The present invention provides a filamentary structure for the introduction of
agents into a living host, comprising a filament comprising a solid core and a
porous sheath which coats at least a portion of the solid core. When the filamentary
structure is to be permanently implanted into a living host, both the solid core
and the porous sheath are bioabsorbable. When the filamentary structure is to be
temporarily implanted into the skin of a living host to deliver agents, such as
cells, therein, the porous sheath is preferably bioabsorbable but the core need
only be biocompatable, not bioabsorabable. The devices and methods of the present
invention enable one to regenerate hair follicles, to introduce genetically altered
cells or encapsulated cells to a living host transdermally, to regenerate bones,
and to deliver drugs transdermally.
