral delivery was assessed in Brown Norway rats after posterior subconjunctival injection of a 1 mg/ml suspension of each corticosteroid. Corticosteroid solubility and partition coefficients ranged from ∼ 17 to 300 μg/ml and 3.0 to 11.4 for sclera and from 7.1 to 35.8 for CRPE, respectively, with the more lipophilic molecules partitioning more into both tissues. Transport across sclera and SCRPE was in the range of 3.9 to 10.7% and 0.3 to 1.8%, respectively, with the transport declining with an increase in lipophilicity. Ex vivo and in vivo transscleral delivery indicated tissue distribution in the order CRPE ≥ sclera > retina > vitreous. Tissue partitioning showed a positive correlation with drug lipophilicity (R(2) = 0.66-0.96). Ex vivo and in vivo sclera, CRPE, retina, and vitreous tissue levels of all corticosteroids showed strong positive correlation with drug solubility (R(2) = 0.91-1.0) but not lipophilicity (R(2) = 0.24-0.41) or tissue partitioning (R(2) = 0.24-0.46) when delivered as suspensions. In vivo delivery was lower in all eye tissues assessed than ex vivo delivery, with the in vivo/ex vivo ratios being the lowest in the vitreous (0.085-0.212). Upon exposure to corticosteroid suspensions ex vivo or in vivo, transscleral intraocular tissue distribution was primarily driven by the drug solubility.
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Affiliation(s)
- Ashish Thakur
- Nanomedicine and Drug Delivery Laboratory, Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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165
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Shikamura Y, Ohtori A, Tojo K. Drug Penetration of the Posterior Eye Tissues after Topical Instillation: In Vivo and in Silico Simulation. Chem Pharm Bull (Tokyo) 2011; 59:1263-7. [DOI: 10.1248/cpb.59.1263] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Yuko Shikamura
- Research Laboratories, Senju Pharmaceutical Co., Ltd
- Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology
| | - Akira Ohtori
- Research Laboratories, Senju Pharmaceutical Co., Ltd
- Laboratory of Ocular Drug Delivery System, Kyushu Institute of Technology
| | - Kakuji Tojo
- Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology
- Laboratory of Ocular Drug Delivery System, Kyushu Institute of Technology
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