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Shah S, Patel V. Targeting posterior eye infections with colloidal carriers: The case of Ganciclovir. Int J Pharm 2023; 645:123427. [PMID: 37729977 DOI: 10.1016/j.ijpharm.2023.123427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 09/09/2023] [Accepted: 09/17/2023] [Indexed: 09/22/2023]
Abstract
The ocular system, unlike any other human body organ, is a system in which foreign bodies appear quite defenceless in front of the eye. Several infections of the ocular system occur due to various opportunistic conditions. Cytomegalovirus (CMV) is one of the opportunivores that causes several posterior eye infections. Ganciclovir (GCV),9-(2-hydroxy-1-(hydroxymethyl) ethoxymethyl), is aguanine-antiviral agent primarily used to treat CMV diseases. However, the major challenge is of lower bioavailability. Hence, GCV must be dosed repeatedly to enhance drug absorption. but this causes side effects like neutropenia and bone marrow suppression. So, formulators have used alternative formulation strategies such as prodrug formulation and colloidal drug delivery systems. In the prodrug strategy, they attempted to bind various compounds into the parent drug to increase the permeability and bioavailability of GCV. In colloidal drug delivery systems, mucoadhesive microspheres, nanoparticles, Niosome and liposome were employed to extend the drug residence time at the application site. This paper discusses several colloidal carriers combined with GCV to treat opportunistic CMV infection in the posterior ocular system. It reviews the limitations of conventional ocular therapy and explores various novel formulation approaches to improve the ocular bioavailability of GCV in the posterior chamber of the eye.
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Affiliation(s)
- Srushti Shah
- Parul Institute of Pharmacy, ParulUniversity, Gujarat 391760, India.
| | - Vandana Patel
- Krishna School of Pharmacy and Research, KPGU, Gujarat 391240, India
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2
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Promising Role of Silk-Based Biomaterials for Ocular-Based Drug Delivery and Tissue Engineering. Polymers (Basel) 2022; 14:polym14245475. [PMID: 36559842 PMCID: PMC9788421 DOI: 10.3390/polym14245475] [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: 03/09/2022] [Revised: 11/14/2022] [Accepted: 12/08/2022] [Indexed: 12/16/2022] Open
Abstract
Silk is a wonderful biopolymer that has a long history of medical applications. Surgical cords and medically authorised human analogues made of silk have a long history of use in management. We describe the use of silk in the treatment of eye diseases in this review by looking at the usage of silk fibroin for eye-related drug delivery applications and medication transfer to the eyes. During this ancient art endeavour, a reduced engineering project that employed silk as a platform for medicine delivery or a cell-filled matrix helped reignite interest. With considerable attention, this study explores the present usage of silk in ocular-based drug delivery. This paper also examines emerging developments with the use of silk as a biopolymer for the treatment of eye ailments. As treatment options for glaucoma, diabetic retinopathy, retinitis pigmentosa, and other retinal diseases and degenerations are developed, the trans-scleral route of drug delivery holds great promise for the selective, sustained-release delivery of these novel therapeutic compounds. We should expect a swarm of silk-inspired materials to enter clinical testing and use on the surface as the secrets of silk are unveiled. This article finishes with a discussion on potential silk power, which adds to better ideas and enhanced ocular medicine delivery.
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Varela-Fernández R, Lema-Gesto MI, González-Barcia M, Otero-Espinar FJ. Design, development, and characterization of an idebenone-loaded poly-ε-caprolactone intravitreal implant as a new therapeutic approach for LHON treatment. Eur J Pharm Biopharm 2021; 168:195-207. [PMID: 34500025 DOI: 10.1016/j.ejpb.2021.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 08/26/2021] [Accepted: 09/01/2021] [Indexed: 11/27/2022]
Abstract
Leber's Hereditary Optic Neuropathy (LHON) is a hereditary mitochondrial neurodegenerative disease of unclear etiology and lack of available therapeutic alternatives. The main goal of the current pilot study was based on the evaluation of the feasibility and characteristics of prolonged and controlled idebenone release from a PCL intravitreal implant. The design, development, and characterization of idebenone-loaded PCL implants prepared by an homogenization/extrusion/solvent evaporation method allowed the obtention of high PY, EE and LC values. In vitro characterization was completed by the assessment of mechanical and instrumental properties. The in vitro release of idebenone from the PCL implants was assessed and the implant erosion was monitored by the mass loss and surface morphology changes. DSC was used to estimate stability and interaction among implant's components. The present work demonstrated the controlled and prolonged idebenone delivery from the PCL implants in an in vitro model. A consistent preclinical base was established, supporting the idea of idebenone-loaded PCL implants as a new strategy of long-term sustained intraocular delivery for the LHON treatment.
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Affiliation(s)
- Rubén Varela-Fernández
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology, University of Santiago de Compostela (USC), Campus vida, Santiago de Compostela 15782, Spain; Clinical Neurosciences Group, University Clinical Hospital, Health Research Institute of Santiago de Compostela (IDIS), Travesía da Choupana s/n, Santiago de Compostela 15706, Spain
| | - María Isabel Lema-Gesto
- Clinical Neurosciences Group, University Clinical Hospital, Health Research Institute of Santiago de Compostela (IDIS), Travesía da Choupana s/n, Santiago de Compostela 15706, Spain.
| | - Miguel González-Barcia
- Clinical Pharmacology Group, University Clinical Hospital, Health Research Institute of Santiago de Compostela (IDIS), Travesía da Choupana s/n, Santiago de Compostela 15706, Spain.
| | - Francisco Javier Otero-Espinar
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology, University of Santiago de Compostela (USC), Campus vida, Santiago de Compostela 15782, Spain.
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Manna S, Donnell AM, Faraj RQC, Riemann BI, Riemann CD, Augsburger JJ, Correa ZM, Banerjee RK. Pharmacokinetics and Toxicity Evaluation of a PLGA and Chitosan-Based Micro-Implant for Sustained Release of Methotrexate in Rabbit Vitreous. Pharmaceutics 2021; 13:pharmaceutics13081227. [PMID: 34452188 PMCID: PMC8398642 DOI: 10.3390/pharmaceutics13081227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/30/2021] [Accepted: 08/05/2021] [Indexed: 12/19/2022] Open
Abstract
The present research investigates the pharmacokinetics and toxicity of a chitosan (CS) and poly(lactic-co-glycolic) acid (PLGA)-based methotrexate (MTX) intravitreal micro-implant in normal rabbit eyes. PLGA and CS-based micro-implants containing 400 µg of MTX were surgically inserted in the vitreous of twenty-four New Zealand rabbits using minimally invasive procedures. The PLGA-coated CS-MTX micro-implant and the placebo micro-implant were inserted in the right eye and in the left eye, respectively, of each rabbit. The intravitreal MTX concentration was evaluated on Days 1, 3, 7, 14, 28 and 56. A therapeutic concentration of MTX (0.1–1.0 µM) in the rabbit vitreous was observed for 56 days. The release of MTX in the therapeutic release phase followed first-order kinetics. Histopathologic evaluation on Days 14, 28 and 56 of the enucleated eyes demonstrated no signs of toxicity or any anatomical irregularity in the vitreoretinal domain. Additionally, the micro-implants were stationary at the position of their implantation throughout the duration of the study. The PLGA-coated CS-MTX micro-implant can serve as a potential alternative to the current treatment modality of intravitreal MTX injections based on its performance, thereby avoiding associated complications and the treatment burden of multiple injections.
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Affiliation(s)
- Soumyarwit Manna
- Department of Mechanical and Materials Engineering, University of Cincinnati, Cincinnati, OH 45221, USA;
| | - Anna M. Donnell
- Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221, USA;
| | - Rafaela Q. Caixeta Faraj
- Department of Ophthalmology, University of Cincinnati, Cincinnati, OH 45221, USA; (R.Q.C.F.); (B.I.R.); (C.D.R.); (J.J.A.); (Z.M.C.)
| | - Blanca I. Riemann
- Department of Ophthalmology, University of Cincinnati, Cincinnati, OH 45221, USA; (R.Q.C.F.); (B.I.R.); (C.D.R.); (J.J.A.); (Z.M.C.)
| | - Christopher D. Riemann
- Department of Ophthalmology, University of Cincinnati, Cincinnati, OH 45221, USA; (R.Q.C.F.); (B.I.R.); (C.D.R.); (J.J.A.); (Z.M.C.)
| | - James J. Augsburger
- Department of Ophthalmology, University of Cincinnati, Cincinnati, OH 45221, USA; (R.Q.C.F.); (B.I.R.); (C.D.R.); (J.J.A.); (Z.M.C.)
| | - Zelia M. Correa
- Department of Ophthalmology, University of Cincinnati, Cincinnati, OH 45221, USA; (R.Q.C.F.); (B.I.R.); (C.D.R.); (J.J.A.); (Z.M.C.)
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL 33146, USA
| | - Rupak K. Banerjee
- Department of Mechanical and Materials Engineering, University of Cincinnati, Cincinnati, OH 45221, USA;
- Correspondence: ; Tel.: +1-5134772124
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Vieira LC, Moreira CPDS, Castro BFM, Cotta OAL, Silva LM, Fulgêncio GDO, Silva-Cunha A, Fialho SL. Rosmarinic Acid Intravitreal Implants: A New Therapeutic Approach for Ocular Neovascularization. PLANTA MEDICA 2020; 86:1286-1297. [PMID: 32797466 DOI: 10.1055/a-1223-2525] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Rosmarinic acid, a plant-derived compound with antiangiogenic activity, can be applied for the treatment of ocular diseases related to neovascularization, such as diabetic retinopathy, macular edema, and age-related macular degeneration. These diseases represent the leading causes of blindness worldwide if they are not properly treated. Intravitreal devices allow for localized drug delivery to the posterior segment, increasing the drug bioavailability and promoting extended release, thus, reducing side effects and enhancing the patient's compliance to the treatment. In this work, rosmarinic acid-loaded poly lactic-co-glycolic acid intraocular implants were developed with a view for the treatment of ocular neovascularization. Physical-chemical, biocompatibility, and safety studies of the implants were carried out in vitro and in vivo as well as an evaluation of the antiangiogenic activity in a chorioallantoic membrane assay. Data obtained showed that rosmarinic acid released from the implants was quantified in the vitreous for 6 weeks, while when it was in the solution formulation, after 24 h, no drug was found in the vitreous. The delivery device did not show any sign of toxicity after clinical evaluation and in electroretinographic findings. Histological analysis showed normal eye tissue. Rosmarinic acid released from implants reduced 30% of new vessel's formation. The intravitreal implant successfully allowed for the prolonged release of rosmarinic acid, was safe to rabbits eyes, and demonstrated activity in vessel reduction, thus demonstrating potential in preventing neovascularization in ophthalmic diseases.
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Affiliation(s)
- Lorena Carla Vieira
- Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | | | | | - Luciana Maria Silva
- Research and Development, Ezequiel Dias Foundation, Belo Horizonte, Minas Gerais, Brazil
| | | | - Armando Silva-Cunha
- Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Sílvia L Fialho
- Research and Development, Ezequiel Dias Foundation, Belo Horizonte, Minas Gerais, Brazil
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Valenti S, Diaz A, Romanini M, del Valle LJ, Puiggalí J, Tamarit JL, Macovez R. Amorphous binary dispersions of chloramphenicol in enantiomeric pure and racemic poly-lactic acid: Morphology, molecular relaxations, and controlled drug release. Int J Pharm 2019; 568:118565. [DOI: 10.1016/j.ijpharm.2019.118565] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/23/2019] [Accepted: 07/24/2019] [Indexed: 12/28/2022]
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Lee K, Song HB, Cho W, Kim JH, Kim JH, Ryu W. Intracorneal injection of a detachable hybrid microneedle for sustained drug delivery. Acta Biomater 2018; 80:48-57. [PMID: 30267886 DOI: 10.1016/j.actbio.2018.09.039] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 09/10/2018] [Accepted: 09/24/2018] [Indexed: 12/31/2022]
Abstract
There are increasing demands for long-term and controlled corneal drug delivery to treat various ocular diseases. Although biodegradable ocular inserts or contact lenses have been developed, the invasiveness and inefficiency of the approaches still need to be improved. Microneedle (MN) technology can deliver therapeutic molecules to the eye in a minimally invasive manner. However, the current ocular MN technology is limited to either short-term corneal drug delivery or retinal drug delivery by suprachoroidal injection. For long-term and minimally invasive corneal drug delivery, we have developed a detachable biodegradable MN that can be delivered to the inside of the cornea for sustained drug release. The detachable and biodegradable MN is a hybrid MN consisting of a drug-loaded biodegradable tip and a supporting base. The hybrid MN can be applied to the cornea by impact insertion, and it leaves only the drug-loaded biodegradable tip within the corneal tissue so that it can release the drug for a certain period. By concentration-controlled molding, the dimension of drug-loaded MN tips was precisely controlled and their detachability was optimized. The detachable tip and a supporting base were assembled to form a hybrid MN by pressure-assisted transfer molding. We carefully optimized the dimension of the drug-tip, injection dwell time, and insertion depth to achieve effective intracorneal injection of the drug-tip. The detachable hybrid MN was applied to an Acanthamoeba keratitis model wherein a biodegradable drug-tip was successfully delivered to the inside of the mouse cornea in vivo. Follow-up of the MN-treated cases for 7 days confirmed the therapeutic efficacy of the detachable biodegradable MN tips. STATEMENT OF SIGNIFICANCE: For the treatment of infectious diseases in the cornea, such as keratitis, eye drops need to be applied topically every hour for a couple of days. This is extremely uncomfortable, and poor compliance to such tightly scheduled drug administration can result in permanent scar formation in the cornea. In this work, we demonstrate a simple and rapid injection of biodegradable microneedle tips in the corneal tissue wherein the tips can deliver antibacterial drugs for 4 days to treat keratitis. Unlike other patch-style microneedle technologies, this approach allows for insertion depth-controlled and highly localized injection of detachable individual microneedle tips to the diseased tissue for sustained drug delivery. This overcomes the limitations of patch-style microneedles such as short-term drug delivery and unnecessary blockage of tissue.
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Affiliation(s)
- KangJu Lee
- Department of Mechanical Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Hyun Beom Song
- Department of Parasitology and Tropical Medicine, Institute of Endemic Diseases, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Fight against Angiogenesis, Related Blindness Laboratory, Biomedical Research Institute, Seoul National University Hospital, Seoul 03080, Republic of Korea
| | - Wonwoo Cho
- Department of Mechanical Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Jin Hyoung Kim
- Fight against Angiogenesis, Related Blindness Laboratory, Biomedical Research Institute, Seoul National University Hospital, Seoul 03080, Republic of Korea
| | - Jeong Hun Kim
- Fight against Angiogenesis, Related Blindness Laboratory, Biomedical Research Institute, Seoul National University Hospital, Seoul 03080, Republic of Korea; Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080, Republic of Korea; Department of Ophthalmology, Seoul National University College of Medicine, Seoul 03080, Republic of Korea.
| | - WonHyoung Ryu
- Department of Mechanical Engineering, Yonsei University, Seoul 03722, Republic of Korea.
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Antileishmanial and Immunomodulatory Effect of Babassu-Loaded PLGA Microparticles: A Useful Drug Target to Leishmania amazonensis Infection. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2018; 2018:3161045. [PMID: 30046335 PMCID: PMC6036798 DOI: 10.1155/2018/3161045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 05/03/2018] [Accepted: 05/16/2018] [Indexed: 01/21/2023]
Abstract
The immunological and the anti-Leishmania amazonensis activity of babassu-loaded poly(lactic-co-glycolic acid) [PLGA] microparticles was evaluated. The anti-Leishmania activity was evaluated against promastigotes or amastigotes forms, in Balb/c macrophages. The size of the microparticles ranged from 3 to 6.4 μm, with a zeta potential of −25 mV and encapsulation efficiency of 48%. The anti-Leishmania activity of the PLGA microparticles loaded with the aqueous extract of babassu mesocarp (MMP) (IC50) was 10-fold higher than that free extract (Meso). MMP exhibited overall bioavailability and was very effective in eliminating intracellular parasites. MMP also reduced ex vivo parasite infectivity probably by the increased production of nitric oxide, hydrogen peroxide, and TNF-α indicating the activation of M1 macrophages. The overexpression of TNF-α did not impair cell viability, suggesting antiapoptotic effects of MMP. In conclusion, babassu-loaded microparticles could be useful for drug targeting in the treatment of leishmaniasis, due to the immunomodulatory effect on macrophage polarization and the increased efficacy as an anti-Leishmania product after the microencapsulation. These findings are of great relevance since the development of new drugs for the treatment of neglected diseases is desirable, mainly if we consider the high morbidity and mortality rates of leishmaniasis worldwide.
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9
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Influence of the test method on in vitro drug release from intravitreal model implants containing dexamethasone or fluorescein sodium in poly (d,l-lactide-co-glycolide) or polycaprolactone. Eur J Pharm Biopharm 2018; 127:270-278. [PMID: 29490233 DOI: 10.1016/j.ejpb.2018.02.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 02/20/2018] [Accepted: 02/23/2018] [Indexed: 11/20/2022]
Abstract
Sustained intravitreal dexamethasone (DX) administration with the FDA and EMA approved Ozurdex® implant is indicated for the treatment of macular edema and non-infectious uveitis. Since drug release after intravitreal application cannot be determined in vivo in human eyes, the characterization of drug release in vitro in addition to animal models is of great importance. The aim of this study was to provide information about the influence of the test method on the in vitro drug release from intravitreal model implants. The following test methods were used: a shaking incubator experiment in reagent tubes, the small volume USP apparatus 7, the Vitreous Model (VM) and a system simulating the impact of movement on the VM (Eye Movement System, EyeMoS). Cylindrical model implants composed of DX and PLGA (poly (d,l-lactide-co-glycolide)) and additional polycaprolactone (PCL) implants containing fluorescein sodium (FS) as a model substance were produced by hot melt extrusion and were cut to a length of approximately 6 mm. Drug release was studied in ringer buffer pH 7.4 and in a modified polyacrylamide gel (PAAG) as vitreous substitute. In combination with the VM, the shape, the gel structure and a partial liquefaction (50%) were simulated in vitro. Swelling, disintegration, fragmentation, surface enlargement and changes in shape of the PLGA model implants were observed during the drug release study. We experienced that not each of the test methods and media were suitable for drug release studies of the PLGA implants. Marked differences in the release profiles were observed depending on the employed test method. These results emphasize the necessity to understand the underlying in vivo processes and to transfer the knowledge about the release determining factors into reliable in vitro test systems.
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Liu R, Chen Y, Liu L, Gong Y, Wang M, Li S, Chen C, Yu B. Long-term delivery of rhIGF-1 from biodegradable poly(lactic acid)/hydroxyapatite@Eudragit double-layer microspheres for prevention of bone loss and articular degeneration in C57BL/6 mice. J Mater Chem B 2018; 6:3085-3095. [PMID: 32254343 DOI: 10.1039/c8tb00324f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Insulin-like growth factor (IGF-1) has encouraged researchers to investigate its various potential therapeutic uses such as in the treatment of osteoporosis and repair of articular cartilage.
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Affiliation(s)
- Rui Liu
- Department of Orthopedics
- Zhujiang Hospital
- Southern Medical University
- Guangzhou 510282
- China
| | - Yan Chen
- Department of Ultrasonic Diagnosis
- Zhujiang Hospital
- Southern Medical University
- Guangzhou 510282
- China
| | - Lanlan Liu
- Key Laboratory of Biomedical Materials and Implant Devices
- Research Institute of Tsinghua University in Shenzhen
- Shenzhen 518057
- P. R. China
| | - Yong Gong
- Department of Orthopedics
- Zhujiang Hospital
- Southern Medical University
- Guangzhou 510282
- China
| | - Mingbo Wang
- Key Laboratory of Biomedical Materials and Implant Devices
- Research Institute of Tsinghua University in Shenzhen
- Shenzhen 518057
- P. R. China
| | - Songjian Li
- Department of Orthopedics
- Zhujiang Hospital
- Southern Medical University
- Guangzhou 510282
- China
| | - Changsheng Chen
- Key Laboratory of Biomedical Materials and Implant Devices
- Research Institute of Tsinghua University in Shenzhen
- Shenzhen 518057
- P. R. China
| | - Bo Yu
- Department of Orthopedics
- Zhujiang Hospital
- Southern Medical University
- Guangzhou 510282
- China
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Yamada S, Nagai N, Saijo S, Kaji H, Nishizawa M, Imura K, Goto M, Abe T. Controlled basic fibroblast growth factor release device made of poly(ethyleneglycol) dimethacrylates for creating a subcutaneous neovascular bed for cell transplantation. J Biomed Mater Res A 2017; 105:3017-3024. [DOI: 10.1002/jbm.a.36153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 06/07/2017] [Accepted: 06/29/2017] [Indexed: 12/11/2022]
Affiliation(s)
- Shinji Yamada
- Division of Clinical Cell Therapy; United Centers for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi; Aoba-ku Sendai 980-8575 Japan
| | - Nobuhiro Nagai
- Division of Clinical Cell Therapy; United Centers for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi; Aoba-ku Sendai 980-8575 Japan
| | - Saaya Saijo
- Division of Clinical Cell Therapy; United Centers for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi; Aoba-ku Sendai 980-8575 Japan
| | - Hirokazu Kaji
- Department of Finemechanics; Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki; Aoba-ku Sendai 980-8579 Japan
| | - Matsuhiko Nishizawa
- Department of Finemechanics; Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki; Aoba-ku Sendai 980-8579 Japan
| | - Kozue Imura
- Division of Transplantation and Regenerative Medicine; United Centers for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku; Sendai 980-0872 Japan
| | - Masafumi Goto
- Division of Transplantation and Regenerative Medicine; United Centers for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku; Sendai 980-0872 Japan
| | - Toshiaki Abe
- Division of Clinical Cell Therapy; United Centers for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi; Aoba-ku Sendai 980-8575 Japan
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12
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Evaluation of polyesteramide (PEA) and polyester (PLGA) microspheres as intravitreal drug delivery systems in albino rats. Biomaterials 2017; 124:157-168. [DOI: 10.1016/j.biomaterials.2017.02.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 01/20/2017] [Accepted: 02/06/2017] [Indexed: 12/17/2022]
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13
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Sharma RK, Yassin AEB. Nanostructure-based platforms-current prospective in ophthalmic drug delivery. Indian J Ophthalmol 2016; 62:768-72. [PMID: 25116766 PMCID: PMC4152643 DOI: 10.4103/0301-4738.138301] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The topically applied drugs as drops are washed off from the eye in very short period, resulting in low ocular bioavailability of drugs. Number of approaches have been attempted to increase the bioavailability and the duration of action of ocular drugs. This review provides an insight into various novel approaches; hydrophilic nanogels, solid lipid nanoparticles, and nanosponges applied very recently in the delivery of insoluble drugs, prolonging the ocular residence time, minimize pre-corneal drug loss and, therefore, bioavailability and therapeutic efficacy of the drugs. Despite various scientific approaches, efficient ocular drug delivery remains a challenge for pharmaceutical scientists.
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Affiliation(s)
- Rakesh Kumar Sharma
- Department of Pharmaceutics, College of Pharmacy, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Kingdom of Saudi Arabia
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14
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Tamaddon L, Mostafavi SA, Karkhane R, Riazi-Esfahani M, Dorkoosh FA, Rafiee-Tehrani M. Design and development of intraocular polymeric implant systems for long-term controlled-release of clindamycin phosphate for toxoplasmic retinochoroiditis. Adv Biomed Res 2015; 4:32. [PMID: 25709997 PMCID: PMC4333484 DOI: 10.4103/2277-9175.150426] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 12/14/2013] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND The release of the anti-toxoplasmosis drug, clindamycin phosphate, from intraocular implants of the biodegradable polymers poly (D, L-lactic acid) (PLA) and poly (D, L-lactide-co-glycolide) (PLGA) has been studied in vitro. MATERIALS AND METHODS The preparation of the implants was performed by a melt-extrusion method. The developed extrudates were characterized and compared in in-vitro release profiles for elucidating the drug release mechanism. The formulations containing up to 40% w/w of drug were prepared. Release data in phosphate buffer (pH 7.4) were analyzed by high performance liquid chromatography. The release kinetics were fitted to the zero-order, Higuchi's square-root, first order and the Korsmeyer-Peppas empirical equations for the estimation of various parameters of the drug release curves. Degradation of implants was also investigated morphologically with time (Scanning Electron Microscopy). RESULTS It was observed that, the release profiles for the formulations exhibit a typical biphasic profile for bulk-eroding systems, characterized by a first phase of burst release (in first 24 hrs), followed by a phase of slower release. The duration of the secondary phase was found to be proportional to the molecular weight and monomer ratio of copolymers and also polymer-to-drug ratios. It was confirmed that Higuchi and first-order kinetics were the predominant release mechanisms than zero order kinetic. The Korsmeyer-Peppas exponent (n) ranged between 0.10 and 0.96. This value, confirmed fickian as the dominant mechanism for PLA formulations (n ≤ 0.45) and the anomalous mechanism, for PLGAs (0.45 < n < 0.90). CONCLUSION The implant of PLA (I.V. 0.2) containing 20% w/w of clindamycin, was identified as the optimum formulation in providing continuous efficient in-vitro release of clindamycin for about 5 weeks.
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Affiliation(s)
- Lana Tamaddon
- Department of Pharmaceutics, School of Pharmacy and Pharmaceutical Sciences and Isfahan Pharmaceutical Sciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - S Abolfazl Mostafavi
- Department of Pharmaceutics, School of Pharmacy and Pharmaceutical Sciences and Isfahan Pharmaceutical Sciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Reza Karkhane
- Department of Ophthalmology, Eye Research Center, Farabi Eye Hospital, Tehran, Iran
| | | | - Farid Abedin Dorkoosh
- Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Morteza Rafiee-Tehrani
- Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
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15
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Nagai N, Kaji H, Onami H, Katsukura Y, Ishikawa Y, Nezhad ZK, Sampei K, Iwata S, Ito S, Nishizawa M, Nakazawa T, Osumi N, Mashima Y, Abe T. A platform for controlled dual-drug delivery to the retina: protective effects against light-induced retinal damage in rats. Adv Healthc Mater 2014; 3:1555-60, 1524. [PMID: 24753450 DOI: 10.1002/adhm.201400114] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 03/26/2014] [Indexed: 11/12/2022]
Abstract
Controlled transscleral co-delivery of two drugs, edaravone (EDV) and unoprostone (UNO), using a platform that comprises a microfabricated reservoir, controlled-release cover, and drug formulations, which are made of photopolymerized poly(ethyleneglycol) dimethacrylates, shows synergistic retinal neuroprotection against light injury in rats when compared with single-drug-loaded devices. The device would offer a safer therapeutic method than intravitreal injections for retinal disease treatments.
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Affiliation(s)
- Nobuhiro Nagai
- Division of Clinical Cell Therapy, United Centers for Advanced Research and Translational Medicine (ART); Tohoku University Graduate School of Medicine; 2-1 Seiryo-machi Aoba-ku, Sendai 980-8575 Japan
| | - Hirokazu Kaji
- Department of Bioengineering and Robotics; Graduate School of Engineering, Tohoku University; 6-6-01 Aramaki Aoba-ku, Sendai 980-8579 Japan
| | - Hideyuki Onami
- Division of Clinical Cell Therapy, United Centers for Advanced Research and Translational Medicine (ART); Tohoku University Graduate School of Medicine; 2-1 Seiryo-machi Aoba-ku, Sendai 980-8575 Japan
- Department of Ophthalmology; Tohoku University Graduate School of Medicine; 1-1 Seiryo-machi Aoba-ku, Sendai 980-8574 Japan
| | - Yuki Katsukura
- Division of Clinical Cell Therapy, United Centers for Advanced Research and Translational Medicine (ART); Tohoku University Graduate School of Medicine; 2-1 Seiryo-machi Aoba-ku, Sendai 980-8575 Japan
| | - Yumi Ishikawa
- Division of Clinical Cell Therapy, United Centers for Advanced Research and Translational Medicine (ART); Tohoku University Graduate School of Medicine; 2-1 Seiryo-machi Aoba-ku, Sendai 980-8575 Japan
| | - Zhaleh Kashkouli Nezhad
- Division of Clinical Cell Therapy, United Centers for Advanced Research and Translational Medicine (ART); Tohoku University Graduate School of Medicine; 2-1 Seiryo-machi Aoba-ku, Sendai 980-8575 Japan
| | - Kaori Sampei
- Division of Clinical Cell Therapy, United Centers for Advanced Research and Translational Medicine (ART); Tohoku University Graduate School of Medicine; 2-1 Seiryo-machi Aoba-ku, Sendai 980-8575 Japan
| | - Satoru Iwata
- Division of Clinical Cell Therapy, United Centers for Advanced Research and Translational Medicine (ART); Tohoku University Graduate School of Medicine; 2-1 Seiryo-machi Aoba-ku, Sendai 980-8575 Japan
| | - Shuntaro Ito
- Department of Bioengineering and Robotics; Graduate School of Engineering, Tohoku University; 6-6-01 Aramaki Aoba-ku, Sendai 980-8579 Japan
| | - Matsuhiko Nishizawa
- Department of Bioengineering and Robotics; Graduate School of Engineering, Tohoku University; 6-6-01 Aramaki Aoba-ku, Sendai 980-8579 Japan
| | - Toru Nakazawa
- Department of Ophthalmology; Tohoku University Graduate School of Medicine; 1-1 Seiryo-machi Aoba-ku, Sendai 980-8574 Japan
| | - Noriko Osumi
- Division of Developmental Neuroscience; United Centers for Advanced Research and Translational Medicine (ART); Tohoku University Graduate School of Medicine; 2-1 Seiryo-machi Aoba-ku, Sendai 980-8575 Japan
| | - Yukihiko Mashima
- R-tech Ueno Ltd.; 1-1-7, Uchisaiwai-cho Chiyoda-ku, Tokyo 100-0011 Japan
| | - Toshiaki Abe
- Division of Clinical Cell Therapy, United Centers for Advanced Research and Translational Medicine (ART); Tohoku University Graduate School of Medicine; 2-1 Seiryo-machi Aoba-ku, Sendai 980-8575 Japan
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16
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A novel technology using transscleral ultrasound to deliver protein loaded nanoparticles. Eur J Pharm Biopharm 2014; 88:104-15. [DOI: 10.1016/j.ejpb.2014.04.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 04/22/2014] [Accepted: 04/28/2014] [Indexed: 12/31/2022]
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17
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Manna S, Augsburger JJ, Correa ZM, Landero JA, Banerjee RK. Development of Chitosan and Polylactic Acid Based Methotrexate Intravitreal Micro-Implants to Treat Primary Intraocular Lymphoma: An In Vitro Study. J Biomech Eng 2014; 136:021018. [DOI: 10.1115/1.4026176] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2013] [Accepted: 12/07/2013] [Indexed: 11/08/2022]
Abstract
Primary intraocular lymphoma (PIOL) is an uncommon but clinically and pathologically distinct form of non-Hodgkin's lymphoma. It provides a therapeutic challenge because of its diverse clinical presentations and variable clinical course. Currently available treatments for PIOL include intravenous multiple drug chemotherapy, external beam radiation therapy, and intravitreal methotrexate (MTX) injection. Each intravitreal injection of MTX is associated with potentially toxic peaks and subtherapeutic troughs of intraocular MTX concentration. Repetitive injections are required to maintain therapeutic levels of MTX in the eye. A sustained release drug delivery system is desired for optimized therapeutic release (0.2–2.0 μg/day) of MTX for over a period of 1 month to achieve effective treatment of PIOL. This study reports development of a unique intravitreal micro-implant, which administers therapeutic release of MTX over a period of 1 month. Chitosan (CS) and polylactic acid (PLA) based micro-implants are fabricated for different MTX loadings (10%, 25%, and 40% w/w). First, CS and MTX mixtures are prepared for different drug loadings, and lyophilized in Tygon® tubing to obtain CS-MTX fibers. The fibers are then cut into desired micro-implant lengths and dip coated in PLA for a hydrophobic surface coating. The micro-implant is characterized using optical microscopy, scanning electron microscopy (SEM), time of flight-secondary ion mass spectroscopy (ToF-SIMS), and differential scanning calorimetry (DSC) techniques. The release rate studies are carried out using a UV-visible spectrophotometer. The total release durations for 10%, 25%, and 40% w/w uncoated CS-MTX micro-implants are only 19, 29, and 32 h, respectively. However, the therapeutic release durations for 10%, 25%, and 40% w/w PLA coated CS-MTX micro-implants significantly improved to 58, 74, and 66 days, respectively. Thus, the PLA coated CS-MTX micro-implants are able to administer therapeutic release of MTX for more than 50 days. The release kinetics of MTX from the coated micro-implants is explained by (a) the Korsmeyer–Peppas and zero order model fit (R2 ∼ 0.9) of the first 60% of the drug release, which indicates the swelling of polymer and initial burst release of the drug; and (b) the first order and Higuchi model fit (R2 ∼ 0.9) from the tenth day to the end of drug release, implying MTX release in the therapeutic window depends on its concentration and follows diffusion kinetics. The PLA coated CS-MTX micro-implants are able to administer therapeutic release of MTX for a period of more than 1 month. The proposed methodology could be used for improved treatment of PIOL.
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Affiliation(s)
- Soumyarwit Manna
- Department of Mechanical and Materials Engineering, University of Cincinnati, Cincinnati, OH 45220
| | | | - Zelia M. Correa
- Department of Ophthalmology, University of Cincinnati, Cincinnati, OH 45220
| | - Julio A. Landero
- Department of Chemistry, University of Cincinnati, Cincinnati, OH 45220
| | - Rupak K. Banerjee
- Department of Mechanical and Materials Engineering, University of Cincinnati, 593 Rhodes Hall, Cincinnati, OH 45221 e-mail:
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Nagai N, Kaji H, Onami H, Ishikawa Y, Nishizawa M, Osumi N, Nakazawa T, Abe T. A polymeric device for controlled transscleral multi-drug delivery to the posterior segment of the eye. Acta Biomater 2014; 10:680-7. [PMID: 24239899 DOI: 10.1016/j.actbio.2013.11.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 10/26/2013] [Accepted: 11/08/2013] [Indexed: 01/02/2023]
Abstract
The design of drug delivery systems that can deliver multiple drugs to the posterior segment of the eye is a challenging task in retinal disease treatments. We report a polymeric device for multi-drug transscleral delivery at independently controlled release rates. The device comprises a microfabricated reservoir, controlled-release cover and three different fluorescent formulations, which were made of photopolymeized tri(ethyleneglycol)dimethacrylate (TEGDM) and poly(ethyleneglycol)dimethacrylate (PEGDM). The release rate of each fluorescent is controlled by varying the PEGDM/TEGDM ratio in its formulation and the cover. The release kinetics appeared to be related to the swelling ratio of the PEGDM/TEGDM polymers. When the devices were implanted onto rat sclerae, fluorescence was observable in the ocular tissues during 4 weeks' implantation and distributed locally around the implantation site. Our polymeric system, which can administer multiple compounds with distinct kinetics, provides prolonged action and less invasive transscleral administration, and is expected to provide new tools for the treatment of posterior eye diseases with new therapeutic modalities.
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Affiliation(s)
- Nobuhiro Nagai
- Division of Clinical Cell Therapy, United Centers for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Hirokazu Kaji
- Department of Bioengineering and Robotics, Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - Hideyuki Onami
- Division of Clinical Cell Therapy, United Centers for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan; Department of Ophthalmology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Yumi Ishikawa
- Division of Clinical Cell Therapy, United Centers for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Matsuhiko Nishizawa
- Department of Bioengineering and Robotics, Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - Noriko Osumi
- Division of Developmental Neuroscience, United Centers for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Toru Nakazawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Toshiaki Abe
- Division of Clinical Cell Therapy, United Centers for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
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19
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Yasukawa T, Tabata Y, Kimura H, Kunou N, Ogura Y. Development of drug-delivery systems to the posterior segments of the eye. EXPERT REVIEW OF OPHTHALMOLOGY 2014. [DOI: 10.1586/17469899.2.2.197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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20
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Critical assessment of implantable drug delivery devices in glaucoma management. JOURNAL OF DRUG DELIVERY 2013; 2013:895013. [PMID: 24066234 PMCID: PMC3770064 DOI: 10.1155/2013/895013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 07/26/2013] [Indexed: 12/21/2022]
Abstract
Glaucoma is a group of heterogeneous disorders involving progressive optic neuropathy that can culminate into visual impairment and irreversible blindness. Effective therapeutic interventions must address underlying vulnerability of retinal ganglion cells (RGCs) to degeneration in conjunction with correcting other associated risk factors (such as elevated intraocular pressure). However, realization of therapeutic outcomes is heavily dependent on suitable delivery system that can overcome myriads of anatomical and physiological barriers to intraocular drug delivery. Development of clinically viable sustained release systems in glaucoma is a widely recognized unmet need. In this regard, implantable delivery systems may relieve the burden of chronic drug administration while potentially ensuring high intraocular drug bioavailability. Presently there are no FDA-approved implantable drug delivery devices for glaucoma even though there are several ongoing clinical studies. The paper critically assessed the prospects of polymeric implantable delivery systems in glaucoma while identifying factors that can dictate (a) patient tolerability and acceptance, (b) drug stability and drug release profiles, (c) therapeutic efficacy, and (d) toxicity and biocompatibility. The information gathered could be useful in future research and development efforts on implantable delivery systems in glaucoma.
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21
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Li D, Guo G, Deng X, Fan R, Guo Q, Fan M, Liang J, Luo F, Qian Z. PLA/PEG-PPG-PEG/Dexamethasone implant prepared by hot-melt extrusion for controlled release of immunosuppressive drug to implantable medical devices, part 2:in vivoevaluation. Drug Deliv 2013; 20:134-42. [DOI: 10.3109/10717544.2013.801049] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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22
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Onami H, Nagai N, Kaji H, Nishizawa M, Sato Y, Osumi N, Nakazawa T, Abe T. Transscleral sustained vasohibin-1 delivery by a novel device suppressed experimentally-induced choroidal neovascularization. PLoS One 2013; 8:e58580. [PMID: 23472209 PMCID: PMC3589385 DOI: 10.1371/journal.pone.0058580] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Accepted: 02/06/2013] [Indexed: 12/03/2022] Open
Abstract
We established a sustained vasohibin-1 (a 42-kDa protein), delivery device by a novel method using photopolymerization of a mixture of polyethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and collagen microparticles. We evaluated its effects in a model of rat laser-induced choroidal neovascularization (CNV) using a transscleral approach. We used variable concentrations of vasohibin-1 in the devices, and used an enzyme-linked immunosorbent assay and Western blotting to measure the released vasohibin-1 (0.31 nM/day when using the 10 μM vasohibin-1 delivery device [10VDD]). The released vasohibin-1 showed suppression activity comparable to native effects when evaluated using endothelial tube formation. We also used pelletized vasohibin-1 and fluorescein isothiocyanate-labeled 40 kDa dextran as controls. Strong fluorescein staining was observed on the sclera when the device was used for drug delivery, whereas pellet use produced strong staining in the conjunctiva and surrounding tissue, but not on the sclera. Vasohibin-1 was found in the sclera, choroid, retinal pigment epithelium (RPE), and neural retina after device implantation. Stronger immunoreactivity at the RPE and ganglion cell layers was observed than in other retinal regions. Significantly lower fluorescein angiography (FA) scores and smaller CNV areas in the flat mounts of RPE-choroid-sclera were observed for the 10VDD, VDD (1 μM vasohibin-1 delivery device), and vasohibin-1 intravitreal direct injection (0.24 μM) groups when compared to the pellet, non-vasohibin-1 delivery device, and intravitreal vehicle injection groups. Choroidal neovascularization can be treated with transscleral sustained protein delivery using our novel device. We offer a safer sustained protein release for treatment of retinal disease using the transscleral approach.
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Affiliation(s)
- Hideyuki Onami
- Division of Clinical Cell Therapy, United Centers for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Nobuhiro Nagai
- Division of Clinical Cell Therapy, United Centers for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hirokazu Kaji
- Department of Bioengineering and Robotics, Graduate School of Engineering, Tohoku University, Sendai, Japan
| | - Matsuhiko Nishizawa
- Department of Bioengineering and Robotics, Graduate School of Engineering, Tohoku University, Sendai, Japan
| | - Yasufumi Sato
- Department of Vascular Biology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Noriko Osumi
- Division of Developmental Neuroscience, United Centers for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Toru Nakazawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Toshiaki Abe
- Division of Clinical Cell Therapy, United Centers for Advanced Research and Translational Medicine (ART), Tohoku University Graduate School of Medicine, Sendai, Japan
- * E-mail:
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23
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Li D, Guo G, Fan R, Liang J, Deng X, Luo F, Qian Z. PLA/F68/Dexamethasone implants prepared by hot-melt extrusion for controlled release of anti-inflammatory drug to implantable medical devices: I. Preparation, characterization and hydrolytic degradation study. Int J Pharm 2013. [DOI: 10.1016/j.ijpharm.2012.11.019] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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24
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Webster RL, Noroozi N, Hatzikiriakos SG, Thomson JA, Schafer LL. Titanium pyridonates and amidates: novel catalysts for the synthesis of random copolymers. Chem Commun (Camb) 2013; 49:57-9. [DOI: 10.1039/c2cc37201k] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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25
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Chiang WL, Ke CJ, Liao ZX, Chen SY, Chen FR, Tsai CY, Xia Y, Sung HW. Pulsatile drug release from PLGA hollow microspheres by controlling the permeability of their walls with a magnetic field. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2012; 8:3584-3588. [PMID: 22893436 DOI: 10.1002/smll.201201743] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Indexed: 06/01/2023]
Abstract
Pulsatile release: When a high-frequency magnetic field is applied, heat will be generated by coupling to the iron oxide nanoparticles encapsulated in the shells of PLGA hollow microspheres. As the temperature approaches the T(g) of PLGA, the polymer chains become more mobile, subsequently increasing the free volume of PLGA matrix and significantly enhancing the diffusion of drug molecules.
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Affiliation(s)
- Wei-Lun Chiang
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan, ROC Taiwan
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26
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Hu C, Cui W. Hierarchical structure of electrospun composite fibers for long-term controlled drug release carriers. Adv Healthc Mater 2012. [PMID: 23184837 DOI: 10.1002/adhm.201200146] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Changmin Hu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, People's Republic of China
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27
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Intravitreal devices for the treatment of vitreous inflammation. Mediators Inflamm 2012; 2012:126463. [PMID: 22988344 PMCID: PMC3441042 DOI: 10.1155/2012/126463] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 07/31/2012] [Indexed: 12/03/2022] Open
Abstract
The eye is a well-suited organ for local delivery of therapeutics to treat vitreous inflammation as well as other pathologic conditions that induce visual loss. Several conditions are particularly challenging to treat and often require chronic courses of therapy. The use of implantable intravitreal devices for drug delivery is an emerging field in the treatment of vitreous inflammation as well as other ophthalmologic diseases. There are unique challenges in the design of these devices which include implants, polymers, and micro- and nanoparticles. This paper reviews current and investigational drug delivery systems for treating vitreous inflammation as well as other pathologic conditions that induce visual loss. The use of nonbiodegradable devices such as polyvinyl alcohol-ethylene vinyl acetate polymers and polysulfone capillary fibers, and biodegradable devices such as polylactic acid, polyglycolic acid, and polylactic-co-glycolic acid, polycaprolactones, and polyanhydrides are reviewed. Clinically used implantable devices for therapeutic agents including ganciclovir, fluocinolone acetonide, triamcinolone acetonide, and dexamethasone are described. Finally, recently developed investigational particulate drug delivery systems in the form of liposomes, microspheres, and nanoparticles are examined.
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28
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Contact lenses in ocular therapeutics. Drug Discov Today 2012; 17:522-7. [PMID: 22305935 DOI: 10.1016/j.drudis.2012.01.014] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Revised: 01/05/2012] [Accepted: 01/19/2012] [Indexed: 12/16/2022]
Abstract
Drug delivery is a difficult task in the field of ocular therapeutics. Owing to the physiological and anatomical constraints of the eye, it is difficult to obtain the correct therapeutic concentration of a drug at the required site of action. This has led to clinicians recommending frequent dosing, which has resulted in noncompliance by patients and decreased cost effectiveness. To overcome these barriers, scientists have explored novel ocular delivery systems, such as in situ gels, ocuserts, nanoparticles and liposomes. A particularly novel form of such a delivery system are contact lenses, which are thin, curved plastic disks that are designed to cover the cornea and which cling to the surface of the eye owing to surface tension. In this article, we describe the introductory literature on ocular delivery using contact lenses, their classification and manufacturing process, and recent advances on drug delivery techniques using such lenses.
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29
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Balasubramaniam J, Srinatha A, Pandit JK. Studies on Indomethacin Intraocular Implants Using Different in vitro Release Methods. Indian J Pharm Sci 2011; 70:216-21. [PMID: 20046715 PMCID: PMC2792478 DOI: 10.4103/0250-474x.41458] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2006] [Revised: 03/02/2008] [Accepted: 03/28/2008] [Indexed: 11/05/2022] Open
Abstract
Intra ocular implants of sodium alginate alone and in combination with hydroxypropylmethylcellulose with or without calcium chloride were formulated with indomethacin as a model drug. The drug release from the implants was evaluated using static method, continuous flow through apparatus (developed in house), USP dissolution and agar diffusion. Except in the static method, indomethacin particle size did not impart any effect on the drug release. In agar diffusion method, an increase in agar concentration from 1 to 2% resulted in a significant decrease (P< 0.005) in the amount of drug released. Inclusion of hydroxypropylmethylcellulose (33.3, 41.6 and 50% w/w), resulted in decrease of indomethacin release irrespective of the method of dissolution study. The agar diffusion method and the continuous flow through methods seem to simulate to a certain extent the in vivo conditions as far as the placement of the device and the hydrodynamic diffusion layer around the intra ocular implant is concerned. The static method and USP method affected the hydrodynamic diffusion layer either too slowly or too fast.
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Affiliation(s)
- J Balasubramaniam
- ISP (Hong Kong) Limited, H. No 6-3-1090/A, Bhupal Towers, Rajbhavan Road, Somajiguda, Hyderabad-500 082, India
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30
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Palakurthi NK, Correa ZM, Augsburger JJ, Banerjee RK. Toxicity of a Biodegradable Microneedle Implant Loaded with Methotrexate as a Sustained Release Device in Normal Rabbit Eye: A Pilot Study. J Ocul Pharmacol Ther 2011; 27:151-6. [DOI: 10.1089/jop.2010.0037] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
| | - Zelia M. Correa
- Department of Ophthalmology, University of Cincinnati, Cincinnati, Ohio
| | | | - Rupak K. Banerjee
- Department of Mechanical Engineering, University of Cincinnati, Cincinnati, Ohio
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio
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31
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Rothstein SN, Little SR. A “tool box” for rational design of degradable controlled release formulations. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c0jm01668c] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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Kawashima T, Nagai N, Kaji H, Kumasaka N, Onami H, Ishikawa Y, Osumi N, Nishizawa M, Abe T. A scalable controlled-release device for transscleral drug delivery to the retina. Biomaterials 2010; 32:1950-6. [PMID: 21112628 DOI: 10.1016/j.biomaterials.2010.11.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 11/03/2010] [Indexed: 10/18/2022]
Abstract
A transscleral drug-delivery device, designed for the administration of protein-type drugs, that consists of a drug reservoir covered with a controlled-release membrane was manufactured and tested. The controlled-release membrane is made of photopolymerized polyethylene glycol dimethacrylate (PEGDM) that contains interconnected collagen microparticles (COLs), which are the routes for drug permeation. The results showed that the release of 40-kDa FITC-dextran (FD40) was dependent on the COL concentration, which indicated that FD40 travelled through the membrane-embedded COLs. Additionally, the sustained-release drug formulations, FD40-loaded COLs and FD40-loaded COLs pelletized with PEGDM, fine-tuned the release of FD40. Capsules filled with COLs that contained recombinant human brain-derived neurotrophic factor (rhBDNF) released bioactive rhBDNF in a manner dependent on the membrane COL concentration, as was found for FD40 release. When capsules were sutured onto sclerae of rabbit eyes, FD40 was found to spread to the retinal pigment epithelium. Implantation of the device was easy, and it did not damage the eye tissues. In conclusion, our capsule is easily modified to accommodate different release rates for protein-type drugs by altering the membrane COL composition and/or drug formulation and can be implanted and removed with minor surgery. The device thus has great potential as a conduit for continuous, controlled drug release.
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Affiliation(s)
- Takeaki Kawashima
- Department of Bioengineering and Robotics, Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki-Aoba, Aoba-ku, Sendai 980-8579, Japan
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Palakurthi NK, Krishnamoorthy M, Augsburger JJ, Correa ZM, Banerjee RK. Investigation of Kinetics of Methotrexate for Therapeutic Treatment of Intraocular Lymphoma. Curr Eye Res 2010; 35:1105-15. [DOI: 10.3109/02713683.2010.513089] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Silva GRD, Fialho SL, Siqueira RC, Jorge R, Cunha Júnior ADS. Implants as drug delivery devices for the treatment of eye diseases. BRAZ J PHARM SCI 2010. [DOI: 10.1590/s1984-82502010000300024] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The treatment of diseases affecting the posterior segment of the eye is limited by the difficulty in transporting effective doses of drugs to the vitreous, retina, and choroid. Topically applied drugs are poorly absorbed due to the low permeability of the external ocular tissues and tearing. The blood-retina barrier limits drug diffusion from the systemic blood to the posterior segment, thus high doses of drug are needed to maintain therapeutic levels. In addition, systemic side effects are common. Intraocular injections could be an alternative, but the fast flowing blood supply in this region, associated with rapid clearance rates, causes drug concentration to quickly fall below therapeutic levels. To obtain therapeutic levels over longer time periods, polymeric sustained-drug release systems implanted within the vitreous are being studied for the treatment of vitreoretinal disorders. These systems are prepared using different kinds of biodegradable or non-biodegradable polymers. This review aims to demonstrate the main characteristics of these drug delivery implants and their potential for clinical application.
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Abstract
Development of intraocular drug delivery systems (DDSs) is urgently required for the treatment of eye diseases, especially in the posterior segment of the eye (the vitreous cavity, retina, and choroid), most of which are refractory to conventional pharmacologic approaches; eye drops and systemically administered drugs cannot achieve therapeutic drug concentrations in the posterior segment of the eye. Repeated intravitreal injections of anti-angiogenic agents are effective in the treatment of age-related macular degeneration, but there remain risks of serious side effects such as endophthalmitis associated with repeated injections. Intraocular DDSs may address these problems. Intraocular sustained drug release from implantable or injectable devices has been investigated to treat vitreoretinal diseases. A reservoir-type nonbiodegradable implant was first launched in the market in 1996 for the treatment of cytomegalovirus retinitis secondary to the acquired immunodeficiency syndrome, followed by clinical trials for a variety of potent devices to treat other challenging eye diseases. An injectable rod-shaped insert releasing a steroid is presently being assessed in a phase III trial to treat macular edema secondary to diabetic retinopathy or retinal vein occlusion. Thus various types of intraocular DDSs will be commercially available to treat vision-threatening intraocular diseases in the near future.
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Affiliation(s)
- Tsutomu Yasukawa
- Department of Ophthalmology and Visual Science, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan.
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Fialho SL, Rêgo MB, Siqueira RC, Jorge R, Haddad A, Rodrigues AL, Maia-Filho A, Silva-Cunha A. Safety and Pharmacokinetics of an Intravitreal Biodegradable Implant of Dexamethasone Acetate in Rabbit Eyes. Curr Eye Res 2009; 31:525-34. [PMID: 16769612 DOI: 10.1080/02713680600719036] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The treatment of vitreoretinal diseases is limited and, nowadays, new drug delivery approaches have been reported in order to increase drug bioavailability. The objective of the current study was to determine the pharmacokinetic profile of a biodegradable dexamethasone acetate implant inserted into the vitreous of rabbits and to evaluate its potential signs of toxicity to the rabbits' eyes. The results showed that the intravitreous drug concentration remained within the therapeutic range along the 8-week period of evaluation. The system under study was not toxic to the normal rabbit retina, and no significant increase in intraocular pressure was observed.
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Affiliation(s)
- S L Fialho
- Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil
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Da Silva GR, Ayres E, Orefice RL, Moura SAL, Cara DC, Cunha ADS. Controlled release of dexamethasone acetate from biodegradable and biocompatible polyurethane and polyurethane nanocomposite. J Drug Target 2009; 17:374-83. [DOI: 10.1080/10611860902839510] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Thermal behavior and stability of biodegradable spray-dried microparticles containing triamcinolone. Int J Pharm 2009; 368:45-55. [DOI: 10.1016/j.ijpharm.2008.09.054] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 09/26/2008] [Accepted: 09/30/2008] [Indexed: 11/16/2022]
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Fialho SL, da Silva Cunha A. Manufacturing Techniques of Biodegradable Implants Intended for Intraocular Application. Drug Deliv 2008; 12:109-16. [PMID: 15824036 DOI: 10.1080/10717540590921432] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Polylactic acid and polylactic-co-glycolic acid are biocompatible and biodegradable polymers with wide utility for the design of controlled release systems for drugs. Regarding intraocular application, polymeric sustained-drug release systems are being studied to treat vitreoretinal diseases. Our work aimed to compare the influence of two implant manufacturing techniques, compression and hot molding, on the in vitro degradation of the polymeric matrices and on the release of dexamethasone acetate. The results showed that the manufacturing technique highly influences degradation and drug release processes. The compressed systems degraded faster and allowed one faster release of the drug.
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Affiliation(s)
- Sílvia Ligório Fialho
- Faculty of Pharmacy, Federal University of Minas Gerais, Avenida Antônio Carlos 6627, CEP 31270-010, Belo Horizonte, Minas Gerais, Brazil.
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Abstract
Anatomy and physiology of the eye makes it a highly protected organ. Designing an effective therapy for ocular diseases, especially for the posterior segment, has been considered as a formidable task. Limitations of topical and intravitreal route of administration have challenged scientists to find alternative mode of administration like periocular routes. Transporter targeted drug delivery has generated a great deal of interest in the field because of its potential to overcome many barriers associated with current therapy. Application of nanotechnology has been very promising in the treatment of a gamut of diseases. In this review, we have briefly discussed several ocular drug delivery systems such as microemulsions, nanosuspensions, nanoparticles, liposomes, niosomes, dendrimers, implants, and hydrogels. Potential for ocular gene therapy has also been described in this article. In near future, a great deal of attention will be paid to develop non-invasive sustained drug release for both anterior and posterior segment eye disorders. A better understanding of nature of ocular diseases, barriers and factors affecting in vivo performance, would greatly drive the development of new delivery systems. Current momentum in the invention of new drug delivery systems hold a promise towards much improved therapies for the treatment of vision threatening disorders.
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Kunii R, Onishi H, Ueki KI, Koyama KI, Machida Y. Particle characteristics and biodistribution of camptothecin-loaded PLA/(PEG-PPG-PEG) nanoparticles. Drug Deliv 2008; 15:3-10. [PMID: 18197517 DOI: 10.1080/10717540701827154] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Poly(DL-lactic acid) (PLA)/poly(ethylene glycol)-block-poly (propylene glycol)-block-poly(ethylene glycol) copolymer (PEG-PPG-PEG) nanoparticles loaded with camptothecin (CPT), called CPT-NP, were prepared and examined for particle size change and drug release in phosphate-buffered saline, pH 7.4, (PBS), and drug biodistribution profiles in mice bearing sarcoma 180 solid tumor. CPT-NP kept an almost constant mean size and exhibited an initial rapid release of approximately 20%, following by very slow release. As compared with CPT solution, CPT-NP showed higher tissue accumulation and better tumor localization, which were considered essentially associated with the better efficacy of CPT-NP reported in the previous study.
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Affiliation(s)
- Ryotaro Kunii
- Department of Drug Delivery Research, Hoshi University, Tokyo, Japan
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Eperon S, Bossy-Nobs L, Petropoulos I, Gurny R, Guex-Crosier Y. A biodegradable drug delivery system for the treatment of postoperative inflammation. Int J Pharm 2008; 352:240-7. [DOI: 10.1016/j.ijpharm.2007.10.054] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Revised: 10/30/2007] [Accepted: 10/31/2007] [Indexed: 10/22/2022]
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Bourges JL, Touchard E, Kowalczuk L, Berdugo M, Thomas-Doyle A, Bochot A, Gomez A, Azan F, Gurny R, Behar-Cohen F. Dispositifs de délivrance de principes actifs pour des applications ophtalmologiques. J Fr Ophtalmol 2007; 30:1070-88. [DOI: 10.1016/s0181-5512(07)79290-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Booth BA, Vidal Denham L, Bouhanik S, Jacob JT, Hill JM. Sustained-release ophthalmic drug delivery systems for treatment of macular disorders: present and future applications. Drugs Aging 2007; 24:581-602. [PMID: 17658909 DOI: 10.2165/00002512-200724070-00006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Macular disease currently poses the greatest threat to vision in aging populations. Historically, most of this pathology could only be dealt with surgically, and then only after much damage to the macula had already occurred. Current pathophysiological insights into macular diseases have allowed the development of effective new pharmacotherapies. The field of drug delivery systems has advanced over the last several years with emphasis placed on controlled release of drug to specific areas of the eye. Its unique location and tendency toward chronic disease make the macula an important and attractive target for drug delivery systems, especially sustained-release systems. This review evaluates the current literature on the research and development of sustained-release posterior segment drug delivery systems that are primarily intended for macular disease with an emphasis on age-related macular degeneration.Current effective therapies include corticosteroids and anti-vascular endothelial growth factor compounds. Recent successes have been reported using anti-angiogenic drugs for therapy of age-related macular degeneration. This review also includes information on implantable devices (biodegradable and non-biodegradable), the use of injected particles (microspheres and liposomes) and future enhanced drug delivery systems, such as ultrasound drug delivery. The devices reviewed show significant drug release over a period of days or weeks. However, macular disorders are chronic diseases requiring years of treatment. Currently, there is no 'gold standard' for therapy and/or drug delivery. Future studies will focus on improving the efficiency and effectiveness of drug delivery to the posterior chamber. If successful, therapeutic modalities will significantly delay loss of vision and improve the quality of life for patients with chronic macular disorders.
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Affiliation(s)
- Blake A Booth
- Department of Ophthalmology, LSU Health Sciences Center, New Orleans, Louisiana, USA
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Abstract
Research into treatment modalities affecting vision is rapidly progressing due to the high incidence of diseases such as diabetic macular edema, proliferative vitreoretinopathy, wet and dry age-related macular degeneration and cytomegalovirus retinitis. The unique anatomy and physiology of eye offers many challenges to developing effective retinal drug delivery systems. Historically, drugs have been administered to the eye as liquid drops instilled in the cul-de-sac. However retinal drug delivery is a challenging area. The transport of molecules between the vitreous/retina and systemic circulation is restricted by the blood-retinal barrier, which is made up of retinal pigment epithelium and endothelial cells of the retinal blood vessels. An increase in the understanding of drug absorption mechanisms into the retina from local and systemic administration has led to the development of various drug delivery systems, such as biodegradable and non-biodegradable implants, microspheres, nanoparticles and liposomes, gels and transporter-targeted prodrugs. Such diversity in approaches is an indication that there is still a need for an optimized noninvasive or minimally invasive drug delivery system to the eye. A number of large molecular weight compounds (i.e., oligonucleotides, RNA aptamers, peptides and monoclonal antibodies) have been and continue to be introduced as new therapeutic entities. However, for high molecular weight polar compounds the mechanism of epithelial transport is primarily through the tight junctions in the retinal pigment epithelium, as these agents undergo limited transcellular diffusion. Delivery and administration of these new drugs in a safe and effective manner is still a major challenge facing pharmaceutical scientists. In this review article, the authors discuss various drug delivery strategies, devices and challenges associated with drug delivery to the retina.
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Affiliation(s)
- Kumar G Janoria
- University of Missouri-Kansas City, Department of Pharmaceutical Sciences, School of Pharmacy, 5005 Rockhill Road, Kansas City, MO 64110, USA
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Duvvuri S, Janoria KG, Pal D, Mitra AK. Controlled delivery of ganciclovir to the retina with drug-loaded Poly(d,L-lactide-co-glycolide) (PLGA) microspheres dispersed in PLGA-PEG-PLGA Gel: a novel intravitreal delivery system for the treatment of cytomegalovirus retinitis. J Ocul Pharmacol Ther 2007; 23:264-74. [PMID: 17593010 DOI: 10.1089/jop.2006.132] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE The aim of this study was to develop a formulation for intravitreal delivery by dispersing ganciclovir (GCV)-loaded Poly(d,L-lactide-co-glycolide (PLGA) microspheres in thermogelling PLGA-PEG-PLGA gel and to study the mechanism of drug-release characteristics both in vitro and in vivo. METHODS PLGA microspheres of GCV were prepared by the solvent evaporation method from Resomer RG 502H (D,L-lactide:glycolide::50:50; Mw, 8000 Da) and a 1:3 polymer blend of Resomer RG 502H and PLGA 6535 (D,L-lactide:glycolide::65:35; Mw, 45,000-75,000 Da). The prepared microspheres were dispersed uniformly and as a mixture (1:1) in 23% w/w of PLGA-PEG-PLGA aqueous gel solutions. GCV release in the aqueous medium was studied in vitro. A conscious rabbit microdialysis model with permanently implanted probes was selected as the method for investigating the vitreous GCV levels following an intravitreal administration of the formulation. RESULTS The formulation prepared, by a physical mixture of microspheres, was prepared from Resomer RG 502H, and the polymer blend exhibited fairly constant in vitro GCV release profiles. The amounts of GCV entrapped in the microspheres were sufficient to administer therapeutically relevant doses in 60 microL of the formulation. The vitreal elimination half-life of GCV in the conscious rabbit microdialysis model was 6.45 +/- 0.83 h, with an apparent volume of distribution (V(z)) of 1.18 +/- 0.61 mL. A direct vitreous injection of GCV resulted in the maintenance of concentrations in the vitreous for only 54 h, whereas the gel formulation produced steady-state GCV levels in the vitreous for at least 14 days. CONCLUSIONS PLGA microspheres containing GCV were prepared by two kinds of PLGA polymers and their blend (1:3). A formulation suitable for in vivo administration was prepared by dispersing GCV-loaded microspheres in a thermogelling PLGA-PEG-PLGA solution. An ideal in vitro release of encapsulated GCV was obtained by physically mixing microspheres prepared from different polymer blends prior to its dispersion in the thermogelling polymer. The formulation maintained mean vitreal concentrations of GCV at approximately 0.8 microg/mL for 14 days, whereas direct injections could maintain drug levels above 0.8 microg/mL for 54 h only.
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Abstract
The rapid prototyping (RP) technology has advanced in various fields such as verification
of design, and functional test. Recently, researchers have studied bio-materials to fabricate
functional bio-RP parts. In this research, a nano composite deposition system (NCDS) was
developed to fabricate three-dimensional functional parts for bio-applications. In the hybrid process,
the material removal process by mechanical micro machining and/or the deposition process are
combined. NCDS uses biocompatible or biodegradable polymer resin as matrix and various bioceramics
to form bio-composite materials. To test drug release rate in vivo environment, two
different types of drug delivery system (DDS) were fabricated using the bio-composite materials. 1)
Container type DDS used poly(DL-lactide-co-glycolide acid)(50:50) and 5-fluorouracil as the drug
composite while polycaprolactone(PCL) served as the container of the drug. 2) Scaffold type DDS
formed porous microstructure with poly(DL-lactide-co-glycolide acid)(50:50) and 5-fluorouracil
composite. The effect of geometry of the DDS on release rate of drug is under investigation.
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50
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Bourges JL, Bloquel C, Thomas A, Froussart F, Bochot A, Azan F, Gurny R, BenEzra D, Behar-Cohen F. Intraocular implants for extended drug delivery: therapeutic applications. Adv Drug Deliv Rev 2006; 58:1182-202. [PMID: 17107737 DOI: 10.1016/j.addr.2006.07.026] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2006] [Accepted: 07/31/2006] [Indexed: 12/16/2022]
Abstract
An overview of ocular implants with therapeutic application potentials is provided. Various types of implants can be used as slow release devices delivering locally the needed drug for an extended period of time. Thus, multiple periocular or intraocular injections of the drug can be circumvented and secondary complications minimized. The various compositions of polymers fulfilling specific delivery goals are described. Several of these implants are undergoing clinical trials while a few are already commercialized. Despite the paramount progress in design, safety and efficacy, the place of these implants in our clinical therapeutic arsenal remains limited. Miniaturization of the implants allowing for their direct injection without the need for a complicated surgery is a necessary development avenue. Particulate systems which can be engineered to target specifically certain cells or tissues are another promising alternative. For ocular diseases affecting the choroid and outer retina, transscleral or intrasscleral implants are gaining momentum.
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Affiliation(s)
- J L Bourges
- INSERM, U598, Physiopathology of Ocular Diseases, Therapeutic Innovations, 15 Rue de l'Ecole de Médecine 75006 Paris, France
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