胶原模拟多肽-PEG杂化水凝胶及用于兔骨髓间充质干细胞的三维培养

目的 构建一种模拟细胞外基质的胶原模拟多肽-聚乙二醇(PEG)杂化水凝胶并应用于兔骨髓间充质干细胞(rBMSCs)的三维(3D)培养.方法 利用胶原模拟多肽末端的半胱氨酸与马来酰亚胺修饰的多臂PEG偶联形成杂化水凝胶,圆二色谱表征胶原模拟多肽的三螺旋结构及其热稳定性,流变学检测和扫描电镜观察研究杂化水凝胶的成胶过程、机械强度及水凝胶内部结构.将rBMSCs包埋于杂化水凝胶中进行3D培养,检测水凝胶的细胞相容性及其对rBMSCs分化的影响.结果 胶原模拟多肽能自发形成天然胶原的三螺旋结构,其热变性温度为49.4℃.胶原模拟多肽-PEG杂化水凝胶成胶迅速,内部呈现多孔的网络状纤维结构;杂化水凝胶3D培养rBMSCs 24 h后,绝大部分细胞保持存活状态,基因表达分析结果显示该水凝胶体系构建的3D培养环境能影响rBMSCs的分化.结论 胶原模拟多肽-PEG杂化水凝胶制备条件温和,具有良好的机械强度和细胞相容性,有利于rBMSCs的软骨分化.

Collagen mimetic peptide-PEG hybrid hydrogel for 3D culture of rabbit bone marrow mesenchymal stem cells

Objective To construct a extracellular matrix-like collagen mimetic peptide-PEG hybrid hydrogel and to study the usage of this hydrogel in 3D culture of rabbit bone marrow mesenchymal stem cells (rBMSCs).Methods The hybrid hydrogel was synthesised by conjugating the cysteine at the end of the collagen mimetic peptide with the maleimine-modified multi-arm PEG.The circular dichroism spectra were used to characterize the triple helix structure and thermal stability of the collagen mimetic peptides.The rheology test and scanning electron microscopy were used to study the gelation process,mechanical strength and internal structure of the hydrogel.The rBMSCs were embedded in the hybrid hydrogel for 3D culture.The cell compatibility of the hydrogel and its effect on differentiation of the cells was studied.Results Collagen mimetic peptides could promote spontaneous formation of triple helix structure in the natural collagen,and the thermal transition temperature was 49.4 ℃.The formation process of the collagen mimetic peptides-PEG hybrid hydrogel was rapid,in which the porous network-like fibrous structure was formed.After the encapsulation of rBMSCs within the hydrogel for 24 h,most of the cells remained viable.Gene expression analysis showed that the hybrid hydrogel could affect the differentiation of rBMSCs.Conclusions The collagen mimetic peptide-PEG hybrid hydrogel possesses the characteristics of mild preparation condition,good mechanical strength and good cell compatibility,and is favorable to chondrocyte differentiation of rBMSCs.