Poly(d,l-lactic-co-glycolic acid) (PLGA) hollow fiber with segmental switchability of its chains sensitive to NIR light for synergistic cancer therapy.

This work introduces a new fibrous system for synergistic cancer therapy. The system consists of poly(d,l-lactic-co-glycolic acid) (PLGA) fibers with a core encapsulating an anticancer drug and a shell entrapping gold nanorods (AuNRs) as a photothermal agent. On exposure to NIR light, the photothermal agent generates heat to raise the local temperature of the fibers. If the temperature is above a glass transition (Tg) of the polymer, the polymer chains will be mobile, increasing free volume in size within the shell. As a result, a rapid release of the drug can be achieved. When NIR light is turned off, the release will stop with inactivity of the photothermal agent, followed by freezing the segmental motion of the polymer chains. The on-off switching of NIR light in a time-controllable manner allows a repeated and accurate release of the drug, leading to the significant enhancement of anticancer activity in combination with the hyperthermia effect arising from the photothermal agent.