Therapeutic agent delivery systems, which include a thermally-sensitive copolymer and optionally a therapeutic agent, are disclosed. The copolymer is water soluble and biodegradable and, in accordance with exemplary embodiments, includes hydrophobic and hydrophilic portions. The systems may include supplemental compounds, such as polymeric nanoparticles, micelle compounds, or a combination thereof, to further provide sustained release of the therapeutic agent.
