The present invention is directed to medial articles having bioerodible
polymeric regions that contain biodegradable block copolymers. The
biodegradable block copolymers include at least one first biodegradable
polymer block and least one second biodegradable polymer block that
differs from the first biodegradable polymer block. The bioerodible
polymeric regions comprise a first phase domain formed from the at least
one first biodegradable polymer block and a second phase domain formed
from the at least one second biodegradable polymer block. At least one of
the first and second phase domains is a discontinuous phase domain in the
form of dispersed phase elements, substantially all of which have a
longest cross-sectional dimension that is less than 1 micron.