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Cheng KKW, Fingerhut L, Duncan S, Prajna NV, Rossi AG, Mills B. In vitro and ex vivo models of microbial keratitis: Present and future. Prog Retin Eye Res 2024; 102:101287. [PMID: 39004166 DOI: 10.1016/j.preteyeres.2024.101287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 07/09/2024] [Accepted: 07/10/2024] [Indexed: 07/16/2024]
Abstract
Microbial keratitis (MK) is an infection of the cornea, caused by bacteria, fungi, parasites, or viruses. MK leads to significant morbidity, being the fifth leading cause of blindness worldwide. There is an urgent requirement to better understand pathogenesis in order to develop novel diagnostic and therapeutic approaches to improve patient outcomes. Many in vitro, ex vivo and in vivo MK models have been developed and implemented to meet this aim. Here, we present current in vitro and ex vivo MK model systems, examining their varied design, outputs, reporting standards, and strengths and limitations. Major limitations include their relative simplicity and the perceived inability to study the immune response in these MK models, an aspect widely accepted to play a significant role in MK pathogenesis. Consequently, there remains a dependence on in vivo models to study this aspect of MK. However, looking to the future, we draw from the broader field of corneal disease modelling, which utilises, for example, three-dimensional co-culture models and dynamic environments observed in bioreactors and organ-on-a-chip scenarios. These remain unexplored in MK research, but incorporation of these approaches will offer further advances in the field of MK corneal modelling, in particular with the focus of incorporation of immune components which we anticipate will better recapitulate pathogenesis and yield novel findings, therefore contributing to the enhancement of MK outcomes.
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Affiliation(s)
- Kelvin Kah Wai Cheng
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, United Kingdom
| | - Leonie Fingerhut
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, United Kingdom
| | - Sheelagh Duncan
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, United Kingdom
| | - N Venkatesh Prajna
- Department of Cornea and Refractive Surgery Services, Aravind Eye Hospital and Postgraduate Institute of Ophthalmology, Madurai, Tamil Nadu, India
| | - Adriano G Rossi
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, United Kingdom
| | - Bethany Mills
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, United Kingdom.
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Qin D, Han Y, Wang L, Yin H. Recent advances in medicinal compounds related to corneal crosslinking. Front Pharmacol 2023; 14:1232591. [PMID: 37841929 PMCID: PMC10570464 DOI: 10.3389/fphar.2023.1232591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 09/21/2023] [Indexed: 10/17/2023] Open
Abstract
Corneal crosslinking (CXL) is the recognized technique to strengthen corneal collagen fibers through photodynamic reaction, aiming to halt progressive and irregular changes in corneal shape. CXL has greatly changed the treatment for keratoconus (KCN) since it was introduced in the late 1990's. Numerous improvements of CXL have been made during its developing course of more than 20 years. CXL involves quite a lot of materials, including crosslinking agents, enhancers, and supplements. A general summary of existing common crosslinking agents, enhancers, and supplements helps give a more comprehensive picture of CXL. Either innovative use of existing materials or research and development of new materials will further improve the safety, effectiveness, stability, and general applicability of CXL, and finally benefit the patients.
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Affiliation(s)
- Danyi Qin
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Eye Institute and Affiliated Xiamen Eye Center, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Yi Han
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Eye Institute and Affiliated Xiamen Eye Center, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Lixiang Wang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Hongbo Yin
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
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3
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Lyu Y, Liu Y, He H, Wang H. Application of Silk-Fibroin-Based Hydrogels in Tissue Engineering. Gels 2023; 9:gels9050431. [PMID: 37233022 DOI: 10.3390/gels9050431] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/12/2023] [Accepted: 05/17/2023] [Indexed: 05/27/2023] Open
Abstract
Silk fibroin (SF) is an excellent protein-based biomaterial produced by the degumming and purification of silk from cocoons of the Bombyx mori through alkali or enzymatic treatments. SF exhibits excellent biological properties, such as mechanical properties, biocompatibility, biodegradability, bioabsorbability, low immunogenicity, and tunability, making it a versatile material widely applied in biological fields, particularly in tissue engineering. In tissue engineering, SF is often fabricated into hydrogel form, with the advantages of added materials. SF hydrogels have mostly been studied for their use in tissue regeneration by enhancing cell activity at the tissue defect site or counteracting tissue-damage-related factors. This review focuses on SF hydrogels, firstly summarizing the fabrication and properties of SF and SF hydrogels and then detailing the regenerative effects of SF hydrogels as scaffolds in cartilage, bone, skin, cornea, teeth, and eardrum in recent years.
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Affiliation(s)
- Yihan Lyu
- Department of Pharmacology, School of Medicine, Southeast University, Nanjing 210009, China
| | - Yusheng Liu
- Department of Pharmacology, School of Medicine, Southeast University, Nanjing 210009, China
| | - Houzhe He
- Department of Pharmacology, School of Medicine, Southeast University, Nanjing 210009, China
| | - Hongmei Wang
- Department of Pharmacology, School of Medicine, Southeast University, Nanjing 210009, China
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Huertas-Bello M, Cuéllar-Sáenz JA, Rodriguez CN, Cortés-Vecino JA, Navarrete ML, Avila MY, Koudouna E. A Pilot Study to Evaluate Genipin in Staphylococcus aureus and Pseudomonas aeruginosa Keratitis Models: Modulation of Pro-Inflammatory Cytokines and Matrix Metalloproteinases. Int J Mol Sci 2023; 24:ijms24086904. [PMID: 37108070 PMCID: PMC10138382 DOI: 10.3390/ijms24086904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/30/2023] [Accepted: 04/01/2023] [Indexed: 04/29/2023] Open
Abstract
Infectious keratitis is a vision-threatening microbial infection. The increasing antimicrobial resistance and the fact that severe cases often evolve into corneal perforation necessitate the development of alternative therapeutics for effective medical management. Genipin, a natural crosslinker, was recently shown to exert antimicrobial effects in an ex vivo model of microbial keratitis, highlighting its potential to serve as a novel treatment for infectious keratitis. This study aimed to evaluate the antimicrobial and anti-inflammatory effects of genipin in an in vivo model of Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) keratitis. Clinical scores, confocal microscopy, plate count, and histology were carried out to evaluate the severity of keratitis. To assess the effect of genipin on inflammation, the gene expression of pro- and anti-inflammatory factors, including matrix metalloproteinases (MMPs), were evaluated. Genipin treatment alleviated the severity of bacterial keratitis by reducing bacterial load and repressing neutrophil infiltration. The expression of interleukin 1B (IL1B), interleukin 6 (IL6), interleukin 8 (IL8), interleukin 15 (IL15), tumor necrosis factor-α (TNF-α), and interferon γ (IFNγ), as well as MMP2 and MMP9, were significantly reduced in genipin-treated corneas. Genipin promoted corneal proteolysis and host resistance to S. aureus and P. aeruginosa infection by suppressing inflammatory cell infiltration, regulating inflammatory mediators, and downregulating the expression of MMP2 and MMP9.
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Affiliation(s)
- Marcela Huertas-Bello
- Department of Ophthalmology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Jerson Andrés Cuéllar-Sáenz
- Grupo de Investigación Parasitología Veterinaria, Department of Animal Health, Faculty of Veterinary Medicine and Zootechnics, Bogota DC, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Cristian Nicolas Rodriguez
- Department of Microbiology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Jesús Alfredo Cortés-Vecino
- Grupo de Investigación Parasitología Veterinaria, Department of Animal Health, Faculty of Veterinary Medicine and Zootechnics, Bogota DC, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Myriam Lucia Navarrete
- Department of Microbiology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Marcel Yecid Avila
- Department of Ophthalmology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Elena Koudouna
- Department of Ophthalmology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogotá 111321, Colombia
- Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, UK
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Donovan C, Sun M, Cogswell D, Margo CE, Avila MY, Espana EM. Genipin increases extracellular matrix synthesis preventing corneal perforation. Ocul Surf 2023; 28:115-123. [PMID: 36871831 PMCID: PMC10440284 DOI: 10.1016/j.jtos.2023.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/04/2023] [Accepted: 02/06/2023] [Indexed: 03/06/2023]
Abstract
PURPOSE Corneal melting and perforation are feared sight-threatening complications of infections, autoimmune disease, and severe burns. Assess the use of genipin in treating stromal melt. METHODS A model for corneal wound healing was created through epithelial debridement and mechanical burring to injure the corneal stromal matrix in adult mice. Murine corneas were then treated with varying concentrations of genipin, a natural occurring crosslinking agent, to investigate the effects that matrix crosslinking using genipin has in wound healing and scar formation. Genipin was used in patients with active corneal melting. RESULTS Corneas treated with higher concentrations of genipin were found to develop denser stromal scarring in a mouse model. In human corneas, genipin promoted stromal synthesis and prevention of continuous melt. Genipin mechanisms of action create a favorable environment for upregulation of matrix synthesis and corneal scarring. CONCLUSION Our data suggest that genipin increases matrix synthesis and inhibits the activation of latent transforming growth factor-β. These findings are translated to patients with severe corneal melting.
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Affiliation(s)
| | - Mei Sun
- Department of Ophthalmology, USA
| | | | - Curtis E Margo
- Department of Ophthalmology, USA; Pathology and Cell Biology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Marcel Y Avila
- Department of Ophthalmology, Universidad Nacional de Colombia, Bogota, Colombia
| | - Edgar M Espana
- Department of Ophthalmology, USA; Molecular Pharmacology and Physiology, USA.
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Chen N, Chang B, Shi N, Yan W, Lu F, Liu F. Cross-linked enzyme aggregates immobilization: preparation, characterization, and applications. Crit Rev Biotechnol 2022; 43:369-383. [PMID: 35430938 DOI: 10.1080/07388551.2022.2038073] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Enzymes are commonly used as biocatalysts for various biological and chemical processes. However, some major drawbacks of free enzymes (e.g. poor reusability and instability) significantly restrict their industrial practices. How to overcome these weaknesses remain considerable challenges. Enzyme immobilization is one of the most effective ways to improve the reusability and stability of enzymes. Cross-linked enzyme aggregates (CLEAs) has been known as a novel and versatile carrier-free immobilization method. CLEAs is attractive due to its simplicity and robustness, without purification. It generally shows: high catalytic specificity and selectivity, good operational and storage stabilities, and good reusability. Moreover, co-immobilization of different kinds of enzymes can be acquired. These CLEAs advantages provide opportunities for further industrial applications. Herein, the preparation parameters of CLEAs were first summarized. Next, characterization of structural and catalytic properties, stability and reusability are also proposed. Finally, some important applications of this technique in: environmental protection, industrial chemistry, food industry, and pharmaceutical synthesis and delivery are introduced. Potential challenges and future research directions, such as improving cross-linking efficiency and internal mass transfer efficiency, are also presented. This implies that CLEAs provide an efficient and feasible technique to improve the properties of enzymes for use in the industry.
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Affiliation(s)
- Ning Chen
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, P. R. China
| | - Baogen Chang
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, P. R. China
| | - Nian Shi
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, P. R. China
| | - Wenxing Yan
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, P. R. China
| | - Fuping Lu
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, P. R. China
| | - Fufeng Liu
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, P. R. China
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Formisano N, Putten C, Grant R, Sahin G, Truckenmüller RK, Bouten CVC, Kurniawan NA, Giselbrecht S. Mechanical Properties of Bioengineered Corneal Stroma. Adv Healthc Mater 2021; 10:e2100972. [PMID: 34369098 DOI: 10.1002/adhm.202100972] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/15/2021] [Indexed: 12/26/2022]
Abstract
For the majority of patients with severe corneal injury or disease, corneal transplantation is the only suitable treatment option. Unfortunately, the demand for donor corneas greatly exceeds the availability. To overcome shortage issues, a myriad of bioengineered constructs have been developed as mimetics of the corneal stroma over the last few decades. Despite the sheer number of bioengineered stromas developed , these implants fail clinical trials exhibiting poor tissue integration and adverse effects in vivo. Such shortcomings can partially be ascribed to poor biomechanical performance. In this review, existing approaches for bioengineering corneal stromal constructs and their mechanical properties are described. The information collected in this review can be used to critically analyze the biomechanical properties of future stromal constructs, which are often overlooked, but can determine the failure or success of corresponding implants.
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Affiliation(s)
- Nello Formisano
- Department of Instructive Biomaterials Engineering MERLN Institute for Technology‐Inspired Regenerative Medicine Maastricht University Maastricht 6229 ER The Netherlands
| | - Cas Putten
- Department of Biomedical Engineering Eindhoven University of Technology Eindhoven 5612 AP The Netherlands
| | - Rhiannon Grant
- Department of Instructive Biomaterials Engineering MERLN Institute for Technology‐Inspired Regenerative Medicine Maastricht University Maastricht 6229 ER The Netherlands
| | - Gozde Sahin
- Department of Instructive Biomaterials Engineering MERLN Institute for Technology‐Inspired Regenerative Medicine Maastricht University Maastricht 6229 ER The Netherlands
| | - Roman K. Truckenmüller
- Department of Instructive Biomaterials Engineering MERLN Institute for Technology‐Inspired Regenerative Medicine Maastricht University Maastricht 6229 ER The Netherlands
| | - Carlijn V. C. Bouten
- Department of Biomedical Engineering Eindhoven University of Technology Eindhoven 5612 AP The Netherlands
| | - Nicholas A. Kurniawan
- Department of Biomedical Engineering Eindhoven University of Technology Eindhoven 5612 AP The Netherlands
| | - Stefan Giselbrecht
- Department of Instructive Biomaterials Engineering MERLN Institute for Technology‐Inspired Regenerative Medicine Maastricht University Maastricht 6229 ER The Netherlands
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8
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Donovan C, Koudouna E, Margo CE, Avila MY, Espana EM. Genipin Delays Corneal Stromal Enzymatic Digestion. Transl Vis Sci Technol 2021; 10:25. [PMID: 34424287 PMCID: PMC8394563 DOI: 10.1167/tvst.10.9.25] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To evaluate the use of genipin in delaying enzymatic digestion of corneal stroma. Methods Human corneal stromal tissue was treated with genipin, a known chemical crosslinker, and then along with control tissue was subjected to enzymatic digestion with collagenase. The effects of genipin treatment in retarding stromal digestion were analyzed with phase contrast microscopy, a protein quantification assay, second harmonic generation imaging, and transmission electron microscopy. Results Genipin increased stromal resistance to enzymatic digestion when compared with untreated stroma. A morphologic analysis and protein quantification showed increased stromal resistance to enzymatic digestion once stromal tissue was treated with genipin. Second harmonic generation imaging revealed persistent fibrillar collagen signaling in genipin-treated tissue in contrast with untreated tissue suggesting that genipin retards collagenolysis. Conclusions Genipin increases stromal resistance to enzymatic digestion in controlled experiments as demonstrated by protein quantification studies and through morphologic imaging. Translational Relevance This study explores the novel use of genipin in delaying enzymatic stromal digestion. Delaying stromal melting in the setting of corneal infectious or autoimmune keratitis can potentially decrease clinical morbidity.
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Affiliation(s)
- Christopher Donovan
- Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Elena Koudouna
- Department of Ophthalmology, School of Medicine, Universidad Nacional de Colombia, Hospital Universitario Nacional, Bogota, Colombia.,Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | - Curtis E Margo
- Department of Pathology and Cell Biology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.,Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Marcel Y Avila
- Department of Ophthalmology, School of Medicine, Universidad Nacional de Colombia, Hospital Universitario Nacional, Bogota, Colombia
| | - Edgar M Espana
- Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.,Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
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Koudouna E, Huertas-Bello M, Rodriguez CN, Consuelo Henao S, Navarrete ML, Avila MY. Genipin in an Ex Vivo Corneal Model of Bacterial and Fungal Keratitis. Transl Vis Sci Technol 2021; 10:31. [PMID: 34436544 PMCID: PMC8399543 DOI: 10.1167/tvst.10.9.31] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 07/06/2021] [Indexed: 01/04/2023] Open
Abstract
Purpose To determine whether genipin (a natural crosslinker) could reduce the colonization and proliferation of bacteria and fungi in an ex vivo model of corneal infection. Methods This study, using an ex vivo model of bacterial and fungal keratitis, investigated the antimicrobial efficacy of genipin crosslinking. Excised corneoscleral buttons were wounded by scalpel incision and subsequently infected with Staphylococcus aureus, Pseudomonas aeruginosa, or Candida albicans. After inoculation, corneas were treated with genipin for 24 hours at 37°C. Histologic examinations were carried out, and the number of viable colony-forming units (CFU)/cornea was determined. Results Genipin exerts bactericidal action against S. aureus and P. aeruginosa, as well as fungicidal action against C. albicans and significantly reduced the CFU compared to contralateral eyes that received saline treatment (P < 0.05). Conclusions These data identify genipin as a novel ocular antimicrobial agent that has the potential to be incorporated into the therapeutic armamentarium against microbial keratitis. Translational Relevance This study provided evidence for the antimicrobial and antifungal properties of genipin as an alternative crosslinker that could be used in the management of infectious keratitis.
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Affiliation(s)
- Elena Koudouna
- Department of Ophthalmology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogota Colombia
- Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, UK
| | - Marcela Huertas-Bello
- Department of Ophthalmology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogota Colombia
| | - Cristian Nicolas Rodriguez
- Department of Microbiology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogota Colombia
| | - Sandra Consuelo Henao
- Department of Microbiology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogota Colombia
| | - Myriam Lucia Navarrete
- Department of Microbiology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogota Colombia
| | - Marcel Yecid Avila
- Department of Ophthalmology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogota Colombia
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Song W, Cheng Y, Yan X, Yang S. Long-Term Study of Corneal Stroma and Endothelium on Structure and Cells After Genipin Treatment of Rabbit Corneas. Transl Vis Sci Technol 2021; 10:9. [PMID: 34529024 PMCID: PMC8447043 DOI: 10.1167/tvst.10.5.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To study the long-term safety of genipin treatment using a vacuum device with or without epithelial cells at different crosslinking times. Methods Twenty-five healthy New Zealand white rabbits were separated into five treatment groups: 0.25% genipin with epithelial cells for 5 minutes (G1), 0.25% genipin without epithelial cells for 5 minutes (G2), 0.25% genipin without epithelial cells for 10 minutes (G3), ultraviolet A–riboflavin collagen crosslinking (UVA), and controls (C). Before and 2, 4, 6, and 8 weeks after crosslinking treatment, anterior segment optical coherence tomography (ASOCT), in vivo confocal microscopy (IVCM), and the Pentacam system were used to evaluate the right eyes. Results A demarcation line (DL) was observed in the corneal stroma in the G2, G3, and UVA groups. The DL depths in the G2 and G3 groups were stable but decreased in the UVA group over time. The density of keratocytes in these groups increased. Endothelial cell density was decreased in the UVA group. There were no differences in the endothelium before and after treatment in the G1, G2, G3, and C groups. The densitometry, as determined using the Pentacam system, significantly increased in the G2, G3, and UVA groups and was positively correlated with keratocyte densities. Conclusions A vacuum ring assisting local genipin immersion crosslinking without corneal epithelium can activate the keratocytes in the corneal stroma and was safe enough for the thin cornea. Translational Relevance Genipin can not only crosslink the collagen fibers but also activate the keratocytes and even may promote collagen fiber secretion.
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Affiliation(s)
- Wenjing Song
- Department of Ophthalmology, Peking University First Hospital, Beijing, China
| | - Yu Cheng
- Department of Ophthalmology, Peking University First Hospital, Beijing, China
| | - Xiaoming Yan
- Department of Ophthalmology, Peking University First Hospital, Beijing, China
| | - Songlin Yang
- Department of Ophthalmology, Peking University First Hospital, Beijing, China
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Hong J, Jung D, Park S, Oh Y, Oh KK, Lee SH. Immobilization of laccase via cross-linked enzyme aggregates prepared using genipin as a natural cross-linker. Int J Biol Macromol 2021; 169:541-550. [PMID: 33358952 DOI: 10.1016/j.ijbiomac.2020.12.136] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 12/17/2020] [Accepted: 12/17/2020] [Indexed: 01/19/2023]
Abstract
Genipin is a nontoxic natural cross-linker that was successfully used to prepare cross-linked enzyme aggregates (CLEAs) of Trametes versicolor laccase. The recovered activity of CLEAs was influenced by the co-solvent type, genipin concentration, cross-linking time, preparation pH, and bovine serum albumin (BSA; amino group feeder) concentration. The characteristics of CLEAs prepared using genipin under optimal conditions (genipin-BSA-CLEAs) were compared with those of typical CLEAs prepared using glutaraldehyde or dextran polyaldehyde. Genipin-BSA-CLEAs were nano-sized (average diameter, approximately 700 nm), had a ball-like shape, showed a narrow size distribution, and exhibited the highest substrate affinity among the prepared CLEAs. The thermal stability of genipin-BSA-CLEAs was 6.8-fold higher than that of free laccase, and their pH stability was also much higher than that of free laccase in the tested range. Additionally, genipin-BSA-CLEAs retained 85% of their initial activity after 10 cycles of reuse. Particularly, genipin-BSA-CLEAs showed higher thermal and pH stability than CLEAs that were cross-linked using glutaraldehyde. Therefore, genipin represents an alternative to toxic compounds such as glutaraldehyde during cross-linking to prepare CLEAs.
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Affiliation(s)
- Jiyeon Hong
- Department of Biological Engineering, Konkuk University, Seoul 05029, South Korea
| | - Dahun Jung
- Department of Biological Engineering, Konkuk University, Seoul 05029, South Korea
| | - Saerom Park
- Department of Biological Engineering, Konkuk University, Seoul 05029, South Korea
| | - Yujin Oh
- Department of Biological Engineering, Konkuk University, Seoul 05029, South Korea
| | - Kyeong Keun Oh
- Department of Chemical Engineering, Dankook University, Yongin 16890, Gyeonggi, South Korea
| | - Sang Hyun Lee
- Department of Biological Engineering, Konkuk University, Seoul 05029, South Korea.
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Saad S, Saad R, Jouve L, Kallel S, Trinh L, Goemaere I, Borderie V, Bouheraoua N. Corneal crosslinking in keratoconus management. J Fr Ophtalmol 2020; 43:1078-1095. [DOI: 10.1016/j.jfo.2020.07.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/09/2020] [Accepted: 07/30/2020] [Indexed: 01/04/2023]
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Zhou H, Wang Z, Cao H, Hu H, Luo Z, Yang X, Cui M, Zhou L. Genipin-crosslinked polyvinyl alcohol/silk fibroin/nano-hydroxyapatite hydrogel for fabrication of artificial cornea scaffolds-a novel approach to corneal tissue engineering. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2019; 30:1604-1619. [PMID: 31438806 DOI: 10.1080/09205063.2019.1652418] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Design of artificial corneal scaffolds substitute is crucial for replacement of impaired cornea. In this paper, porous polyvinyl alcohol/silk fibroin/nano-hydroxyapatite (PVA/SF/n-HA) composite hydrogel was prepared via the genipin (GP) cross-linking, the pore diameter of the hydrogel ranged from 8.138 nm and 90.269 nm, and the physical and physiological function of hydrogel were investigated. The resulting hydrogel exhibited favourable physical properties. With the GP content increasing, the structural regularity of PVA/SF/n-HA composite hydrogel was enhanced and the thermal stability was improved. The moisture content was slightly decreased and generally maintained at approximately 70%. The tensile strength was heightened up to 0.64 MPa, while the breaking elongation was decreased slightly. Moreover, the biofunction was investigated. The in vitro degradation test demonstrated that with the addition of GP, the stability of the composite hydrogels in protease XIV solution was promoted and the three-dimensional porosity structure of composite hydrogels was maintained as ever. And the human corneal fibroblasts (HCFs) were employed to examine the cells cytotoxicity of the PVA/SF/n-HA composite hydrogels with different GP content by CCK-8 assay. Based on confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM), HCFs had individually commendable adhesion and proliferation on PVA/n-HA/SF composite hydrogel. HCFs proliferated and grew into the pores of composite hydrogel. The results of biocompatibility experiments of composite hydrogel suggested that it was no acute toxicity, in vitro cytotoxicity was 0 or 1 grade. Overall, results from this paper, PVA/n-HA/SF composite hydrogel was a qualified medical material which conformed to the national standard, could be a promising alternative for artificial cornea scaffold material-a novel approach to corneal tissue engineering.
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Affiliation(s)
- Haohao Zhou
- College of Chemistry and Environmental Engineering, Shenzhen University , Shenzhen , China
| | - Zegong Wang
- College of Chemistry and Environmental Engineering, Shenzhen University , Shenzhen , China
| | - Huiqun Cao
- College of Chemistry and Environmental Engineering, Shenzhen University , Shenzhen , China
| | - Huiyuan Hu
- College of Chemistry and Environmental Engineering, Shenzhen University , Shenzhen , China
| | - Zhongkuan Luo
- College of Chemistry and Environmental Engineering, Shenzhen University , Shenzhen , China
| | - Xinlin Yang
- College of Chemistry and Environmental Engineering, Shenzhen University , Shenzhen , China
| | - Mengmeng Cui
- College of Chemistry and Environmental Engineering, Shenzhen University , Shenzhen , China
| | - Li Zhou
- College of Chemistry and Environmental Engineering, Shenzhen University , Shenzhen , China
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Gharaibeh AM, Saez V, Garcia N, Bataille L, Alió JL. Optimizing Genipin Concentration for Corneal Collagen Cross-Linking: An ex vivo Study. Ophthalmic Res 2018; 60:100-108. [PMID: 29804113 DOI: 10.1159/000487950] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 02/25/2018] [Indexed: 11/19/2022]
Abstract
PURPOSE Studying genipin variable concentrations, treatment durations, and delivery methods as a substance to increase corneal stiffness by inducing corneal collagen cross-linking (CXL). MATERIALS AND METHODS 100 bovine corneas treated with different genipin concentrations (0.1, 0.5, and 1%) and treatment durations (15 min, 40 min, 2 h, and 3 days) through different delivery methods compared to 10 controls treated with riboflavin/UV. Histology examination, enzymatic digestion with collagenase and thermal differential scanning calorimetry were performed on the different samples. RESULTS Bovine corneas soaked in 0.5% genipin morphologically showed 4.7% CXL in comparison to 5.6% in controls (p < 0.05). Corneas treated with topical 0.5% genipin, by a 140-µL drop applied hourly for 2 h, showed 7% corneal CXL. Corneas treated with topical genipin 0.5% for 30 min, 1 and 2 h showed 54 ± 6, 40 ± 7, and 39 ± 9% enzymatic degradation, respectively, in comparison to controls (74%). Corneas treated with 0.5% genipin for 1, 2, and 8 h showed higher thermal denaturation resistance (Td values of 64.9 ± 0.3, 64.7 ± 0.0 and 67.3 ± 0.9), respectively, in comparison to the control group (64.6 ± 0.5) (p < 0.05). CONCLUSIONS Genipin 0.5%, in a 140-µL drop applied hourly for 2 h, showed better potential to enhance corneal stiffness and stability through inducing CXL.
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Affiliation(s)
- Almutez M Gharaibeh
- Faculty of Medicine, The University of Jordan, Amman, Jordan.,Vissum Instituto Oftalmológico de Alicante, Universidad Miguel Hernández, Alicante, Spain
| | - Virginia Saez
- Tecnalia Research and Innovation - Health Division, San Sebastián, Spain
| | - Nerea Garcia
- Tecnalia Research and Innovation - Health Division, San Sebastián, Spain
| | - Laurent Bataille
- Vissum Instituto Oftalmológico de Alicante, Universidad Miguel Hernández, Alicante, Spain
| | - Jorge L Alió
- Vissum Instituto Oftalmológico de Alicante, Universidad Miguel Hernández, Alicante, Spain.,Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain
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