Large-pore mesoporous silica nanoparticles (MSN) were prepared and functionalized to serve as a robust and biocompatible delivery platform for platinum-acridine (PA) anticancer agents. The material showed a high loading capacity for the dicationic, hydrophilic hybrid agent [PtCl(en)(N-[acridin-9-ylaminoethyl]-N-methylpropionamidine)] dinitrate salt (P1 A1) and virtually complete retention of payload at neutral pH in a high-chloride buffer. In acidic media mimicking the pH inside the cells' lysosomes, rapid, burst-like release of P1 A1 from the nanoparticles is observed. Coating of the materials in phospholipid bilayers resulted in nanoparticles with greatly improved colloidal stability. The lipid and carboxylate- modified nanoparticles containing 40 wt.% drug caused S phase arrest and inhibited cell proliferation in pancreatic cancer cells at submicromolar concentrations similar to carrier-free P1A1. One feature of the nanoparticle-delivered P1A1 was that the payload did not escape from the acidified lysosomal vesicles into the cytoplasm, but was shuttled to the nuclear membrane and released into the nucleus.