Disclosed herein are methods of treating/inhibiting/reducing a non-immunogenic cancer in a subject or inducing blockade inhibitor susceptibility (such as, for example, PD-1/PDLI, CTLA-4/B7-1/2, and/or CD47/SIRPa inhibitor susceptibility) in a tumor in a subject with a cancer, said methods comprising administering to the subject a hydrogel matrix comprising a chemotherapeutic agent (including, but not limited to gemcitabine) and a blockade inhibitor (including, but not limited to a PD-1/PD-LI blockade inhibitor, such as, for example nivolumab, pembrolizumab, pidilizumab, atezolizumab, avelumab, durvalumab, and BMS-936559; a CTLA-4/B7-1/2 inhibitor such as, for example, Ipilimumab; and/or a CD47/SIRPa inhibitor such as, for example Hu5F9-G4, CVI, B6H12, 2D3, CC-90002, and TTI-621).