Polymeric delivery devices have been developed which combine
high loading /
high density of molecules to be delivered with the option of targeting. As used herein, “
high density” refers to microparticles having a
high density of ligands or
coupling agents, which is in the range of 1000-10,000,000, more preferably between 10,000 and 1,000,000 ligands per square micron of
microparticle surface area. A
general method for incorporating molecules into the surface of
biocompatible polymers using materials with an HLB of less than 10, more preferably less than 5, such as fatty acids, has been developed. Because of its ease, generality and flexibility, this method has widespread utility in modifying the surface of polymeric materials for applications in
drug delivery and
tissue engineering, as well other other fields. Targeted polymeric microparticles have also been developed which encapsulate therapeutic compounds such as drugs, cellular materials or components, and antigens, and have
targeting ligands directly bound to the
microparticle surface. Preferred applications include use in
tissue engineering matrices, wound dressings, bone repair or regeneration materials, and other applications where the microparticles are retained at the site of application or implantation. Another preferred application is in the use of microparticles to deliver anti-proliferative agents to the lining of blood vessels following
angioplasty,
transplantation or
bypass surgery to prevent or decrease
restenosis, and in
cancer therapy. In still another application, the microparticles are used to treat or prevent
macular degeneration when administered to the eye, where agents such as
complement inhibitors are administered.