Abstract: A cell collecting device having a housing with an inlet for receiving cells, a cell attractant cavity have a cell attractant, a cell collection channel running from the inlet to the cell attractant cavity, and a plurality of electrodes positioned to detect the presence of cells is disclosed. The cell attractant cavity may include a porous medium, such as, a hydrogel, containing the cell attractant, such as, epidermal growth factor. The channel may include a plurality of restrictions and expansions to assist in maintaining the porous medium while permitting the passage of attractant and cells. The device may be implanted into a patient for an extended period of time, and then removed and examined. A method for collecting cells, an implantable attractant dispersing device, and a porous medium for controlled releasing of a compound are also disclosed.