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Salehi S, Czugala M, Stafiej P, Fathi M, Bahners T, Gutmann JS, Singer BB, Fuchsluger TA. Poly (glycerol sebacate)-poly (ε-caprolactone) blend nanofibrous scaffold as intrinsic bio- and immunocompatible system for corneal repair. Acta Biomater 2017; 50:370-380. [PMID: 28069498 DOI: 10.1016/j.actbio.2017.01.013] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 12/09/2016] [Accepted: 01/05/2017] [Indexed: 11/26/2022]
Abstract
A major challenge in corneal tissue engineering and lamellar corneal transplantation is to develop synthetic scaffolds able to simulate the optical and mechanical properties of the native cornea. As a carrier, the graft scaffolds should provide the basis for anchorage, repair and regeneration. Although quite a number of scaffolds have been engineered to date, they have not been able to simultaneously recapitulate chemical, mechanical, and structural properties of the corneal extracellular matrix (ECM). Here, we examined different compositions of elastomeric biodegradable poly (glycerol sebacate) (PGS)-poly (ε-caprolactone) (PCL) nanofibrous scaffolds with respect to their cyto- and immunocompatibility. These scaffolds were semi-transparent with well-defined mechanical properties and direct positive effects on viability of human corneal endothelial cells (HCEC) and human conjunctival epithelial cells (HCjEC). Moreover, within 3days HCEC established monolayers with the hexagonal morphology typical for this cell type. All PGS-PCL mixtures analyzed did not trigger effects in granulocytes, naïve and activated peripheral blood mononuclear cells (PBMCs). However, scaffolds with a higher content of PGS-PCL ratio showed the best cell organization, cyto- and immunocompatibility. Subsequently, this PGS-PCL composition could be used for further development of clinical constructs to support corneal tissue repair. STATEMENT OF SIGNIFICANCE In corneal tissue engineering a major challenge is the development of synthetic scaffolds with similar properties to native cornea. In our recent works, we introduced the biodegradable, polymeric nanofibrous scaffolds with similar optical and mechanical properties for corneal regeneration and here we examined the cyto- and immunocompatibility of biodegradable nanofibrous scaffolds in contact to white blood cells. Directing the alignment of human corneal cells by nanofibrous scaffolds and high viability of cells was detected by forming of endothelium monolayer with hexagonal morphology on the nanofibrous scaffold. In addition, our results for the first time show that these nanofibrous scaffolds did not trigger effects in white blood cells. These results highlight the considerable translational potential of the nanofibrous scaffolds to clinical applications.
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Gomes BF, Santhiago MR, Gomes SF, Kara-Junior N, Moraes HV. Longitudinal Evaluation of Central Corneal Thickness in Patients With Systemic Sclerosis. Cornea 2016; 35:1584-1588. [PMID: 27442319 DOI: 10.1097/ico.0000000000000950] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To investigate the longitudinal change of central corneal thickness (CCT) in patients with systemic sclerosis (SSc) and to elucidate whether it contributes to misinterpretation of intraocular pressure (IOP) in this group of patients. METHODS Twenty patients with SSc and 20 sex- and age-matched controls were examined at 2 visits 5 years apart. Age, sex, race, subtype of SSc, disease duration, autoantibody profile, use of disease-modifying antirheumatic drugs (DMARDs), best-corrected visual acuity, spherical equivalent refraction, IOP, and CCT were recorded. IOP was assessed by applanation tonometry and CCT by ultrasonic pachymetry. RESULTS CCT decreased by 7.2 μm [95% confidence interval (CI), -2.1 to -12.2 μm] between the first and second measurements (P = 0.008) in patients with SSc and by 2.4 μm (P = 0.39, 95% CI, -8.0 to 3.3 μm) in the control group. Considering patients with SSc, CCT decreased by a mean of 11.6 μm [95% CI, -4.3 to -19.0 μm (P = 0.007)] among those taking DMARDs at the second visit and by 4.2 μm [95% CI, -3.0 to -11.5 μm (P = 0.2)] in patients not taking any DMARDs. There was no statistically significant change in IOP between the 2 visits for either the SSc group (P = 0.84) or the control group (P = 0.29). Mean change in CCT was not associated with either IOP at first visit or with change in IOP in SSc patients. CONCLUSIONS CCT decreased with time in SSc. However, the slight rates of thinning observed are unlikely to considerably influence applanation tonometry or clinical decision-making over the short to intermediate term.
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Affiliation(s)
- Beatriz F Gomes
- *Department of Ophthalmology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil;†Department of Ophthalmology, Federal Hospital of Bonsucesso, Rio de Janeiro, Brazil;‡Department of Ophthalmology, University of São Paulo, São Paulo, Brazil; and§Department of Dermatology, Rubem David Azulay Dermatology Institute, Santa Casa da Misericórdia do Rio de Janeiro, Rio de Janeiro, Brazil
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Spadea L, Maraone G, Verboschi F, Vingolo EM, Tognetto D. Effect of corneal light scatter on vision: a review of the literature. Int J Ophthalmol 2016; 9:459-64. [PMID: 27158621 DOI: 10.18240/ijo.2016.03.24] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Accepted: 06/08/2015] [Indexed: 11/23/2022] Open
Abstract
The cornea is the transparent connective tissue window at the front of the eye. The physiological role of the cornea is to conduct external light into the eye, focus it, together with the lens, onto the retina, and to provide rigidity to the entire eyeball. Therefore, good vision requires maintenance of the transparency and proper refractive shape of the cornea. The surface structures irregularities can be associated with wavefront aberrations and scattering errors. Light scattering in the human cornea causes a reduction of visual quality. In fact, the cornea must be transparent and maintain a smooth and stable curvature since it contributes to the major part of the focusing power of the eye. In most cases, a simple examination of visual acuity cannot demonstrate the reduction of visual quality secondary light scattering. In fact, clinical techniques for examining the human cornea in vivo have greatly expanded over the last few decades. The measurement of corneal back scattering qualifies the degree of corneal transparency. The measurement of corneal forward-scattering quantifies the amount of visual impairment that is produced by the alteration of transparency. The aim of this study was to review scattering in the human cornea and methods of measuring it.
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Affiliation(s)
- Leopoldo Spadea
- Department of Biotechnology and Medical-Surgical Sciences, "Sapienza" University of Rome, Latina 04100, Italy
| | - Giorgia Maraone
- Department of Biotechnology and Medical-Surgical Sciences, "Sapienza" University of Rome, Latina 04100, Italy
| | - Francesca Verboschi
- Department of Biotechnology and Medical-Surgical Sciences, "Sapienza" University of Rome, Latina 04100, Italy
| | - Enzo Maria Vingolo
- Department of Biotechnology and Medical-Surgical Sciences, "Sapienza" University of Rome, Latina 04100, Italy
| | - Daniele Tognetto
- Eye Clinic, Ospedale Maggiore, University of Trieste, Trieste 34010, Italy
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de Andrade FA, Fiorot SHS, Benchimol EI, Provenzano J, Martins VJ, Levy RA. The autoimmune diseases of the eyes. Autoimmun Rev 2016; 15:258-71. [DOI: 10.1016/j.autrev.2015.12.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 11/27/2015] [Indexed: 02/06/2023]
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Celebi ARC, Kilavuzoglu AE, Altiparmak UE, Cosar CB. Corneal Biomechanical Properties in Aspirin Users. Ophthalmic Res 2016; 55:199-204. [DOI: 10.1159/000443892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 01/09/2016] [Indexed: 11/19/2022]
Abstract
<b><i>Purpose:</i></b> To analyze corneal biomechanical properties in aspirin users using an ocular response analyzer. <b><i>Methods:</i></b> This study included 80 eyes of 40 aspirin users and 80 eyes of 40 individuals who did not use aspirin. Corneal hysteresis (CH), the corneal resistance factor (CRF), Goldman-correlated intraocular pressure (IOPg), and corneal compensated intraocular pressure (IOPcc) were measured in all participants. The independent samples t test was used to compare measurements in the aspirin users and nonusers in the total study population, and in the diabetic patient subgroup. Pearson's correlation analysis was used to examine the relationship between the measured variables in the aspirin users and nonusers. <b><i>Results:</i></b> Aspirin users (59.08 ± 11.83 years) were older than nonusers (39.82 ± 12.97 years; p < 0.001). The mean CH was significantly lower in the aspirin user group than in the nonuser group (p = 0.013). Mean IOPg and mean IOPcc were also significantly higher in the aspirin user group (p = 0.027 and p = 0.002, respectively). The mean CRF was lower in the aspirin user group, but not significantly (p = 0.70). There was a positive correlation between CH and CRF (r = 0.767, p < 0.001), and between CRF and IOPg (r = 0.680, p < 0.001), and a negative correlation between CH and IOPcc (r = -0.415, p < 0.001). <b><i>Conclusions:</i></b> Aspirin should be taken into account when interpreting the results of corneal biomechanical measurements.
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Anterior segment parameters and eyelids in systemic sclerosis. Int Ophthalmol 2015; 36:577-83. [PMID: 26694912 DOI: 10.1007/s10792-015-0165-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 12/13/2015] [Indexed: 10/22/2022]
Abstract
To evaluate main numerical parameters of anterior segment and the effects of eyelid skin changes on these parameters in patients with systemic sclerosis (SSc). Thirty-four patients with SSc and 34 healthy individuals were enrolled. Besides full eye examination, anterior segment measurements including anterior chamber depth (ACD), anterior chamber volume, anterior chamber angle width, central corneal thickness, pupil size, corneal volume and keratometry were obtained using a Sirius Scheimpflug/Placido photography-based topography system. Eyelid thickness was evaluated using the scala of the modified Rodnan skin score and the patients were subgrouped with respect to these scores to evaluate the effect of eyelid thickening on the anterior segment parameters. Age and sex distributions of the groups were similar (p > 0.05). SSc patients had steeper and thinner corneas, smaller corneal volumes, narrower, shallower and smaller anterior segments but only the mean ACD value of right eyes was found significantly less than those of the controls (p = 0.047). The mean ACD values of SSc subgroup patients with moderate to severe eyelid thickening (50 %) had lower ACD measurements compared to those of control group. (p = 0.043 for the right eyes, p = 0.070 for the left eyes). However, SSc subgroup patients with none to mild eyelid thickening (50 %) had similar anterior segment parameters with control subjects (p > 0.05). Anterior chamber parameters of the SSc patients could show significant differences. These differences occur parallel to the eyelid changes but not secondary to it.
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Proteomic Analysis of the Vitreous following Experimental Retinal Detachment in Rabbits. J Ophthalmol 2015; 2015:583040. [PMID: 26664739 PMCID: PMC4667062 DOI: 10.1155/2015/583040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Revised: 10/17/2015] [Accepted: 10/19/2015] [Indexed: 01/04/2023] Open
Abstract
Purpose. The pathogenesis of rhegmatogenous retinal detachment (RRD) remains incompletely understood, with no clinically effective treatment for potentially severe complications such as photoreceptor cell death and proliferative vitreoretinopathy. Here we investigate the protein profile of the vitreous following experimental retinal detachment using a comparative proteomic based approach. Materials and Methods. Retinal detachment was created in the right eyes of six New Zealand red pigmented rabbits. Sham surgery was undertaken in five other rabbits that were used as controls. After seven days the eyes were enucleated and the vitreous was removed. The vitreous samples were evaluated with two-dimensional polyacrylamide gel electrophoresis and the differentially expressed proteins were identified with tandem mass spectrometry. Results. Ten protein spots were found to be at least twofold differentially expressed when comparing the vitreous samples of the sham and retinal detachment surgery groups. Protein spots that were upregulated in the vitreous following retinal detachment were identified as albumin fragments, and those downregulated were found to be peroxiredoxin 2, collagen-Iα1 fragment, and α-1-antiproteinase F. Conclusions. Proteomic investigation of the rabbit vitreous has identified a set of proteins that help further our understanding of the pathogenesis of rhegmatogenous retinal detachment and its complications.
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Hayes S, Lewis P, Islam MM, Doutch J, Sorensen T, White T, Griffith M, Meek KM. The structural and optical properties of type III human collagen biosynthetic corneal substitutes. Acta Biomater 2015; 25:121-130. [PMID: 26159106 PMCID: PMC4570929 DOI: 10.1016/j.actbio.2015.07.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 06/03/2015] [Accepted: 07/06/2015] [Indexed: 11/30/2022]
Abstract
The structural and optical properties of clinically biocompatible, cell-free hydrogels comprised of synthetically cross-linked and moulded recombinant human collagen type III (RHCIII) with and without the incorporation of 2-methacryloyloxyethyl phosphorylcholine (MPC) were assessed using transmission electron microscopy (TEM), X-ray scattering, spectroscopy and refractometry. These findings were examined alongside similarly obtained data from 21 human donor corneas. TEM demonstrated the presence of loosely bundled aggregates of fine collagen filaments within both RHCIII and RHCIII-MPC implants, which X-ray scattering showed to lack D-banding and be preferentially aligned in a uniaxial orientation throughout. This arrangement differs from the predominantly biaxial alignment of collagen fibrils that exists in the human cornea. By virtue of their high water content (90%), very fine collagen filaments (2–9 nm) and lack of cells, the collagen hydrogels were found to transmit almost all incident light in the visible spectrum. They also transmitted a large proportion of UV light compared to the cornea which acts as an effective UV filter. Patients implanted with these hydrogels should be cautious about UV exposure prior to regrowth of the epithelium and in-growth of corneal cells into the implants.
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Tidu A, Ghoubay-Benallaoua D, Lynch B, Haye B, Illoul C, Allain JM, Borderie VM, Mosser G. Development of human corneal epithelium on organized fibrillated transparent collagen matrices synthesized at high concentration. Acta Biomater 2015; 22:50-8. [PMID: 25931016 DOI: 10.1016/j.actbio.2015.04.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 03/06/2015] [Accepted: 04/14/2015] [Indexed: 12/13/2022]
Abstract
Several diseases can lead to opacification of cornea requiring transplantation of donor tissue to restore vision. In this context, transparent collagen I fibrillated matrices have been synthesized at 15, 30, 60 and 90 mg/mL. The matrices were evaluated for fibril organizations, transparency, mechanical properties and ability to support corneal epithelial cell culture. The best results were obtained with 90 mg/mL scaffolds. At this concentration, the fibril organization presented some similarities to that found in corneal stroma. Matrices had a mean Young's modulus of 570 kPa and acellular scaffolds had a transparency of 87% in the 380-780 nm wavelength range. Human corneal epithelial cells successfully colonized the surface of the scaffolds and generated an epithelium with characteristics of corneal epithelial cells (i.e. expression of cytokeratin 3 and presence of desmosomes) and maintenance of stemness during culture (i.e. expression of ΔNp63α and formation of holoclones in colony formation assay). Presence of cultured epithelium on the matrices was associated with increased transparency (89%).
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Affiliation(s)
- Aurélien Tidu
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Collège de France, UMR 7574, Chimie de la Matière Condensée de Paris, F-75005 Paris, France
| | - Djida Ghoubay-Benallaoua
- Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris F75012, France; INSERM, U968, Paris F75012, France; CNRS, UMR_7210, Paris F75012, France; Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU View Maintain, INSERM-DHOS CIC 1423, Paris F-75012, France
| | - Barbara Lynch
- Solids Mechanics Laboratory, Ecole Polytechnique, Centre National de la Recherche Scientifique, Palaiseau, France
| | - Bernard Haye
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Collège de France, UMR 7574, Chimie de la Matière Condensée de Paris, F-75005 Paris, France
| | - Corinne Illoul
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Collège de France, UMR 7574, Chimie de la Matière Condensée de Paris, F-75005 Paris, France
| | - Jean-Marc Allain
- Solids Mechanics Laboratory, Ecole Polytechnique, Centre National de la Recherche Scientifique, Palaiseau, France
| | - Vincent M Borderie
- Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris F75012, France; INSERM, U968, Paris F75012, France; CNRS, UMR_7210, Paris F75012, France; Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU View Maintain, INSERM-DHOS CIC 1423, Paris F-75012, France
| | - Gervaise Mosser
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Collège de France, UMR 7574, Chimie de la Matière Condensée de Paris, F-75005 Paris, France.
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Reinhard J, Joachim SC, Faissner A. Extracellular matrix remodeling during retinal development. Exp Eye Res 2015; 133:132-40. [DOI: 10.1016/j.exer.2014.07.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/30/2014] [Accepted: 07/01/2014] [Indexed: 10/25/2022]
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Catita J, López-Luppo M, Ramos D, Nacher V, Navarro M, Carretero A, Sánchez-Chardi A, Mendes-Jorge L, Rodriguez-Baeza A, Ruberte J. Imaging of cellular aging in human retinal blood vessels. Exp Eye Res 2015; 135:14-25. [PMID: 25818511 DOI: 10.1016/j.exer.2015.03.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/13/2015] [Accepted: 03/25/2015] [Indexed: 01/10/2023]
Abstract
To date two main aging vascular lesions have been reported in elderly human retinas: acellular capillaries and microaneurysms. However, their exact mechanism of formation remains unclear. Using high resolution microscopy techniques we revise cellular alterations observed in aged human retinal vessels, such as lipofuscin accumulation, caveolae malfunction, blood basement membrane disruption and enhanced apoptosis that could trigger the development of these aging vascular lesions. Moreover, we have generated a set of original images comparing retinal vasculature between middle and old aged healthy humans to show in a comprehensive manner the main structural and ultrastructural alterations occurred during age in retinal blood vessels.
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Affiliation(s)
- J Catita
- Center of Animal Biotechnology and Gene Therapy, Universitat Autònoma de Barcelona, Bellaterra, Spain; Department of Animal Health and Anatomy, School of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - M López-Luppo
- Center of Animal Biotechnology and Gene Therapy, Universitat Autònoma de Barcelona, Bellaterra, Spain; Department of Animal Health and Anatomy, School of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain; Interdisciplinary Centre of Research in Animal Health, Faculty of Veterinary Medicine, Universidade de Lisboa, Lisbon, Portugal
| | - D Ramos
- Center of Animal Biotechnology and Gene Therapy, Universitat Autònoma de Barcelona, Bellaterra, Spain; Department of Animal Health and Anatomy, School of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - V Nacher
- Center of Animal Biotechnology and Gene Therapy, Universitat Autònoma de Barcelona, Bellaterra, Spain; Department of Animal Health and Anatomy, School of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain; Interdisciplinary Centre of Research in Animal Health, Faculty of Veterinary Medicine, Universidade de Lisboa, Lisbon, Portugal
| | - M Navarro
- Center of Animal Biotechnology and Gene Therapy, Universitat Autònoma de Barcelona, Bellaterra, Spain; Department of Animal Health and Anatomy, School of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain; Interdisciplinary Centre of Research in Animal Health, Faculty of Veterinary Medicine, Universidade de Lisboa, Lisbon, Portugal
| | - A Carretero
- Center of Animal Biotechnology and Gene Therapy, Universitat Autònoma de Barcelona, Bellaterra, Spain; Department of Animal Health and Anatomy, School of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain; Interdisciplinary Centre of Research in Animal Health, Faculty of Veterinary Medicine, Universidade de Lisboa, Lisbon, Portugal
| | - A Sánchez-Chardi
- Microscopy Facility, Faculty of Science, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - L Mendes-Jorge
- Center of Animal Biotechnology and Gene Therapy, Universitat Autònoma de Barcelona, Bellaterra, Spain; Interdisciplinary Centre of Research in Animal Health, Faculty of Veterinary Medicine, Universidade de Lisboa, Lisbon, Portugal; Department of Morphology and Function, Faculty of Veterinary Medicine, Universidade de Lisboa, Lisbon, Portugal
| | - A Rodriguez-Baeza
- Department of Morphological Sciences, School of Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - J Ruberte
- Center of Animal Biotechnology and Gene Therapy, Universitat Autònoma de Barcelona, Bellaterra, Spain; Department of Animal Health and Anatomy, School of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain; Interdisciplinary Centre of Research in Animal Health, Faculty of Veterinary Medicine, Universidade de Lisboa, Lisbon, Portugal; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain.
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Remodeling of epithelial cells and basement membranes in a corneal deficiency model with long-term follow-up. J Transl Med 2015; 95:168-79. [PMID: 25531563 DOI: 10.1038/labinvest.2014.146] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 10/20/2014] [Accepted: 10/22/2014] [Indexed: 01/16/2023] Open
Abstract
The ocular surface consists of the cornea, conjunctiva, and the limbus that is located in the transitional zone between the cornea and conjunctiva. The corneal epithelial cells are generated through the mitosis of corneal epithelial stem cells in the limbus. This study investigated a rabbit corneal deficiency model prepared by the surgical removal of the corneal and limbal epithelia, which express cytokeratin 12 (K12). After the surgery, K13-expressing conjunctival epithelium migrated onto the corneal surface and completely covered the surface, leading to neovascularization and corneal opacification. However, at 24 and 48 weeks after the surgery, K12-expressing cornea-like cells reappeared on the model ocular surface. These cells formed an island surrounded by invaded conjunctiva and were isolated from the limbus. Interestingly, in the 24-week model surface, α1(IV) and α2(IV) collagen chains, which are normally found in the basement membrane of the native limbus and conjunctiva, and not in the cornea, were continuously deposited throughout the entire basement membrane, including the basement membrane under cornea-like cells. By contrast, in the 48-week model surface, α1(IV) and α2(IV) collagen chains were absent from the basement membrane beneath the central part of cornea-like cells and were localized below the invaded conjunctiva and the transitional zone between cornea-like cells and the invaded conjunctiva, which had similar distribution to the native ocular basement membrane. Moreover, K12, K14, p63, vimentin, and α1(IV) and α2(IV) collagen chains, which are colocalized in the native limbus, were all present at the transitional zone of the 48-week model surface. Therefore, a limbus-like structure appeared to be reconstructed on the surface of the 48-week model as a stem cell niche. This study should aid in the understanding of human corneal deficiency, the correlation between the epithelial cell phenotype and the composition of the basement membrane, and the epithelial stem cell niche.
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Navarro R, Casaroli-Marano R, Mateo C, Gris O, Adan A, Corcóstegui B. Optical coherence tomography findings in alport syndrome. Retin Cases Brief Rep 2014; 2:47-9. [PMID: 25389617 DOI: 10.1097/01.iae.0000247169.26035.cd] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To describe the optical coherence tomography (OCT) findings of the macular area in patients with Alport syndrome (AS), a disease caused by mutations in genes coding for type IV collagen (Col4), which is the main component of the internal limiting membrane (ILM). METHODS We reviewed the files for six eyes of three patients with AS. All patients were evaluated by OCT throughout the macula. RESULTS One patient had a giant macular hole surrounded by areas of loss of inner retinal tissue that had grown over time. The other two patients had focal zones of inner retinal thinning. CONCLUSIONS We postulate that the structural abnormalities of the ILM due to altered Col4 play a more important role in macular hole formation than hemodynamic alterations characteristic of AS. Several hypotheses could be expounded. Future OCT macular studies involving asymptomatic patients with AS would be useful in detecting and monitoring macular alterations. They would also contribute to a greater knowledge of this disease.
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Affiliation(s)
- Rafael Navarro
- From the *Vitreo-retinal Unit, Instituto de Microcirugía Ocular de Barcelona, and Universidad Autónoma de Barcelona, Barcelona, Spain; and †Hospital Clínic I Provincial de Barcelona, Barcelona, Spain
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Fuchsluger T, Salehi S, Petsch C, Bachmann B. Neue Möglichkeiten der Augenoberflächenrekonstruktion. Ophthalmologe 2014; 111:1019-26. [DOI: 10.1007/s00347-013-3010-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Ye J, Shi X, Chen X, Xie J, Wang C, Yao K, Gao C, Gou Z. Chitosan-modified, collagen-based biomimetic nanofibrous membranes as selective cell adhering wound dressings in the treatment of chemically burned corneas. J Mater Chem B 2014; 2:4226-4236. [PMID: 32261561 DOI: 10.1039/c3tb21845g] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Corneal chemical injury is a general but intractable ocular emergency, the sequelae of which are particularly challenging to treat. Human amniotic membrane (HAM) is one of the resources as a wound dressing for damaged corneal reconstruction, but the concerns related to the possible transmission of infectious diseases are the main drawbacks. Here we present a versatile method utilizing electrospinning and surface modification processes to develop optically highly transparent, microstructurally stable (>20 MPa in tensile strength in the wet state) biomimetic nanofibrous membranes. These membrane nanofibers, mainly consisting of a collagen-hyaluronate interior and a chitosan surface coating, showed superior mechanical and biological performances compared to HAM, and were favorable to the selective adhesion of epithelial cells (corneal, conjunctival) and fibroblasts. The alkali-burned corneal damage model in rats demonstrated that the biomimetic membranes could markedly improve re-epithelialization in corneal tissue within one week. Therefore, such bioactive multifunctional membranes may find widespread biomedical applications in wound healing and postoperative anti-adhesion in the near future.
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Affiliation(s)
- Juan Ye
- Eye Center, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310009, China.
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Tomita M, Mita M, Huseynova T. Accelerated versus conventional corneal collagen crosslinking. J Cataract Refract Surg 2014; 40:1013-20. [DOI: 10.1016/j.jcrs.2013.12.012] [Citation(s) in RCA: 153] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 12/15/2013] [Accepted: 12/20/2013] [Indexed: 10/25/2022]
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Nita M, Michalska-Małecka K, Mazurek U, Kimsa M, Strzałka-Mrozik B, Grzybowski A, Romaniuk D. Influence of ranibizumab treatment on the extracellular matrix in patients with neovascular age-related macular degeneration. Med Sci Monit 2014; 20:875-83. [PMID: 24866589 PMCID: PMC4049949 DOI: 10.12659/msm.890031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 12/13/2013] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND We know the influence of the intravitreal anti-vascular endothelial growth factor (VEGF) injections on the choroidal neovascularization in the course of exudative age-related macular degeneration (AMD). However, the influence of the ranibizumab therapy in question on the extracellular matrix (ECM) remains unknown. We aimed to estimate the influence of Lucentis intravitreal injections on the gene expression of structural components of the extracellular matrix in patients with neovascular AMD. MATERIAL AND METHODS Patients with subfoveal localization of neovascularization in AMD, which was clinically active and observed using optical coherence tomography, were treated with ranibizumab (0.5 mg/0.05 mL) in accordance with the PrONTO scheme. Total RNA was extracted from peripheral blood mononuclear cells, and an oligonucleotide microarray technique enabled comparison of the expression level of genes encoding collagens, elastin, and laminins in AMD patients compared to control subjects. RESULTS After 3 intravitreal injections of ranibizumab (Lucentis), COL1A1 and COL6A1 genes showed increased expression, whereas decreased expression mainly occurred for the following genes: COL4A5, COL11A1, OL4A6C, LAMB4, and LAMC2. CONCLUSIONS Anti-VEGF local therapy influences the gene expression of structural components of the ECM as measured from blood samples. The loading dose of ranibizumab for the retina changes the expression of collagen and laminin genes, but does not influence the expression of the elastin gene.
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Affiliation(s)
- Małgorzata Nita
- Domestic and Specialized Medicine Centre “Dilmed”, Katowice, Poland
| | - Katarzyna Michalska-Małecka
- Department of Ophthalmology, Medical University of Silesia, Independent Public Clinical Hospital, Katowice, Poland
| | - Urszula Mazurek
- Department of Molecular Biology, Medical University of Silesia, Sosnowiec, Poland
| | - Małgorzata Kimsa
- Department of Molecular Biology, Medical University of Silesia, Sosnowiec, Poland
| | | | - Andrzej Grzybowski
- Department of Ophthalmology, Poznań City Hospital, Poznań, Poland
- Medical Faculty, University of Warmia and Mazury, Olsztyn, Poland
| | - Dorota Romaniuk
- Department of Ophthalmology, Medical University of Silesia, Independent Public Clinical Hospital, Katowice, Poland
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69
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Salehi S, Bahners T, Gutmann JS, Gao SL, Mäder E, Fuchsluger TA. Characterization of structural, mechanical and nano-mechanical properties of electrospun PGS/PCL fibers. RSC Adv 2014. [DOI: 10.1039/c4ra01237b] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Structural and mechanical properties of aligned PGS/PCL nanofibers for cornea tissue engineering are studied and compared to natural corneal stroma.
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Affiliation(s)
- S. Salehi
- Deutsches Textilforschungszentrum Nord-West gGmbH
- 47798 Krefeld, Germany
- Augenklinik
- Universitätsklinikum Düsseldorf
- Heinrich-Heine-Universität
| | - T. Bahners
- Deutsches Textilforschungszentrum Nord-West gGmbH
- 47798 Krefeld, Germany
| | - J. S. Gutmann
- Deutsches Textilforschungszentrum Nord-West gGmbH
- 47798 Krefeld, Germany
- Physikalische Chemie
- Universität Duisburg-Essen
- 45141 Essen, Germany
| | - S.-L. Gao
- Leibniz Institut für Polymerforschung e.V
- D-01069 Dresden, Germany
| | - E. Mäder
- Leibniz Institut für Polymerforschung e.V
- D-01069 Dresden, Germany
| | - T. A. Fuchsluger
- Augenklinik
- Universitätsklinikum Düsseldorf
- Heinrich-Heine-Universität
- 40225 Düsseldorf, Germany
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Abstract
BACKGROUND Calcium is considered an important factor in the development of both osteoporosis and cataract. This study evaluated the association between osteoporosis and cataracts. OBJECTIVE To evaluate the prevalence of osteoporosis among patients undergoing cataract surgery, and the association between the two. PATIENTS AND METHODS This was a retrospective observational case-control study, conducted in the Central District of Clalit Health Services (a district of the largest health maintenance organization in Israel). All Clalit members in the district older than 50 years who underwent cataract surgery from 2000 to 2007 (n=12,984) and 25,968 age- and sex-matched controls comprised the sample. Electronic medical records of all patients in the study were reviewed. The main outcome measure was the prevalence of osteoporosis and the odds ratio of having osteoporosis among cataract patients compared with controls. RESULTS Demographically, 41.8% were men with a mean age of 68.7 ± 8.2 years. A logistic regression model for osteoporosis showed that age, female sex, higher socioeconomic class, smoking, chronic renal failure, hyperthyroidism, rheumatoid arthritis, inflammatory bowel diseases, and cataract are all associated with increased prevalence of osteoporosis. Obesity is a protective factor for osteoporosis. In all age-groups, osteoporosis was more prevalent in cataract patients than in the control group. CONCLUSION Among other well-known risk factors, osteoporosis is associated with the presence of cataracts. Common pathophysiological associations with both conditions, such as calcium imbalance, hormonal abnormalities, and shared genetic predisposition, are discussed.
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Affiliation(s)
- Arie Y Nemet
- Department of Ophthalmology, Meir Medical Center, Kfar Saba, Israel
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71
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Xiao X, Pan S, Liu X, Zhu X, Connon CJ, Wu J, Mi S. In vivo study of the biocompatibility of a novel compressed collagen hydrogel scaffold for artificial corneas. J Biomed Mater Res A 2013; 102:1782-7. [PMID: 23813783 DOI: 10.1002/jbm.a.34848] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 06/08/2013] [Accepted: 06/11/2013] [Indexed: 12/13/2022]
Abstract
The experiments were designed to evaluate the biocompatibility of a plastically compressed collagen scaffold (PCCS). The ultrastructure of the PCCS was observed via scanning electron microscopy. Twenty New Zealand white rabbits were randomly divided into experimental and control groups that received corneal pocket transplantation with PCCS and an amniotic membrane, respectively. And the contralateral eye of the implanted rabbit served as the normal group. On the 1st, 7th, 14th, 21st, 30th, 60th, 90th, and 120th postoperative day, the eyes were observed via a slit lamp. On the 120th postoperative day, the rabbit eyes were enucleated to examine the tissue compatibility of the implanted stroma. The PCCS was white and translucent. The scanning electron microscopy results showed that fibers within the PCCS were densely packed and evenly arranged. No edema, inflammation, or neovascularization was observed on ocular surface under a slit lamp and few lymphocytes were observed in the stroma of rabbit cornea after histological study. In conclusion, the PCCS has extremely high biocompatibility and is a promising corneal scaffold for an artificial cornea.
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Affiliation(s)
- Xianghua Xiao
- Shaanxi Institute of Ophthalmology, Xi'an, Shaanxi, 710002, People's Republic of China; Shaanxi Key Laboratory of Eye, Xi'an, Shaanxi, 710002, People's Republic of China; Xi'an First Hospital, Xi'an, Shaanxi, 710002, People's Republic of China
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72
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Moshirfar M, Edmonds JN, Behunin NL, Christiansen SM. Corneal biomechanics in iatrogenic ectasia and keratoconus: A review of the literature. Oman J Ophthalmol 2013; 6:12-7. [PMID: 23772119 PMCID: PMC3678190 DOI: 10.4103/0974-620x.111895] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Ocular Response Analyzer (ORA) (Reichert Ophthalmic Instruments, Buffalo, NY) allows direct measurement of corneal biomechanical properties. Since its introduction, many studies have sought to elucidate the clinical applications of corneal hysteresis (CH) and corneal resistance factor (CRF). More recently, detailed corneal deformation signal waveform analysis (WA) has potentially expanded the diagnostic capabilities of the ORA. In this review, the role of CH, CRF, and WA are examined in keratoconus (KC) and iatrogenic ectasia (IE). The PubMed database was searched electronically for peer-reviewed literature in July 2012 and August 2012 without date restrictions. The search strategy included medical subject heading (MeSH) and natural language terms to retrieve references on corneal biomechanics, CH, CRF, corneal deformation signal WA, IE, and KC. The evidence suggests that while CH and CRF are poor screening tools when used alone, increased sensitivity and specificity of KC and IE screening result when these parameters are combined with tomography and topography. Recent advances in WA are promising, but little is currently understood about its biomechanical and clinical relevance. Future studies should seek to refine the screening protocols for KC and IE as well as define the clinical applicability of WA parameters.
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Affiliation(s)
- Majid Moshirfar
- Department of Ophthalmology, John A. Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah, USA
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73
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Becerra NY, López BL, Restrepo LM. Thermosensitive behavior in cell culture media and cytocompatibility of a novel copolymer: poly(N-isopropylacrylamide-co-butylacrylate). JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2013; 24:1043-1052. [PMID: 23361967 DOI: 10.1007/s10856-013-4861-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 01/18/2013] [Indexed: 06/01/2023]
Abstract
Cell sheet technology is a promising step forward in tissue engineering. Cell sheets are usually generated using Poly(N-isopropylacrylamide) hydrogels due to their swelling change around the lower critical solution temperature (LCST). Nevertheless, LCST can be affected by cell culture medium components and therefore it is necessary to ensure that the polymer preserves its thermosensitivity under these conditions. We propose a novel thermosensitive crosslinked-copolymer: Poly(N-isopropylacrylamide-co-butylacrylate). This copolymer is shown to be cytocompatible and thermosensitive under cell culture medium conditions, and besides, it can be synthesized inexpensively. Thermosensitivity was investigated by determining the LCST with differential scanning calorimetry and swelling/ratio measurements. Cytocompatibility and capacity to deliver cell sheets were studied employing 3T3 and human oral epithelial cells. In conclusion, we obtained a thermosensitive copolymer that allows cell sheet formation/detachment by using a simple and low-cost polymerization method. Furthermore, crosslinking allows easy manipulation of cell sheets growing on the copolymer for potential in situ applications.
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Affiliation(s)
- Natalia Y Becerra
- Grupo Ciencia de los Materiales, Sede de Investigación Universitaria (SIU), Universidad de Antioquia, Medellín, Colombia.
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74
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Mi S, Connon CJ. The formation of a tissue-engineered cornea using plastically compressed collagen scaffolds and limbal stem cells. Methods Mol Biol 2013; 1014:143-155. [PMID: 23690010 DOI: 10.1007/978-1-62703-432-6_9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Collagen has excellent biocompatibility, is biodegradable, and possesses low immunogenicity. Therefore, this protein is a very suitable substrate for the formation of a corneal scaffold for therapeutic use. The highly hydrated nature of conventional collagen gels, however, results in a gel that is structurally weak and difficult to manipulate. In this chapter, we describe a novel method to cultivate limbal epithelial cells (LEC) on a compressed collagen scaffold. The compressed collagen scaffold can be rapidly constructed using a cell-independent process, which produces dense and mechanically strong collagen constructs with controllable microscale features.We embedded corneal keratocytes in a collagen gel, which we subsequently compressed and coated with laminin. The resulting construct supported the physiological morphology and stratification of LEC. The expression of a specific marker for differentiated LEC, cytokeratin 3 (CK3), and a marker for undifferentiated LEC, cytokeratin 14 (CK14), were similar in LEC expanded on both the compressed collagen construct and the leading conventional scaffold, denuded amniotic membrane (AM). We therefore demonstrate that a laminin-coated, compressed collagen gel containing keratocytes can support LEC expansion, stratification, and differentiation to a degree that is comparable to denuded AM. Our novel compressed collagen/keratocyte construct has potential for use as a tissue-engineered artificial cornea.
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Affiliation(s)
- Shengli Mi
- Graduate School at Shenzhen, Tsinghua University, Shenzhen, People's Republic of China
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75
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Structure and properties of collagen vitrigel membranes for ocular repair and regeneration applications. Biomaterials 2012; 33:8286-95. [DOI: 10.1016/j.biomaterials.2012.07.062] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 07/28/2012] [Indexed: 11/19/2022]
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76
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Liu Z, Ji J, Zhang J, Huang C, Meng Z, Qiu W, Li X, Wang W. Corneal reinforcement using an acellular dermal matrix for an analysis of biocompatibility, mechanical properties, and transparency. Acta Biomater 2012; 8:3326-32. [PMID: 22588070 DOI: 10.1016/j.actbio.2012.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Revised: 05/04/2012] [Accepted: 05/07/2012] [Indexed: 11/26/2022]
Abstract
The aim of this study was to analyze the viability of using an acellular dermal matrix (ADM) as a reinforcement material for peripheral corneal thinning disease. The complete removal of cell components was confirmed by hematoxylin and eosin (H&E) and 4',6-diamidino-2-phenylindole (DAPI) staining. Transmission electron microscopy determined that the stromal structure was well preserved. Uniaxial tests revealed that the ADM had strong mechanical properties. After being implanted into rabbit cornea the ADM showed no sign of rejection and even achieved good transparency 24weeks post-surgery. H&E staining demonstrated that keratocytes grew in the ADM and the ADM-cornea interface became blurry. Picrosirius red staining revealed great changes of collagen in the ADM. Uniaxial testing of the reinforced cornea showed better mechanical strength than the normal rabbit cornea, but this did not exhibit statistical significance. These results suggest that ADM is a worthy candidate for future exploration as a reinforcement material for peripheral corneal thinning problems.
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77
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Hoffmann A, Huang Y, Suetsugu-Maki R, Ringelberg CS, Tomlinson CR, Del Rio-Tsonis K, Tsonis PA. Implication of the miR-184 and miR-204 competitive RNA network in control of mouse secondary cataract. Mol Med 2012; 18:528-38. [PMID: 22270329 DOI: 10.2119/molmed.2011.00463] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 01/17/2012] [Indexed: 11/06/2022] Open
Abstract
The high recurrence rate of secondary cataract (SC) is caused by the intrinsic differentiation activity of residual lens epithelial cells after extra-capsular lens removal. The objective of this study was to identify changes in the microRNA (miRNA) expression profile during mouse SC formation and to selectively manipulate miRNA expression for potential therapeutic intervention. To model SC, mouse cataract surgery was performed and temporal changes in the miRNA expression pattern were determined by microarray analysis. To study the potential SC counterregulative effect of miRNAs, a lens capsular bag in vitro model was used. Within the first 3 wks after cataract surgery, microarray analysis demonstrated SC-associated expression pattern changes of 55 miRNAs. Of the identified miRNAs, miR-184 and miR-204 were chosen for further investigations. Manipulation of miRNA expression by the miR-184 inhibitor (anti-miR-184) and the precursor miRNA for miR-204 (pre-miR-204) attenuated SC-associated expansion and migration of lens epithelial cells and signs of epithelial to mesenchymal transition such as α-smooth muscle actin expression. In addition, pre-miR-204 attenuated SC-associated expression of the transcription factor Meis homeobox 2 (MEIS2). Examination of miRNA target binding sites for miR-184 and miR-204 revealed an extensive range of predicted target mRNA sequences that were also a target to a complex network of other SC-associated miRNAs with possible opposing functions. The identification of the SC-specific miRNA expression pattern together with the observed in vitro attenuation of SC by anti-miR-184 and pre-miR-204 suggest that miR-184 and miR-204 play a significant role in the control of SC formation in mice that is most likely regulated by a complex competitive RNA network.
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Affiliation(s)
- Andrea Hoffmann
- Department of Biology and Center for Tissue Regeneration and Engineering, University of Dayton, Dayton, Ohio 45469-2320, USA
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78
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Vrana NE, Builles N, Kocak H, Gulay P, Justin V, Malbouyres M, Ruggiero F, Damour O, Hasirci V. EDC/NHS cross-linked collagen foams as scaffolds for artificial corneal stroma. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012. [DOI: 10.1163/156856207794761961] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- N. E. Vrana
- a METU, BIOMAT, Department of Biological Sciences, Biotechnology Research Unit, Ankara 06531, Turkey
| | - N. Builles
- b Banque de Cornées des Hospices Civils de Lyon, 69437 Lyon, France
| | - H. Kocak
- c METU, BIOMAT, Department of Biological Sciences, Biotechnology Research Unit, Ankara 06531, Turkey
| | - P. Gulay
- d METU, BIOMAT, Department of Biological Sciences, Biotechnology Research Unit, Ankara 06531, Turkey
| | - V. Justin
- e Banque de Cornées des Hospices Civils de Lyon, 69437 Lyon, France
| | | | | | - O. Damour
- h Banque de Cornées des Hospices Civils de Lyon, 69437 Lyon, France
| | - V. Hasirci
- i METU, BIOMAT, Department of Biological Sciences, Biotechnology Research Unit, Ankara 06531, Turkey
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79
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Rogers RS, Dharsee M, Ackloo S, Sivak JM, Flanagan JG. Proteomics analyses of human optic nerve head astrocytes following biomechanical strain. Mol Cell Proteomics 2011; 11:M111.012302. [PMID: 22126795 DOI: 10.1074/mcp.m111.012302] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
We investigate the role of glial cell activation in the human optic nerve caused by raised intraocular pressure, and their potential role in the development of glaucomatous optic neuropathy. To do this we present a proteomics study of the response of cultured, optic nerve head astrocytes to biomechanical strain, the magnitude and mode of strain based on previously published quantitative models. In this case, astrocytes were subjected to 3 and 12% stretches for either 2 h or 24 h. Proteomic methods included nano-liquid chromatography, tandem mass spectrometry, and iTRAQ labeling. Using controls for both stretch and time, a six-plex iTRAQ liquid chromatography- tandem MS (LC/MS/MS) experiment yielded 573 proteins discovered at a 95% confidence limit. The pathways included transforming growth factor β1, tumor necrosis factor, caspase 3, and tumor protein p53, which have all been implicated in the activation of astrocytes and are believed to play a role in the development of glaucomatous optic neuropathy. Confirmation of the iTRAQ analysis was performed by Western blotting of various proteins of interest including ANXA 4, GOLGA2, and αB-Crystallin.
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Affiliation(s)
- Ronan S Rogers
- Institute of Medical Science, University of Toronto, Toronto, Canada.
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80
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Mi S, Khutoryanskiy VV, Jones RR, Zhu X, Hamley IW, Connon CJ. Photochemical cross-linking of plastically compressed collagen gel produces an optimal scaffold for corneal tissue engineering. J Biomed Mater Res A 2011; 99:1-8. [PMID: 21732526 DOI: 10.1002/jbm.a.33152] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Revised: 03/30/2011] [Accepted: 04/27/2011] [Indexed: 12/13/2022]
Abstract
The experiments were designed to use photochemically cross-linked plastically compressed collagen (PCPCC) gel to support corneal epithelial cells. A plastically compressed collagen (PCC) scaffold was photo cross-linked by UVA in the presence of riboflavin to form a biomaterial with optimal mechanical properties. The breaking force, rheology, surgical suture strength, transparency, ultrastructure, and cell-based biocompatibility were compared between PCPCC and PCC gels. The breaking force increased proportionally with an increased concentration of riboflavin. The stress required to reach breaking point of the PCPCC scaffolds was over two times higher compared to the stress necessary to break PCC scaffolds in the presence of 0.1% riboflavin. Rheology results indicated that the structural properties of PCC remain unaltered after UVA cross-linking. The PCC gels were more easily broken than PCPCC gels when sutured on to bovine corneas. The optical density values of PCPCC and PCC showed no significant differences (p > 0.05). SEM analyses showed that the collagen fibres within the PCPCC gels were similar in morphology to PCC gels. No difference in cell-based biocompatibility was seen between the PCPCC and PCC scaffolds in terms of their ability to support the ex vivo expansion of corneal epithelial cells or their subsequent differentiation evidenced by similar levels of cytokeratin 14. In conclusion, PCPCC scaffold is an optimal biomaterial for use in therapeutic tissue engineering of the cornea.
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Affiliation(s)
- Shengli Mi
- Stem Cells and Nanomaterials Laboratory, Reading School of Pharmacy, School of Chemistry, Food and Pharmacy, University of Reading, Reading, RG6 6UB, United Kingdom
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81
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Fullwood NJ, Martin FL, Bentley AJ, Lee JP, Lee SJ. Imaging sclera with hard X-ray microscopy. Micron 2011; 42:506-11. [DOI: 10.1016/j.micron.2011.01.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 01/27/2011] [Accepted: 01/29/2011] [Indexed: 11/26/2022]
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82
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Meyer-Blazejewska EA, Call MK, Yamanaka O, Liu H, Schlötzer-Schrehardt U, Kruse FE, Kao WW. From hair to cornea: toward the therapeutic use of hair follicle-derived stem cells in the treatment of limbal stem cell deficiency. Stem Cells 2011; 29:57-66. [PMID: 20957740 DOI: 10.1002/stem.550] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Limbal stem cell deficiency (LSCD) leads to severe ocular surface abnormalities that can result in the loss of vision. The most successful therapy currently being used is transplantation of limbal epithelial cell sheets cultivated from a limbal biopsy obtained from the patient's healthy, contralateral eye or cadaveric tissue. In this study, we investigated the therapeutic potential of murine vibrissae hair follicle bulge-derived stem cells (HFSCs) as an autologous stem cell (SC) source for ocular surface reconstruction in patients bilaterally affected by LSCD. This study is an expansion of our previously published work showing transdifferentiation of HFSCs into cells of a corneal epithelial phenotype in an in vitro system. In this study, we used a transgenic mouse model, K12(rtTA/rtTA) /tetO-cre/ROSA(mTmG) , which allows for HFSCs to change color, from red to green, once differentiation to corneal epithelial cells occurs and Krt12, the corneal epithelial-specific differentiation marker, is expressed. HFSCs were isolated from transgenic mice, amplified by clonal expansion on a 3T3 feeder layer, and transplanted on a fibrin carrier to the eye of LSCD wild-type mice (n = 31). The HFSC transplant was able to reconstruct the ocular surface in 80% of the transplanted animals; differentiating into cells with a corneal epithelial phenotype, expressing Krt12, and repopulating the corneal SC pool while suppressing vascularization and conjunctival ingrowth. These data highlight the therapeutic properties of using HFSC to treat LSCD in a mouse model while demonstrating a strong translational potential and points to the niche as a key factor for determining stem cell differentiation.
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83
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Phu D, Wray LS, Warren RV, Haskell RC, Orwin EJ. Effect of substrate composition and alignment on corneal cell phenotype. Tissue Eng Part A 2011; 17:799-807. [PMID: 20964577 PMCID: PMC3043982 DOI: 10.1089/ten.tea.2009.0724] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Corneal blindness is a significant problem treated primarily by corneal transplants. Donor tissue supply is low, creating a growing need for an alternative. A tissue-engineered cornea made from patient-derived cells and biopolymer scaffold materials would be widely accessible to all patients and would alleviate the need for donor sources. Previous work in this lab led to a method for electrospinning type I collagen scaffolds for culturing corneal fibroblasts ex vivo that mimics the microenvironment in the native cornea. This electrospun scaffold is composed of small-diameter, aligned collagen fibers. In this study, we investigate the effect of scaffold nanostructure and composition on the phenotype of corneal stromal cells. Rabbit-derived corneal fibroblasts were cultured on aligned and unaligned collagen type I fibers ranging from 50 to 300 nm in diameter and assessed for expression of α-smooth muscle actin, a protein marker upregulated in hazy corneas. In addition, the optical properties of the cell-matrix constructs were assessed using optical coherence microscopy. Cells grown on collagen scaffolds had reduced myofibroblast phenotype expression compared to cells grown on tissue culture plates. Cells grown on aligned collagen type I fibers downregulated α-smooth muscle actin protein expression significantly more than unaligned collagen scaffolds, and also exhibited reduced overall light scattering by the tissue construct. These results suggest that aligned collagen type I fibrous scaffolds are viable platforms for engineering corneal replacement tissue.
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Affiliation(s)
- Donna Phu
- Department of Biology, Harvey Mudd College, Claremont, CA 91711, USA
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84
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Mi S, Chen B, Wright B, Connon CJ. Plastic compression of a collagen gel forms a much improved scaffold for ocular surface tissue engineering over conventional collagen gels. J Biomed Mater Res A 2011; 95:447-53. [PMID: 20648540 DOI: 10.1002/jbm.a.32861] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We compare the use of plastically compressed collagen gels to conventional collagen gels as scaffolds onto which corneal limbal epithelial cells (LECs) are seeded to construct an artificial corneal epithelium. LECs were isolated from bovine corneas (limbus) and seeded onto either conventional uncompressed or novel compressed collagen gels and grown in culture. Scanning electron microscopy (SEM) results showed that fibers within the uncompressed gel were loose and irregularly ordered, whereas the fibers within the compressed gel were densely packed and more evenly arranged. Quantitative analysis of LECs expansion across the surface of the two gels showed similar growth rates (p > 0.05). Under SEM, the LECs, expanded on uncompressed gels, showed a rough and heterogeneous morphology, whereas on the compressed gel, the cells displayed a smooth and homogeneous morphology. Transmission electron microscopy (TEM) results showed the compressed scaffold to contain collagen fibers of regular diameter and similar orientation resembling collagen fibers within the normal cornea. TEM and light microscopy also showed that cell-cell and cell-matrix attachment, stratification, and cell density were superior in LECs expanded upon compressed collagen gels. This study demonstrated that the compressed collagen gel was an excellent biomaterial scaffold highly suited to the construction of an artificial corneal epithelium and a significant improvement upon conventional collagen gels.
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Affiliation(s)
- Shengli Mi
- School of Pharmacy, University of Reading, Reading, RG6 6UB, United Kingdom
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85
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Abstract
Chondrocyte differentiation in the growth plate is an important process for the longitudinal growth of endochondral bones. Sox9 and Runx2 are the most often-studied transcriptional regulators of the chondrocyte differentiation process, but the importance of additional factors is also becoming apparent. Mafs are a subfamily of the basic ZIP (bZIP) transcription factor superfamily, which act as key regulators of tissue-specific gene expression and terminal differentiation in many tissues. There is increasing evidence that c-Maf and its splicing variant Lc-Maf play a role in chondrocyte differentiation in a temporal-spatial manner. This review summarizes the functions of c-Maf in chondrocyte differentiation and discusses the possible role of c-Maf in osteoarthritis progression.
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Affiliation(s)
| | | | - Dominik R. Haudenschild
- Dominik R. Haudenschild, Department of Orthopaedic Surgery, Division of Orthopaedic Research, University of California Davis Medical Center, 4635 Second Street, Sacramento, CA 95817, USA
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Ponsioen TL, Hooymans JM, Los LI. Remodelling of the human vitreous and vitreoretinal interface – A dynamic process. Prog Retin Eye Res 2010; 29:580-95. [DOI: 10.1016/j.preteyeres.2010.07.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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88
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Corneal hysteresis, corneal resistance factor, and intraocular pressure measurement in patients with scleroderma using the reichert ocular response analyzer. Cornea 2010; 29:628-31. [PMID: 20458219 DOI: 10.1097/ico.0b013e3181c3306a] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The Reichert ocular response analyzer (ORA) measures corneal biomechanical properties in vivo by monitoring and analyzing the corneal behavior when its structure is submitted to a force induced by an air jet. This study was designed to examine corneal biomechanical properties and intraocular pressure in patients with systemic sclerosis (SSc) and to compare with control eyes. PATIENTS AND METHODS ORA measurements were performed on the right eyes of 29 patients with SSc (group 1) and 29 healthy people who served as the control group (group 2). Corneal hysteresis, corneal resistance factor (CRF), and intraocular pressure [Goldmann correlated (IOPg) and corneal compensated] were recorded with ORA. RESULTS Mean age of patients with SSc and control groups were 51.7 +/- 11.1 and 50.3 +/- 10.8 years, respectively. Mean (+/-SD) of the corneal hysteresis and CRF readings were 9.8 +/- 1.7 versus 9.5 +/- 1.2 mm Hg (P > 0.05) and 10.0 +/- 1.5 versus 9.2 +/- 1.4 mm Hg (P < 0.05), in groups 1 and 2, respectively. Mean (+/-SD) of the IOPg and intraocular pressure corneal-compensated recordings were 15.9 +/- 2.5 versus 14.1 +/- 2.4 mm Hg (P < 0.05) and 16.9 +/- 3.2 versus 15.6 +/- 2.9 mm Hg (P > 0.05), in groups 1 and 2, respectively. Statistical analysis revealed significant differences for CRF and IOPg between the study groups. CONCLUSIONS The mean CRF and IOPg values of patients with SSc were higher when compared with normal controls. According to the results of our study, one can conclude that corneal biomechanical properties would be changed in patients with SSc and this can be determined by CRF.
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89
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Su J, Wall ST, Healy KE, Wildsoet CF. Scleral reinforcement through host tissue integration with biomimetic enzymatically degradable semi-interpenetrating polymer network. Tissue Eng Part A 2010; 16:905-16. [PMID: 19814587 DOI: 10.1089/ten.tea.2009.0488] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Enzymatically degradable semi-interpenetrating polymer networks (edsIPNs) were explored for their biocompatibility and ability to promote new scleral tissue growth, as a means of reinforcing the posterior wall of the eye. The edsIPNs comprised thermoresponsive poly(N-isopropylacrylamide-co-acrylic acid), customizable peptide crosslinkers cleavable by matrix metalloproteinases, and interpenetrating linear poly(acrylic acid)-graft-peptide chains to engage with cell surface receptors. Rheological studies revealed an increase in stiffness at body temperature; the complex shear modulus |G*| was 14.13 +/- 6.13 Pa at 22 degrees C and 63.18 +/- 12.24 Pa at 37 degrees C, compatible with injection at room temperature. Primary chick scleral fibroblasts and chondrocytes cultured on edsIPN increased by 15.1- and 11.1-fold, respectively, over 11 days; both exhibited delayed onset of exponential growth compared with the cells plated on tissue culture polystyrene. The edsIPN was delivered by retrobulbar injection (100 microL) to nine 2-week-old chicks to assess biocompatibility in vivo. Ocular axial dimensions were assessed using A-scan ultrasonography over 28 days, after which eyes were processed for histological analysis. Although edsIPN injections did not affect the rate of ocular elongation, the outer fibrous sclera showed significant thickening. The demonstration that injectable biomimetic edsIPNs stimulate scleral fibrous tissue growth represents proof-of-principle for a novel approach for scleral reinforcement and a potential therapy for high myopia.
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Affiliation(s)
- James Su
- Vision Science Group, School of Optometry, University of California, Berkeley, CA 94720-2020, USA
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90
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Ex Vivo Construction of an Artificial Ocular Surface by Combination of Corneal Limbal Epithelial Cells and a Compressed Collagen Scaffold Containing Keratocytes. Tissue Eng Part A 2010; 16:2091-100. [DOI: 10.1089/ten.tea.2009.0748] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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91
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Kashiwagi Y, Nishitsuka K, Namba H, Kamiryo M, Takamura H, Yamashita H. Cloning and characterization of cell strains derived from human corneal stroma and sclera. Jpn J Ophthalmol 2010; 54:74-80. [PMID: 20151280 DOI: 10.1007/s10384-009-0749-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Accepted: 07/30/2009] [Indexed: 11/28/2022]
Abstract
PURPOSE To establish human corneal stroma- and sclera-derived cells as models for studying diseases of the anterior segment of the eye. METHODS Using a recombinant retrovirus system, we transfected human papilloma virus 16 E6 and E7 (HPV16 E6/E7) into human corneal stroma- and sclera-derived cells. The primary cells and established cell strains were characterized by assessing the mRNA expression of collagen, matrix metalloproteinase, and tissue inhibitor of metalloproteinase by reverse transcription-polymerase chain reaction. We also examined the effects of inflammatory cytokines on hyaluronan synthase expression and hyaluronan products. RESULTS Both a corneal stroma-derived cell strain, Cs3, and a sclera-derived cell strain, Sc1, were obtained, and both cell strains could be passaged up to 25 times. The mRNA expression pattern observed in the primary cells was identical to that observed in the cell strains. Hyaluronan synthase 1 and 2 mRNAs were increased by transforming growth factor beta and platelet-derived growth factor BB. Significant differences were observed between the hyaluronan products with and without cytokine treatment. CONCLUSION Cell strains derived from corneal stroma and sclera fibroblast cells can be established using HPV16 E6/E7 immortalized genes of the same origin. The phenotypic cell characteristics did not change after transfection, immortalization, or successive passages in culture.
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Affiliation(s)
- Yoshiko Kashiwagi
- Department of Ocular Cellar Engineering, Yamagata University, Yamagata, Japan.
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92
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McIntosh Ambrose W, Salahuddin A, So S, Ng S, Ponce Márquez S, Takezawa T, Schein O, Elisseeff J. Collagen vitrigel membranes for thein vitroreconstruction of separate corneal epithelial, stromal, and endothelial cell layers. J Biomed Mater Res B Appl Biomater 2009; 90:818-31. [DOI: 10.1002/jbm.b.31351] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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93
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Gisladottir S, Loftsson T, Stefansson E. Diffusion characteristics of vitreous humour and saline solution follow the Stokes Einstein equation. Graefes Arch Clin Exp Ophthalmol 2009; 247:1677-84. [PMID: 19639333 DOI: 10.1007/s00417-009-1141-3] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Accepted: 06/27/2009] [Indexed: 11/25/2022] Open
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94
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Meek KM. Corneal collagen-its role in maintaining corneal shape and transparency. Biophys Rev 2009; 1:83-93. [PMID: 28509987 PMCID: PMC5425665 DOI: 10.1007/s12551-009-0011-x] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Accepted: 05/14/2009] [Indexed: 10/20/2022] Open
Abstract
Corneal collagen has a number of properties that allow it to fulfil its role as the main structural component within the tissue. Fibrils are narrow, uniform in diameter and precisely organised. These properties are vital to maintain transparency and to provide the biomechanical prerequisites necessary to sustain shape and provide strength. This review describes the structure and arrangement of corneal collagen from the nanoscopic to the macroscopic level, and how this relates to the maintenance of the form and transparency of the cornea.
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Affiliation(s)
- Keith M Meek
- Structural Biophysics Research Group, School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4LU, UK.
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95
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Wray LS, Orwin EJ. Recreating the Microenvironment of the Native Cornea for Tissue Engineering Applications. Tissue Eng Part A 2009; 15:1463-72. [DOI: 10.1089/ten.tea.2008.0239] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Lindsay S. Wray
- Department of Biology, Harvey Mudd College, Claremont, California
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96
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Chang CH, Chiao CC, Yan HY. The structure and possible functions of the milkfish Chanos chanos adipose eyelid. JOURNAL OF FISH BIOLOGY 2009; 75:87-99. [PMID: 20738484 DOI: 10.1111/j.1095-8649.2009.02266.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Basic histological sections (with different staining methods) and scanning electron microscopy (SEM) examinations showed that there were three distinctive layers in the adipose eyelid of milkfish Chanos chanos, which is found in the cephalie region and covers the entire eye. The outer and inner layers were epithelial tissues and the middle layer was composed of connective tissue formed by type I collagen fibrils. No adipose tissue was found in any of the three layers of the so-called adipose eyelid. Examination by transmission spectrophotometer showed that the adipose tissue could filter out ambient light with a wavelength shorter than 305 nm. A photoretinoscope was used to investigate whether the adipose eyelid influenced the mechanism of eye focusing. Eye diopter values did not differ before or after eyelid removal, which indicated that the adipose eyelid did not play a role in eye focusing. In light of these findings, it is suggested that the adipose eyelid serves to block exposure of harmful ultraviolet light into eyes and may also to offer some protection against impact to the eye in the aquatic environment.
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Affiliation(s)
- C-H Chang
- Marine Research Station, Institute of Cellular and Organismic Biology Academia Sinica, Jiaoshi Township, I-Lan County 26242, Taiwan
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97
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Ahmadiankia N, Ebrahimi M, Hosseini A, Baharvand H. Effects of different extracellular matrices and co-cultures on human limbal stem cell expansion in vitro. Cell Biol Int 2009; 33:978-87. [PMID: 19559803 DOI: 10.1016/j.cellbi.2009.06.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Revised: 03/06/2009] [Accepted: 06/03/2009] [Indexed: 11/17/2022]
Abstract
To elucidate the effect of extracellular matrices (ECMs) and related and nonrelated-limbal feeder cells as substitutes for the in vivo niche on the phenotype and genotype of the limbal stem cell (SC) expansion in vitro, human limbal SCs were used. The limbus explants were expanded on human amniotic membrane (AM), commercial ECMs including matrigel (MAT), collagen (COL), and control (no ECM) in presence and absence of feeder cells including human limbal fibroblasts (LFs), a limbus-specific cell and mouse embryonic fibroblasts (MEFs). Proliferation, cell death, immunocytochemistry, expression of specific genes, ultrastructural characteristics, and size and granularity of expanded human limbal SCs in different groups were evaluated. The growth, cell proliferation, and survival of limbal SCs were enhanced by AM and MAT matrices. Ultrastructure and expression of stemness markers revealed that there was no significance difference between AM and MAT. However, flow cytometric analysis showed that the size and granularity of cultured cells increased in the presence of MAT and COL as well as in no ECM group. Moreover, co-culturing of limbal explants with LFs and MEFs on AM and MAT groups, enhanced the expansion and survival of cultured cells in comparison with others. In conclusion, the cultivation of human limbal explants on AM co-culturing with human LFs promises to be a good model for preparing undifferentiated epithelial sheets suitable for transplantation.
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Affiliation(s)
- Naghmeh Ahmadiankia
- Department of Stem Cells and Developmental Biology, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
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98
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Corneal transparency: genesis, maintenance and dysfunction. Brain Res Bull 2009; 81:198-210. [PMID: 19481138 DOI: 10.1016/j.brainresbull.2009.05.019] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2009] [Revised: 04/14/2009] [Accepted: 05/20/2009] [Indexed: 02/01/2023]
Abstract
Optimal vision is contingent upon transparency of the cornea. Corneal neovascularization, trauma and, surgical procedures such as photorefractive keratectomy and graft rejection after penetrating keratoplasty can lead to corneal opacification. In this article we identify the underlying basis of corneal transparency and factors that compromise the integrity of the cornea. With evidence from work on animal models and clinical studies, we explore the molecular mechanisms of both corneal avascularity and its dysfunction. We also seek to review therapeutic regimens that can safely salvage and restore corneal transparency.
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99
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Blazejewska EA, Schlötzer-Schrehardt U, Zenkel M, Bachmann B, Chankiewitz E, Jacobi C, Kruse FE. Corneal limbal microenvironment can induce transdifferentiation of hair follicle stem cells into corneal epithelial-like cells. Stem Cells 2009; 27:642-52. [PMID: 19074417 PMCID: PMC2729676 DOI: 10.1634/stemcells.2008-0721] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Accepted: 11/15/2008] [Indexed: 12/17/2022]
Abstract
The aim of this study was to investigate the transdifferentiation potential of murine vibrissa hair follicle (HF) stem cells into corneal epithelial-like cells through modulation by corneal- or limbus-specific microenvironmental factors. Adult epithelial stem cells were isolated from the HF bulge region by mechanical dissection or fluorescence-activated cell sorting using antibodies to alpha6 integrin, enriched by clonal expansion, and subcultivated on various extracellular matrices (type IV collagen, laminin-1, laminin-5, fibronectin) and in different conditioned media derived from central and peripheral corneal fibroblasts, limbal stromal fibroblasts, and 3T3 fibroblasts. Cellular phenotype and differentiation were evaluated by light and electron microscopy, real-time reverse transcription-polymerase chain reaction, immunocytochemistry, and Western blotting, using antibodies against putative stem cell markers (K15, alpha6 integrin) and differentiation markers characteristic for corneal epithelium (K12, Pax6) or epidermis (K10). Using laminin-5, a major component of the corneo-limbal basement membrane zone, and conditioned medium from limbal stromal fibroblasts, clonally enriched HF stem and progenitor cells adhered rapidly and formed regularly arranged stratified cell sheets. Conditioned medium derived from limbal fibroblasts markedly upregulated expression of cornea-specific K12 and Pax6 on the mRNA and protein level, whereas expression of the epidermal keratinocyte marker K10 was strongly downregulated. These findings suggest that adult HF epithelial stem cells are capable of differentiating into corneal epithelial-like cells in vitro when exposed to a limbus-specific microenvironment. Therefore, the HF may be an easily accessible alternative therapeutic source of autologous adult stem cells for replacement of the corneal epithelium and restoration of visual function in patients with ocular surface disorders.
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100
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Su J, Iomdina E, Tarutta E, Ward B, Song J, Wildsoet CF. Effects of poly(2-hydroxyethyl methacrylate) and poly(vinyl-pyrrolidone) hydrogel implants on myopic and normal chick sclera. Exp Eye Res 2008; 88:445-57. [PMID: 19109950 DOI: 10.1016/j.exer.2008.10.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 10/07/2008] [Accepted: 10/23/2008] [Indexed: 10/21/2022]
Abstract
There has been generally little attention paid to the utilization of biomaterials as an anti-myopia treatment. The purpose of this study was to investigate whether polymeric hydrogels, either implanted or injected adjacent to the outer scleral surface, slow ocular elongation. White Leghorn (Gallus gallus domesticus) chicks were used at 2 weeks of age. Chicks had either (1) a strip of poly(2-hydroxyethyl methacrylate) (pHEMA) implanted monocularly against the outer sclera at the posterior pole, or (2) an in situ polymerizing gel [main ingredient: poly(vinyl-pyrrolidone) (PVP)] injected monocularly at the same location. Some of the eyes injected with the polymer were fitted with a diffuser or a -10D lens. In each experiment, ocular lengths were measured at regular intervals by high frequency A-scan ultrasonography, and chicks were sacrificed for histology at staged intervals. No in vivo signs of either orbital or ocular inflammation were observed. The pHEMA implant significantly increased scleral thickness by the third week, and the implant became encapsulated with fibrous tissue. The PVP-injected eyes left otherwise untreated, showed a significant increase in scleral thickness, due to increased chondrocyte proliferation and extracellular matrix deposition. However, there was no effect of the PVP injection on ocular elongation. In eyes wearing optical devices, there was no effect on either scleral thickness or ocular elongation. These results represent "proof of principle" that scleral growth can be manipulated without adverse inflammatory responses. However, since neither approach slowed ocular elongation, additional factors must influence scleral surface area expansion in the avian eye.
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Affiliation(s)
- James Su
- Vision Science Group, School of Optometry, UC Berkeley, Berkeley, CA 94720-2020, USA.
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