In this study, a biomimetic eggshell reactor capable of highly efficient gas transfer was developed for in vitro tissue cultures. The reactor consisted of a natural eggshell (working volume approximate to 50-60 mL) for the containment of medium and a chamber-stirrer assembly for the containment of tissue constructs and for agitation. The pores on the eggshell allowed for gas transfer; thus, no air sparging was required. Compared with commercial spinner flasks, the eggshell reactor resulted in slightly better oxygen transfer rates at low agitation speeds, but significantly higher volumetric mass transfer coefficients at high agitation speeds. The highly efficient gas transfer in the eggshell reactor enabled the in vitro cultivation of actively growing E coli and long-term cultivation of tissue engineered cartilage-like constructs. Taken together, our results implicate the potential application of this reactor as a low-cost alternative for cell and tissue cultures.