Novel core–shell structured Paclitaxel-loaded PLGA@Ag–Au nanoparticles

Novel core–shell structured anti-cancer drug-loaded poly(lactide-co-glycolide) @Ag–Au nanoparticles (NPs) for medical applications were synthesized and characterized. Monodispersed, Paclitaxel (PTX)-loaded PLGA NPs, which were fabricated using a stabilizer-free method, served as the device core and facilitated Ag NP nucleation on their surface. A shell of Ag NPs was formed in situ on PLGA NPs through the controlled reduction of AgNO3 by polyvinylpyrrolidone (PVP). The intermediate PLGA@Ag NPs were used to grow Ag–Au nanoshells on PLGA core in a replacement reaction. The bimetallic Ag–Au nanoshell could serve as an optimal metal enhancer for surface enhanced Raman spectroscopy (SERS). SERS experiments using 4-MBA as the Raman reporter showed that the PTX-loaded PLGA@Ag–Au hybrid NPs provided enormously amplified SERS signals, which would make them as highly desirable SERS optical tags in biomedical imaging. With a combination of functions of high SERS activity, controlled anti-cancer drug release and hyperthermal effect, the PTX-loaded PLGA@Ag–Au NPs have the potential as new theranostics for effective cancer detection and treatment.

► Anti-cancer drug Paclitaxel-loaded PLGA@Ag–Au NPs were successfully fabricated using a three-step process.
► SERS intensity of Raman reporter molecules (4-MBA) was greatly enhanced by the Ag–Au nanoshell formed on PLGA, making the PLGA@Ag–Au NPs very attractive for high-sensitivity biodetection.
► Combining various desirable functions in a single nanoparticle platform, the drug-loaded PLGA@Ag–Au NPs have great potential as new theranostics for early cancer detection and treatment.