We investigate holographic optical trapping combined with step-and-repeat maskless projection stereolithography for fine control of 3D position of living cells within a 3D microstructured hydrogel. C2C12 myoblast cells were chosen as a demonstration platform because their development into multinucleated myotubes requires linear arrangements of myoblasts. C2C12 cells are positioned in the monomer solution with multiple optical traps at 1064 nm and then are encapsulated by photopolymerization of monomer via projection of a 512x512 spatial light modulator (SLM) illuminated at 405 nm. High 405 nm sensitivity and complete insensitivity to 1064 nm is enabled by a lithium acylphosphinate (LAP) salt photoinitiator. Use of a polyethylene glycol dimethacrylate (PEGDMA) based monomer is compared to that of polyethylene glycol (PEG) hydrogels formed by thiol-ene photo-click chemistry for patterning structures with cellular resolution, and for maintaining cell viability. Cells patterned in thiol-ene with RGD are shown to retain viability up to 4 days after the trapping and encapsulation procedure. Further, cells patterned in thiol-ene with RGD and a degradable ester link, are shown to fuse, indicating the initial stages of development of multi-nucleated cells.