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Ruiz-Franco J, Rivas-Barbosa R, Lara-Peña MA, Villanueva-Valencia JR, Licea-Claverie A, Zaccarelli E, Laurati M. Concentration and temperature dependent interactions and state diagram of dispersions of copolymer microgels. SOFT MATTER 2023; 19:3614-3628. [PMID: 37161724 DOI: 10.1039/d3sm00120b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We investigate by means of small angle neutron scattering experiments and numerical simulations the interactions and inter-particle arrangements of concentrated dispersions of copolymer poly(N-isopropylacrylamide)-poly(ethylene glycol methyl ether methacrylate) (PNIPAM-PEGMA) microgels across the volume phase transition (VPT). The scattering data of moderately concentrated dispersions are accurately modeled at all temperatures by using a star polymer form factor and static structure factors calculated from the effective potential obtained from simulations. Interestingly, for temperatures below the VPT temperature (VPTT), the radius of gyration and blob size of the particles significantly decrease with increasing the effective packing fraction in the non-overlapping regime. This is attributed to the presence of charges in the system associated with the use of an ionic initiator in the synthesis. Simulations using the experimentally corroborated interaction potential are used to explore the state diagram in a wide range of effective packing fractions. Below and slightly above the VPTT, the system undergoes an arrest transition mainly driven by the soft repulsion between the particles. Only well above the VPTT the system is found to phase separate before arresting. Our results highlight the versatility and potential of copolymer PNIPAM-PEGMA microgels to explore different kinds of arrested states balancing attraction and repulsion by changing temperature and packing fraction.
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Affiliation(s)
- José Ruiz-Franco
- CNR Institute of Complex Systems, Uos Sapienza, Piazzale Aldo Moro 2, 00185, Roma, Italy.
- Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, 00185 Roma, Italy
- Physical Chemistry and Soft Matter, Wageningen University & Research, Stippeneng 4, 6708WE Wageningen, The Netherlands
| | - Rodrigo Rivas-Barbosa
- Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, 00185 Roma, Italy
- División de Ciencias e Ingenierías, Universidad de Guanajuato, Lomas del Bosque 103, 37150 León, Mexico
| | - Mayra A Lara-Peña
- División de Ciencias e Ingenierías, Universidad de Guanajuato, Lomas del Bosque 103, 37150 León, Mexico
- Dipartimento di Chimica and CSGI, Università di Firenze, 50019 Sesto Fiorentino, Italy.
| | | | - Angel Licea-Claverie
- Centro de Graduados e Investigación en Química del Tecnológico Nacional de México/Instituto Tecnológico de Tijuana, 22500 Tijuana, Mexico
| | - Emanuela Zaccarelli
- CNR Institute of Complex Systems, Uos Sapienza, Piazzale Aldo Moro 2, 00185, Roma, Italy.
- Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, 00185 Roma, Italy
| | - Marco Laurati
- Dipartimento di Chimica and CSGI, Università di Firenze, 50019 Sesto Fiorentino, Italy.
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Pan J, Zhang W, Zhu J, Tan J, Huang Y, Mo K, Tong Y, Xie Z, Ke Y, Zheng H, Ouyang H, Shi X, Gao L. Arrested Phase Separation Enables High-Performance Keratoprostheses. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2207750. [PMID: 36680510 DOI: 10.1002/adma.202207750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 12/24/2022] [Indexed: 06/17/2023]
Abstract
Corneal transplantation is impeded by donor shortages, immune rejection, and ethical reservations. Pre-made cornea prostheses (keratoprostheses) offer a proven option to alleviate these issues. Ideal keratoprostheses must possess optical clarity and mechanical robustness, but also high permeability, processability, and recyclability. Here, it is shown that rationally controlling the extent of arrested phase separation can lead to optimized multiscale structure that reconciles permeability and transparency, a previously conflicting goal by common pore-forming strategies. The process is simply accomplished by hydrothermally treating a dense and transparent hydrophobic association hydrogel. The examination of multiscale structure evolution during hydrothermal treatment reveals that the phase separation with upper miscibility gap evolves to confer time-dependent pore growth due to slow dynamics of polymer-rich phase which is close to vitrification. Such a process can render a combination of multiple desired properties that equal or surpass those of the state-of-the-art keratoprostheses. In vivo tests confirm that the keratoprosthesis can effectively repair corneal perforation and restore a transparent cornea with treatment outcomes akin to that of allo-keratoplasty. The keratoprosthesis is easy to access and convenient to carry, and thus would be an effective temporary substitute for a corneal allograft in emergency conditions.
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Affiliation(s)
- Jiageng Pan
- School of Chemical Engineering and Light Industry, Gangdong University of Technology, Guangzhou, 510006, P. R. China
| | - Wang Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, P. R. China
| | - Jin Zhu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, P. R. China
| | - Jieying Tan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, P. R. China
| | - Ying Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, P. R. China
| | - Kunlun Mo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, P. R. China
| | - Yan Tong
- School of Materials, Sun Yat-sen University, Guangzhou, 510060, P. R. China
| | - Zhenhua Xie
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P. R. China
- Spallation Neutron Source Science Center, Dongguan, 523803, P. R. China
| | - Yubin Ke
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P. R. China
- Spallation Neutron Source Science Center, Dongguan, 523803, P. R. China
| | - Huade Zheng
- School of Materials Science and Engineering, South China University of Technology, Guanghzhou, 510640, P. R. China
| | - Hong Ouyang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, P. R. China
| | - Xuetao Shi
- School of Materials Science and Engineering, South China University of Technology, Guanghzhou, 510640, P. R. China
| | - Liang Gao
- School of Chemical Engineering and Light Industry, Gangdong University of Technology, Guangzhou, 510006, P. R. China
- Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory (Rongjiang Laboratory), Jieyang, 515200, P. R. China
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Li S, Ma X, Zhang Y, Qu Y, Wang L, Ye L. Applications of hydrogel materials in different types of corneal wounds. Surv Ophthalmol 2023:S0039-6257(23)00040-1. [PMID: 36854372 DOI: 10.1016/j.survophthal.2023.02.005] [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: 08/10/2022] [Revised: 02/20/2023] [Accepted: 02/21/2023] [Indexed: 02/27/2023]
Abstract
Severe corneal injury can lead to a decrease in light transmission and even blindness. Currently, corneal transplantation has been applied as the primary treatment for corneal blindness; however, the worldwide shortage of suitable corneal donor tissue means that a large proportion of patients have no access to corneal transplants. This situation has contributed to the rapid development of various corneal substitutes. The development and optimization of novel hydrogels that aim to replace partial or full-thickness pathological corneas have advanced in the last decade. Meanwhile, with the help of 3D bioprinting technology, hydrogel materials can be molded to a refined and controllable shape, attracting many scientists to the field of corneal reconstruction research. Although hydrogels are not yet available as a substitute for traditional clinical methods of corneal diseases, their rapid development makes us confident that they will be in the near future. We summarize the application of hydrogel materials for various types of corneal injuries frequently encountered in clinical practice, especially focusing on animal experiments and preclinical studies. Finally, we discuss the development and achievements of 3D bioprinting in the treatment of corneal injury.
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Affiliation(s)
- Shixu Li
- Shenzhen Eye Hospital, Jinan University, Shenzhen, China; Shenzhen Eye Institute, Shenzhen, China
| | - Xudai Ma
- Shenzhen Eye Hospital, Jinan University, Shenzhen, China; Shenzhen Eye Institute, Shenzhen, China
| | - Yongxin Zhang
- Shenzhen Eye Hospital, Jinan University, Shenzhen, China; Shenzhen Eye Institute, Shenzhen, China
| | - Yunhao Qu
- Shenzhen Eye Hospital, Jinan University, Shenzhen, China; Shenzhen Eye Institute, Shenzhen, China
| | - Ling Wang
- Shenzhen Eye Hospital, Jinan University, Shenzhen, China; Shenzhen Eye Institute, Shenzhen, China.
| | - Lin Ye
- Shenzhen Eye Hospital, Jinan University, Shenzhen, China; Shenzhen Eye Institute, Shenzhen, China.
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Rathod S. Interpenetrating polymeric network (IPNs) in ophthalmic drug delivery: Breaking the barriers. Int Ophthalmol 2022; 43:1063-1074. [PMID: 36053474 DOI: 10.1007/s10792-022-02482-4] [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: 09/30/2021] [Accepted: 08/20/2022] [Indexed: 10/14/2022]
Abstract
To maintain the therapeutic drug concentration for a prolonged period of time in aqueous and vitreous humor is primary challenge for ophthalmic drug delivery. Majority of the locally administered drug into the eye is lost as to natural reflexes like blinking and lacrimation resulting in the short span of drug residence. Consequently, less than 5% of the applied drug penetrate through the cornea and reaches the intraocular tissues. The major targets for optimal ophthalmic drug delivery are increasing drug residence time in cul-de-sac of the eye, prolonging intraocular exposure, modulating drug release from the delivery system, and minimizing pre-corneal drug loss. Development of in situ gel, contact lens, intraocular lens, inserts, artificial cornea, scaffold, etc., for ophthalmic drug delivery are few approaches to achieve these major targeted objectives for delivering the drug optimally. Interpenetrating polymeric network (IPN) or smart hydrogels or stimuli sensitive hydrogels are the class of polymers that can help to achieve the targets in ophthalmic drug delivery due to their versatility, biocompatibility and biodegradability. These novel ''smart" materials can alter their molecular configuration and result in volume phase transition in response to environmental stimuli, such as temperature, pH, ionic strength, electric and magnetic field. Hydrogel and tissue interaction, mechanical/tensile properties, pore size and surface chemistry of IPNs can also be modulated for tuning the drug release kinetics. Stimuli sensitive IPNs has been widely exploited to prepare in situ gelling formulations for ophthalmic drug delivery. Low refractive index hydrogel biomaterials with high water content, soft tissue-like physical properties, wettability, oxygen, glucose permeability and desired biocompatibility makes IPNs versatile candidate for contact lenses and corneal implants. This review article focuses on the exploration of these smart polymeric networks/IPNs for therapeutically improved ophthalmic drug delivery that has unfastened novel arenas in ophthalmic drug delivery.
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Affiliation(s)
- Sachin Rathod
- Maliba Pharmacy College, UKA Tarsadia University, Gopal-Vidyanagar Campus, Surat, 394350, India. .,Parul Institute of Pharmacy and Research, Parul University, Waghodia, Vadodara, 391760, India.
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Touchet T, Briggs S, Graul L, Maitland DJ. Development and Characterization of Oxidatively Responsive Thiol-Ene Networks for Bone Graft Applications. ACS APPLIED BIO MATERIALS 2022; 5:2633-2642. [PMID: 35658422 DOI: 10.1021/acsabm.2c00103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
First metatarsophalangeal joint (MPJ) arthroplasty procedures are a common podiatric procedure. However, almost one-third of cases require revision surgeries because of nonunions. Revision or salvage surgery requires more extensive hardware and bone grafts to recreate the first metatarsal. Unfortunately, salvage surgeries have a similar rate of failure attributed to delayed healing, bone graft dissolution, and the lack of bone ingrowth. Furthermore, patients who suffer from neuropathic comorbidities such as diabetes suffer from a diminished healing capacity. An increase in proinflammatory factors and the high presence of reactive oxygen species (ROS) present in diabetics are linked to lower fusion rates. To this end, there is a need for a clinically relevant bone graft to promote bone fusions in patients with neuropathic comorbidities. Incorporating thiol-ene networks for bone scaffolds has demonstrated increased osteogenic biomarkers over traditional polymeric materials. Furthermore, thiol-ene networks can act as antioxidants. Sulfide linkages within the network have an inherent ability to consume radical oxygen to create sulfoxide and sulfone groups. These unique properties of thiol-ene networks make them a promising candidate as bone grafts for diabetic patients. In this work, we propose a thiol-ene biomaterial to address the current limitations of MPJ fusion in diabetics by characterizing mechanical properties, degradation rates under accelerated conditions, and oxidative responsiveness under pathophysiologic conditions. We also demonstrated that thiol-ene-based materials could reduce the number of hydroxyl radicals associated with neuropathic comorbidities.
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Affiliation(s)
- Tyler Touchet
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas 77480, United States.,DJO Foot and Ankle, 727 N. Shepherd Drive Suite 100, Houston, Texas 77007, United States
| | - Samuel Briggs
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas 77480, United States
| | - Lance Graul
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas 77480, United States
| | - Duncan J Maitland
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas 77480, United States
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Significance of Crosslinking Approaches in the Development of Next Generation Hydrogels for Corneal Tissue Engineering. Pharmaceutics 2021; 13:pharmaceutics13030319. [PMID: 33671011 PMCID: PMC7997321 DOI: 10.3390/pharmaceutics13030319] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/19/2021] [Accepted: 02/24/2021] [Indexed: 02/07/2023] Open
Abstract
Medical conditions such as trachoma, keratoconus and Fuchs endothelial dystrophy can damage the cornea, leading to visual deterioration and blindness and necessitating a cornea transplant. Due to the shortage of donor corneas, hydrogels have been investigated as potential corneal replacements. A key factor that influences the physical and biochemical properties of these hydrogels is how they are crosslinked. In this paper, an overview is provided of different crosslinking techniques and crosslinking chemical additives that have been applied to hydrogels for the purposes of corneal tissue engineering, drug delivery or corneal repair. Factors that influence the success of a crosslinker are considered that include material composition, dosage, fabrication method, immunogenicity and toxicity. Different crosslinking techniques that have been used to develop injectable hydrogels for corneal regeneration are summarized. The limitations and future prospects of crosslinking strategies for use in corneal tissue engineering are discussed. It is demonstrated that the choice of crosslinking technique has a significant influence on the biocompatibility, mechanical properties and chemical structure of hydrogels that may be suitable for corneal tissue engineering and regenerative applications.
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Guérin LP, Le-Bel G, Desjardins P, Couture C, Gillard E, Boisselier É, Bazin R, Germain L, Guérin SL. The Human Tissue-Engineered Cornea (hTEC): Recent Progress. Int J Mol Sci 2021; 22:ijms22031291. [PMID: 33525484 PMCID: PMC7865732 DOI: 10.3390/ijms22031291] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 12/11/2022] Open
Abstract
Each day, about 2000 U.S. workers have a job-related eye injury requiring medical treatment. Corneal diseases are the fifth cause of blindness worldwide. Most of these diseases can be cured using one form or another of corneal transplantation, which is the most successful transplantation in humans. In 2012, it was estimated that 12.7 million people were waiting for a corneal transplantation worldwide. Unfortunately, only 1 in 70 patients received a corneal graft that same year. In order to provide alternatives to the shortage of graftable corneas, considerable progress has been achieved in the development of living corneal substitutes produced by tissue engineering and designed to mimic their in vivo counterpart in terms of cell phenotype and tissue architecture. Most of these substitutes use synthetic biomaterials combined with immortalized cells, which makes them dissimilar from the native cornea. However, studies have emerged that describe the production of tridimensional (3D) tissue-engineered corneas using untransformed human corneal epithelial cells grown on a totally natural stroma synthesized by living corneal fibroblasts, that also show appropriate histology and expression of both extracellular matrix (ECM) components and integrins. This review highlights contributions from laboratories working on the production of human tissue-engineered corneas (hTECs) as future substitutes for grafting purposes. It overviews alternative models to the grafting of cadaveric corneas where cell organization is provided by the substrate, and then focuses on their 3D counterparts that are closer to the native human corneal architecture because of their tissue development and cell arrangement properties. These completely biological hTECs are therefore very promising as models that may help understand many aspects of the molecular and cellular mechanistic response of the cornea toward different types of diseases or wounds, as well as assist in the development of novel drugs that might be promising for therapeutic purposes.
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Affiliation(s)
- Louis-Philippe Guérin
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Gaëtan Le-Bel
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Pascale Desjardins
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Camille Couture
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Elodie Gillard
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Élodie Boisselier
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Richard Bazin
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Lucie Germain
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Sylvain L. Guérin
- CUO-Recherche, Médecine Régénératrice—Centre de Recherche du CHU de Québec, Université Laval, Québec, QC G1S 4L8, Canada; (L.-P.G.); (G.L.-B.); (P.D.); (C.C.); (E.G.); (É.B.); (R.B.); (L.G.)
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Correspondence: ; Tel.: +1-418-682-7565
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Hancox Z, Heidari Keshel S, Yousaf S, Saeinasab M, Shahbazi MA, Sefat F. The progress in corneal translational medicine. Biomater Sci 2020; 8:6469-6504. [PMID: 33174878 DOI: 10.1039/d0bm01209b] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cornea tissue is in high demand by tissue donation centres globally, and thus tissue engineering cornea, which is the main topic of corneal translational medicine, can serve as a limitless alternative to a donated human cornea tissue. Tissue engineering aims to produce solutions to the challenges associated with conventional cornea tissue, including transplantation and use of human amniotic membrane (HAM), which have issues with storage and immune rejection in patients. Accordingly, by carefully selecting biomaterials and fabrication methods to produce these therapeutic tissues, the demand for cornea tissue can be met, with an improved healing outcome for recipients with less associated harmful risks. In this review paper, we aim to present the recent advancements in the research and clinical applications of cornea tissue, applications including biomaterial selection, fabrication methods, scaffold structure, cellular response to these scaffolds, and future advancements of these techniques.
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Affiliation(s)
- Zoe Hancox
- Department of Biomedical and Electronics Engineering, School of Engineering, University of Bradford, Bradford, UK.
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Fuest M, Yam GHF, Mehta JS, Duarte Campos DF. Prospects and Challenges of Translational Corneal Bioprinting. Bioengineering (Basel) 2020; 7:bioengineering7030071. [PMID: 32640721 PMCID: PMC7552635 DOI: 10.3390/bioengineering7030071] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/01/2020] [Accepted: 07/04/2020] [Indexed: 12/13/2022] Open
Abstract
Corneal transplantation remains the ultimate treatment option for advanced stromal and endothelial disorders. Corneal tissue engineering has gained increasing interest in recent years, as it can bypass many complications of conventional corneal transplantation. The human cornea is an ideal organ for tissue engineering, as it is avascular and immune-privileged. Mimicking the complex mechanical properties, the surface curvature, and stromal cytoarchitecure of the in vivo corneal tissue remains a great challenge for tissue engineering approaches. For this reason, automated biofabrication strategies, such as bioprinting, may offer additional spatial control during the manufacturing process to generate full-thickness cell-laden 3D corneal constructs. In this review, we discuss recent advances in bioprinting and biomaterials used for in vitro and ex vivo corneal tissue engineering, corneal cell-biomaterial interactions after bioprinting, and future directions of corneal bioprinting aiming at engineering a full-thickness human cornea in the lab.
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Affiliation(s)
- Matthias Fuest
- Department of Ophthalmology, RWTH Aachen University, 52074 Aachen, Germany
- Correspondence: (M.F.); (D.F.D.C.)
| | - Gary Hin-Fai Yam
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA 15260, USA;
| | - Jodhbir S. Mehta
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore 169856, Singapore;
- Singapore National Eye Centre, Singapore 169856, Singapore
| | - Daniela F. Duarte Campos
- Institute of Applied Medical Engineering, RWTH Aachen University, 52074 Aachen, Germany
- DWI Leibniz Institute for Interactive Materials, 52074 Aachen, Germany
- Correspondence: (M.F.); (D.F.D.C.)
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Moetazedian A, Gleadall A, Han X, Silberschmidt VV. Effect of environment on mechanical properties of 3D printed polylactide for biomedical applications. J Mech Behav Biomed Mater 2020; 102:103510. [DOI: 10.1016/j.jmbbm.2019.103510] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/14/2019] [Accepted: 10/23/2019] [Indexed: 01/20/2023]
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Bidaguren A, Mendicute J, Madarieta I, Garagorri N. Confocal and Histological Features After Poly(Ethylene Glycol) Diacrylate Corneal Inlay Implantation. Transl Vis Sci Technol 2019; 8:39. [PMID: 31867140 PMCID: PMC6922274 DOI: 10.1167/tvst.8.6.39] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 10/24/2019] [Indexed: 11/24/2022] Open
Abstract
Purpose To evaluate the in vivo biocompatibility of photopolymerized poly(ethylene glycol) diacrylate (PEGDA) intrastromal inlays in rabbit corneas. Methods Sixty-three eyes of 42 New Zealand rabbits were included. Manual intrastromal pockets were dissected in 42 eyes. PEGDA inlays were obtained using a specifically designed photomask and were inserted in the intrastromal pocket of 21 eyes (inlay group); the remaining 21 right eyes did not receive any implant (pocket-only group). Twenty-one eyes with no intervention were used as controls. In vivo confocal microscopy (IVCM) was performed at every visit. After 2 months, rabbits were sacrificed and corneas removed for histological analysis. Results Corneas remained clear in all but two animals, and five cases of corneal neovascularization were seen (P = 0.2). Inlays remained stable without evidence of lateral or anterior migration, and no other complications were observed. No changes in anterior and posterior keratocyte density (P = 0.3 and P = 0.1, respectively) or endothelial cell density (P = 0.23) were observed between groups during the study time by IVCM. On pathology samples, thinning of the epithelium over the inlay area and epithelial hyperplasia over the edges were observed. A polygonal empty space with no evidence of PEGDA hydrogel within the midstroma was seen in the inlay group. Keratocytes were normal in shape and number in the vicinity of the PEGDA implant area. Conclusions Photopolymerized PEGDA intrastromal inlays have shown relatively good safety and stability in rabbit corneas. Inlays were biostable in the corneal environment and remained transparent during follow up. Translational Relevance The investigated PEGDA is promising for the development of biocompatible intrastromal implants.
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12
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Constructing Three-Dimensional Microenvironments Using Engineered Biomaterials for Hematopoietic Stem Cell Expansion. TISSUE ENGINEERING PART B-REVIEWS 2019; 25:312-329. [DOI: 10.1089/ten.teb.2018.0286] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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13
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Facile fabrication of superporous and biocompatible hydrogel scaffolds for artificial corneal periphery. Colloids Surf B Biointerfaces 2019; 175:26-35. [DOI: 10.1016/j.colsurfb.2018.11.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 10/04/2018] [Accepted: 11/06/2018] [Indexed: 12/18/2022]
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14
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Trujillo-de Santiago G, Sharifi R, Yue K, Sani ES, Kashaf SS, Alvarez MM, Leijten J, Khademhosseini A, Dana R, Annabi N. Ocular adhesives: Design, chemistry, crosslinking mechanisms, and applications. Biomaterials 2019; 197:345-367. [PMID: 30690421 PMCID: PMC6687460 DOI: 10.1016/j.biomaterials.2019.01.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 12/16/2018] [Accepted: 01/05/2019] [Indexed: 12/12/2022]
Abstract
Closure of ocular wounds after an accident or surgery is typically performed by suturing, which is associated with numerous potential complications, including suture breakage, inflammation, secondary neovascularization, erosion to the surface and secondary infection, and astigmatism; for example, more than half of post-corneal transplant infections are due to suture related complications. Tissue adhesives provide promising substitutes for sutures in ophthalmic surgery. Ocular adhesives are not only intended to address the shortcomings of sutures, but also designed to be easy to use, and can potentially minimize post-operative complications. Herein, recent progress in the design, synthesis, and application of ocular adhesives, along with their advantages, limitations, and potential are discussed. This review covers two main classes of ocular adhesives: (1) synthetic adhesives based on cyanoacrylates, polyethylene glycol (PEG), and other synthetic polymers, and (2) adhesives based on naturally derived polymers, such as proteins and polysaccharides. In addition, different technologies to cover and protect ocular wounds such as contact bandage lenses, contact lenses coupled with novel technologies, and decellularized corneas are discussed. Continued advances in this area can help improve both patient satisfaction and clinical outcomes.
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Affiliation(s)
- Grissel Trujillo-de Santiago
- Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge 02139, MA, USA; Biomaterials Innovation Research Center, Division of Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston 02139, MA, USA; Microsystems Technologies Laboratories, MIT, Cambridge, 02139, MA, USA; Centro de Biotecnología-FEMSA, Tecnológico de Monterrey, Monterrey, NL 64849, Mexico
| | - Roholah Sharifi
- Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge 02139, MA, USA; Biomaterials Innovation Research Center, Division of Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston 02139, MA, USA
| | - Kan Yue
- Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge 02139, MA, USA; Biomaterials Innovation Research Center, Division of Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston 02139, MA, USA
| | - Ehsan Shrizaei Sani
- Chemical and Biomolecular Engineering Department, University of California - Los Angeles, Los Angeles, CA 90095, USA
| | - Sara Saheb Kashaf
- Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge 02139, MA, USA; Biomaterials Innovation Research Center, Division of Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston 02139, MA, USA
| | - Mario Moisés Alvarez
- Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge 02139, MA, USA; Biomaterials Innovation Research Center, Division of Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston 02139, MA, USA; Microsystems Technologies Laboratories, MIT, Cambridge, 02139, MA, USA; Centro de Biotecnología-FEMSA, Tecnológico de Monterrey, Monterrey, NL 64849, Mexico
| | - Jeroen Leijten
- Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge 02139, MA, USA; Biomaterials Innovation Research Center, Division of Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston 02139, MA, USA; Department of Developmental BioEngineering, Faculty of Science and Technology, Technical Medicine, University of Twente, Drienerlolaan 5, 7522 NB, Enschede, The Netherlands
| | - Ali Khademhosseini
- Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge 02139, MA, USA; Biomaterials Innovation Research Center, Division of Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston 02139, MA, USA; Chemical and Biomolecular Engineering Department, University of California - Los Angeles, Los Angeles, CA 90095, USA; Department of Bioengineering, University of California - Los Angeles, Los Angeles, CA 90095, USA; Center for Minimally Invasive Therapeutics (C-MIT), California NanoSystems Institute (CNSI), University of California - Los Angeles, Los Angeles, CA 90095, USA; Department of Radiology, David Geffen School of Medicine, University of California - Los Angeles, 10833 Le Conte Ave, Los Angeles, CA 90095, USA
| | - Reza Dana
- Massachusetts Eye and Ear Infirmary and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Nasim Annabi
- Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge 02139, MA, USA; Biomaterials Innovation Research Center, Division of Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston 02139, MA, USA; Chemical and Biomolecular Engineering Department, University of California - Los Angeles, Los Angeles, CA 90095, USA; Center for Minimally Invasive Therapeutics (C-MIT), California NanoSystems Institute (CNSI), University of California - Los Angeles, Los Angeles, CA 90095, USA.
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15
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Bhamra TS, Tighe BJ, Li J. High modulus hydrogels for ophthalmic and related biomedical applications. J Biomed Mater Res B Appl Biomater 2018; 107:1645-1653. [PMID: 30296363 DOI: 10.1002/jbm.b.34257] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 08/07/2018] [Accepted: 08/31/2018] [Indexed: 02/06/2023]
Abstract
This paper presents three families of semi-interpenetrating polymer network (SIPN) hydrogels based on an ester-based polyurethane (EBPU) and hydrophilic monomers: N,N-dimethylacrylamide (NNDMA), N-vinyl pyrrolidone (NVP) and acryloylmorpholine (AMO) as potential materials for keratoprosthesis, orthokeratology and mini-scleral lens application. Hydrogels sheets were synthesized via free-radical polymerization with methods developed in-house. SIPN hydrogels were characterized for their equilibrium water content, mechanical and surface properties. Three families of optically clear SIPN-based hydrogels have been synthesized in the presence of water with >10% of composition attributable to EBPU. Water contents of SIPN materials ranged from 30% to 70%. SIPNs with ≤15% EBPU of total composition showed little influence to mechanical properties, whereas >15% EBPU contributed significantly to an increase in material stiffness. In the hydrated state, SIPNs with ≤15% EBPU of total composition show little difference in polar component (γp ) of surface free energy, whereas for >15% EBPU there is a decrease in γp . The EBPU SIPN hydrogels display complementary material properties for keratoprosthesis, orthokeratology, and mini-scleral applications. © 2018 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1645-1653, 2019.
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Affiliation(s)
- Tarnveer S Bhamra
- Biomaterials Research Unit, Chemical Engineering and Applied Chemistry, Aston University, Aston Triangle, Birmingham, B4 7ET, UK
| | - Brian J Tighe
- Biomaterials Research Unit, Chemical Engineering and Applied Chemistry, Aston University, Aston Triangle, Birmingham, B4 7ET, UK
| | - Jiffan Li
- Biomaterials Research Unit, Chemical Engineering and Applied Chemistry, Aston University, Aston Triangle, Birmingham, B4 7ET, UK
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17
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Ludwig PE, Huff TJ, Zuniga JM. The potential role of bioengineering and three-dimensional printing in curing global corneal blindness. J Tissue Eng 2018; 9:2041731418769863. [PMID: 29686829 PMCID: PMC5900811 DOI: 10.1177/2041731418769863] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Accepted: 03/20/2018] [Indexed: 02/06/2023] Open
Abstract
An insufficiency of accessible allograft tissue for corneal transplantation leaves many impaired by untreated corneal disease. There is promise in the field of regenerative medicine for the development of autologous corneal tissue grafts or collagen-based scaffolds. Another approach is to create a suitable corneal implant that meets the refractive needs of the cornea and is integrated into the surrounding tissue but does not attempt to perfectly mimic the native cornea on a cellular level. Materials that have been investigated for use in the latter concept include natural polymers such as gelatin, semisynthetic polymers like gelatin methacrylate, and synthetic polymers. There are advantages and disadvantages inherent in natural and synthetic polymers: natural polymers are generally more biodegradable and biocompatible, while synthetic polymers typically provide greater control over the characteristics or property adjustment of the materials. Additive manufacturing could aid in the precision production of keratoprostheses and the personalization of implants.
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Affiliation(s)
| | - Trevor J Huff
- Creighton University School of Medicine, Omaha, NE, USA
| | - Jorge M Zuniga
- Department of Biomechanics, University of Nebraska Omaha, Omaha, NE, USA.,Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
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18
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Chen Z, You J, Liu X, Cooper S, Hodge C, Sutton G, Crook JM, Wallace GG. Biomaterials for corneal bioengineering. ACTA ACUST UNITED AC 2018; 13:032002. [PMID: 29021411 DOI: 10.1088/1748-605x/aa92d2] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Corneal transplantation is an important surgical treatment for many common corneal diseases. However, a worldwide shortage of tissue from suitable corneal donors has meant that many people are not able to receive sight-restoring operations. In addition, rejection is a major cause of corneal transplant failure. Bioengineering corneal tissue has recently gained widespread attention. In order to facilitate corneal regeneration, a range of materials is currently being investigated. The ideal substrate requires sufficient tectonic durability, biocompatibility with cultured cellular elements, transparency, and perhaps biodegradability and clinical compliance. This review considers the anatomy and function of the native cornea as a precursor to evaluating a variety of biomaterials for corneal regeneration including key characteristics for optimal material form and function. The integration of appropriate cells with the most appropriate biomaterials is also discussed. Taken together, the information provided offers insight into the requirements for fabricating synthetic and semisynthetic corneas for in vitro modeling of tissue development and disease, pharmaceutical screening, and in vivo application for regenerative medicine.
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Affiliation(s)
- Zhi Chen
- ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, AIIM Facility, Innovation Campus, University of Wollongong, Squires Way, Fairy Meadow, New South Wales 2519, Australia
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19
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Nguyen KN, Bobba S, Richardson A, Park M, Watson SL, Wakefield D, Di Girolamo N. Native and synthetic scaffolds for limbal epithelial stem cell transplantation. Acta Biomater 2018; 65:21-35. [PMID: 29107055 DOI: 10.1016/j.actbio.2017.10.037] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 10/22/2017] [Accepted: 10/25/2017] [Indexed: 12/13/2022]
Abstract
UNLABELLED Limbal stem cell deficiency (LSCD) is a complex blinding disease of the cornea, which cannot be treated with conventional corneal transplants. Instead, a stem cell (SC) graft is required to replenish the limbal epithelial stem cell (LESC) reservoir, which is ultimately responsible for regenerating the corneal epithelium. Current therapies utilize limbal tissue biopsies that harbor LESCs as well as tissue culture expanded cells. Typically, this tissue is placed on a scaffold that supports the formation of corneal epithelial cell sheets, which are then transferred to diseased eyes. A wide range of biological and synthetic materials have been identified as carrier substrates for LESC, some of which have been used in the clinic, including amniotic membrane, fibrin, and silicon hydrogel contact lenses, each with their own advantages and limitations. This review will provide a brief background of LSCD, focusing on bio-scaffolds that have been utilized in limbal stem cell transplantation (LSCT) and materials that are being developed as potentially novel therapeutics for patients with this disease. STATEMENT OF SIGNIFICANCE The outcome of patients with corneal blindness that receive stem cell grafts to restore eye health and correct vision varies considerably and may be due to the different biological and synthetic scaffolds used to deliver these cells to the ocular surface. This review will highlight the positive attributes and limitations of the myriad of carriers developed for clinical use as well as those that are being trialled in pre-clinical models. The overall focus is on developing a standardized therapy for patients, however due to the multiple causes of corneal blindness, a personal regenerative medicine approach may be the best option.
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Affiliation(s)
- Kim N Nguyen
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Samantha Bobba
- Prince of Wales Hospital Clinical School, Sydney, Australia
| | | | - Mijeong Park
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | | | - Denis Wakefield
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Nick Di Girolamo
- School of Medical Sciences, University of New South Wales, Sydney, Australia.
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20
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Aslan B, Guler S, Tevlek A, Aydin HM. Evaluation of collagen foam, poly(l-lactic acid) nanofiber mesh, and decellularized matrices for corneal regeneration. J Biomed Mater Res B Appl Biomater 2017; 106:2157-2168. [DOI: 10.1002/jbm.b.34022] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 06/06/2017] [Accepted: 07/25/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Bahar Aslan
- Institute of Science, Bioengineering Division; , Hacettepe University; Ankara Turkey
| | - Selcan Guler
- Institute of Science, Bioengineering Division; , Hacettepe University; Ankara Turkey
| | - Atakan Tevlek
- Institute of Science, Bioengineering Division; , Hacettepe University; Ankara Turkey
| | - Halil Murat Aydin
- Environmental Engineering Department and Bioengineering Division and Centre for Bioengineering; Hacettepe University; Ankara Turkey
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21
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Brunette I, Roberts CJ, Vidal F, Harissi-Dagher M, Lachaine J, Sheardown H, Durr GM, Proulx S, Griffith M. Alternatives to eye bank native tissue for corneal stromal replacement. Prog Retin Eye Res 2017; 59:97-130. [DOI: 10.1016/j.preteyeres.2017.04.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 04/15/2017] [Accepted: 04/21/2017] [Indexed: 12/13/2022]
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22
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Maier M, Schmidt MS, Ringwald M, Fik CP. Highly reactive, liquid diacrylamides via synergistic combination of spatially arranged curing moieties. Beilstein J Org Chem 2017; 13:372-383. [PMID: 28382175 PMCID: PMC5355936 DOI: 10.3762/bjoc.13.40] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 02/02/2017] [Indexed: 12/04/2022] Open
Abstract
Six polymerizable N,N’-diacylamides containing spatially arranged N-acryl, N-allyl and/or N-alkyl groups were prepared via two-step syntheses and characterized by 1H/13C NMR-spectra, refractive index (RI) and viscosity measurements. Photo DSC measurements on activated samples provided reactivity parameters ∆Hp, Rp,max and tmax, while FTIR spectra before and after curing elucidated the underlying polymerization mechanism. Mechanical testing of the obtained polymers exhibited gradual differences in network densities, depending on the intramolecular arrangement and number of functional groups. Overall, a general building principle for highly reactive, liquid diacrylamides via synergistic combination of optimally arranged functional groups could be identified. The highest possible level of intramolecular synergism was found for low viscous N,N'-diacryloyl-N,N'-diallyl-1,4-but-2-enediamine.
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Affiliation(s)
- Maximilian Maier
- Dentsply Sirona Restorative, De-Trey-Str. 1, 78467 Konstanz, Germany
| | | | | | - Christoph P Fik
- Dentsply Sirona Restorative, De-Trey-Str. 1, 78467 Konstanz, Germany
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23
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Kumar P, Satyam A, Cigognini D, Pandit A, Zeugolis DI. Low oxygen tension and macromolecular crowding accelerate extracellular matrix deposition in human corneal fibroblast culture. J Tissue Eng Regen Med 2017; 12:6-18. [PMID: 27592127 DOI: 10.1002/term.2283] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 07/30/2016] [Accepted: 08/26/2016] [Indexed: 12/13/2022]
Abstract
Development of implantable devices based on the principles of in vitro organogenesis has been hindered due to the prolonged time required to develop an implantable device. Herein we assessed the influence of serum concentration (0.5% and 10%), oxygen tension (0.5%, 2% and 20%) and macromolecular crowding (75 μg/ml carrageenan) in extracellular matrix deposition in human corneal fibroblast culture (3, 7 and 14 days). The highest extracellular matrix deposition was observed after 14 days in culture at 0.5% serum, 2% oxygen tension and 75 μg/ml carrageenan. These data indicate that low oxygen tension coupled with macromolecular crowding significantly accelerate the development of scaffold-free tissue-like modules. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Pramod Kumar
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Biosciences Research Building, National University of Ireland Galway (NUI Galway), Galway, Ireland.,Centre for Research in Medical Devices (CÚRAM), Biosciences Research Building, National University of Ireland Galway (NUI Galway), Galway, Ireland
| | - Abhigyan Satyam
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Biosciences Research Building, National University of Ireland Galway (NUI Galway), Galway, Ireland.,Centre for Research in Medical Devices (CÚRAM), Biosciences Research Building, National University of Ireland Galway (NUI Galway), Galway, Ireland
| | - Daniela Cigognini
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Biosciences Research Building, National University of Ireland Galway (NUI Galway), Galway, Ireland.,Centre for Research in Medical Devices (CÚRAM), Biosciences Research Building, National University of Ireland Galway (NUI Galway), Galway, Ireland
| | - Abhay Pandit
- Centre for Research in Medical Devices (CÚRAM), Biosciences Research Building, National University of Ireland Galway (NUI Galway), Galway, Ireland
| | - Dimitrios I Zeugolis
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Biosciences Research Building, National University of Ireland Galway (NUI Galway), Galway, Ireland.,Centre for Research in Medical Devices (CÚRAM), Biosciences Research Building, National University of Ireland Galway (NUI Galway), Galway, Ireland
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24
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Kumar P, Pandit A, Zeugolis DI. Progress in Corneal Stromal Repair: From Tissue Grafts and Biomaterials to Modular Supramolecular Tissue-Like Assemblies. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:5381-5399. [PMID: 27028373 DOI: 10.1002/adma.201503986] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Revised: 12/31/2015] [Indexed: 06/05/2023]
Abstract
Corneal injuries and degenerative conditions have major socioeconomic consequences, given that in most cases, they result in blindness. In the quest of the ideal therapy, tissue grafts, biomaterials, and modular engineering approaches are under intense investigation. Herein, advancements and shortfalls are reviewed and future perspectives for these therapeutic strategies discussed.
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Affiliation(s)
- Pramod Kumar
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Biosciences Research Building, National University of Ireland Galway (NUI Galway), Galway, Ireland
- Center for Research in Medical Devices (CÚRAM), Biosciences Research Building, National University of Ireland Galway (NUI Galway), Galway, Ireland
| | - Abhay Pandit
- Center for Research in Medical Devices (CÚRAM), Biosciences Research Building, National University of Ireland Galway (NUI Galway), Galway, Ireland
| | - Dimitrios I Zeugolis
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Biosciences Research Building, National University of Ireland Galway (NUI Galway), Galway, Ireland
- Center for Research in Medical Devices (CÚRAM), Biosciences Research Building, National University of Ireland Galway (NUI Galway), Galway, Ireland
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25
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Limbal Stem Cell Deficiency: Current Treatment Options and Emerging Therapies. Stem Cells Int 2015; 2016:9798374. [PMID: 26788074 PMCID: PMC4691643 DOI: 10.1155/2016/9798374] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 08/18/2015] [Indexed: 12/15/2022] Open
Abstract
Severe ocular surface disease can result in limbal stem cell deficiency (LSCD), a condition leading to decreased visual acuity, photophobia, and ocular pain. To restore the ocular surface in advanced stem cell deficient corneas, an autologous or allogenic limbal stem cell transplantation is performed. In recent years, the risk of secondary LSCD due to removal of large limbal grafts has been significantly reduced by the optimization of cultivated limbal epithelial transplantation (CLET). Despite the great successes of CLET, there still is room for improvement as overall success rate is 70% and visual acuity often remains suboptimal after successful transplantation. Simple limbal epithelial transplantation reports higher success rates but has not been performed in as many patients yet. This review focuses on limbal epithelial stem cells and the pathophysiology of LSCD. State-of-the-art therapeutic management of LSCD is described, and new and evolving techniques in ocular surface regeneration are being discussed, in particular, advantages and disadvantages of alternative cell scaffolds and cell sources for cell based ocular surface reconstruction.
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26
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van Essen TH, van Zijl L, Possemiers T, Mulder AA, Zwart SJ, Chou CH, Lin CC, Lai HJ, Luyten GPM, Tassignon MJ, Zakaria N, El Ghalbzouri A, Jager MJ. Biocompatibility of a fish scale-derived artificial cornea: Cytotoxicity, cellular adhesion and phenotype, and in vivo immunogenicity. Biomaterials 2015; 81:36-45. [PMID: 26717247 DOI: 10.1016/j.biomaterials.2015.11.015] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 11/06/2015] [Indexed: 01/30/2023]
Abstract
PURPOSE To determine whether a fish scale-derived collagen matrix (FSCM) meets the basic criteria to serve as an artificial cornea, as determined with in vitro and in vivo tests. METHODS Primary corneal epithelial and stromal cells were obtained from human donor corneas and used to examine the (in)direct cytotoxicity effects of the scaffold. Cytotoxicity was assessed by an MTT assay, while cellular proliferation, corneal cell phenotype and adhesion markers were assessed using an EdU-assay and immunofluorescence. For in vivo-testing, FSCMs were implanted subcutaneously in rats. Ologen(®) Collagen Matrices were used as controls. A second implant was implanted as an immunological challenge. The FSCM was implanted in a corneal pocket of seven New Zealand White rabbits, and compared to sham surgery. RESULTS The FSCM was used as a scaffold to grow corneal epithelial and stromal cells, and displayed no cytotoxicity to these cells. Corneal epithelial cells displayed their normal phenotypical markers (CK3/12 and E-cadherin), as well as cell-matrix adhesion molecules: integrin-α6 and β4, laminin 332, and hemi-desmosomes. Corneal stromal cells similarly expressed adhesion molecules (integrin-α6 and β1). A subcutaneous implant of the FSCM in rats did not induce inflammation or sensitization; the response was comparable to the response against the Ologen(®) Collagen Matrix. Implantation of the FSCM in a corneal stromal pocket in rabbits led to a transparent cornea, healthy epithelium, and, on histology, hardly any infiltrating immune cells. CONCLUSION The FSCM allows excellent cell growth, is not immunogenic and is well-tolerated in the cornea, and thus meets the basic criteria to serve as a scaffold to reconstitute the cornea.
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Affiliation(s)
- T H van Essen
- Department of Ophthalmology, J3-S, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands.
| | - L van Zijl
- Department of Research, Aeon Astron Europe B.V., J.H. Oortweg 19, 2333 CH, Leiden, The Netherlands.
| | - T Possemiers
- Department of Ophthalmology, Antwerp University Hospital, Wilrijkstraat 10, 2650 Edegem, Belgium.
| | - A A Mulder
- Department of Molecular Cell-biology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands.
| | - S J Zwart
- Department of Research, Aeon Astron Europe B.V., J.H. Oortweg 19, 2333 CH, Leiden, The Netherlands.
| | - C-H Chou
- Department of Research, Body Organ Biomedical Corporation, 5F, No. 153, Section 3, Xinyi Road, Da'an District, Taipei City 106, Taiwan, ROC.
| | - C C Lin
- Department of Research, Body Organ Biomedical Corporation, 5F, No. 153, Section 3, Xinyi Road, Da'an District, Taipei City 106, Taiwan, ROC.
| | - H J Lai
- Department of Research, Aeon Astron Europe B.V., J.H. Oortweg 19, 2333 CH, Leiden, The Netherlands.
| | - G P M Luyten
- Department of Ophthalmology, J3-S, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands.
| | - M J Tassignon
- Department of Ophthalmology, Antwerp University Hospital, Wilrijkstraat 10, 2650 Edegem, Belgium.
| | - N Zakaria
- Department of Ophthalmology, Antwerp University Hospital, Wilrijkstraat 10, 2650 Edegem, Belgium; University of Antwerp, Prinsstraat 13, 2000 Antwerpen, Belgium.
| | - A El Ghalbzouri
- Department of Molecular Cell-biology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands.
| | - M J Jager
- Department of Ophthalmology, J3-S, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands.
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27
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Schmidt S, Wang H, Pussak D, Mosca S, Hartmann L. Probing multivalency in ligand–receptor-mediated adhesion of soft, biomimetic interfaces. Beilstein J Org Chem 2015; 11:720-9. [PMID: 26124875 PMCID: PMC4464160 DOI: 10.3762/bjoc.11.82] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 04/28/2015] [Indexed: 12/15/2022] Open
Abstract
Many biological functions at cell level are mediated by the glycocalyx, a dense carbohydrate-presenting layer. In this layer specific interactions between carbohydrate ligands and protein receptors are formed to control cell–cell recognition, cell adhesion and related processes. The aim of this work is to shed light on the principles of complex formation between surface anchored carbohydrates and receptor surfaces by measuring the specific adhesion between surface bound mannose on a concanavalin A (ConA) layer via poly(ethylene glycol)-(PEG)-based soft colloidal probes (SCPs). Special emphasis is on the dependence of multivalent presentation and density of carbohydrate units on specific adhesion. Consequently, we first present a synthetic strategy that allows for controlled density variation of functional groups on the PEG scaffold using unsaturated carboxylic acids (crotonic acid, acrylic acid, methacrylic acid) as grafting units for mannose conjugation. We showed by a range of analytic techniques (ATR–FTIR, Raman microscopy, zeta potential and titration) that this synthetic strategy allows for straightforward variation in grafting density and grafting length enabling the controlled presentation of mannose units on the PEG network. Finally we determined the specific adhesion of PEG-network-conjugated mannose units on ConA surfaces as a function of density and grafting type. Remarkably, the results indicated the absence of a molecular-level enhancement of mannose/ConA interaction due to chelate- or subsite-binding. The results seem to support the fact that weak carbohydrate interactions at mechanically flexible interfaces hardly undergo multivalent binding but are simply mediated by the high number of ligand–receptor interactions.
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Affiliation(s)
- Stephan Schmidt
- Universität Leipzig, Institut für Biochemie, Johannisalle 21–23, D-04103 Leipzig, Germany
| | - Hanqing Wang
- Max Planck Institute of Colloids and Interfaces, Research Campus Golm, 14424 Potsdam, Germany
- Heinrich-Heine-Universität Düsseldorf, Institut für Organische und Makromolekulare Chemie, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Daniel Pussak
- Max Planck Institute of Colloids and Interfaces, Research Campus Golm, 14424 Potsdam, Germany
| | - Simone Mosca
- Max Planck Institute of Colloids and Interfaces, Research Campus Golm, 14424 Potsdam, Germany
| | - Laura Hartmann
- Max Planck Institute of Colloids and Interfaces, Research Campus Golm, 14424 Potsdam, Germany
- Heinrich-Heine-Universität Düsseldorf, Institut für Organische und Makromolekulare Chemie, Universitätsstr. 1, 40225 Düsseldorf, Germany
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28
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Xiang J, Sun J, Hong J, Wang W, Wei A, Le Q, Xu J. T-style keratoprosthesis based on surface-modified poly (2-hydroxyethyl methacrylate) hydrogel for cornea repairs. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2015; 50:274-85. [DOI: 10.1016/j.msec.2015.01.089] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 12/11/2014] [Accepted: 01/30/2015] [Indexed: 10/24/2022]
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29
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Zheng LL, Vanchinathan V, Dalal R, Noolandi J, Waters DJ, Hartmann L, Cochran JR, Frank CW, Yu CQ, Ta CN. Biocompatibility of poly(ethylene glycol) and poly(acrylic acid) interpenetrating network hydrogel by intrastromal implantation in rabbit cornea. J Biomed Mater Res A 2015; 103:3157-65. [PMID: 25778285 DOI: 10.1002/jbm.a.35453] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 02/24/2015] [Accepted: 03/09/2015] [Indexed: 11/08/2022]
Abstract
We evaluated the biocompatibility of a poly(ethylene glycol) and poly(acrylic acid) (PEG/PAA) interpenetrating network hydrogel designed for artificial cornea in a rabbit model. PEG/PAA hydrogel measuring 6 mm in diameter was implanted in the corneal stroma of twelve rabbits. Stromal flaps were created with a microkeratome. Randomly, six rabbits were assigned to bear the implant for 2 months, two rabbits for 6 months, two rabbits for 9 months, one rabbit for 12 months, and one rabbit for 16 months. Rabbits were evaluated monthly. After the assigned period, eyes were enucleated, and corneas were processed for histology and immunohistochemistry. There were clear corneas in three of six rabbits that had implantation of hydrogel for 2 months. In the six rabbits with implant for 6 months or longer, the corneas remained clear in four. There was a high rate of epithelial defect and corneal thinning in these six rabbits. One planned 9-month rabbit developed extrusion of implant at 4 months. The cornea remained clear in the 16-month rabbit but histology revealed epithelial in-growth. Intrastromal implantation of PEG/PAA resulted in a high rate of long-term complications.
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Affiliation(s)
- Luo Luo Zheng
- Byers Eye Institute at Stanford, Stanford University School of Medicine, Stanford, California.,Department of Bioengineering, Stanford University School of Engineering, Stanford, California
| | - Vijay Vanchinathan
- Byers Eye Institute at Stanford, Stanford University School of Medicine, Stanford, California
| | - Roopa Dalal
- Byers Eye Institute at Stanford, Stanford University School of Medicine, Stanford, California
| | - Jaan Noolandi
- Byers Eye Institute at Stanford, Stanford University School of Medicine, Stanford, California
| | - Dale J Waters
- Department of Chemical Engineering, Stanford University School of Engineering, Stanford, California
| | - Laura Hartmann
- Department of Chemical Engineering, Stanford University School of Engineering, Stanford, California
| | - Jennifer R Cochran
- Department of Bioengineering, Stanford University School of Engineering, Stanford, California
| | - Curtis W Frank
- Department of Chemical Engineering, Stanford University School of Engineering, Stanford, California
| | - Charles Q Yu
- Byers Eye Institute at Stanford, Stanford University School of Medicine, Stanford, California
| | - Christopher N Ta
- Byers Eye Institute at Stanford, Stanford University School of Medicine, Stanford, California
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30
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Glaubitz M, Medvedev N, Pussak D, Hartmann L, Schmidt S, Helm CA, Delcea M. A novel contact model for AFM indentation experiments on soft spherical cell-like particles. SOFT MATTER 2014; 10:6732-6741. [PMID: 25068646 DOI: 10.1039/c4sm00788c] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The use of the simple Hertz model for the analysis of Atomic Force Microscopy (AFM) force-distance curves measured on soft spherical cell-like particles leads to significant underestimations of the objects Young's modulus E. To correct this error, a mixed double contact model (based on the simple Hertz model and the Johnson-Kendall-Roberts (JKR) model) was derived. The model considers two independent particle deformation sites: (i) the upper part of the particle is deformed by the AFM indenter, (ii) the bottom part is deformed by the substrate, which is usually unnoticed. It becomes apparent that for soft particles even small forces between substrate and particle can influence the resulting force-distance curves. For instance we show, that a gravity-induced compression on the particle bottom side can have significant influence on the measurements. To highlight these observations, the deviation of the particle Young's modulus E between the simple Hertz model and our model is calculated. This error strongly depends on the ratio of the three involved radii: (i) the radius of the AFM indenter, (ii) the radius of the particle and (iii) the radius of the substrate as well as on the acting gravity force. Overall, the analysis suggests that for nanoscopic indenters the deviation is negligible, whereas the use of microscopic indenters results in significant errors that can be corrected via the presented model. This is important especially for very soft particles, since larger indenters can achieve higher signal to noise ratios. Furthermore, the applicability of the model was confirmed by indentation experiments on hydrogel microbeads. The mixed double contact model is applicable to a large range of indenter geometries and can be adapted for other contact models.
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Affiliation(s)
- Michael Glaubitz
- ZIK-HIKE - Zentrum für Innovationskompetenz "Humorale Immunreaktionen bei Kardiovaskulären Erkrankungen", Fleischmannstr. 42 - 44, D-17489 Greifswald, Germany.
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31
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Biomaterials for refractive correction: corneal onlays and inlays. Sci China Chem 2014. [DOI: 10.1007/s11426-014-5083-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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32
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Engineering interpenetrating network hydrogels as biomimetic cell niche with independently tunable biochemical and mechanical properties. Biomaterials 2014; 35:1807-15. [DOI: 10.1016/j.biomaterials.2013.11.064] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 11/21/2013] [Indexed: 01/29/2023]
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33
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Feng Y, Borrelli M, Reichl S, Schrader S, Geerling G. Review of alternative carrier materials for ocular surface reconstruction. Curr Eye Res 2014; 39:541-52. [PMID: 24405104 DOI: 10.3109/02713683.2013.853803] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Severe ocular surface disorders can result in deficiency of limbal stem cells that is potentially associated with chronic inflammation, impaired vision and even blindness. Advanced stem cells deficiency requires reconstruction of the OS with autologous or allogeneic limbal stem cells. To address such deficiency, a limbal tissue biopsy is taken and limbal cells are expanded on a carrier, which then can be used for OS reconstruction. Human amniotic membrane - currently the most common carrier for transplantation of limbal epithelial stem cells - has the downsides of carrying the risk of disease transmission, limited transparency, variable and unstable quality and low mechanical strength. This article reviews the advantages and disadvantages of the established carrier materials for limbal stem cell transplantation, as well as discussing emerging alternatives, including carriers based on collagen, fibrin, siloxane hydrogel contact lenses, poly(ε-caprolactone), gelatin-chitosan, silk fibroin, human anterior lens capsule, keratin, poly(lactide-co-glycolide), polymethacrylate, hydroxyethylmethacrylate and poly(ethylene glycol) for their potential use in the treatment of limbal stem cell deficiency.
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Affiliation(s)
- Yaqing Feng
- Department of Ophthalmology, University of Düsseldorf , Düsseldorf , Germany and
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34
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Tan XW, Hartman L, Tan KP, Poh R, Myung D, Zheng LL, Waters D, Noolandi J, Beuerman RW, Frank CW, Ta CN, Tan DTH, Mehta JS. In vivo biocompatibility of two PEG/PAA interpenetrating polymer networks as corneal inlays following deep stromal pocket implantation. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2013; 24:967-977. [PMID: 23354737 PMCID: PMC3620449 DOI: 10.1007/s10856-012-4848-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 12/29/2012] [Indexed: 06/01/2023]
Abstract
This study compared the effects of implanting two interpenetrating polymer networks (IPNs) into rabbit corneas. The first (Implant 1) was based on PEG-diacrylate, the second (Implant 2) was based on PEG-diacrylamide. There were inserted into deep stromal pockets created using a manual surgical technique for either 3 or 6 months. The implanted corneas were compared with normal and sham-operated corneas through slit lamp observation, anterior segment optical coherence tomography, in vivo confocal scanning and histological examination. Corneas with Implant 1 (based on PEG-diacrylate) developed diffuse haze, ulcers and opacities within 3 months, while corneas with Implant 2 (based on PEG-diacrylamide) remained clear at 6 months. They also exhibited normal numbers of epithelial cell layers, without any immune cell infiltration, inflammation, oedema or neovascularisation at post-operative 6 month. Morphological studies showed transient epithelial layer thinning over the hydrogel inserted area and elevated keratocyte activity at 3 months; however, the epithelium thickness and keratocyte morphology were improved at 6 months. Implant 2 exhibited superior in vivo biocompatibility and higher optical clarity than Implant 1. PEG-diacrylamide-based IPN hydrogel is therefore a potential candidate for corneal inlays to correct refractive error.
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Affiliation(s)
- Xiao Wei Tan
- Tissue Engineering and Stem Cell Research Group, Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, Singapore
| | - Laura Hartman
- Department of Chemical Engineering, Stanford University, Stanford, CA USA
| | - Kim Peng Tan
- Tissue Engineering and Stem Cell Research Group, Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, Singapore
| | - Rebekah Poh
- Tissue Engineering and Stem Cell Research Group, Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, Singapore
| | - David Myung
- Department of Chemical Engineering, Stanford University, Stanford, CA USA
- Department of Bioengineering, Stanford University, Stanford, CA USA
| | - Luo Luo Zheng
- Department of Ophthalmology, Stanford University, School of Medicine, Stanford, CA USA
| | - Dale Waters
- Department of Chemical Engineering, Stanford University, Stanford, CA USA
| | - Jaan Noolandi
- Department of Bioengineering, Stanford University, Stanford, CA USA
| | - Roger W. Beuerman
- Tissue Engineering and Stem Cell Research Group, Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Curtis W. Frank
- Department of Chemical Engineering, Stanford University, Stanford, CA USA
| | | | - Donald TH Tan
- Tissue Engineering and Stem Cell Research Group, Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Clinical Sciences, Duke-NUS Graduate Medical School, National University of Singapore, Singapore, Singapore
| | - Jodhbir S. Mehta
- Tissue Engineering and Stem Cell Research Group, Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Clinical Sciences, Duke-NUS Graduate Medical School, National University of Singapore, Singapore, Singapore
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35
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Behra M, Schmidt S, Hartmann J, Volodkin DV, Hartmann L. Synthesis of Porous PEG Microgels Using CaCO3
Microspheres as Hard Templates. Macromol Rapid Commun 2012; 33:1049-54. [DOI: 10.1002/marc.201100863] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 01/25/2012] [Indexed: 01/31/2023]
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