Development of Long-Acting Treatments for HCV Cure: In the United States, an estimated 15 to 30% of persons living with HIV (PLWH) are also living with HCV, but these rates vary significantly based on the individual's risk factor for acquiring HIV. Among PLWH, the odds of acquiring HCV are six times higher than for their HIV-negative counterparts, and acquiring viral hepatitis increases mortality and morbidity, including for PLWH on antiretroviral therapy. Compared with individuals who are only living with HCV, persons living with HIV and HCV have accelerated rates of liver fibrosis and a more aggressive course of liver disease, they typically develop hepatocellular carcinoma at a younger age with more aggressive tumors, and they have higher rates of death. The development and use of long-acting drug products has the potential to significantly reduce the burden of disease caused by HCV in PLWH and will ultimately help to eradicate HCV. The goal of this contract is to develop a thermo-responsive hydrogel implant with two direct-acting antivirals, sofosbuvir and daclatasvir, incorporated as polymer complexes. The implant solidifies upon subcutaneous injection and forms a depot enabling sustained drug release via enzymatic degradation.