Three-dimensional freeform fabrication, a technique which capitalizes on the ability to print various biological materials and cells along with various tissue scaffold materials, is gaining popularity in tissue engineering due to its potential role in the creation of biomimetic tissues and organs. The flexibility to design and create various 3D cell-scaffold composites gives direct bioprinting a significant advantage over conventional lithography-based approaches in tissue engineering. In this chapter, we present our computer-assisted 3D biological printer, which allows dispensing of various types of hydrogel-based scaffold materials and cells, as well as the techniques to construct multi-layered cell-hydrogel composites. The strategies to generate hydrogel channels and to embed hydrogel matrix to time-release water-soluble factors are introduced together with several production examples using adult mammalian cells and stem cells for the on-demand composition of artificial tissues.