| Decellularized vascular matrices are used as scaffolds in cardiovascular tissue engineering because they retain the natural biological compositions and three-dimensional architecture suitable for cell adhesion and proliferation. However, cell repopulation of these scaffolds was shown to be unsatisfactory due to their dense collagen and elastin fiber networks.; To create more porous structures for cell repopulation, we selectively removed matrix components from decellularized porcine arteries to obtain two types of scaffolds, namely elastin and collagen scaffolds. Elastin scaffolds were prepared by cyanogen bromide extraction. Collagen scaffolds were prepared by sodium dodecyl sulfate (SDS) decellularization followed by carbodiimide fixation and elastase digestion. Both elastin and collagen scaffolds were shown to have a well-oriented porous decellularized structure that maintained the natural architecture of the porcine arteries. Both scaffolds are manageable and exhibit adequate mechanical characteristics, porosity, biodegradability and lack of cytotoxicity.; In vitro cell culture studies demonstrated both elastin and collagen scaffolds support endothelial cell, fibroblast and smooth muscle cell adhesion and proliferation with excellent cell viability. However, in vitro cell infiltration into the scaffolds was limited to superficial layers. On the other hand, in vivo cell repopulation by rat subdermal and intramuscular implantation demonstrated significant host cell infiltration in the elastin and collagen scaffolds in both models. These infiltrated cells were capable of synthesizing new extracellular matrix. Compared to control samples in which both collagen and elastin components were retained, significantly more cells infiltrated into elastin and collagen scaffolds, demonstrating that the removal of elastin or collagen facilitates in vivo cell repopulation.; Calcification is a problem associated with elastin scaffolds prepared by cyanogen bromide treatment. We addressed this issue by developing an alternative scaffold preparation method involving SDS decellularization and collagenase digestion. This elastin scaffold preparation maintained the native arterial architecture with superior elasticity and desirable biodegradability. After subdermal implantation in adult rats, the scaffolds showed excellent cell infiltration, collagen deposition, and no calcification for samples with or without aluminum chloride pretreatment. These scaffolds are thus promising candidates for cardiovascular tissue engineering. |
