摘要 |
Improved controlled therapy is provided with a polymer multi-layer structure having a predetermined micro-fabricated spatial pattern (e.g., reservoirs and channels). More specifically, all geometrical details of the spatial pattern are substantially predetermined. The increased control of pattern geometry provided by the invention allows for improved control of therapy. In preferred embodiments, the polymer multi-layer structure of the invention is biodegradable, but has an in vivo lifetime that is greater than the duration of the therapy being provided. Thus, the geometrical pattern of the polymer structure that controls delivery of the therapy persists without significant change during therapy, and the structure degrades after completion of therapy. In this manner, possible interference of degradation by-products with therapy is minimized, and delivery of therapy does not depend on details of how degradation proceeds. |