Injectable delivery systems for tissue engineering

Abstract

The number of cells and biologically derived drugs (e.g., growth factors) used to treat disease are growing rapidly. However, appropriate carriers for the introduction of these therapeutics into the body are often lacking. Hydrogels are particularly attractive vehicles for these purposes, as they may be introduced into the body in a minimally invasive manner (e.g., injection) to avoid major surgery and reduce patient`s pain. A number of different mechanisms have been exploited to promote gel formation from various polymers, including ionic and covalent cross-linking, and the intrinsic temperature-dependent phase transition behavior of certain polymers. However, the ability of cells immobilized within the gels to participate in gel formation has been largely ignored. In this talk, not only can cells participate in this process, but one can specifically form hydrogels via the cross-linking of polymers by the cells they are intended to immobilize, will be discussed. This approach to gel formation may create important vehicles for the delivery of therapeutic cells into the body and provide a new model system to study cell-ligand interactions.