Rodlike Particles of Polydopamine-CdTe Quantum Dots: An Actuator As a Photothermal Agent and Reactive Oxygen Species-Generating Nanoplatform for Cancer Therapy

Herein, novel rodlike CdTe@MPA-PDA particles based on polydopamine (PDA) loaded with CdTe quantum dots (QDs) capped with mercaptopropionic acid (CdTe@MPA QDs) with atypical chemical features are evaluated as a potential actuator for photothermal therapy and oxidative stress induction. Under mild conditions established for the safe and efficient use of lasers, temperature increases of 10.2 and 7.8 degrees C, photothermal conversion efficiencies of 37.7 and 26.2%, and specific absorption rates of 99 and 69 W/g were obtained for CdTe@MPA-PDA and traditional PDA particles in water, respectively. The particles were set to interact with the human breast adenocarcinoma cell line MDA-MB-231. A significant cellular uptake with the majority of particles colocalized into the lysosomes was obtained at a concentration of 100 mu g/mL after 24 h. Additionally, CdTe@MPA-PDA and CdTe@MPA QDs showed significantly different internalization levels and loading kinetics profiles. For the first time, the thermal lens technique was used to demonstrate the stability of particle-like CdTe@MPA-PDA after heating at pH 7 and their migration within the heating region due to the thermodiffusion effect. However, under acidic pH-type lysosomes, a performance decrease in heating was observed, and the chemical feature of the particles was damaged as well. Besides, the internalized rodlike CdTe@MPA-PDA notably enhanced the induction of oxidative stress compared with PDA alone and CdTe@MPA QDs in MDA-MB-231 cells initiating apoptosis. Combining these effects suggests that after meticulous optimizations of the conditions, the CdTe@MPA-PDA particles could be used as a photothermal agent under mild conditions and short incubation time, allowing cytoplasmatic subcellular localization. On the other hand, the same particles act as cell killers by triggering reactive oxygen species after a longer incubation time and lysosomal subcellular localization due to the pH effect on the chemical morphology features of the CdTe@MPA-PDA particles.

Automated summary

Novel rodlike CdTe@MPA-PDA particles loaded with CdTe quantum dots and polydopamine have unique chemical features and show potential as an actuator for photothermal therapy and oxidative stress induction. These particles interact with cancer cells, induce oxidative stress, and enhance apoptosis, demonstrating their effectiveness as a photothermal agent with subcellular localization capabilities.