Irina Y Zhuravleva1, Nataliya R Nichay2, Yuriy Y Kulyabin2, Tatyana P Timchenko1, Alexander A Korobeinikov1, Yuliya F Polienko3, Svetlana S Shatskaya4, Elena V Kuznetsova1, Alexey V Voitov2, Alexander V Bogachev-Prokophiev5, Alexander M Karaskov5. 1. Laboratory of Biological Prostheses, E. Meshalkin National Medical Research Center, Novosibirsk, Russian Federation. 2. Department of Congenital Heart Disease, E. Meshalkin National Medical Research Center, Novosibirsk, Russian Federation. 3. Laboratory of Nitrogen Compounds, N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, SB RAS, Novosibirsk, Russian Federation. 4. Laboratory of Intercalation and Mechanochemical Reactions, Institute of Solid State Chemistry and Mechanochemistry, SB RAS, Novosibirsk, Russian Federation. 5. Heart Valve Surgery Department, E. Meshalkin National Medical Research Center, Novosibirsk, Russian Federation.
Abstract
OBJECTIVES: The development of calcification-resistant bioprosthetic materials is a very important challenge for paediatric surgery. The subcutaneous implantation in rats is the well-known first-stage model for this kind of research. Using this model, we aimed to compare calcification of the porcine aortic wall and bovine pericardium and jugular vein wall cross-linked with glutaraldehyde (GA) and ethylene glycol diglycidyl ether (DE). We also determined the efficacy of DE-preserved tissue modification with 2-(2-carboxyethylamino)ethylidene-1,1-bisphosphonic acid (CEABA). METHODS: Three groups of each biomaterial were evaluated: GA-treated, DE-treated and DE + CEABA-treated. The microstructure of non-implanted biomaterials was assessed by light microscopy after Picro Mallory staining; the phosphorus content of the DE and DE + CEABA samples was assessed by atomic emission spectrometry. Samples were implanted subcutaneously into young rats for 10 and 60 days. The explant end-point included quantitative calcification assessment by atomic absorption spectrophotometry and light microscopy examination after von Kossa staining. RESULTS: All GA-treated biomaterials had a high calcium-binding capacity (>100 μg/mg dry tissue). DE preservation decreased the vein wall and pericardium calcium content by 4- and 40-fold, respectively, but was ineffective for the aortic wall. The calculated CEABA content was almost equal in the vein wall and pericardium (17.7 and 18.5 μM/g) and slightly less in the aortic wall (15 μM/g) (P = 0.011). CEABA effectively reduced mineralization in the DE aortic wall and DE pericardium to 10.1 (7.8-21.1) and 0.95 (0.57-1.38) μg/mg but had no effect in the DE vein wall. Mineralization in the GA- and DE-treated aortic and vein walls was predominantly associated with elastin. CEABA modification decreased elastin calcification but did not block it completely. CONCLUSIONS: Each xenogeneic material requires individual anticalcification strategy. DE + CEABA pretreatment demonstrates a high mineralization-blocking efficacy for the bovine pericardium and should be employed to further develop the paediatric pericardial conduit. Aortic wall calcification cannot be blocked completely using this strategy.
OBJECTIVES: The development of calcification-resistant bioprosthetic materials is a very important challenge for paediatric surgery. The subcutaneous implantation in rats is the well-known first-stage model for this kind of research. Using this model, we aimed to compare calcification of the porcine aortic wall and bovine pericardium and jugular vein wall cross-linked with glutaraldehyde (GA) and ethylene glycol diglycidyl ether (DE). We also determined the efficacy of DE-preserved tissue modification with 2-(2-carboxyethylamino)ethylidene-1,1-bisphosphonic acid (CEABA). METHODS: Three groups of each biomaterial were evaluated: GA-treated, DE-treated and DE + CEABA-treated. The microstructure of non-implanted biomaterials was assessed by light microscopy after Picro Mallory staining; the phosphorus content of the DE and DE + CEABA samples was assessed by atomic emission spectrometry. Samples were implanted subcutaneously into young rats for 10 and 60 days. The explant end-point included quantitative calcification assessment by atomic absorption spectrophotometry and light microscopy examination after von Kossa staining. RESULTS: All GA-treated biomaterials had a high calcium-binding capacity (>100 μg/mg dry tissue). DE preservation decreased the vein wall and pericardium calcium content by 4- and 40-fold, respectively, but was ineffective for the aortic wall. The calculated CEABA content was almost equal in the vein wall and pericardium (17.7 and 18.5 μM/g) and slightly less in the aortic wall (15 μM/g) (P = 0.011). CEABA effectively reduced mineralization in the DE aortic wall and DE pericardium to 10.1 (7.8-21.1) and 0.95 (0.57-1.38) μg/mg but had no effect in the DE vein wall. Mineralization in the GA- and DE-treated aortic and vein walls was predominantly associated with elastin. CEABA modification decreased elastincalcification but did not block it completely. CONCLUSIONS: Each xenogeneic material requires individual anticalcification strategy. DE + CEABA pretreatment demonstrates a high mineralization-blocking efficacy for the bovine pericardium and should be employed to further develop the paediatric pericardial conduit. Aortic wall calcification cannot be blocked completely using this strategy.