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Zorn-Kruppa M, Tykhonova S, Belge G, Bednarz J, Diehl HA, Engelke M. A Human Corneal Equivalent Constructed from SV40-immortalised Corneal Cell Lines. Altern Lab Anim 2019; 33:37-45. [PMID: 15813699 DOI: 10.1177/026119290503300107] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Within the last decade, extensive research in the field of tissue and organ engineering has focused on the development of in vitro models of the cornea. The use of organotypic, three-dimensional corneal equivalents has several advantages over simple monolayer cultures. The aim of this study was to develop a corneal equivalent model composed of the same cell types as in the natural human tissue, but by using immortalised cell lines to ensure reproducibility and to minimise product variation. We report our success in the establishment of an SV40-immortalised human corneal keratocyte cell line (designated HCK). A collagen matrix, built up with these cells, displayed the morphological characteristics of the human stromal tissue and served as a biomatrix for the immortalised human corneal epithelial and endothelial cells. Histological cross-sections of the whole-cornea equivalents resemble human corneas in tissue structure. This organotypic in vitro model may serve as a research tool for the ophthalmic science community, as well as a model system for testing for eye irritancy and drug efficacy.
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Affiliation(s)
- Michaela Zorn-Kruppa
- Institute of Biophysics, University of Bremen, Otto Hahn Allee 1, 28359 Bremen, Germany.
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2
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Nordic symposium on “toxicology and pharmacology without animal experiments—Will it be possible in the next 10 years?”. Basic Clin Pharmacol Toxicol 2019; 124:560-567. [DOI: 10.1111/bcpt.13193] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 12/11/2018] [Indexed: 11/26/2022]
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Rönkkö S, Vellonen KS, Järvinen K, Toropainen E, Urtti A. Human corneal cell culture models for drug toxicity studies. Drug Deliv Transl Res 2017; 6:660-675. [PMID: 27613190 PMCID: PMC5097077 DOI: 10.1007/s13346-016-0330-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In vivo toxicity and absorption studies of topical ocular drugs are problematic, because these studies involve invasive tissue sampling and toxic effects in animal models. Therefore, different human corneal models ranging from simple monolayer cultures to three-dimensional models have been developed for toxicological prediction with in vitro models. Each system has its own set of advantages and disadvantages. Use of non-corneal cells, inadequate characterization of gene-expression profiles, and accumulation of genomic aberrations in human corneal models are typical drawbacks that decrease their reliability and predictive power. In the future, further improvements are needed for verifying comparable expression profiles and cellular properties of human corneal models with their in vivo counterparts. A rapidly expanding stem cell technology combined with tissue engineering may give future opportunities to develop new tools in drug toxicity studies. One approach may be the production of artificial miniature corneas. In addition, there is also a need to use large-scale profiling approaches such as genomics, transcriptomics, proteomics, and metabolomics for understanding of the ocular toxicity.
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Affiliation(s)
- Seppo Rönkkö
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O.Box 1627, 70211, Kuopio, Finland
| | - Kati-Sisko Vellonen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O.Box 1627, 70211, Kuopio, Finland
| | - Kristiina Järvinen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O.Box 1627, 70211, Kuopio, Finland
| | - Elisa Toropainen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O.Box 1627, 70211, Kuopio, Finland
| | - Arto Urtti
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O.Box 1627, 70211, Kuopio, Finland. .,Centre for Drug Research, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland.
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Monti D, Egiziano E, Burgalassi S, Chetoni P, Chiappe C, Sanzone A, Tampucci S. Ionic liquids as potential enhancers for transdermal drug delivery. Int J Pharm 2016; 516:45-51. [PMID: 27836753 DOI: 10.1016/j.ijpharm.2016.11.020] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 11/04/2016] [Accepted: 11/05/2016] [Indexed: 10/20/2022]
Abstract
The aim of this study was to verify the effect of several cyclic onium based ionic liquids (ILs), including mono- and dicationic derivatives of 1,4-diazabicyclo[2.2.2]octane (DABCO), a dialkyl morpholinium salt and a Brønsted acidic IL, as enhancers of the in vitro transdermal permeation and skin retention of diltiazem through and into hairless rat skin. The drug was used as both the hydrochloride salt (DZHCl) and the free base (DZB) to highlight the relationship between the enhancement effect and the physico-chemical characteristics of the active agent. Permeation tests were carried out using Gummer-type diffusion cells and excised rat skin with a 0.005M aqueous solution of diltiazem hydrochloride or diltiazem free base with and without the addition of 1% w/w ionic liquids. At the end of the permeation experiments with diltiazem hydrochloride, a suitable extraction procedure allowed for the determination of the drug content retained in the skin. Depending on the ionic liquid structure, a significant enhancement in diltiazem hydrochloride levels in the receiving phase was observed, and the transdermal permeation of the diltiazem free base was markedly increased by treatment with all of the ionic liquids. N-dodecyldabco bromide was the best enhancer for both salified and free base drug forms, even though it showed a certain toxicity. On the other hand, N-methyl-N-decylmorpholinium bromide showed a good balance between enhancer activity and cytotoxicity.
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Affiliation(s)
- Daniela Monti
- Department of Pharmacy, University of Pisa, Via Bonanno 33, I-56126, Pisa, Italy.
| | - Emanuele Egiziano
- Department of Pharmacy, University of Pisa, Via Bonanno 33, I-56126, Pisa, Italy
| | - Susi Burgalassi
- Department of Pharmacy, University of Pisa, Via Bonanno 33, I-56126, Pisa, Italy
| | - Patrizia Chetoni
- Department of Pharmacy, University of Pisa, Via Bonanno 33, I-56126, Pisa, Italy
| | - Cinzia Chiappe
- Department of Pharmacy, University of Pisa, Via Bonanno 33, I-56126, Pisa, Italy
| | - Angelo Sanzone
- Department of Pharmacy, University of Pisa, Via Bonanno 33, I-56126, Pisa, Italy
| | - Silvia Tampucci
- Department of Pharmacy, University of Pisa, Via Bonanno 33, I-56126, Pisa, Italy
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Covalent immobilization of lysozyme onto woven and knitted crimped polyethylene terephthalate grafts to minimize the adhesion of broad spectrum pathogens. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 58:78-87. [DOI: 10.1016/j.msec.2015.08.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 03/11/2015] [Accepted: 08/04/2015] [Indexed: 12/27/2022]
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Abstract
Benzalkonium chloride (BAK) is the principal preservative employed in topical ocular hypotensive medications, although alternative compounds recently have begun to be employed or examined. Individual clinical trials have shown that exposure to BAK concentrations contained in ophthalmic solutions does not produce adverse sequelae in the majority of glaucoma patients, but concerns continue with regard to its long-term use. These concerns have resulted from an extensive research effort, including preclinical studies with in vitro and in vivo models, as well as recent clinical investigations dedicated specifically to this issue. The aim of this systematic literature review of both preclinical and clinical data was to determine the relevance of these findings to clinical practice. Most preclinical studies reported negative effects of BAK exposure, but with few exceptions, BAK concentrations and exposure times greatly exceeded those likely to be experienced by patients, given the normal physiological dilution by the tear film. In addition, consistent evidence of BAK-related toxicity did not emerge from our review of dedicated clinical investigations. Thus, taken together, current evidence supports the safety of BAK for most glaucoma patients, although subpopulations with abnormal tearing may benefit from alternative preservative compounds or preservative-free formulations. Further studies to identify these populations are needed.
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Chen P, Lingen M, Sonis ST, Walsh-Reitz MM, Toback FG. Role of AMP-18 in oral mucositis. Oral Oncol 2011; 47:831-9. [PMID: 21737340 DOI: 10.1016/j.oraloncology.2011.06.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Revised: 05/27/2011] [Accepted: 06/10/2011] [Indexed: 12/30/2022]
Abstract
Oral mucositis (OM) is a devasting toxicity associated with cytotoxic cancer therapy. Antrum mucosal protein (AMP)-18 and a synthetic peptide surrogate, exhibit cell protective and mitogenic properties in in vitro and in vivo models of gastrointestinal epithelial cell injury. The mucosal barrier-protective effects may be mediated by AMP-18's capacity to increase accumulation of specific tight junction (TJ) and adherens junction proteins, and also protect against their loss after injury. Here we asked if AMP peptide could protect the oral mucosa and speed healing from radiation-induced injury. We found AMP peptide prevented radiation-induced OM in a murine model. The peptide also stimulated HaCaT cell growth used to model the oral mucosa. Binding of recombinant human (rh) AMP-18 to the plasma membrane of keratinocytes in normal human oral mucosal tissue suggested that its effects may be receptor mediated. Using an immobilized His-tagged rhAMP-18 fusion protein the receptor was identified as the cholecystokinin-B/gastrin receptor (CCKBR) by affinity purification and mass spectrometry analysis. CCKBR was expressed and co-immunoprecipitated with exogenous rhAMP-18 in diverse epithelial cell lines. Immunofluorescence staining revealed that rhAMP-18 colocalized with CCKBR on the surface of CCKBR-transfected cells. Furthermore, rhAMP-18-stimulated signaling pathways were blocked by a CCKBR-specific antagonist, YM022. rhAMP-18 enhanced viability and growth of CCKBR-transfected, but not empty vector-transfected cells. These results suggest the importance of epithelial junctional integrity in the pathogenesis of OM and demonstrate that AMP-18, by targeting TJ proteins through the activation of CCKBR, could provide a novel strategy for the prevention and treatment of OM.
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Affiliation(s)
- Peili Chen
- Department of Medicine, University of Chicago, Chicago, IL 60637, United States
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Reichl S, Kölln C, Hahne M, Verstraelen J. In vitro cell culture models to study the corneal drug absorption. Expert Opin Drug Metab Toxicol 2011; 7:559-78. [PMID: 21381983 DOI: 10.1517/17425255.2011.562195] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Many diseases of the anterior eye segment are treated using topically applied ophthalmic drugs. For these drugs, the cornea is the main barrier to reaching the interior of the eye. In vitro studies regarding transcorneal drug absorption are commonly performed using excised corneas from experimental animals. Due to several disadvantages and limitations of these animal experiments, establishing corneal cell culture models has been attempted as an alternative. AREAS COVERED This review summarizes the development of in vitro models based on corneal cell cultures for permeation studies during the last 20 years, starting with simple epithelial models and moving toward complex organotypical 3D corneal equivalents. EXPERT OPINION Current human 3D corneal cell culture models have the potential to replace excised animal corneas in drug absorption studies. However, for widespread use, the contemporary validation of existent systems is required.
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Affiliation(s)
- Stephan Reichl
- Technische Universita¨t Braunschweig, Institut fu¨r Pharmazeutische Technologie, Braunschweig, Germany.
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Epstein SP, Ahdoot M, Marcus E, Asbell PA. Comparative toxicity of preservatives on immortalized corneal and conjunctival epithelial cells. J Ocul Pharmacol Ther 2009; 25:113-9. [PMID: 19284328 DOI: 10.1089/jop.2008.0098] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE Nearly all eye drops contain preservatives to decrease contamination. Nonpreservatives such as disodium-ethylene diamine tetra-acetate (EDTA) and phosphate-buffered saline are also regularly added as buffering agents. These components can add to the toxicity of eye drops and cause ocular surface disease. To evaluate the potential toxicity of these common components and their comparative effects on the ocular surface, a tissue culture model utilizing immortalized corneal and conjunctival epithelial cells was utilized. METHODS Immortalized human conjunctival and corneal epithelial cells were grown. At confluency, medium was replaced with 100 microL of varying concentrations of preservatives: benzalkonium chloride (BAK), methyl paraben (MP), sodium perborate (SP), chlorobutanol (Cbl), and stabilized thimerosal (Thi); varying concentrations of buffer: EDTA; media (viable control); and formalin (dead control). After 1 h, solutions were replaced with 150 microL of MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazonium bromide). After 4 h, solutions decanted, 100 microL of acid isopropanol added, and the optical density determined at 572 nm to evaluate cell viability. RESULTS Conjunctival and corneal cell toxicity was seen with all preservatives. Depending upon concentration, BAK exhibited from 56% to 89% toxicity. In comparison, Cbl exhibited from 50% to 86%, MP from 30% to 76%, SP from 23% to 59%, and Thi from 70% to 95%. EDTA with minimal toxicity (from 6% to 59%) was indistinguishable from SP. CONCLUSIONS Generally, the order of decreasing toxicity at the most commonly used concentrations: Thi (0.0025%) > BAK (0.025%) > Cbl (0.25%) > MP (0.01%) > SP (0.0025%) approximately EDTA (0.01%). Even at low concentration, these agents will cause some degree of ocular tissue damage.
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Affiliation(s)
- Seth P Epstein
- Department of Ophthalmology, Mount Sinai Medical Center, New York, NY 10029-6574, USA.
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Martin J, Malreddy P, Iwamoto T, Freeman LC, Davidson HJ, Tomich JM, Schultz BD. NC-1059: a channel-forming peptide that modulates drug delivery across in vitro corneal epithelium. Invest Ophthalmol Vis Sci 2009; 50:3337-45. [PMID: 19234338 DOI: 10.1167/iovs.08-3053] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The goal of this study was to determine whether a synthetic peptide, NC-1059, can modulate the corneal epithelium to increase the permeation of therapeutic agents across this barrier. METHODS An in vitro system employing transformed human corneal epithelial (THCE) cells was optimized for this study. Culture conditions were identified to promote formation of a confluent monolayer that rapidly develops a substantial transepithelial electrical resistance. Electrical parameters were measured with a modified Ussing flux chamber, and solute flux was quantified with fluorescently labeled compounds. RESULTS NC-1059 causes a concentration-dependent increase in short-circuit current and an increase in transepithelial electrical conductance when assessed in modified Ussing chambers. The effect of NC-1059 on transepithelial electrical resistance was reversible. To test for paracellular permeability and size exclusion, FITC-labeled dextran ranging in size from 10 to 70 kDa was used. Dextran permeated the corneal cell monolayer in the presence, but not the absence, of NC-1059. Fluorescein sodium and carboxyfluorescein were then used as low molecular weight markers with similar NC-1059-modulated kinetics being observed. Maximum permeation for the fluorescein derivatives occurred 30 to 90 minutes after a 5-minute NC-1059 exposure. A prototypical drug, methotrexate, also exhibited increased permeation in the presence of NC-1059. CONCLUSIONS NC-1059 enhances drug permeation across cultured corneal epithelial cell monolayers by transiently affecting the paracellular pathway. Thus, NC-1059 is a lead compound for development of cotherapeutic agents to enhance access and effectiveness of ophthalmic compounds.
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Affiliation(s)
- Jesica Martin
- Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas 66506, USA
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Frentz M, Goss M, Reim M, Schrage NF. Repeated exposure to benzalkonium chloride in the Ex Vivo Eye Irritation Test (EVEIT): observation of isolated corneal damage and healing. Altern Lab Anim 2008; 36:25-32. [PMID: 18333712 DOI: 10.1177/026119290803600105] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The prediction of side-effects is a key issue in the REACH initiative on chemicals, in the production of cosmetics and in the preclinical testing of drugs. A new ex vivo test for repeated substance application is presented, that is able to identify corrosive and irritant effects on the eye by using crucial endpoints, such as cellular and morphological damage, and healing characteristics. The test is intended to replace the Draize eye test and to improve the preclinical testing of drugs and chemicals that are likely to come into direct contact with the cornea. The Ex Vivo Eye Irritation Test (EVEIT) is a self-healing system, involving living corneas obtained from abattoir rabbit eyes. The corneas are cultured in a similar way to the method used during the transplantation of corneal grafts. The corneas are exposed to multiple small, mechanical abrasions, and then test substances are repeatedly dropped onto the centres of the corneas. The test substances applied in this study were citrate-buffered hyaluronate eye drops and an artificial tear replacement, with increasing concentrations of up to 0.1% benzalkonium chloride. A dose-dependent inhibition of recovery and impairment of the lactate production mechanism in the cornea was observed with benzalkonium chloride treatment.
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Affiliation(s)
- Markus Frentz
- Aachen Centre of Technology Transfer in Ophthalmology, Aachen, Germany
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Abstract
Implantable devices are highly susceptible to infection and are therefore a major risk in surgery. The present work presents a novel strategy to prevent the formation of a biofilm on polytetrafluoroethylene (PTFE) grafts. PTFE grafts were coated with gentamicin and teicoplanin incorporated into different lipid-like carriers under aseptic conditions in a dipping process. Poly-d,l-lactic acid, tocopherol acetate, the diglyceride Softisan 649, and the triglyceride Dynasan 118 were used as drug carriers. The drug release kinetics, anti-infective characteristics, biocompatibility, and hemocompatibility of the coatings developed were studied. All coatings showed an initial drug burst, followed by a low continuous drug release over 96 h. The dimension of release kinetics depended on the carrier used. All coated prostheses reduced bacterial growth drastically over 24 h, even below pathologically relevant concentrations. Different cytotoxic levels could be observed, revealing tocopherol acetate as the most promising biocompatible carrier. A possible reason for the highly cytotoxic effect of Softisan 649 could be assessed by demonstrating incorporated lipids in the cell soma with Oil Red O staining. Tromboelastography studies, enzyme-linked immunosorbent assays, and an amidolytic substrate assay could confirm the hemocompatibility of individual coatings. The development of the biodegradable drug delivery systems described here and in vitro studies of those systems highlight the most important requirements for effective as well as compatible anti-infective coatings of PTFE grafts. Through continuous local release, high drug levels can be produced at only the targeted area and physiological bacterial proliferation can be completely inhibited, while biocompatibility as well as hemocompatibility can be ensured.
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Ubels JL, Clousing DP. In vitro alternatives to the use of animals in ocular toxicology testing. Ocul Surf 2007; 3:126-42. [PMID: 17131018 DOI: 10.1016/s1542-0124(12)70195-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Chemical substances, including household products, industrial chemicals, and cosmetics, must be tested for ocular toxicity or irritancy so that the public can be assured of their safety or warned of dangers associated with their use. The in vivo Draize test is the standard method used to meet this requirement; however, this test is coming under increasing criticism on scientific and ethical grounds. This has led to the development of a large number of proposed in vitro tests, some of which are routinely used to screen chemicals in toxicology laboratories. This review addresses regulations governing ocular irritancy testing and the current status of the movement toward use of alternative methods. Such methods include the use of cultured cells, hen's eggs, isolated animal eyes and corneas, human corneal epithelial cell lines, and the recently developed in vitro corneal equivalent models. The protocols for these methods are outlined, and their endpoints are described with respect to prediction of in vivo responses. The tests are evaluated in the context of the outcomes of validation studies and acceptance by regulatory agencies. While several of these tests yield useful information concerning ocular irritancy, to date, no in vitro alternative test has been validated as a replacement for the Draize test. If the goal of replacing the in vivo test while protecting the public from chemical eye injury is to be achieved, further development and improvement of alternative tests, as well as establishment of a human ocular toxicity data base, are required.
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Affiliation(s)
- John L Ubels
- Department of Biology, Calvin College, Grand Rapids, MI 49546, USA.
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Hornof M, Toropainen E, Urtti A. Cell culture models of the ocular barriers. Eur J Pharm Biopharm 2005; 60:207-25. [PMID: 15939234 DOI: 10.1016/j.ejpb.2005.01.009] [Citation(s) in RCA: 193] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Revised: 12/28/2004] [Accepted: 01/10/2005] [Indexed: 12/21/2022]
Abstract
The presence of tight barriers, which regulate the environment of ocular tissues in the anterior and posterior part of the eye, is essential for normal visual function. The development of strategies to overcome these barriers for the targeted ocular delivery of drugs, e.g. to the retina, remains a major challenge. During the last years numerous cell culture models of the ocular barriers (cornea, conjunctiva, blood-retinal barrier) have been established. They are considered to be promising tools for studying the drug transport into ocular tissues, and for numerous other purposes, such as the investigation of pathological ocular conditions, and the toxicological screening of compounds as alternative to in vivo toxicity tests. The further development of these in vitro models will require more detailed investigations of the barrier properties of both the cell culture models and the in vivo ocular barriers. It is the aim of this review to describe the current status in the development of cell culture models of the ocular barriers, and to discuss the applicability of these models in pharmaceutical research.
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Affiliation(s)
- Margit Hornof
- Department of Pharmaceutics, University of Kuopio, Kuopio, Finland
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Di Colo G, Burgalassi S, Zambito Y, Monti D, Chetoni P. Effects of Different N-Trimethyl Chitosans on In Vitro/In Vivo Ofloxacin Transcorneal Permeation. J Pharm Sci 2004; 93:2851-62. [PMID: 15389666 DOI: 10.1002/jps.20197] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
N-trimethyl chitosan (TMC) polymers differing in quaternization degree (QD) and molecular weight (MW) were prepared from two chitosans 90% deacetylated, one of higher MW (1460 kDa) (TMCH), the other of lower MW (580 kDa) (TMCL), by one (TMCH1, QD = 4%; TMCL1, QD = 3%), two (TMCH2, QD = 35%; TMCL2, QD = 46%), or three (TMCH3, QD = 90%; TMCL3, QD = 78%) reductive methylation steps. The derivatives were tested and compared for their ability to enhance the permeability of ofloxacin across rabbit corneal epithelium, reconstituted in vitro. TMC polymers of intermediate QD (TMCH2 and TMCL2), at the concentration of 0.001% w/v, produced significant permeability enhancements, independent of polymer MW. The enhancing effect did not increase when QD was increased (TMCH3 and TMCL3), while it was not significant with low QD values (TMCH1 and TMCL1). Such an effect was specific of chitosan derivatives, because fully quaternized DEAE-dextran (MeDD) was ineffective. The transcorneal permeability-enhancing property of TMCH2 and TMCL2, and the inefficacy of MeDD were confirmed by in vivo tests on rabbit eyes. However, unlike the in vitro experiments, the in vivo ones showed a stronger effect of the TMC having higher MW. TMCH2 produced antibiotic levels in the aqueous humor higher than the MIC(90%) for the more resistant ocular pathogens. These results point to this derivative as a potential ofloxacin absorption enhancer for the topical treatment of endophthalmitis.
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Affiliation(s)
- Giacomo Di Colo
- Department of Bioorganic Chemistry and Biopharmaceutics, University of Pisa Via Bonanno 33, 56126 Pisa, Italy.
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Kim BH, Chung EY, Ryu JC, Jung SH, Min KR, Kim Y. Anti-inflammatory mode of isoflavone glycoside sophoricoside by inhibition of interleukin-6 and cyclooxygenase-2 in inflammatory response. Arch Pharm Res 2003; 26:306-11. [PMID: 12735689 DOI: 10.1007/bf02976960] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Soy, high dietary intake for the oriental population, is a main source of isoflavonoids. Sophoricoside (SOP) an isoflavone glycoside was isolated from immature fruits of Sophora japonica (Leguminosae family) and its inhibitory effect on chemical mediators involved in inflammatory response was investigated in this study. SOP inhibited the interleukin (IL)-6 bioactivity with an IC50 value of 6.1 microM whereas it had no effects on IL-1beta and TNF-alpha bioactivities. SOP was identified as a selective inhibitor of cyclooxygenase (COX)-2 activity with an IC50 value of 4.4 microM, but did not show inhibitory effect on the synthesis of COX-2. However, SOP had no effect on the production of reactive oxygen species including superoxide anions and nitric oxide. These results revealed that in vitro anti-inflammatory action of SOP is significantly different from that of genistein known as a phytoestrogen of soy products. This experimental study has documented an importance of dietary soy isoflavonoids as multifunctional agents beneficial to human health, and will help to clarify protective mechanisms of SOP against inflammatory conditions.
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Affiliation(s)
- Byung Hak Kim
- College of Pharmacy and Research Center for Bioresource and Health, Chungbuk National University, Cheongju 361-763, Korea
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