Abstract: A lattice structure for culturing cells in a bioreactor is effective for culturing high density cells and maintaining cell type homogeneity. The lattice structure includes a plurality of channels forming a set of channels, each of the plurality of channels extending between a first channel pore surface and a second channel pore surface and each of the plurality of channels having a first channel pore and a second channel pore altogether forming a plurality of channel pores on each of the first channel pore surface and the second channel pore surface, wherein each of the channel pores has an area of between about 0.01 mm2 to about 1 mm2, and wherein the lattice structure is made of a biocompatible rigid material having a Young's modulus value of at least 0.5 GPa.