A one-step microfluidic system is developed in this study which enables the encapsulation of stem cells and genetically engineered non-pathogenic bacteria into a so-called three-dimensional (3D) pearl lace–like microgel of alginate with high level of monodispersity and cell viability. The alginate-based microgel constitutes living materials that control stem cell differentiation in either an autonomous or heteronomous manner. The bacteria (Lactococcus lactis) encapsulated within the construct surface display adhesion fragments (III_7-10 fragment of human fibronectin) for integrin binding while secreting growth factors (recombinant human bone morphogenetic protein-2) to induce osteogenic differentiation of human bone marrow–derived mesenchymal stem cells. We concentrate on interlinked pearl lace microgels that enabled us to prototype a low-cost 3D bioprinting platform with highly tunable properties.

本研究开发了一种单步微流控系统，该系统能够将干细胞和基因工程非病原性细菌包封到所谓的三维（3D）珍珠花边状藻酸盐微凝胶中，具有高水平的单分散性和细胞可行性。基于藻酸盐的微凝胶构成了以自主或异质方式控制干细胞分化的生物材料。包裹在构建体表面的细菌（乳酸乳球菌）显示出粘附片段（III _7-10）人纤连蛋白的片段）整合素结合，同时分泌生长因子（重组人骨形态发生蛋白2）以诱导人骨髓间充质干细胞的成骨分化。我们专注于互连的珍珠花边微凝胶，这些凝胶使我们能够为具有高度可调特性的低成本3D生物打印平台制作原型。