Star-shaped polylactide dipyridamole conjugated to 5-fluorouracil and 4-piperidinopiperidine nanocarriers for bioimaging and dual drug delivery in cancer cells

Star-shaped polylactide (SSPLA) nanoparticles (NPs) with dipyridamole (DIP) core conjugated with 5-fluorouracil (5FU) and 4-piperidinopiperidine (4PIP) were designed and synthesized to achieve apoptosis by synergistic dose-dependent delivery than using free drugs. In our current investigation, DIP was employed as the initiator in ring-opening polymerization reaction to make SSPLADIP. We then described the synthesis of tailor-made, self-assembled, carboxyl group-substituted fluorescent SSPLADIP conjugated with a secondary amine group of 5FU anticancer drug to form a dual prodrug complex (SSPLADIP5FU). To compare the efficacy of this combination, another anticancer drug 4PIP was also covalently conjugated with a hydroxyl-end terminal by nucleophilic substitution on SSPLADIP to form SSPLADIP4PIP. 4PIP inhibits the topoisomerase enzyme in DNA replication. Synthesized star-shaped drug constructs were characterized by atomic force microscopy, scanning electron microscopy, NMR, fluorescence spectroscopy, gel permeation chromatography, and MALDI-TOF. This is the first report on these drug combinations (DIP-5FU and DIP-4PIP) fabricated on the polylactic acid biopolymer to form NPs of size