The Use of Sonication Treatment to Completely Decellularize Aorta Tissue

A Comparison between Ultrasonic Bath and Direct Sonicator on Osteochondral Tissue Decellularization

Background:

Decellularization techniques have been widely used in tissue engineering recently. However, applying these methods which are based on removing cells and maintaining the extracellular matrix (ECM) encountered some difficulties for dense tissues such as articular cartilage. Together with chemical agents, using physical methods is suggested to help decellularization of tissues.

Methods:

In this study, to improve decellularization of articular cartilage, the effects of direct and indirect ultrasonic waves as a physical method in addition to sodium dodecyl sulfate (SDS) as chemical agents with 0.1% and 1% (w/v) concentrations were examined. Decellularization process was evaluated by nucleus staining with hematoxylin and eosin (H and E) and by staining glycosaminoglycans (GAG) and collagen.

Results:

The H and E staining indicated that 1% (w/v) SDS in addition to ultrasonic bath for 5 h significantly decreased the cell nucleus residue to lacuna ratio by 66%. Scanning electron microscopy showed that using direct sonication caused formation of micropores on the surface of the sample which results in better penetration of decellularization material and better cell attachment after decellularization. Alcian Blue and Picrosirius Red staining represented GAG and collagen, respectively, which maintained in ECM structure after decellularization by ultrasonic bath and direct sonicator.

Conclusion:

Ultrasonic bath can help better penetration of the decellularization material into the cartilage. This improves the speed of the decellularization process while it has no significant defect on the structure of the tissue.

Evaluation of recellularization on decellularized aorta scaffolds engineered by ultrasonication treatment

Aortic scaffolds prepared using sonication decellularization treatment has provided a successful medium for repopulation with vascular smooth muscle cells (VSMCs). The objective of this study is to explore the potential of tissue decellularization using ultrasonication treatment and its recellularization before implantation of the cell-seeded scaffolds into host. Aorta tissue samples are decellularized in 2% SDS with sonication for 10 hours and compared with the native tissues. The 4',6-diamidino-2-phenylindole (DAPI) staining was used to evaluate the decellularization and Hematoxylin-Eosin (H-E) staining was used to compare the VSMCs infiltrations onto the decellularized tissues at day-0 and day-6 after cell-seeding. The results histologically showed complete DNA removal from scaffolds after decellularization and subsequent recellularization resulted in successful VSMCs infiltration. Accordingly, the decellularized tissues treated with 2% SDS in sonication demonstrated successful VSMCs repopulation afterward and is speculated to have less toxicity and able to be effectively implanted into host.

Evaluation of histological and biomechanical properties on engineered meniscus tissues using sonication decellularization

Sonication decellularization treatment requires proper evaluations on its ability to decellularize meniscus tissue efficiently. This study was done to evaluate the histological and biomechanical properties within meniscus scaffolds. Van Gieson staining was done to evaluate the efficiency of cell removal in meniscus tissues. The consequences of treatment on viscoelastic properties are vital for scaffolds quality and were properly investigated. Picrosirius red and Safranin-O/Fast green staining was carried out to detect extracellular matrix materials (ECM). Sonication decellularization treatment has the ability to demonstrated complete nuclei removal compare to control samples as well as maintaining viscoelastic properties, namely stiffness, compression and residual force. Thus, sonication decellularization treatment had successfully produced and prepared a meniscus bioscaffold candidate in which its biomechanical strength is sustained through protection of ECM properties.