A device and a method of maintaining vascularization near an implant, especially a bioartificial hemofilter. By associating cells that excrete angiogenic factors with such an implant, vascularization to the tissue surrounding the implant can be maintained. In a bioartificial hemofilter, this facilitates filtrate transport to a collection fiber for drainage from the body. The cells can be genetically engineered, for example using an adenovirus vector encoding for vascular endothelial growth factor. Myoblasts and myotubes may be used in one embodiment of the present invention.