ABSTRACT
The multipotent nature of stem cells provides enormous potential for clinical applications for treatment of disease, cancers, and for organ replacement. Despite decades of research, robust culture techniques that consistently permit isolation, expansion, and directed differentiation of stem and progenitor cells in adequate numbers remains a major hurdle to ensure full clinical usage of stem cell therapies. In vivo, stem cell
4.1 Introduction .................................................................................................. 107 4.2 Three-Dimensional Environments and the Stem Cell Niche ....................... 109
4.2.1 Extracellular Matrix ......................................................................... 111 4.2.2 Extrinsic Factors ............................................................................... 111 4.2.3 Cell-Cell Interactions ....................................................................... 112
4.3 Engineering Technologies to Guide Stem Cell Fate ..................................... 112 4.3.1 Biomaterial Scaffolds ....................................................................... 113 4.3.2 Microfabrication Technologies ......................................................... 113
4.3.2.1 Photolithography ................................................................ 113 4.3.2.2 Soft Lithography ................................................................ 116 4.3.2.3 Optical Fabrication ............................................................ 118 4.3.2.4 Dielectrophoresis ............................................................... 119 4.3.2.5 Inkjet Printing .................................................................... 120
4.4 Culture Handling Systems ............................................................................ 120 4.4.1 Bioreactors ........................................................................................ 120 4.4.2 MicroŒuidics ..................................................................................... 123
4.5 Readout Systems ........................................................................................... 123 4.6 Conclusions and Future Directions ...............................................................124 Acknowledgments ..................................................................................................124 References ..............................................................................................................124
