PTGS2 and breast neoplasm: A combinatorial delivery system—thermosensitive biodegradable poly(lactic acid) hydrogel (PLA-gel) incorporating celecoxib-encapsulated poly(lactic-co-glycolic acid) nanoparticles (Cx-NP/PLA-gel)—was injected into the biopsy cavity of Py230 murine breast tumors to achieve local control of COX-2 activity in the wound stroma.