Drug delivery to the tumor site and minimizing adverse effects on surrounding tissues remains a fundamental issue. In this study, pH and radiation-responsive PLGA-PEG-PLGA amphiphilic copolymers were terminally conjugated with hydrophobic tryptophan (Try), tyrosine (Tyr), or histidine (His) amino acids (aa). To synthesize the tri-copolymers, PEG was employed as an initiator and Sn (Oct) ₂ as a catalyst. In this system, micelles were developed with an inner core comprised of hydrophobic blocks (PLGA and Try/Tyr/His) and PEG as a hydrophilic corona to improve the stability. The rise in DOX fluorescence intensity and particle size shift because of light and pH stimulation supported structural destabilization of the micelle. Try-PLGA-PEG-PLGA-Try and Tyr-PLGA-PEG-PLGA-Tyr micelles had negligible cytotoxicity (more than 90% cell viability at 100 g/mL) when incubated with NIH-3T3 and HeLa cell lines using MTT assays. DOX-loaded micelles (Try/Tyr), on the other hand, had a greater impact on HeLa cells, with roughly 30% of cells were survived at a maximum DOX dosage (10 g/mL). The cellular uptake experiment further verified that DOX-loaded micelles were internalized in the cytoplasm and nucleus of cancer cells. Therefore, the prepared copolymer systems have the potential to be employed as stimuli-responsive carriers for the delivery of anti-cancer drugs.