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Global Translational Medicine

ORIGINAL RESEARCH ARTICLE
Ultraviolet-induced mechanical augmentation

of the degraded porcine aortic adventitia: Its
significance for preventing aneurysmal rupture

Traian V. Chirila 1,2,3,4,5 * and Shuko Suzuki 1

1 Queensland Eye Institute, South Brisbane, Queensland, Australia
2 School of Chemistry and Physics, Queensland University of Technology, Brisbane, Queensland,
Australia
3 Australian Institute of Bioengineering and Nanotechnology, University of Queensland, St Lucia,
Queensland, Australia
4 School of Molecular Sciences, University of Western Australia, Crawley, Western Australia, Australia
5 Faculty of Medicine, George E. Palade University of Medicine, Pharmacy, Sciences and Technology,
Târgu Mureş, Romania

Abstract

In the previous studies, we have shown that the tunica adventitia of porcine
abdominal aorta could be mechanically reinforced by irradiating it with ultraviolet A
(UV-A) rays to promote the photocrosslinking of constitutive collagen, and we have
proposed the method as a procedure to prevent or delay abdominal aortic aneurysm
(AAA) ruptures. We have also demonstrated that UV irradiation-induced mechanical
augmentation despite the degradation of the adventitia through collagenolysis
in vitro. Considering that elastolysis is equally a relevant event in the pathogenesis
*Corresponding author: of AAA, the degradation of elastin was also investigated in the present study. A total
Traian V. Chirila of 50 porcine aortas were used in the study. All processed samples were evaluated in
(traian.chirila@qei.org.au)
a mechanical tester before and after degradation and/or irradiation. The adventitial
Citation: Chirila TV, Suzuki S, layer was isolated and subjected to elastase for either 1 – 48 h. We found that both
(2023), Ultraviolet-induced
mechanical augmentation of the elastin and collagen were digested by elastase, with the former being completely
degraded porcine aortic adventitia: digested after 48 h. The samples degraded for 1 h were subsequently irradiated with
Its significance for preventing UV-A (365 nm) in the presence of riboflavin as a photoinitiator, a process that induced
aneurysmal rupture. Global
Transl Med, 2(2): 0897. an enhancement of the strength and stiffness of the tissue. This is an indication that
https://doi.org/10.36922/gtm.0897 a partly degenerated aortic wall, like that in an aneurysmal region, can be reinforced
Received: May 4, 2023 mechanically by UV irradiation, possibly to the extent of delaying, or preventing
Accepted: June 25, 2023 altogether, the wall’s rupture. It appears important to irradiate the wall as early as
Published Online: July 5, 2023 possible.
Copyright: © 2022 Author(s).
This is an Open Access article
distributed under the terms of the Keywords: Aortic aneurysms; Tunica adventitia; Photocrosslinking; Elastolysis; Vascular
Creative Commons Attribution biomechanics
License, permitting distribution,
and reproduction in any medium,
provided the original work is
properly cited.
Publisher’s Note: AccScience 1. Introduction
Publishing remains neutral with A vascular aneurysm is caused by the progressive loss of structural integrity and
regard to jurisdictional claims in
published maps and institutional mechanical strength of the blood vessel’s wall. The resulting dilated region, which is
affiliations. termed aneurysm, bulge, or sac, develops commonly in arteries, and the abdominal aortic

Volume 2 Issue 2 (2023) 1 https://doi.org/10.36922/gtm.0897