The present invention provides a biointerface membrane for use with an
implantable device that interferes with the formation of a barrier cell
layer including; a first domain distal to the implantable device wherein
the first domain supports tissue attachment and interferes with barrier
cell layer formation and a second domain proximal to the implantable
device wherein the second domain is resistant to cellular attachment and
is impermeable to cells. In addition, the present invention provides
sensors including the biointerface membrane, implantable devices
including these sensors or biointerface membranes, and methods of
monitoring glucose levels in a host utilizing the analyte detection
implantable device of the invention. Other implantable devices which
include the biointerface membrane of the present invention, such as
devices for cell transplantation, drug delivery devices, and electrical
signal delivery or measuring devices are also provided.