hese porous silk microtubes can address this need. The porous silk microtubes were characterized in terms of pore size, burst pressure, protein diffusion, enzymatic degradation, and cell migration. Higher concentrations of silk fibroin (100/0, 99/1 wt% silk fibroin/PEO) produced microtubes that exhibited the lowest pore sizes, highest burst pressures, and strongest barrier function for both protein diffusion and cell migration.