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Dittfeld C, Bähring S, Welzel C, Jannasch A, Matschke K, Tugtekin SM, Alexiou K. Tissue requirements for the application of aortic valve neocuspidization - appropriate pericardium properties and homogeneity? JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2024; 35:26. [PMID: 38683259 PMCID: PMC11058761 DOI: 10.1007/s10856-024-06790-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 03/05/2024] [Indexed: 05/01/2024]
Abstract
OBJECTIVE Aortic valve neocuspidization (AVNeo) using autologous pericardium is a promising technique. Expected advantages are reduced immune response, appropriate biomechanics and lower treatment expenses. Nevertheless, autologous pericardium can be affected by patient's age and comorbidities. Usually, glutaraldehyde (GA) - fixed bovine pericardium is the basic material for aortic valve prostheses, easy available and carefully pre-examined in a standardized fabrication process. Aim of the study is the verification of autologous pericardial tissue homogeneity by analysing tissue thickness, biomechanics and extracellular matrix (ECM) composition. METHODS Segments of human GA-fixed pericardium selected by the surgeon based on visual criteria for cusp pre-cut and remaining after surgical AV replacement were investigated in comparison to bovine standard tissue treated equivalently. Pericardium sampling was performed at up to three positions of each sutured cusp for histological or biomechanical analysis, according to tissue availability. RESULTS AND CONCLUSIONS Human pericardia exhibited a higher heterogeneity in collagen content, density of vessel structures and elastic moduli. Thickness, vessel density and collagen and elastin content differed significantly between the species. In contrast, significant interindividual differences were detected in most properties investigated for human pericardial samples but only for tissue thickness in bovine tissues. Higher heterogeneity of human pericardium, differing vessel and collagen content compared to bovine state-of-the-art material might be detrimental for long term AV functionality or deterioration and have to be intensely investigated in patients follow up after autologous cusp replacement.
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Affiliation(s)
- Claudia Dittfeld
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Dresden, Germany.
| | - Sophia Bähring
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Dresden, Germany
| | - Cindy Welzel
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Dresden, Germany
| | - Anett Jannasch
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Dresden, Germany
| | - Klaus Matschke
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Dresden, Germany
| | - Sems-Malte Tugtekin
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Dresden, Germany
| | - Konstantin Alexiou
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Dresden, Germany
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Dittfeld C, Welzel C, König U, Jannasch A, Alexiou K, Blum E, Bronder S, Sperling C, Maitz MF, Tugtekin SM. Hemocompatibility tuning of an innovative glutaraldehyde-free preparation strategy using riboflavin/UV crosslinking and electron irradiation of bovine pericardium for cardiac substitutes. BIOMATERIALS ADVANCES 2023; 147:213328. [PMID: 36764200 DOI: 10.1016/j.bioadv.2023.213328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 01/17/2023] [Accepted: 02/01/2023] [Indexed: 02/09/2023]
Abstract
Hemocompatibility tuning was adopted to explore and refine an innovative, GA-free preparation strategy combining decellularization, riboflavin/UV crosslinking, and low-energy electron irradiation (SULEEI) procedure. A SULEEI-protocol was established to avoid GA-dependent deterioration that results in insufficient long-term aortic valve bioprosthesis durability. Final SULEEI-pericardium, intermediate steps and GA-fixed reference pericardium were exposed in vitro to fresh human whole blood to elucidate effects of preparation parameters on coagulation and inflammation activation and tissue histology. The riboflavin/UV crosslinking step showed to be less efficient in inactivating extracellular matrix (ECM) protein activity than the GA fixation, leading to tissue-factor mediated blood clotting. Intensifying the riboflavin/UV crosslinking with elevated riboflavin concentration and dextran caused an enhanced activation of the complement system. Yet activation processes induced by the previous protocol steps were quenched with the final electron beam treatment step. An optimized SULEEI protocol was developed using an intense and extended, trypsin-containing decellularization step to inactivate tissue factor and a dextran-free, low riboflavin, high UV crosslinking step. The innovative and improved GA-free SULEEI-preparation protocol results in low coagulant and low inflammatory bovine pericardium for surgical application.
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Affiliation(s)
- Claudia Dittfeld
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Germany.
| | - Cindy Welzel
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Germany
| | - Ulla König
- Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, Dresden, Germany
| | - Anett Jannasch
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Germany
| | - Konstantin Alexiou
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Germany
| | - Ekaterina Blum
- Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, Dresden, Germany
| | - Saskia Bronder
- Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, Dresden, Germany
| | - Claudia Sperling
- Leibniz-Institut für Polymerforschung Dresden e.V., Institute Biofunctional Polymer Materials, Dresden, Germany
| | - Manfred F Maitz
- Leibniz-Institut für Polymerforschung Dresden e.V., Institute Biofunctional Polymer Materials, Dresden, Germany
| | - Sems-Malte Tugtekin
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Germany
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Welzel C, König U, Jannasch A, Matschke K, Tugtekin SM, Dittfeld C, Steiner G. Infrared Spectroscopic Verification of a α-Helical Collagen Structure in Glutaraldehyde-Free Crosslinked Bovine Pericardium for Cardiac Implants. LIFE (BASEL, SWITZERLAND) 2022; 12:life12122035. [PMID: 36556400 PMCID: PMC9785276 DOI: 10.3390/life12122035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/23/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022]
Abstract
The degeneration of heart valve bioprostheses due to calcification processes is caused by the intercalation of calciumhydroxyapatite in pericardium collagen bundles. Variations of the protein secondary structure of biomaterials according to preparation are relevant for this mineralization process and thus the structural characterization of innovative bioprostheses materials is of great importance. The gold standard for prostheses preparation is glutaraldehyde (GA)-fixation of bovine pericardium that adversely promotes calcification. The novel GA-free SULEEI-treatment of bovine pericardium includes decellularization, UV-crosslinking, and electron beam sterilization. The aim of this study is the structural characterization of SULEEI-treated and GA-fixed bovine pericardium. IR spectroscopic imaging combined with multivariate data and curve fit analysis was applied to investigate the amide I and amide II regions of SULEEI-treated and GA-fixed samples. The spectroscopic images of GA-fixed pericardial tissue exhibited a generally high content of amine groups and side chains providing nucleation points for calcification processes. In contrast, in SULEEI-treated tissue, the typical α-helical structure was retained and was supposed to be less prone to deterioration.
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Affiliation(s)
- Cindy Welzel
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, 01307 Dresden, Germany
- Correspondence:
| | - Ulla König
- Department of Medical and Biotechnological Applications, Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology, 01277 Dresden, Germany
| | - Anett Jannasch
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, 01307 Dresden, Germany
| | - Klaus Matschke
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, 01307 Dresden, Germany
| | - Sems-Malte Tugtekin
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, 01307 Dresden, Germany
| | - Claudia Dittfeld
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, 01307 Dresden, Germany
| | - Gerald Steiner
- Department of Anaesthesiology and Critical Care Medicine, Clinical Sensoring and Monitoring, Faculty of Medicine, Technische Universität Dresden, 01307 Dresden, Germany
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Yang W, Shan Z. Application of wool keratin: an anti-ultraviolet wall material in spray drying. JOURNAL OF FOOD SCIENCE AND TECHNOLOGY 2021; 58:4235-4244. [PMID: 34538906 DOI: 10.1007/s13197-020-04897-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 07/01/2020] [Accepted: 07/08/2020] [Indexed: 11/30/2022]
Abstract
Low-molecular-weight keratin (LMWK) obtained from wool was employed as a wall material for the spray drying encapsulation of fish oil. Microcapsules with different LMWK contents were prepared, and their anti-ultraviolet performance and other features were studied. The results showed that LMWK was able to improve the encapsulation efficiency of fish oil because of its good emulsifying properties. When the LMWK content was increased from 0 to 10, 30 and 50%, the shelf life of the microcapsules under ultraviolet irradiation increased from 48 to 96 h, 144 h and 168 h, respectively. The strongest absorption efficiency of LMWK is shown in the UVc band. The chemical structure of LMWK did not change during an ultraviolet accelerating ageing test.
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Affiliation(s)
- Wenhua Yang
- College of Biomass Science and Engineering, Sichuan University, No.24 South Section 1, Yihuan Road, Chengdu, 610065 China.,National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University, Chengdu, 610065 China
| | - Zhihua Shan
- College of Biomass Science and Engineering, Sichuan University, No.24 South Section 1, Yihuan Road, Chengdu, 610065 China.,National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University, Chengdu, 610065 China
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Grandis RAD, Miotto LN, Genaro LE, Migliatti Polli L, Plepis AMDG, Rodrigues FT, Martins VDCA, Pereira Franchi L, Scarel-Caminaga RM, Sidorenko de Oliveira Capote T. In Vitro Evaluation of Acellular Collagen Matrices Derived from Porcine Pericardium: Influence of the Sterilization Method on Its Biological Properties. MATERIALS (BASEL, SWITZERLAND) 2021; 14:6255. [PMID: 34771781 PMCID: PMC8584648 DOI: 10.3390/ma14216255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 08/29/2021] [Accepted: 09/02/2021] [Indexed: 01/31/2023]
Abstract
The aim of this study were characterize acellular collagen matrices derived from porcine pericardium (PP) and to evaluate their properties after sterilization by ethylene oxide and gamma ray. PP matrices were subjected to alkaline hydrolysis (AH), and samples were characterized for biological stability, membrane thickness measurements, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Subsequently, the matrices were frozen, lyophilized and sterilized by ethylene oxide or gamma radiation. For in vitro assays, CHO-K1 cell culture was used and evaluated for cytotoxicity, clonogenic survival assay, genotoxicity and mutagenicity. Analysis of variance (ANOVA) was used, followed by Dunnett's post-test, with a significance level of 5%. After AH, there was no significant change in matrix thickness. The relative biodegradability of the material after implantation was observed. Morphology and dimensions had small changes after AH. As for cell viability, none of the tested matrices showed a statistically significant difference (p > 0.05; Dunnett) regardless of the sterilization method. Furthermore, it was found that PP matrices did not interfere with the proliferation capacity of CHO-K1 cells (p > 0.05; Dunnett). As for genotoxicity, when sterilized with ethylene oxide (NP, P12 and P24), it showed genotoxic potential, but it was not genotoxic when sterilized by gamma radiation. No mutagenic effects were observed in either group. PP-derived collagen matrices hydrolyzed at different times were not cytotoxic. It is concluded that the best method of sterilization is through gamma radiation, since no significant changes were observed in the properties of the PP matrices.
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Affiliation(s)
- Rone Aparecido De Grandis
- Faculty of Pharmaceutical Sciences-FCFar, Paulista State University, Araraquara 14801-903, SP, Brazil; (R.A.D.G.); (L.M.P.)
| | - Larissa Natiele Miotto
- Department of Morphology, Genetics, Orthodontic and Pediatric Dentistry, Araraquara School of Dentistry, Paulista State University, Araraquara 14801-903, SP, Brazil; (L.N.M.); (L.E.G.); (R.M.S.-C.)
| | - Luis Eduardo Genaro
- Department of Morphology, Genetics, Orthodontic and Pediatric Dentistry, Araraquara School of Dentistry, Paulista State University, Araraquara 14801-903, SP, Brazil; (L.N.M.); (L.E.G.); (R.M.S.-C.)
| | - Larissa Migliatti Polli
- Faculty of Pharmaceutical Sciences-FCFar, Paulista State University, Araraquara 14801-903, SP, Brazil; (R.A.D.G.); (L.M.P.)
| | - Ana Maria de Guzzi Plepis
- Department of Chemistry and Molecular Physics, Institute of Chemistry of São Carlos, University of São Paulo, Sao Carlos 13566-590, SP, Brazil; (A.M.d.G.P.); (F.T.R.); (V.d.C.A.M.)
| | - Fabiana Tessari Rodrigues
- Department of Chemistry and Molecular Physics, Institute of Chemistry of São Carlos, University of São Paulo, Sao Carlos 13566-590, SP, Brazil; (A.M.d.G.P.); (F.T.R.); (V.d.C.A.M.)
| | - Virginia da Conceição Amaro Martins
- Department of Chemistry and Molecular Physics, Institute of Chemistry of São Carlos, University of São Paulo, Sao Carlos 13566-590, SP, Brazil; (A.M.d.G.P.); (F.T.R.); (V.d.C.A.M.)
| | - Leonardo Pereira Franchi
- Department of Genetics, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Sao Carlos 13566-590, SP, Brazil;
| | - Raquel Mantuaneli Scarel-Caminaga
- Department of Morphology, Genetics, Orthodontic and Pediatric Dentistry, Araraquara School of Dentistry, Paulista State University, Araraquara 14801-903, SP, Brazil; (L.N.M.); (L.E.G.); (R.M.S.-C.)
| | - Ticiana Sidorenko de Oliveira Capote
- Department of Morphology, Genetics, Orthodontic and Pediatric Dentistry, Araraquara School of Dentistry, Paulista State University, Araraquara 14801-903, SP, Brazil; (L.N.M.); (L.E.G.); (R.M.S.-C.)
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Jannasch A, Rix J, Welzel C, Schackert G, Kirsch M, König U, Koch E, Matschke K, Tugtekin SM, Dittfeld C, Galli R. Brillouin confocal microscopy to determine biomechanical properties of SULEEI-treated bovine pericardium for application in cardiac surgery. Clin Hemorheol Microcirc 2021; 79:179-192. [PMID: 34487036 DOI: 10.3233/ch-219119] [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: 11/15/2022]
Abstract
BACKGROUND Heart valves are exposed to a highly dynamic environment and underlie high tensile and shear forces during opening and closing. Therefore, analysis of mechanical performance of novel heart valve bioprostheses materials, like SULEEI-treated bovine pericardium, is essential and usually carried out by uniaxial tensile tests. Nevertheless, major drawbacks are the unidirectional strain, which does not reflect the in vivo condition and the deformation of the sample material. An alternative approach for measurement of biomechanical properties is offered by Brillouin confocal microscopy (BCM), a novel, non-invasive and three-dimensional method based on the interaction of light with acoustic waves. OBJECTIVE BCM is a powerful tool to determine viscoelastic tissue properties and is, for the first time, applied to characterize novel biological graft materials, such as SULEEI-treated bovine pericardium. Therefore, the method has to be validated as a non-invasive alternative to conventional uniaxial tensile tests. METHODS Vibratome sections of SULEEI-treated bovine pericardium (decellularized, riboflavin/UV-cross-linked and low-energy electron irradiated) as well as native and GA-fixed controls (n = 3) were analyzed by BCM. In addition, uniaxial tensile tests were performed on equivalent tissue samples and Young's modulus as well as length of toe region were analyzed from stress-strain diagrams. The structure of the extracellular matrix (ECM), especially collagen and elastin, was investigated by multiphoton microscopy (MPM). RESULTS SULEEI-treated pericardium exhibited a significantly higher Brillouin shift and hence higher tissue stiffness in comparison to native and GA-fixed controls (native: 5.6±0.2 GHz; GA: 5.5±0.1 GHz; SULEEI: 6.3±0.1 GHz; n = 3, p < 0.0001). Similarly, a significantly higher Young's modulus was detected in SULEEI-treated pericardia in comparison to native tissue (native: 30.0±10.4 MPa; GA: 31.8±10.7 MPa; SULEEI: 42.1±7.0 MPa; n = 3, p = 0.027). Native pericardia showed wavy and non-directional collagen fibers as well as thin, linear elastin fibers generating a loose matrix. The fibers of GA-fixed and SULEEI-treated pericardium were aligned in one direction, whereat the SULEEI-sample exhibited a much denser matrix. CONCLUSION BCM is an innovative and non-invasive method to analyze elastic properties of novel pericardial graft materials with special mechanical requirements, like heart valve bioprostheses.
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Affiliation(s)
- Anett Jannasch
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Dresden, Germany
| | - Jan Rix
- Clinical Sensoring and Monitoring, Department of Anesthesiology and Intensive Care Medicine, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
| | - Cindy Welzel
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Dresden, Germany
| | - Gabriele Schackert
- Neurosurgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Matthias Kirsch
- Neurosurgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,Klinik für Neurochirurgie, Asklepios Kliniken Schildautal, Seesen, Germany
| | - Ulla König
- Department of Medical and Biotechnological Applications, Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology, Dresden, Germany
| | - Edmund Koch
- Clinical Sensoring and Monitoring, Department of Anesthesiology and Intensive Care Medicine, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
| | - Klaus Matschke
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Dresden, Germany
| | - Sems Malte Tugtekin
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Dresden, Germany
| | - Claudia Dittfeld
- Department of Cardiac Surgery, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Heart Centre Dresden, Dresden, Germany
| | - Roberta Galli
- Department of Medical Physics and Biomedical Technology, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
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Walker S, Dittfeld C, Jakob A, Schönfelder J, König U, Tugtekin SM. Sterilization and Cross-Linking Combined with Ultraviolet Irradiation and Low-Energy Electron Irradiation Procedure: New Perspectives for Bovine Pericardial Implants in Cardiac Surgery. Thorac Cardiovasc Surg 2020; 70:33-42. [PMID: 32114687 DOI: 10.1055/s-0040-1705100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND Bovine pericardium is the major natural source of patches and aortic valve substitutes in cardiac repair procedures. However, long-term tissue durability and biocompatibility issues lead to degeneration (e.g., calcification) that requires reoperation. Tissue preparation strategies, including glutaraldehyde fixation, are reasons for the deterioration of pericardial tissues. We describe a pretreatment procedure involving sterilization and cross-linking combined with ultraviolet (UV) irradiation and low-energy electron irradiation (SULEEI). This innovative, glutaraldehyde-free protocol improves the mechanical aspects and biocompatibility of porcine pericardium patches. METHODS We adopted the SULEEI protocol, which combines decellularization, sterilization, and cross-linking, along with UV irradiation and low-energy electron irradiation, to pretreat bovine pericardium. Biomechanics, such as ultimate tensile strength and elasticity, were investigated by comparing SULEEI-treated tissue with glutaraldehyde-fixed analogues, clinical patch materials, and an aortic valve substitute. Histomorphological and cellular aspects were investigated by histology, DNA content analysis, and degradability. RESULTS Mechanical parameters, including ultimate tensile strength, elasticity (Young's modulus), and suture retention strength, were similar for SULEEI-treated and clinically applied bovine pericardium. The SULEEI-treated tissues showed well-preserved histoarchitecture that resembled all pericardial tissues investigated. Fiber density did not differ significantly. DNA content after the SULEEI procedure was reduced to less than 10% of the original tissue material, and more than 50% of the SULEEI-treated pericardium was digested by collagenase. CONCLUSION The SULEEI procedure represents a new treatment protocol for the preparation of patches and aortic valve prostheses from bovine pericardial tissue. The avoidance of glutaraldehyde fixation may lessen the tissue degeneration processes in cardiac repair patches and valve prostheses.
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Affiliation(s)
- Simona Walker
- Department of Medical and Biotechnological Applications, Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology, Dresden, Germany
| | - Claudia Dittfeld
- Department of Cardiac Surgery, Faculty of Medicine Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - Aline Jakob
- Department of Cardiac Surgery, Faculty of Medicine Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - Jessy Schönfelder
- Department of Medical and Biotechnological Applications, Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology, Dresden, Germany
| | - Ulla König
- Department of Medical and Biotechnological Applications, Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology, Dresden, Germany
| | - Sems-Malte Tugtekin
- Department of Cardiac Surgery, Faculty of Medicine Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
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