Engineering vascularized soft tissue flaps in an animal model using human adipose-derived stem cells and VEGF+PLGA/PEG microspheres on a collagen-chitosan scaffold with a flow-through vascular pedicle.
Engineering vascularized soft tissue flaps in an animal model using human adipose-derived stem cells and VEGF+PLGA/PEG microspheres on a collagen-chitosan scaffold with a flow-through vascular pedicle.
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DOI：
10.1016/j.biomaterials.2015.09.024
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发表时间：
2015-12
期刊：
影响因子：
14
通讯作者：
Butler CE
中科院分区：
文献类型：
--
作者：
Zhang Q;Hubenak J;Iyyanki T;Alred E;Turza KC;Davis G;Chang EI;Branch-Brooks CD;Beahm EK;Butler CE
新生血管不足与自体脂肪移植物和工程脂肪移植物的高水平吸收和坏死相关。我们测试的假设，将血管生成生长因子纳入支架干细胞结构和周围血管蒂植入这种结构，改善工程软组织皮瓣的新血管形成和脂肪生成。将含有血管内皮生长因子（VEGF）的聚乳酸-羟基乙酸/聚乙二醇（PLGA/PEG）微球浸渍到种植有人脂肪干细胞（hASCs）的胶原-壳聚糖支架中。该装置在体外进行分析，然后植入裸大鼠离散血管蒂周围的隔离室中。收获腔室内的工程化组织样品并分析血管化和脂肪组织生长的差异。体外实验表明，胶原-壳聚糖支架为hASC整合和增殖提供了支持性环境。缓释VEGF的PLGA/PEG微球对胶原-壳聚糖支架中的细胞存活没有负面影响。在体内，该系统导致新血管形成的统计学显著增加，这反过来导致8周后脂肪组织持久性相对于对照构建体显著增加。这些数据表明，我们的模型-hASCs与胶原蛋白-壳聚糖支架整合，并与含VEGF的PLGA/PEG微球结合，由腔室内的主要血管支持-为工程化血管化软组织皮瓣提供了一个有前途的，临床可移植的平台。带血管蒂的工程化脂肪组织可以作为带血管蒂的软组织瓣或游离皮瓣转移到受区修复软组织缺损。
Insufficient neovascularization is associated with high levels of resorption and necrosis in autologous and engineered fat grafts. We tested the hypothesis that incorporating angiogenic growth factor into a scaffold–stem cell construct and implanting this construct around a vascular pedicle improves neovascularization and adipogenesis for engineering soft tissue flaps. Poly(lactic-co-glycolic-acid/polyethylene glycol (PLGA/PEG) microspheres containing vascular endothelial growth factor (VEGF) were impregnated into collagen-chitosan scaffolds seeded with human adipose-derived stem cells (hASCs). This setup was analyzed in vitro and then implanted into isolated chambers around a discrete vascular pedicle in nude rats. Engineered tissue samples within the chambers were harvested and analyzed for differences in vascularization and adipose tissue growth. In vitro testing showed that the collagen-chitosan scaffold provided a supportive environment for hASC integration and proliferation. PLGA/PEG microspheres with slow-release VEGF had no negative effect on cell survival in collagen-chitosan scaffolds. In vivo, the system resulted in a statistically significant increase in neovascularization that in turn led to a significant increase in adipose tissue persistence after 8 weeks versus control constructs. These data indicate that our model—hASCs integrated with a collagen-chitosan scaffold incorporated with VEGF-containing PLGA/PEG microspheres supported by a predominant vascular vessel inside a chamber—provides a promising, clinically translatable platform for engineering vascularized soft tissue flap. The engineered adipose tissue with a vascular pedicle could conceivably be transferred as a vascularized soft tissue pedicle flap or free flap to a recipient site for the repair of soft-tissue defects.