The extracellular matrix (ECM) is a complex structural entity surrounding and supporting cells that
are found within mammalian tissue. This study presents the effect of ionizing radiation on the physical
properties of elastin which is usually found within arteries, lung, skin, ligantum nuchae, vocal chords
and elastic cartilage as a function of their composition and organization or architecture. X-ray from
an electron linac were used to give doses of 10-50Gy to cover the range of irradiation exposure during
radiotherapy. A uniaxial mechanical testing protocol was used to characterize the fibrous protein. For
pericardial the major change was an increase in the elastic modulus in the toe region of the curve (≤
20% strain), from 23±18 kPa for controls to 57±22 kPa at a dose of 10 Gy (p=0.01, α=0.05). At a
larger strain (≤ 20%), the elastic modulus in the region decreased from 1.92±0.70 MPa for control
pericardium tissue to 1.31±0.56 MPa (p=0.01, α=0.05) for 10 Gy X-irradiated sample. For elastin,
the stress-strain relationship was linear up to 30% strain, but the elastic modulus decreased
significantly with irradiation (controls 626±65 kPa, irradiated 474±121 kPa (p=0.02, α=0.05). The
results suggest that for elastin chain scissions are the primary effect of irradiation. The Raman
microspectrometry was employed to characterize these changes on ECM conformation.