Synthesis and Evaluation of Peptide-based Hybrid Scaffold for Tissue Engineering

在组织工程和伤口愈合应用中，支架材料被用来为细胞生长和组织形成提供机械支持。这些支架可以经过修饰，从而向细胞提供特定的生物信号，以控制或促进组织的形成或再生。细胞粘附肽Arg-Gly-Asp （RGD）已被加入到支架中以增强细胞粘附或允许生物特异性细胞粘附。在这项工作中，为了提高Arg-Gly-Asp-Ser肽在组织工程支架上的细胞附着活性，我们试图通过设计在c端具有Arg-Gly-Asp-Ser序列的ss-链肽来稳定这些肽的折叠构象。这些序列（Ala-Glu-Ala-Glu-Ala-Lys-Ala-Lys）_2 （EAK16）或（Arg-Ala-Arg-Ala-Asp-Ala-Asp-Ala）_2 （RAD16）被选为具有高ss-链形成倾向的典型序列。采用液相法和固相法合成了含ss-链模型肽的RGDS。成纤维细胞附着在肽固定化细胞培养皿上，表明这些肽固定化细胞培养皿的细胞附着活性存在差异。EAK16RGDS和RAD16RGDS固定化聚苯乙烯培养皿在肽固定化聚苯乙烯培养皿中扩散活性最高。由于ss-股结构的形成所引起的构象约束太强，无法稳定在Arg-Gly-Asp-Ser部分的理想构象，其中Arg-Gly-Asp-Ser序列直接连接到用于形成ss-股结构的序列。设计一个间隔序列可以提高Arg-Gly-Asp-Ser序列与形成ss-链结构的序列之间的活性。EAK16RGDS和RAD16RGDS溶液变成凝胶状，然后形成纤维。EAK16RGDS和RAD16RGDS肽相互作用，并在纤维形成时变得更加结构化。这种多肽可能会在体内组织工程3D支架中找到用途。少

In tissue engineering and wound-healing application, scaffold materials are utilized to provide a mechanical support for cell growth and tissue formation. These scaffold can be modified such that they also provide specific biologic signals to cell in order to control or facilitate tissue formation or regeneration. Cell adhesion peptides Arg-Gly-Asp (RGD) have been incorporated into scaffolds to enhance cell adhesion or to allow biospecific cell adhesion.In this work, for improving the cell-attachment activity of the Arg-Gly-Asp-Ser peptides to tissue engineering scaffold, we tried to stabilize the folded conformations of such peptides by designing the ss-strands peptides, which have the Arg-Gly-Asp-Ser sequence at the C-terminal. These sequence, (Ala-Glu-Ala-Glu-Ala-Lys-Ala-Lys)_2 (EAK16) or (Arg-Ala-Arg-Ala-Asp-Ala-Asp-Ala)_2 (RAD16) of the peptides is selected as a typical sequence for having high propensity to form ss-strands.RGDS containing ss-strands model peptides were synthesize … More d using liquid and solid phase procedures. Fibroblast cells attaching to the peptide-immobilized cell culture dishes, indicating that difference in the cell-attachment activity were found for these peptides-immobilized cell culture dishes. EAK16RGDS and RAD16RGDS immobilized polystyrene-dish has the highest spreading activity among the peptide-immobilized ones.The conformational constraint caused by the formation of ss-strands structure is too strong to stabilize the desired conformation at the Arg-Gly-Asp-Ser portion for the peptides in which the Arg-Gly-Asp-Ser sequence is directly linked to the sequences designed for forming ss-strands structure. It is also suggested that designing a spacer sequence is desirable for improving the activity between the Arg-Gly-Asp-Ser sequence and the sequence forming ss-strand structure. Solutions of EAK16RGDS and RAD16RGDS become gelatinous and then form fibers. EAK16RGDS and RAD16RGDS peptides interact with each other and become more structured upon fiber formation. Such peptides may find utility as in vivo tissue engineering 3D scaffolds. Less