Investigation of the biomechanical integrity of decellularized rat abdominal aorta.

OBJECTIVES: The loss or damage of an organ or tissue is one of the most common and devastating problems in healthcare today. Tissue engineering applies the principles of engineering and biology toward the development of functional biological replacements that are able to maintain, improve, or restore the function of pathological tissues. The aim of the overall project is to study an already existing method for the decellularization of homograft vascular grafts for use in vascular surgery. MATERIALS AND METHODS: The biomechanical integrity of native and decellularized rat aortas was assessed under uniaxial tension tests. For this purpose, 36 male rats (12 Wistar and 24 Dark Agouti [DA]) were used to excise their abdominal aortas. Twelve of the aortas were tested fresh (Wistar and DA rats), within 24 hours from euthanasia, and the rest were decellularized using a modified protocol (DA rats only). Fresh and decellularized samples (n = 12) were subjected to uniaxial tensile loading to failure, and the recorded stress-strain behaviour of each specimen was assessed in terms of 6 biomechanical parameters. RESULTS: No statistically significant differences were found in any of the biomechanical parameters studied between the decellularized DA rat aorta group and both the native DA and Wistar rat aorta groups (P > .05). Also, no significant difference was shown between the native DA and native Wistar rat aorta groups. CONCLUSIONS: The results from this study have shown that the decellularization protocol did not affect the mechanical properties of the native rat aorta. In addition to this, both native Wistar and native/decellularized DA rat aorta groups shared similar mechanical properties.

Evaluation of decellularization in umbilical cord artery.

Major achievements in creating decellularized whole tissue scaffolds have drawn considerable attention to decellularization as a promising approach for tissue engineering. Developing a tissue-engineered small-diameter (≤2 mm) vascular graft, using decellularized human umbilical arteries (hUAs), for reconstructive surgery is a challenging task. Polymers used in the past, proved unsuitable due to serious adverse effects and autologous vessels are available only in 40% of patients. In this study, histological and proteomic analysis was performed to evaluate the efficiency of two decellularization protocols. In decellularization protocol A, hUAs were incubated in 3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate (CHAPS) and sodium dodecyl sulfate (SDS) followed by incubation in alpha minimal essential medium (α-MEM) with foetal bovine serum (FBS) while in decellularization protocol B the hUAs were incubated in Hypotonic Tris and SDS followed by incubation in nuclease solution. Histological analysis of decelullarised hUA with both protocols revealed good preservation of extracellular cell matrix (ECM) proteins and immunofluorescent staining detected collagen I and fibronectin. The DNA content within the hUAs after decellularization with protocol A was 6.2% and with protocol B 17.3%. Proteomic analysis identified cytoplasmic enzymes such as, dehydrogenase X, α-enolase and peptidyl-prolyl cis-trans isomerase A only in native samples, while, cytoskeletal proteins such as a-actin, filamin and ECM proteins like collagens were found both in native and decellularised hUA. In conclusion, both decellularization protocols effectively removed the cellular material while the ECM remained intact. Future studies are warranted to elucidate the specific effects of altered structure-function relationships on the overall fate of decellularized hUAs.