Nora Lang1, Elena Merkel2, Franziska Fuchs2, Dieter Schumann3, Dieter Klemm3, Friederike Kramer3, Susanne Mayer-Wagner4, Christian Schroeder4, Franz Freudenthal5, Heinrich Netz2, Rainer Kozlik-Feldmann2, Matthias Sigler6. 1. Department of Pediatric Cardiology and Intensive Care Medicine, Ludwig-Maximilians-University, Munich, Germany Department of Congenital Heart Defects and Pediatric Cardiology, Heart Center, University of Freiburg, Freiburg, Germany nora.lang@universitaets-herzzentrum.de nora.f.lang80@gmail.com. 2. Department of Pediatric Cardiology and Intensive Care Medicine, Ludwig-Maximilians-University, Munich, Germany. 3. Transfer Group Polymet e.V, Jena, Germany. 4. Department of Orthopedic Surgery, Ludwig-Maximilians-University, Munich, Germany. 5. Kardiozentrum, La Paz, Bolivia. 6. Department of Pediatric Cardiology and Intensive Care Medicine, Georg-August-University Göttingen, Göttingen, Germany.
Abstract
OBJECTIVES: Current materials for closure of cardiac defects such as ventricular septal defects (VSDs) are associated with compliance mismatch and a chronic inflammatory response. Bacterial nanocellulose (BNC) is a non-degradable biomaterial with promising properties such as high mechanical strength, favourable elasticity and a negligible inflammatory reaction. The aim of this study was the evaluation of a BNC patch for VSD closure and the investigation of its in vivo biocompatibility in a chronic pig model. METHODS: Young's modulus and tensile strength of BNC patches were determined before and after blood exposure. Muscular VSDs were created and closed with a BNC patch on the beating heart in an in vivo pig model. Hearts were explanted after 7, 30 or 90 days. Macropathology, histology and immunohistochemistry were performed. RESULTS: Young's modulus and tensile strength of the BNC patch decreased after blood contact from 6.3 ± 1.9 to 3.86 ± 2.2 MPa (P < 0.01) and 0.33 ± 0.06 to 0.26 ± 0.06 MPa (P < 0.01), respectively, indicating the development of higher elasticity. Muscular VSDs were closed with a BNC patch without residual shunting. After 90 days, a mild chronic inflammatory reaction was present. Moreover, there was reduced tissue overgrowth in comparison with polyester. Proceeding cellular organization characterized by fibromuscular cells, production of extracellular matrix, neoangiogenesis and complete neoendothelialization were found. There were no signs of thrombogenicity. CONCLUSIONS: BNC patches can close VSDs with good mid-term results and its biocompatibility can be considered as satisfactory. Its elasticity increases in the presence of blood, which might be advantageous. Therefore, it has potential to be used as an alternative patch material in congenital heart disease.
OBJECTIVES: Current materials for closure of cardiac defects such as ventricular septal defects (VSDs) are associated with compliance mismatch and a chronic inflammatory response. Bacterial nanocellulose (BNC) is a non-degradable biomaterial with promising properties such as high mechanical strength, favourable elasticity and a negligible inflammatory reaction. The aim of this study was the evaluation of a BNC patch for VSD closure and the investigation of its in vivo biocompatibility in a chronic pig model. METHODS: Young's modulus and tensile strength of BNC patches were determined before and after blood exposure. Muscular VSDs were created and closed with a BNC patch on the beating heart in an in vivo pig model. Hearts were explanted after 7, 30 or 90 days. Macropathology, histology and immunohistochemistry were performed. RESULTS: Young's modulus and tensile strength of the BNC patch decreased after blood contact from 6.3 ± 1.9 to 3.86 ± 2.2 MPa (P < 0.01) and 0.33 ± 0.06 to 0.26 ± 0.06 MPa (P < 0.01), respectively, indicating the development of higher elasticity. Muscular VSDs were closed with a BNC patch without residual shunting. After 90 days, a mild chronic inflammatory reaction was present. Moreover, there was reduced tissue overgrowth in comparison with polyester. Proceeding cellular organization characterized by fibromuscular cells, production of extracellular matrix, neoangiogenesis and complete neoendothelialization were found. There were no signs of thrombogenicity. CONCLUSIONS: BNC patches can close VSDs with good mid-term results and its biocompatibility can be considered as satisfactory. Its elasticity increases in the presence of blood, which might be advantageous. Therefore, it has potential to be used as an alternative patch material in congenital heart disease.
Authors: Olga L Evdokimova; Carla S Alves; Radenka M Krsmanović Whiffen; Zaida Ortega; Helena Tomás; João Rodrigues Journal: J Zhejiang Univ Sci B Date: 2021-06-15 Impact factor: 3.066