An angiogenic material is prepared which promotes extensive vascularization when implanted in animal tissue. The angiogenic material is preferably used in microcapsule coatings and microspheres for implantation in animals. In microcapsules, the angiogenic material promotes better exchange of nutrients, waste products and cellular products between encapsulated cells and the circulatory system of the host animal. Preferably, the angiogenic material consists of a biocompatible polymer and a vascularizing compound consisting of polymerizable compounds capable of forming anions. Microspheres containing the angiogenic material may be used to assist in recovery of ischemic heart muscle by injection of the microspheres into the heart muscle or blood vessels serving the ischemic area. Also disclosed is a method of forming small microcapsules and microspheres by passing cell aggregates or air bubbles through layers of a density gradient.
RELATED APPLICATIONS
This application is a divisional application of applicants' pending U.S. patent application Ser. No. 09/069,544 filed on Apr. 30, 1998, now U.S. Pat. No. 6,261,585, as a continuation application of PCT International patent application Serial No. PCT/CA96/00725 designating the United States, filed on Oct. 31, 1996.
