A bioreactor includes a plastic enclosure for containing a biological medium, the enclosure being integrally formed to have one or more elongate port extensions projecting outwardly from the enclosure and communicating from the exterior to the interior of the enclosure. Such surgical coils may be implanted in the body by deforming them to a small cross section profile, sliding it them through a low profile delivery device then deploying them from an embodiment of a delivery device at a targeted site. A method for determining glomerular filtration rate in a mammal.