Abstract: A method is described including introducing a delivery device to a point within a renal artery or a renal segmental artery and delivering a treatment agent from the delivery device according to conditions that create a turbulent blood flow and wherein the treatment agent is capable of inhibiting a biological process contributing to nephropathy. In other embodiments, an apparatus and kit are described including a delivery device for insertion to a point within a renal artery or renal segmental artery and delivery of a treatment agent capable of inhibiting a biological process contributing to nephropathy.

Abstract: A balloon catheter having a multilayer catheter shaft is formed to have an inner layer and an outer layer, where the inner layer and outer layer are selected from materials that enhance the pushability of the catheter while preserving the flexibility. Using a combination of a high Shore D duromater value material and a lower Shore D duromater value material, various combinations of multilayer catheter shafts are disclosed utilizing different glass transition temperatures and block copolyamides to obtain the desired characteristics.