The vascularization within the scaffold is still a significant challenge in tissue engineering applications. Sulfated chitosan (SCS) as an amazing substance have been used in tissue engineering to stimulate angiogenesis. However, it is not clear whether they have difference in the ability to promote vascularization of SCS with different sulfonic acid group sites. The aim of this study was to evaluate human umbilical vein endothelial cells (HUVECs) viability and differentiation in vitro, affected by three types of sulfated chitosan' i.e. 2-N-6-O-sulfated chitosan (2,6-SCS), 3'6-O-sulfated chitosan (3,6-SCS) and 6-O-sulfated chitosan (6-SCS). The results are showed that all the SCS possesses excellent biological properties to promote HUVECs viability and proliferation. Especially, 2,6-SCS promotes desirable intracellular nitric oxide secretion and capillary tube formation. Meanwhile, 2,6-SCS up-regulate the related gene and protein expression compared with other sulfonic acid group sites SCS and heparin. Therefore, 2,6-SCS is a promising substitute material for angiogenesis and as aqueous formulation can be employed to fabrication functionalization scaffold surface with promoted angiogenesis.

中文翻译：

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不同磺酸基位点硫酸化壳聚糖对HUVECs行为的不同影响。

支架内的血管化仍然是组织工程应用中的一个重大挑战。硫酸化壳聚糖 (SCS) 作为一种神奇的物质已被用于组织工程以刺激血管生成。但它们促进不同磺酸基位点SCS血管化的能力是否存在差异尚不清楚。本研究的目的是评估体外受三种硫酸化壳聚糖影响的人脐静脉内皮细胞 (HUVEC) 的活力和分化，即 2-N-6-O-硫酸化壳聚糖 (2,6-SCS)，3 '6-O-硫酸化壳聚糖 (3,6-SCS) 和 6-O-硫酸化壳聚糖 (6-SCS)。结果表明，所有SCS都具有促进HUVECs活力和增殖的优良生物学特性。特别是，2，6-SCS 促进理想的细胞内一氧化氮分泌和毛细管形成。同时，与其他磺酸基位点SCS和肝素相比，2,6-SCS上调相关基因和蛋白的表达。因此，2,6-SCS 是一种很有前景的血管生成替代材料，作为水性制剂可用于制造促进血管生成的功能化支架表面。