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Burkert J, Kochová P, Tonar Z, Cimrman R, Blassová T, Jashari R, Fiala R, Špatenka J. The time has come to extend the expiration limit of cryopreserved allograft heart valves. Cell Tissue Bank 2020; 22:161-184. [PMID: 32583302 DOI: 10.1007/s10561-020-09843-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/13/2020] [Indexed: 12/12/2022]
Abstract
Despite the wide choice of commercial heart valve prostheses, cryopreserved semilunar allograft heart valves (C-AHV) are required, and successfully transplanted in selected groups of patients. The expiration limit (EL) criteria have not been defined yet. Most Tissue Establishments (TE) use the EL of 5 years. From physiological, functional, and surgical point of view, the morphology and mechanical properties of aortic and pulmonary roots represent basic features limiting the EL of C-AHV. The aim of this work was to review methods of AHV tissue structural analysis and mechanical testing from the perspective of suitability for EL validation studies. Microscopic structure analysis of great arterial wall and semilunar leaflets tissue should clearly demonstrate cells as well as the extracellular matrix components by highly reproducible and specific histological staining procedures. Quantitative morphometry using stereological grids has proved to be effective, as the exact statistics was feasible. From mechanical testing methods, tensile test was the most suitable. Young's moduli of elasticity, ultimate stress and strain were shown to represent most important AHV tissue mechanical characteristics, suitable for exact statistical analysis. C-AHV are prepared by many different protocols, so as each TE has to work out own EL for C-AHV.
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Affiliation(s)
- Jan Burkert
- Department of Transplantation and Tissue Banking, Czech National Allograft Heart Valve Bank, Department of Cardiovascular Surgery, Motol University Hospital, and Second Faculty of Medicine Charles University in Prague, V Úvalu 84, 150 06, Prague, Czech Republic
| | - Petra Kochová
- Department of Transplantation and Tissue Banking, Czech National Allograft Heart Valve Bank, Department of Cardiovascular Surgery, Motol University Hospital, and Second Faculty of Medicine Charles University in Prague, V Úvalu 84, 150 06, Prague, Czech Republic. .,NTIS - New Technologies for the Information Society, Faculty of Applied Sciences, University of West Bohemia, Technická 8, Pilsen, Czech Republic.
| | - Zbyněk Tonar
- NTIS - New Technologies for the Information Society, Faculty of Applied Sciences, University of West Bohemia, Technická 8, Pilsen, Czech Republic.,Department of Histology and Embryology, Biomedical Centre, Faculty of Medicine in Pilsen, Charles University in Prague, Karlovarská 48, 301 66, Pilsen, Czech Republic
| | - Robert Cimrman
- NTIS - New Technologies for the Information Society, Faculty of Applied Sciences, University of West Bohemia, Technická 8, Pilsen, Czech Republic
| | - Tereza Blassová
- Department of Histology and Embryology, Biomedical Centre, Faculty of Medicine in Pilsen, Charles University in Prague, Karlovarská 48, 301 66, Pilsen, Czech Republic
| | - Ramadan Jashari
- European Homograft Bank, Saint-Jean Clinic, Rue du Meridien 100, 1210, Brussels, Belgium
| | - Radovan Fiala
- Department of Transplantation and Tissue Banking, Czech National Allograft Heart Valve Bank, Department of Cardiovascular Surgery, Motol University Hospital, and Second Faculty of Medicine Charles University in Prague, V Úvalu 84, 150 06, Prague, Czech Republic
| | - Jaroslav Špatenka
- Department of Transplantation and Tissue Banking, Czech National Allograft Heart Valve Bank, Department of Cardiovascular Surgery, Motol University Hospital, and Second Faculty of Medicine Charles University in Prague, V Úvalu 84, 150 06, Prague, Czech Republic
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Vasudevan B, Chang Q, Wang B, Huang S, Sui Y, Zhu W, Fan Q, Song Y. Effect of intracellular uptake of nanoparticle-encapsulated trehalose on the hemocompatibility of allogeneic valves in the VS83 vitrification protocol. Nanobiomedicine (Rij) 2020; 7:1849543520983173. [PMID: 33447299 PMCID: PMC7780325 DOI: 10.1177/1849543520983173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 12/03/2020] [Indexed: 11/16/2022] Open
Abstract
Trehalose is a disaccharide molecule consisting of two molecules of glucose. Industrially, trehalose is derived from corn starch and utilized as a drug. This study aims to examine whether the integration of nanoparticle-encapsulated trehalose to the Ice-Free Cryopreservation (IFC) method for preserving heart valves has better cell viability, benefits to protect the extracellular matrix (ECM), and reduce immune response after storage. For the experiment to be carried out, we obtained materials, and the procedures were carried out in the following manner. The initial step was the preparation of hydroxyapatite nanoparticles, followed by precipitation to acquire Apatite colloidal suspensions. Animals were obtained, and their tissue isolation and grouping were done ethically. All samples were then divided into four groups, Control group, Conventional Frozen Cryopreservation (CFC) group, IFC group, and IFC + T (IFC with the addition of 0.2 M nanoparticle-encapsulated Trehalose) group. Histological analysis was carried out via H&E staining, ECM components were stained with Modified Weigert staining, and the Gomori Ammonia method was used to stain reticular fibers. Alamar Blue assay was utilized to assess cell viability. Hemocompatibility was evaluated, and samples were processed for immunohistochemistry (TNFα and IL-10). Hemocompatibility was quantified using Terminal Complement Complex (TCC) and Neutrophil elastase (NE) as an indicator. The results of the H&E staining revealed less formation of extracellular ice crystals and intracellular vacuoles in the IFC + T group compared with all other groups. The CFC group's cell viability showed better viability than the IFC group, but the highest viability was exhibited in the IFC + T group (70.96 ± 2.53, P < 0.0001, n = 6). In immunohistochemistry, TNFα levels were lowest in both IFC and IFC + T group, and IL-10 expression had significantly reduced in IFC and IFC + T group. The results suggested that the nanoparticle encapsulated trehalose did not show significant hemocompatibility issues on the cryopreserved heart valves.
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Affiliation(s)
| | - Qing Chang
- Affiliated Hospital of Medical College, Qingdao University, Qingdao, China
| | - Bin Wang
- Affiliated Hospital of Medical College, Qingdao University, Qingdao, China
| | - Siyang Huang
- Affiliated Hospital of Medical College, Qingdao University, Qingdao, China
| | - Yulong Sui
- Affiliated Hospital of Medical College, Qingdao University, Qingdao, China
| | - Wenjie Zhu
- Affiliated Hospital of Medical College, Qingdao University, Qingdao, China
| | - Qing Fan
- Affiliated Hospital of Medical College, Qingdao University, Qingdao, China
| | - Yisheng Song
- Affiliated Hospital of Medical College, Qingdao University, Qingdao, China
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Preservation strategies for decellularized pericardial scaffolds for off-the-shelf availability. Acta Biomater 2019; 84:208-221. [PMID: 30342283 DOI: 10.1016/j.actbio.2018.10.026] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 09/26/2018] [Accepted: 10/16/2018] [Indexed: 02/06/2023]
Abstract
Decellularized biological scaffolds hold great promise in cardiovascular surgery. In order to ensure off-the-shelf availability, routine use of decellularized scaffolds requires tissue banking. In this study, the suitability of cryopreservation, vitrification and freeze-drying for the preservation of decellularized bovine pericardial (DBP) scaffolds was evaluated. Cryopreservation was conducted using 10% DMSO and slow-rate freezing. Vitrification was performed using vitrification solution (VS83) and rapid cooling. Freeze-drying was done using a programmable freeze-dryer and sucrose as lyoprotectant. The impact of the preservation methods on the DBP extracellular matrix structure, integrity and composition was assessed using histology, biomechanical testing, spectroscopic and thermal analysis, and biochemistry. In addition, the cytocompatibility of the preserved scaffolds was also assessed. All preservation methods were found to be suitable to preserve the extracellular matrix structure and its components, with no apparent signs of collagen deterioration or denaturation, or loss of elastin and glycosaminoglycans. Biomechanical testing, however, showed that the cryopreserved DBP displayed a loss of extensibility compared to vitrified or freeze-dried scaffolds, which both displayed similar biomechanical behavior compared to non-preserved control scaffolds. In conclusion, cryopreservation altered the biomechanical behavior of the DBP scaffolds, which might lead to graft dysfunction in vivo. In contrast to cryopreservation and vitrification, freeze-drying is performed with non-toxic protective agents and does not require storage at ultra-low temperatures, thus allowing for a cost-effective and easy storage and transport. Due to these advantages, freeze-drying is a preferable method for the preservation of decellularized pericardium. STATEMENT OF SIGNIFICANCE: Clinical use of DBP scaffolds for surgical reconstructions or substitutions requires development of a preservation technology that does not alter scaffold properties during long-term storage. Conclusive investigation on adverse impacts of the preservation methods on DBP matrix integrity is still missing. This work is aiming to close this gap by studying three potential preservation technologies, cryopreservation, vitrification and freeze-drying, in order to achieve the off-the-shelf availability of DBP patches for clinical application. Furthermore, it provides novel insights for dry-preservation of decellularized xenogeneic scaffolds that can be used in the routine clinical cardiovascular practice, allowing the surgeon the opportunity to choose an ideal implant matching with the needs of each patient.
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Sui Y, Fan Q, Wang B, Wang J, Chang Q. Ice-free cryopreservation of heart valve tissue: The effect of adding MitoQ to a VS83 formulation and its influence on mitochondrial dynamics. Cryobiology 2018; 81:153-159. [DOI: 10.1016/j.cryobiol.2018.01.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 01/18/2018] [Accepted: 01/23/2018] [Indexed: 10/18/2022]
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Goecke T, Theodoridis K, Tudorache I, Ciubotaru A, Cebotari S, Ramm R, Höffler K, Sarikouch S, Vásquez Rivera A, Haverich A, Wolkers WF, Hilfiker A. In vivo performance of freeze-dried decellularized pulmonary heart valve allo- and xenografts orthotopically implanted into juvenile sheep. Acta Biomater 2018; 68:41-52. [PMID: 29191508 DOI: 10.1016/j.actbio.2017.11.041] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 11/10/2017] [Accepted: 11/14/2017] [Indexed: 11/16/2022]
Abstract
The decellularization of biological tissues decreases immunogenicity, allows repopulation with cells, and may lead to improved long-term performance after implantation. Freeze drying these tissues would ensure off-the-shelf availability, save storage costs, and facilitates easy transport. This study evaluates the in vivo performance of freeze-dried decellularized heart valves in juvenile sheep. TritonX-100 and sodium dodecylsulfate decellularized ovine and porcine pulmonary valves (PV) were freeze-dried in a lyoprotectant sucrose solution. After rehydration for 24 h, valves were implanted into the PV position in sheep as allografts (fdOPV) and xenografts (fdPPV), while fresh dezellularized ovine grafts (frOPV) were implanted as controls. Functional assessment was performed by transesophageal echocardiography at implantation and at explantation six months later. Explanted grafts were analysed histologically to assess the matrix, and immunofluorescence stains were used to identify the repopulating cells. Although the graft diameters and orifice areas increased, good function was maintained, except for one insufficient, strongly deteriorated frOPV. Cells which were positive for either endothelial or interstitial markers were found in all grafts. In fdPPV, immune-reactive cells were also found. Our findings suggest that freeze-drying does not alter the early hemodynamic performance and repopulation potential of decellularized grafts in vivo, even in the challenging xenogeneic situation. Despite evidence of an immunological reaction for the xenogenic valves, good early functionalities were achieved. STATEMENT OF SIGNIFICANCE Decellularized allogeneic heart valves show excellent results as evident from large animal experiments and clinical trials. However, a long-term storing method is needed for an optimal use of this limited resource in the clinical setting, where an optimized matching of graft and recipient is requested. As demonstrated in this study, freeze-dried and freshly decellularized grafts reveal equally good results after implantation in the juvenile sheep concerning function and repopulation with recipients' cells. Thus, freeze-drying arises as a promising method to extend the shelf-life of valvular grafts compared to those stored in antibiotic-solution as currently practised.
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Affiliation(s)
- Tobias Goecke
- Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany; Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany
| | - Karolina Theodoridis
- Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany; Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany
| | - Igor Tudorache
- Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany; Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany
| | - Anatol Ciubotaru
- Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Serghei Cebotari
- Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany; Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany
| | - Robert Ramm
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany
| | - Klaus Höffler
- Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Samir Sarikouch
- Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | | | - Axel Haverich
- Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany; Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany
| | - Willem F Wolkers
- Institute of Multiphase Processes, Leibniz Universität Hannover, Hannover, Germany
| | - Andres Hilfiker
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany.
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Wang S, Oldenhof H, Goecke T, Ramm R, Harder M, Haverich A, Hilfiker A, Wolkers WF. Sucrose Diffusion in Decellularized Heart Valves for Freeze-Drying. Tissue Eng Part C Methods 2015; 21:922-31. [PMID: 25809201 DOI: 10.1089/ten.tec.2014.0681] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Decellularized heart valves can be used as starter matrix implants for heart valve replacement therapies in terms of guided tissue regeneration. Decellularized matrices ideally need to be long-term storable to assure off-the-shelf availability. Freeze-drying is an attractive preservation method, allowing storage at room temperature in a dried state. However, the two inherent processing steps, freezing and drying, can cause severe damage to extracellular matrix (ECM) proteins and the overall tissue histoarchitecture and thus impair biomechanical characteristics of resulting matrices. Freeze-drying therefore requires a lyoprotective agent that stabilizes endogenous structural proteins during both substeps and that forms a protective glassy state at room temperature. To estimate incubation times needed to infiltrate decellularized heart valves with the lyoprotectant sucrose, temperature-dependent diffusion studies were done using Fourier transform infrared spectroscopy. Glycerol, a cryoprotective agent, was studied for comparison. Diffusion of both protectants was found to exhibit Arrhenius behavior. The activation energies of sucrose and glycerol diffusion were found to be 15.9 and 37.7 kJ·mol(-1), respectively. It was estimated that 4 h of incubation at 37°C is sufficient to infiltrate heart valves with sucrose before freeze-drying. Application of a 5% sucrose solution was shown to stabilize acellular valve scaffolds during freeze-drying. Such freeze-dried tissues, however, displayed pores, which were attributed to ice crystal damage, whereas vacuum-dried scaffolds in comparison revealed no pores after drying and rehydration. Exposure to a hygroscopic sucrose solution (80%) before freeze-drying was shown to be an effective method to diminish pore formation in freeze-dried ECMs: matrix structures closely resembled those of control samples that were not freeze-dried. Heart valve matrices were shown to be in a glassy state after drying, suggesting that they can be stored at room temperature.
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Affiliation(s)
- Shangping Wang
- 1 Institute of Multiphase Processes, Leibniz Universität Hannover , Hannover, Germany
| | - Harriëtte Oldenhof
- 2 Clinic for Horses-Unit for Reproductive Medicine, University of Veterinary Medicine Hannover , Hannover, Germany
| | - Tobias Goecke
- 3 Leibniz Research Laboratories for Biotechnology and Artificial Organs, Hannover Medical School , Hannover, Germany
| | - Robert Ramm
- 3 Leibniz Research Laboratories for Biotechnology and Artificial Organs, Hannover Medical School , Hannover, Germany
| | | | - Axel Haverich
- 3 Leibniz Research Laboratories for Biotechnology and Artificial Organs, Hannover Medical School , Hannover, Germany
| | - Andres Hilfiker
- 3 Leibniz Research Laboratories for Biotechnology and Artificial Organs, Hannover Medical School , Hannover, Germany
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Xeno-immunogenicity of ice-free cryopreserved porcine leaflets. J Surg Res 2014; 193:933-41. [PMID: 25454969 DOI: 10.1016/j.jss.2014.10.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 10/09/2014] [Accepted: 10/15/2014] [Indexed: 11/21/2022]
Abstract
BACKGROUND Undesirable processes of inflammation, calcification, or immune-mediated reactions are limiting factors in long-term survival of heart valves in patients. In this study, we target the modulatory effects of ice-free cryopreservation (IFC) of xenogeneic heart valve leaflet matrices, without decellularization, on the adaptive human immune responses in vitro. METHODS We tested porcine leaflet matrices from fresh untreated, conventionally cryopreserved (CFC), and IFC pulmonary valves by culturing them with human blood mononuclear cells for 5 d in vitro. No other tissue treatment protocols to modify possible immune responses were used. Matrices alone or in addition with a low-dose second stimulus were analyzed for induction of proliferation and cytokine release by flow cytometry-based techniques. Evaluation of the α-Gal epitope expression was performed by immunohistochemistry with fluorochrome-labeled B4 isolectin. RESULTS None of the tested leaflet treatment groups directly triggered the proliferation of immune cells. But when tested in combination with a second trigger by anti-CD3, IFC valves showed significantly reduced proliferation of T cells, especially effector memory T cells, in comparison with fresh or CFC tissue. Moreover, the cytokine levels for interferon-γ (IFNγ), tumor necrosis factor α, and interleukin-10 were reduced for the IFC-treated group being significantly different compared with the CFC group. However, no difference between treatment groups in the expression of the α-Gal antigen was observed. CONCLUSIONS IFC of xenogeneic tissue might be an appropriate treatment method or processing step to prevent responses of the adaptive immune system.
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