GEM and pancreatic neoplasm: The results obtained from the 2D and 3D models of the pancreatic cancer cells and in the more physiologically relevant system of PDAC—obtained by co-culturing CAF and pancreatic tumor cells in 3D—confirmed the high level of cell internalization, the ability to control the release of the loaded drug, and a relevant antitumor efficacy, compared with unformulated Gem.