(1) Background: Decellularized xenogeneic tissues are promising matrices for developing tissue-engineered cardiovascular grafts. In vitro recellularization of these tissues with stromal cells can provide a better in vivo remodelling and a lower thrombogenicity of the graft. The process of recellularization can be accelerated using a cultivation bioreactor simulating physiological conditions and stimuli. (2) Methods: Porcine pericardium was decellularized using a custom-built decellularization system with an optimized protocol. Autologous porcine adipose-derived stromal cells (PrASCs), isolated from the subcutaneous fat tissue, were used for recellularizing the decellularized pericardium. A custom cultivation bioreactor allowing the fixing of the decellularized tissue into a special cultivation chamber was created. The bioreactor maintained micro-perfusion and pulsatile pressure stimulation in order to promote the ingrowth of PrASCs inside the tissue and their differentiation. (3) Results: The dynamic cultivation promoted the ingrowth of cells into the decellularized tissue. Under static conditions, the cells penetrated only to the depth of 50 µm, whereas under dynamic conditions, the tissue was colonized up to 250 µm. The dynamic cultivation also supported the cell differentiation towards smooth muscle cells (SMCs). In order to ensure homogeneous cell colonization of the decellularized matrices, the bioreactor was designed to allow seeding of the cells from both sides of the tissue prior to the stimulation. In this case, the decellularized tissue was recolonized with cells within 5 days of dynamic cultivation. (4) Conclusions: Our newly designed dynamic bioreactor markedly accelerated the colonization of decellularized pericardium with ASCs and cell differentiation towards the SMC phenotype.

中文翻译：

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生物反应器处理的基质细胞接种并在用于心血管的脱细胞心包膜片上培养

（1）背景：脱细胞异种组织是用于开发组织工程化的心血管移植物的有前途的基质。用间质细胞对这些组织进行体外再细胞化可提供更好的体内重塑，并降低移植物的血栓形成性。可以使用模拟生理条件和刺激的培养生物反应器来加速重新细胞化的过程。（2）方法：使用定制的脱细胞系统和优化的方案对猪心包进行脱细胞。从皮下脂肪组织分离出的自体猪脂肪基质细胞（PrASCs）用于使脱细胞的心包膜重新细胞化。创建了一个定制的培养生物反应器，该反应器可以将脱细胞的组织固定到一个特殊的培养室中。生物反应器维持微灌流和搏动压力刺激，以促进组织内PrASC的向内生长及其分化。（3）结果：动态培养促进细胞向脱细胞组织内生长。在静态条件下，细胞只能穿透到50 µm的深度，而在动态条件下，组织则可以定植到250 µm。动态培养还支持细胞向平滑肌细胞（SMC）分化。为了确保脱细胞基质的均匀细胞定殖，将生物反应器设计为允许在刺激之前从组织的两侧播种细胞。在这种情况下，将脱细胞的组织在动态培养的5天内与细胞重新定殖。（4）结论：我们新设计的动态生物反应器显着加速了ASCs对脱细胞心包膜的定植和细胞向SMC表型的分化。