Fig. 4.

Microscale tissue engineering using template-based cell assembly. (A) A schematic diagram of the template-based assembly method. PEG microwells were fabricated so that cells could dock within the low-shear-stress regions generated within the microstructures. Once cells had immobilized within the microwells, other cells were washed away, and the cells within the microwells formed aggregates of controlled properties. (B) A light microscope image of 100-μm PEG wells that were seeded with ES cells and washed. (C) A scanning electron micrograph of cells within PEG microwells (A.K., J. Yeh, G. Eng, J. Fukuda, O. Farokhzad, J. J. Cheng, J. Bumbling, and R.L., unpublished data).