Zhang Xiaofei, Li Jun, Ye Pengxiang, Gao Guifang, Hubbell Karen, Cui Xiaofeng
School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China.
College of Life Sciences, Wuhan University, Wuhan 430072, China.
Acta Biomater. 2017 Sep 1;59:317-326. doi: 10.1016/j.actbio.2017.07.001. Epub 2017 Jul 3.
A major challenge for clinical use of skin substitutes is insufficient host tissue integration leading to loosening and partial necrosis of the implant. In this present study, a three-dimensional (3D) coculture system constructed using human umbilical cord mesenchymal stem cells (uc-MSCs) and umbilical vein endothelial cells (HUVECs) encapsulated in gelatin methacryloyl (GelMA) hydrogels was evaluated to determine the outcomes of cell-cell interactions in vitro and in vivo. The results revealed that GelMA hydrogels displayed minor cytotoxicity on both cell types. An uc-MSC:HUVEC ratio of 50:50 demonstrated the highest cell proliferation and expression of angiogenic markers. The supplement of basic fibroblast growth factors (bFGF) in coculture system further induced cell proliferation and gene expression in vitro. In vivo transplantation of this cocultured constructs efficiently enhanced the implant and host tissue integration. Additionally, the proliferation of keratinocytes was well maintained on GelMA hydrogels and the gene expression related to cell proliferation and differentiation was significantly increased in coculture system comparing to monoculture. Mechanistically, AKT signaling pathways were activated in cocultures. Our findings suggest that coculturing MSC and EC in GelMA hydrogels could be a promising approach to substantially improve the integration of exogenous skin substitutes and host tissues.
In this study, the co-culture of uc-MSCs and HUVECs in photocrosslinkable GelMA hydrogels significantly enhanced host tissue integration. Cell proliferation, ECM deposition and angiogenic genes expression were all substantially improved in vitro and the excellent host tissue integration into the implanted tissue was observed in vivo. When served as a dermal layer, the scaffold with co-cultured cells enhanced the proliferation and differentiation of keratinocytes. AKT signaling was proved to be involved in the regulation of cell survival and fate determination. This work demonstrated the importance of 3D cell co-culture to facilitate host tissue integration that can be a promising approach for long-term survival of skin substitutes.
皮肤替代物临床应用面临的一个主要挑战是宿主组织整合不足，导致植入物松动和部分坏死。在本研究中，评估了一种使用封装在甲基丙烯酰化明胶（GelMA）水凝胶中的人脐带间充质干细胞（uc-MSCs）和脐静脉内皮细胞（HUVECs）构建的三维（3D）共培养系统，以确定体外和体内细胞间相互作用的结果。结果显示，GelMA水凝胶对两种细胞类型均显示出轻微的细胞毒性。uc-MSC:HUVEC比例为50:50时，细胞增殖和血管生成标志物的表达最高。共培养系统中添加碱性成纤维细胞生长因子（bFGF）进一步诱导了体外细胞增殖和基因表达。这种共培养构建体的体内移植有效地增强了植入物与宿主组织的整合。此外，角质形成细胞在GelMA水凝胶上的增殖得到良好维持，与单培养相比，共培养系统中与细胞增殖和分化相关的基因表达显著增加。从机制上讲，共培养中AKT信号通路被激活。我们的研究结果表明，在GelMA水凝胶中共培养MSC和EC可能是一种有前景的方法，可显著改善外源性皮肤替代物与宿主组织的整合。
在本研究中，uc-MSCs和HUVECs在可光交联的GelMA水凝胶中共培养显著增强了宿主组织整合。体外细胞增殖、细胞外基质沉积和血管生成基因表达均得到显著改善，体内观察到宿主组织与植入组织的良好整合。当用作真皮层时，共培养细胞的支架增强了角质形成细胞的增殖和分化。AKT信号被证明参与细胞存活和命运决定的调节。这项工作证明了3D细胞共培养对促进宿主组织整合的重要性，这可能是皮肤替代物长期存活的一种有前景的方法。
