title: Influence of selective digestion of elastin and collagen on mechanical properties of human aortas.
abstract: OBJECTIVE
  There are two families of fibres taking part in the process of mechanical loads transfer, i.e. elastin and collagen fibres. Their number, spatial arrangement and specific properties determine the capacity of a blood vessels to resist mechanical loads resulting from the impact of blood on vessel walls. The purpose of the present paper is to define the load-bearing capacities of elastin and collagen scaffolds equivalent to natural fibre arrangements of human aorta and produced by selective digestion.
  
  
  METHODS
  Samples of thoracic human aortas were digested by using phosphate buffer of trypsin at pH 8.0 for 22 hours in order to degrade elastin and by autoclaving followed by incubation in 90% formic acid for 22 hours. The efficacy of digestion was assessed immunohistochemically. Mechanical properties of pre-stretched native and digested samples were determined by uniaxial tensile test.
  
  
  RESULTS
  Samples subjected to autoclaving have been successfully deprived of both types of collagen and elastin has been intact. Treatment with trypsin caused a removal of elastin and the presence of type I and IV collagen was demonstrated. Digestion of aortic samples either by formic acid or trypsin has resulted significantly decreasing mechanical properties in comparison with native samples.
  
  
  CONCLUSIONS
  Collagen and elastin scaffold-like stuctures have been effectively produced by selective digestion of thoracic human aorta and their contribution to the load-bearing process was evaluated. Isolated collagen network are more durable and stiffer and less deformable than elastin network, hence are responsible for load-bearing process at higher strain since the range of working of elastin is at lower strain values.
authors.affiliation: Department of Biomedical Engineering, Mechatronics and Theory of Mechanisms, Wroclaw University of Technology, Wrocław, Poland.|Regional Specialist Hospital in Wrocław, Research and Development Centre, Wrocław, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Kobielarz
authors.affiliation: Department of Medical Biochemistry, Medical University, Wrocław, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Chwiłkowska
authors.affiliation: School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Katowice, Poland, Chair and Department of Biopharmacy, Sosnowiec, Poland.|Centre of Polymer and Carbon Materials, Polish Academy of Sciences, Zabrze, Poland.
authors.forename: Artur
authors.initials: A
authors.lastname: Turek
authors.affiliation: Department of Forensic Medicine, Medical Faculty, Wrocław Medical University, Wrocław, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Maksymowicz
authors.affiliation: Department of Plastic Forming and Metrology, Wrocław University of Technology, Wrocław, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Marciniak
mesh_terms: D000328:Adult; D001013:Aorta, Thoracic / Q000502:physiology*; D003094:Collagen / Q000502:physiology*; D019245:Compressive Strength / Q000502:physiology; D003198:Computer Simulation; D055119:Elastic Modulus / Q000502:physiology; D004549:Elastin / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D008875:Middle Aged; D008955:Models, Cardiovascular; D013314:Stress, Mechanical; D013718:Tensile Strength / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology*
chemical_list: D003094:Collagen; D004549:Elastin