The invention provides an inflammation-responsive implantable device for the in situ delivery of one or more pharmaceutically active agents to a human or animal. The device comprises two differential release bioresponsive polymeric matrices (BPMs): an outer polymetric matrix and an inner polymeric matrix, both of which contain at least one pharmaceutically active agent or drug, typically an antibiotic and an anti-inflammatory agent, respectively. The therapeutically effective agent may be embedded in nanoparticles or nanobubbles. In response to inflammation, the pharmaceutically active agents are released, but at different rates: the rate of drug release from the inner polymeric matrix is lower than the rate of drug release from the outer polymeric matrix. Suitable polymers for forming the outer and inner polymeric matrices are hyaluronic acid and chitosan, respectively. A method of making the device and a method of treatment are also described.