Chung Cindy, Pruitt Beth L, Heilshorn Sarah C
Materials Science and Engineering, McCullough Building, 476 Lomita Mall, Stanford, CA, USA. ; Tel: 650 723 3763 ; Mechanical Engineering, Durand Building, 496 Lomita Mall, Stanford, CA, USA.
Mechanical Engineering, Durand Building, 496 Lomita Mall, Stanford, CA, USA.
Biomater Sci. 2013 Oct 1;1(10):1082-1090. doi: 10.1039/C3BM60139K.
Cellular therapies have great potential to provide alternative treatment options for those suffering from heart disease. In order to optimize cell delivery for therapeutic efficacy, a greater understanding of parameters that impact stem cell differentiation, survival, growth, and development are needed. In this study, we examine the role of hydrogel crosslink density on spontaneous cardiomyocyte (CM) differentiation of murine embryoid bodies (EBs). CM differentiation was accelerated in hydrogels of low crosslink density, where 100% of the hydrogels were positive for CM differentiation compared to only 53% in the high crosslink density group after 8 days of culture. DNA microarray data suggests that enhanced CM differentiation in the low crosslink density hydrogels was not tissue specific but rather a result of favoured EB development and cell proliferation. Additionally, enhanced EB growth and differentiation in low crosslink density hydrogels was independent of RGD ligand density and not a consequence of enhanced diffusion. We also demonstrate that matrix metalloproteinase activity is required for spontaneous CM differentiation in 3D hydrogels. Low hydrogel crosslink density regulates spontaneous EB differentiation by promoting EB growth and development. Elucidating the effects of microenvironmental cues on cell differentiation can aid in the optimization of stem cell-based therapies for tissue regeneration.
细胞疗法具有为心脏病患者提供替代治疗方案的巨大潜力。为了优化细胞递送以提高治疗效果，需要更深入地了解影响干细胞分化、存活、生长和发育的参数。在本研究中，我们研究了水凝胶交联密度对小鼠胚胎体（EBs）自发分化为心肌细胞（CM）的作用。在低交联密度的水凝胶中，CM分化加速，培养8天后，100%的水凝胶CM分化呈阳性，而高交联密度组仅为53%。DNA微阵列数据表明，低交联密度水凝胶中CM分化增强并非组织特异性的，而是EB发育和细胞增殖受到促进的结果。此外，低交联密度水凝胶中EB生长和分化的增强与RGD配体密度无关，也不是扩散增强的结果。我们还证明，基质金属蛋白酶活性是3D水凝胶中CM自发分化所必需的。低水凝胶交联密度通过促进EB生长和发育来调节EB的自发分化。阐明微环境信号对细胞分化的影响有助于优化基于干细胞的组织再生疗法。
