We investigate holographic optical tweezing combined with step-and-repeat projection micro-stereolithography for fine control of live cell positioning within a three-dimensional (3D) hydrogel microstructure. Samples are fabricated using NT2 cells, which have been pre-differentiated into NT2-N human neurons. A twisted nematic 256x256 pixel SLM is used to pattern the supporting hydrogel structures. Neurons are shown to grow along printed hydrogel channels, demonstrating that the structure can be used to pre-determine the path of cellular growth. Sample viability is assessed for a variety of hydrogel geometries. This work demonstrates biocompatibility of the printing method. The samples fabricated with this system are a useful model for future studies of neural circuit formation, neurological disease, cellular communication, plasticity, and repair mechanisms.
|