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Hu M, Peng X, Zhao Y, Yu X, Cheng C, Yu X. Dialdehyde pectin-crosslinked and hirudin-loaded decellularized porcine pericardium with improved matrix stability, enhanced anti-calcification and anticoagulant for bioprosthetic heart valves. Biomater Sci 2021; 9:7617-7635. [PMID: 34671797 DOI: 10.1039/d1bm01297e] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
To conveniently and effectively cure heart valve diseases or defects, combined with transcatheter valve technology, bioprosthetic heart valves (BHVs) originated from the decellularized porcine pericardium (D-PP) have been broadly used in clinics. Unfortunately, most clinically available BHVs crosslinked with glutaraldehyde (GA) were challenged in their long-term tolerance, degenerative structural changes, and even failure, owing to the synergistic impact of multitudinous elements (cytotoxicity, calcification, immune responses, etc.). In this work, dialdehyde pectin (AP) was prepared by oxidizing the o-dihydroxy of pectin with sodium periodate. Hereafter, the AP-fixed PP model was obtained by crosslinking D-PP with AP with high aldehyde content (6.85 mmol g-1), for acquiring excellent mechanical properties and outstanding biocompatibility. To further improve the hemocompatibility of the AP-fixed PP, a natural and specific inhibitor of thrombin (hirudin) was introduced to achieve surface modification of the AP-fixed PP. The feasibility of crosslinking and functionalizing AP-fixed PP, which was a potential leaflet material of BHVs, was exhaustively and systematically evaluated. In vitro studies found that hirudin-loaded and AP-fixed PP (AP + Hirudin-PP) had synchronously achieved effective fixation of collagen, highly effective anticoagulation, and good HUVECs-cytocompatibility. In vivo results revealed that the AP + Hirudin-PP specimens recruited the minimum immune cells in the implantation experiment, and also presented an excellent anti-calcification effect. Overall, AP + Hirudin-PP was endowed with competitive collagen stability (compared with GA-fixed PP), excellent hemocompatibility, good HUVECs-cytocompatibility, low immunogenicity and outstanding anti-calcification, suggesting that AP + Hirudin-PP might be a promising alternative to GA-fixed PP and exhibited a bright prospect in the clinical applications of BHVs.
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Affiliation(s)
- Mengyue Hu
- College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, P.R. China.
| | - Xu Peng
- College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, P.R. China. .,Experimental and Research Animal Institute, Sichuan University, Chengdu 610065, P.R. China
| | - Yang Zhao
- College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, P.R. China.
| | - Xiaoshuang Yu
- College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, P.R. China.
| | - Can Cheng
- College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, P.R. China.
| | - Xixun Yu
- College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, P.R. China.
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Gruening M, Neuber S, Nestler P, Lehnfeld J, Dubs M, Fricke K, Schnabelrauch M, Helm CA, Müller R, Staehlke S, Nebe JB. Enhancement of Intracellular Calcium Ion Mobilization by Moderately but Not Highly Positive Material Surface Charges. Front Bioeng Biotechnol 2020; 8:1016. [PMID: 33015006 PMCID: PMC7505933 DOI: 10.3389/fbioe.2020.01016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 08/03/2020] [Indexed: 12/17/2022] Open
Abstract
Electrostatic forces at the cell interface affect the nature of cell adhesion and function; but there is still limited knowledge about the impact of positive or negative surface charges on cell-material interactions in regenerative medicine. Titanium surfaces with a variety of zeta potentials between −90 mV and +50 mV were generated by functionalizing them with amino polymers, extracellular matrix proteins/peptide motifs and polyelectrolyte multilayers. A significant enhancement of intracellular calcium mobilization was achieved on surfaces with a moderately positive (+1 to +10 mV) compared with a negative zeta potential (−90 to −3 mV). Dramatic losses of cell activity (membrane integrity, viability, proliferation, calcium mobilization) were observed on surfaces with a highly positive zeta potential (+50 mV). This systematic study indicates that cells do not prefer positive charges in general, merely moderately positive ones. The cell behavior of MG-63s could be correlated with the materials’ zeta potential; but not with water contact angle or surface free energy. Our findings present new insights and provide an essential knowledge for future applications in dental and orthopedic surgery.
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Affiliation(s)
- Martina Gruening
- Department of Cell Biology, Rostock University Medical Center, Rostock, Germany
| | - Sven Neuber
- Soft Matter and Biophysics, Institute of Physics, University of Greifswald, Greifswald, Germany
| | - Peter Nestler
- Soft Matter and Biophysics, Institute of Physics, University of Greifswald, Greifswald, Germany
| | - Jutta Lehnfeld
- Colloid and Interface Chemistry, Institute of Physical and Theoretical Chemistry, University of Regensburg, Regensburg, Germany
| | - Manuela Dubs
- Department of Biomaterials, INNOVENT e.V., Jena, Germany
| | - Katja Fricke
- Leibniz Institute for Plasma Science and Technology e.V. (INP), Greifswald, Germany
| | | | - Christiane A Helm
- Soft Matter and Biophysics, Institute of Physics, University of Greifswald, Greifswald, Germany
| | - Rainer Müller
- Colloid and Interface Chemistry, Institute of Physical and Theoretical Chemistry, University of Regensburg, Regensburg, Germany
| | - Susanne Staehlke
- Department of Cell Biology, Rostock University Medical Center, Rostock, Germany
| | - J Barbara Nebe
- Department of Cell Biology, Rostock University Medical Center, Rostock, Germany.,Department Science and Technology of Life, Light and Matter, Faculty of Interdisciplinary, University of Rostock, Rostock, Germany
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Beshchasna N, Saqib M, Kraskiewicz H, Wasyluk Ł, Kuzmin O, Duta OC, Ficai D, Ghizdavet Z, Marin A, Ficai A, Sun Z, Pichugin VF, Opitz J, Andronescu E. Recent Advances in Manufacturing Innovative Stents. Pharmaceutics 2020; 12:E349. [PMID: 32294908 PMCID: PMC7238261 DOI: 10.3390/pharmaceutics12040349] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 04/09/2020] [Accepted: 04/10/2020] [Indexed: 02/07/2023] Open
Abstract
Cardiovascular diseases are the most distributed cause of death worldwide. Stenting of arteries as a percutaneous transluminal angioplasty procedure became a promising minimally invasive therapy based on re-opening narrowed arteries by stent insertion. In order to improve and optimize this method, many research groups are focusing on designing new or improving existent stents. Since the beginning of the stent development in 1986, starting with bare-metal stents (BMS), these devices have been continuously enhanced by applying new materials, developing stent coatings based on inorganic and organic compounds including drugs, nanoparticles or biological components such as genes and cells, as well as adapting stent designs with different fabrication technologies. Drug eluting stents (DES) have been developed to overcome the main shortcomings of BMS or coated stents. Coatings are mainly applied to control biocompatibility, degradation rate, protein adsorption, and allow adequate endothelialization in order to ensure better clinical outcome of BMS, reducing restenosis and thrombosis. As coating materials (i) organic polymers: polyurethanes, poly(ε-caprolactone), styrene-b-isobutylene-b-styrene, polyhydroxybutyrates, poly(lactide-co-glycolide), and phosphoryl choline; (ii) biological components: vascular endothelial growth factor (VEGF) and anti-CD34 antibody and (iii) inorganic coatings: noble metals, wide class of oxides, nitrides, silicide and carbide, hydroxyapatite, diamond-like carbon, and others are used. DES were developed to reduce the tissue hyperplasia and in-stent restenosis utilizing antiproliferative substances like paclitaxel, limus (siro-, zotaro-, evero-, bio-, amphi-, tacro-limus), ABT-578, tyrphostin AGL-2043, genes, etc. The innovative solutions aim at overcoming the main limitations of the stent technology, such as in-stent restenosis and stent thrombosis, while maintaining the prime requirements on biocompatibility, biodegradability, and mechanical behavior. This paper provides an overview of the existing stent types, their functionality, materials, and manufacturing conditions demonstrating the still huge potential for the development of promising stent solutions.
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Affiliation(s)
- Natalia Beshchasna
- Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Maria-Reiche-Str. 2, 01109 Dresden, Germany; (M.S.); (J.O.)
| | - Muhammad Saqib
- Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Maria-Reiche-Str. 2, 01109 Dresden, Germany; (M.S.); (J.O.)
| | | | - Łukasz Wasyluk
- Balton Sp. z o.o. Modlińska 294, 03-152 Warsaw, Poland; (H.K.); (Ł.W.)
| | - Oleg Kuzmin
- VIP Technologies, Prospect Academicheskiy 8/2, 634055 Tomsk, Russia;
| | - Oana Cristina Duta
- Department of Science and Engineering of Oxide Materials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, Spl. Independentei 313, 060042 Bucharest, Romania; (O.C.D.); (D.F.); (Z.G.); (E.A.)
| | - Denisa Ficai
- Department of Science and Engineering of Oxide Materials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, Spl. Independentei 313, 060042 Bucharest, Romania; (O.C.D.); (D.F.); (Z.G.); (E.A.)
| | - Zeno Ghizdavet
- Department of Science and Engineering of Oxide Materials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, Spl. Independentei 313, 060042 Bucharest, Romania; (O.C.D.); (D.F.); (Z.G.); (E.A.)
| | - Alexandru Marin
- Department of Hydraulics, Hydraulic Machinery and Environmental Engineering, Faculty of Power Engineering, University Politehnica of Bucharest, Spl. Independentei 313, 060042 Bucharest, Romania;
| | - Anton Ficai
- Department of Science and Engineering of Oxide Materials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, Spl. Independentei 313, 060042 Bucharest, Romania; (O.C.D.); (D.F.); (Z.G.); (E.A.)
- Academy of Romanian Scientists, Spl. Independentei 54, 050094 Bucharest, Romania
| | - Zhilei Sun
- Research School of High-Energy Physics, Tomsk Polytechnic University, Lenin Avenue 30, 634050 Tomsk, Russia;
| | - Vladimir F. Pichugin
- Research School of High-Energy Physics, Tomsk Polytechnic University, Lenin Avenue 30, 634050 Tomsk, Russia;
| | - Joerg Opitz
- Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Maria-Reiche-Str. 2, 01109 Dresden, Germany; (M.S.); (J.O.)
| | - Ecaterina Andronescu
- Department of Science and Engineering of Oxide Materials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, Spl. Independentei 313, 060042 Bucharest, Romania; (O.C.D.); (D.F.); (Z.G.); (E.A.)
- Academy of Romanian Scientists, Spl. Independentei 54, 050094 Bucharest, Romania
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Chakraborty Banerjee P, Al-Saadi S, Choudhary L, Harandi SE, Singh R. Magnesium Implants: Prospects and Challenges. MATERIALS 2019; 12:ma12010136. [PMID: 30609830 PMCID: PMC6337251 DOI: 10.3390/ma12010136] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 12/21/2018] [Accepted: 12/27/2018] [Indexed: 12/24/2022]
Abstract
Owing to their suitable mechanical property and biocompatibility as well as the technological possibility of controlling their high corrosion rates, magnesium and its alloys have attracted significant attention as temporary bio-implants. Though the ability of magnesium to harmlessly biodegrade and its inherent biocompatibility make magnesium alloys a suitable choice for a temporary implant, their high corrosion rates limit their practical application, as the implants can potentially corrode away even before the healing process has completed. Different approaches, such as alloying, surface modification, and conversion coatings, have been explored to improve the corrosion resistance of various magnesium alloys. However, the corrosion behavior of magnesium implants with and without a surface modification has been generally investigated under in-vitro conditions, and studies under in-vivo conditions are limited, which has contributed to the lack of translation of magnesium implants in practical applications. This paper comprehensively reviews the prospects of magnesium alloy implants and the current challenges due to their rapid degradation in a physiological environment. This paper also provides a comprehensive review of the corrosion mitigation measures for these temporary implants.
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Affiliation(s)
| | - Saad Al-Saadi
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia.
| | - Lokesh Choudhary
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia.
| | - Shervin Eslami Harandi
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia.
| | - Raman Singh
- Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia.
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia.
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Moorthi A, Tyan YC, Chung TW. Surface-modified polymers for cardiac tissue engineering. Biomater Sci 2018; 5:1976-1987. [PMID: 28832034 DOI: 10.1039/c7bm00309a] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cardiovascular disease (CVD), leading to myocardial infarction and heart failure, is one of the major causes of death worldwide. The physiological system cannot significantly regenerate the capabilities of a damaged heart. The current treatment involves pharmacological and surgical interventions; however, less invasive and more cost-effective approaches are sought. Such new approaches are developed to induce tissue regeneration following injury. Hence, regenerative medicine plays a key role in treating CVD. Recently, the extrinsic stimulation of cardiac regeneration has involved the use of potential polymers to stimulate stem cells toward the differentiation of cardiomyocytes as a new therapeutic intervention in cardiac tissue engineering (CTE). The therapeutic potentiality of natural or synthetic polymers and cell surface interactive factors/polymer surface modifications for cardiac repair has been demonstrated in vitro and in vivo. This review will discuss the recent advances in CTE using polymers and cell surface interactive factors that interact strongly with stem cells to trigger the molecular aspects of the differentiation or formulation of cardiomyocytes for the functional repair of heart injuries or cardiac defects.
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Affiliation(s)
- Ambigapathi Moorthi
- Department of Biomedical Engineering, National Yang Ming University, Taipei 112, Taiwan.
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Staehlke S, Rebl H, Finke B, Mueller P, Gruening M, Nebe JB. Enhanced calcium ion mobilization in osteoblasts on amino group containing plasma polymer nanolayer. Cell Biosci 2018; 8:22. [PMID: 29588849 PMCID: PMC5863460 DOI: 10.1186/s13578-018-0220-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 03/14/2018] [Indexed: 11/23/2022] Open
Abstract
Background Biomaterial modifications—chemical and topographical—are of particular importance for the integration of materials in biosystems. Cells are known to sense these biomaterial characteristics, but it has remained unclear which physiological processes bio modifications trigger. Hence, the question arises of whether the dynamic of intracellular calcium ions is important for the characterization of the cell–material interaction. In our prior research we could demonstrate that a defined geometrical surface topography affects the cell physiology; this was finally detectable in a reduced intracellular calcium mobilization after the addition of adenosine triphosphate (ATP). Results This new contribution examines the cell physiology of human osteoblasts concerning the relative cell viability and the calcium ion dynamic on different chemical modifications of silicon–titanium (Ti) substrates. Chemical modifications comprising the coating of Ti surfaces with a plasma polymerized allylamine (PPAAm)-layer or with a thin layer of collagen type-I were compared with a bare Ti substrate as well as tissue culture plastic. For this purpose, the human osteoblasts (MG-63 and primary osteoblasts) were seeded onto the surfaces for 24 h. The relative cell viability was determined by colorimetric measurements of the cell metabolism and relativized to the density of cells quantified using crystal violet staining. The calcium ion dynamic of osteoblasts was evaluated by the calcium imaging analysis of fluo-3 stained vital cells using a confocal laser scanning microscope. The positively charged nano PPAAm-layer resulted in enhanced intracellular calcium ion mobilization after ATP-stimulus and cell viability. This study underlines the importance of the calcium signaling for the manifestation of the cell physiology. Conclusions Our current work provides new insights into the intracellular calcium dynamic caused by diverse chemical surface compositions. The calcium ion dynamic appears to be a sensitive parameter for the cell physiology and, thus, may represent a useful approach for evaluating a new biomaterial. In this regard, reliable in vitro-tests of cell behavior at the interface to a material are crucial steps in securing the success of a new biomaterial in medicine.
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Affiliation(s)
- Susanne Staehlke
- Dept. of Cell Biology, University Medical Center Rostock, Schillingallee 69, 18057 Rostock, Germany
| | - Henrike Rebl
- Dept. of Cell Biology, University Medical Center Rostock, Schillingallee 69, 18057 Rostock, Germany
| | - Birgit Finke
- 2Leibniz-Institute for Plasma Science and Technology (INP), Felix-Hausdorff-Str. 2, 17489 Greifswald, Germany
| | - Petra Mueller
- Dept. of Cell Biology, University Medical Center Rostock, Schillingallee 69, 18057 Rostock, Germany
| | - Martina Gruening
- Dept. of Cell Biology, University Medical Center Rostock, Schillingallee 69, 18057 Rostock, Germany
| | - J Barbara Nebe
- Dept. of Cell Biology, University Medical Center Rostock, Schillingallee 69, 18057 Rostock, Germany
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Hexagonal Boron Nitride Impregnated Silane Composite Coating for Corrosion Resistance of Magnesium Alloys for Temporary Bioimplant Applications. METALS 2017. [DOI: 10.3390/met7120518] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Intracellular calcium dynamics dependent on defined microtopographical features of titanium. Biomaterials 2015; 46:48-57. [DOI: 10.1016/j.biomaterials.2014.12.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 12/10/2014] [Accepted: 12/16/2014] [Indexed: 02/06/2023]
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Wang L, Liu L, Magome N, Agladze K, Chen Y. Influence of patterned topographic features on the formation of cardiac cell clusters and their rhythmic activities. Biofabrication 2013; 5:035013. [DOI: 10.1088/1758-5082/5/3/035013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Davis H, Guo X, Lambert S, Stancescu M, Hickman JJ. Small Molecule Induction of Human Umbilical Stem Cells into MBP-positive Oligodendrocytes in a Defined Three-Dimensional Environment. ACS Chem Neurosci 2012; 3:31-39. [PMID: 22582139 DOI: 10.1021/cn200082q] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Stem cells from umbilical cord would be a favorable alternative to embryonic stem cells for therapeutic applications. In this study, human multipotent progenitor cells (MLPCs) from umbilical cord were differentiated into oligodendrocytes by exposure to a range of microenvironmental chemical and physical cues. Chemical cues were represented by a novel defined differentiation medium containing the neurotransmitter norepinephrine (NE). In traditional 2 dimensional (2D) conditions, the MLPCs differentiated into oligodendrocyte precursors, but did not progress further. However, in a 3 dimensional (3D) environment, the MLPCs differentiated into committed oligodendrocytes that expressed MBP. The apparent method of interaction of NE in stimulating the differentiation process was identified to occur through the adenergic pathway while all prior differentiation methods have used other routes. This novel method of obtaining functional human oligodendrocytes from MLPCs would eliminate many of the difficulties associated with their differentiation from embryonic stem cells.
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Affiliation(s)
- Hedvika Davis
- Hybrid Systems Laboratory, NanoScience
Technology Center, University of Central Florida, Orlando, Florida 32826, United States
- College of Medicine, Biomedical
Science Program, University of Central Florida, Orlando, Florida 32826, United States
| | - Xiufang Guo
- Hybrid Systems Laboratory, NanoScience
Technology Center, University of Central Florida, Orlando, Florida 32826, United States
| | - Stephen Lambert
- Hybrid Systems Laboratory, NanoScience
Technology Center, University of Central Florida, Orlando, Florida 32826, United States
- College of Medicine, Biomedical
Science Program, University of Central Florida, Orlando, Florida 32826, United States
| | - Maria Stancescu
- Hybrid Systems Laboratory, NanoScience
Technology Center, University of Central Florida, Orlando, Florida 32826, United States
| | - James J. Hickman
- Hybrid Systems Laboratory, NanoScience
Technology Center, University of Central Florida, Orlando, Florida 32826, United States
- College of Medicine, Biomedical
Science Program, University of Central Florida, Orlando, Florida 32826, United States
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Lorentz H, Heynen M, Kay LM, Dominici CY, Khan W, Ng WW, Jones L. Contact lens physical properties and lipid deposition in a novel characterized artificial tear solution. Mol Vis 2011; 17:3392-405. [PMID: 22219635 PMCID: PMC3247163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 12/20/2011] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To characterize various properties of a physiologically-relevant artificial tear solution (ATS) containing a range of tear film components within a complex salt solution, and to measure contact lens parameters and lipid deposition of a variety of contact lens materials after incubation in this ATS. METHODS A complex ATS was developed that contains a range of salts, proteins, lipids, mucin, and other tear film constituents in tear-film relevant concentrations. This ATS was tested to confirm that its pH, osmolality, surface tension, and homogeneity are similar to human tears and remain so throughout the material incubation process, for up to 4 weeks. To confirm that silicone hydrogel and conventional hydrogel contact lens materials do not alter in physical characteristics beyond what is allowed by the International Organization for Standardization (ISO) 18369-2. The diameter, center thickness, and calculated base curve were measured for five different lens materials directly out of the blister pack, after a rinse in saline and then following a two week incubation in the modified ATS. To test the ATS and the effect of its composition on lipid deposition, two lens materials were incubated in the ATS and a modified version for several time points. Both ATS solutions contained trace amounts of carbon-14 cholesterol and phosphatidylcholine, such that deposition of these specific lipids could be quantified using standard methods. RESULTS This ATS is a complex mixture that remains stable at physiologically relevant pH (7.3-7.6), osmolality (304-306 mmol/kg), surface tension (40-46 dynes/cm) and homogeneity over an incubation period of three weeks or more. The physical parameters of the lenses tested showed no changes beyond that allowed by the ISO guidelines. Incubations with the ATS found that balafilcon A lenses deposit significantly more cholesterol and phosphatidylcholine than omafilcon A lenses (p<0.05) and that removing lactoferrin and immunoglobulin G from the ATS can significantly decrease the mass of lipid deposited. CONCLUSIONS This paper describes a novel complex artificial tear solution specially designed for in-vial incubation of contact lens materials. This solution was stable and did not adversely affect the physical parameters of the soft contact lenses incubated within it and showed that lipid deposition was responsive to changes in ATS composition.
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