Development of a new bioengineered patch for promoting in situ cellularization and the regeneration of autologous tissue in cardiovascular surgery

具有自体细胞种子的可生物降解材料作为潜在的心血管移植材料引起了人们的广泛关注。但是，这些材料的预处理需要一个复杂的侵入性程序，有感染的风险。为了解决这些问题，我们试图开发一种含有胶原蛋白微海绵的可生物降解移植物材料，这种材料可以使自体血管组织再生。这种材料促进自体内皮细胞和平滑肌细胞原位细胞化的能力在有和没有细胞前化的情况下进行了测试。将聚乳酸-羟基乙酸作为可生物降解支架与胶原蛋白微海绵复合，形成血管贴片材料。这些聚乳酸-羟基乙酸-胶原贴片经或不经自体血管细胞化后用于犬肺动脉干贴片。植入后2、6个月分别进行组织学和生化评价。两组均无血栓形成，聚乳酸-羟基乙酸支架几乎完全被吸收。组织学结果显示内皮细胞单层形成，平滑肌细胞平行排列，弹性蛋白和胶原纤维重建血管壁。6个月时，贴片中的细胞和细胞外成分增加到与天然组织相似的水平。有无细胞前形成的聚乳酸-羟基乙酸-胶原微海绵贴片均表现出良好的组织学表现和耐久性。该贴片有望作为一种生物工程材料，在心血管手术中加速原位细胞化和自体组织再生。

Biodegradable materials with autologous cell seeding have attracted much interest as potential cardiovascular graft. But, pretreatment of these materials requires a complicated and invasive procedure that carries the risk of infection. To resolve these problems we sought to develop a biodegradable graft material containing collagen microsponge that would permit the regeneration of autologous vessel tissue. The ability of this material to promote in situ cellularization with autologous endothelial an smooth muscle cells was tested with and without precellularization.Poly(lactic-co-glycolic acid) as a biodegradable scaffold was compounded with collagen microsponge to form a vascular patch material. These poly(lactic-co-glycolic acid)-collagen patches with or without autologous vessel cellularization were used to patch the canine pulmonary artery trunk. Histologic and biochemical assessment were performed 2 and 6 months after the implantation.There was no thrombus formation in either group, and the poly(lactic-co-glycolic acid) scaffold was almost completely absorbed in both groups. Histologic results showed the formation of an endothelial cell monolayer, a parallel alignment of smooth muscle cells, and reconstructed vessel wall with elastin and collagen fibers. The cellular and extracellular components in the patch had increased to levels similar to those in native tissue at 6 months.The poly(lactic-co-glycolic acid)-collagen microsponge patch with and without precellularization showed good histological findings and durability. This patch shows promise as a bioengineered material for accelerate in situ cellularization and the regeneration of autologous tissue in cardiovascular surgery.