Extraction-Induced Fabrication of Yolk-Shell Structured Nanoparticles with Deformable Micellar Cores and Mesoporous Silica Shells for Multi-Drug Delivery

Yolk-shell structured nanoparticles (YSNs) provide useful carriers for applications in biomedicine and catalysis due to the excellent loading capability and versatile functionality of the flexible core and porous shell. Unfortunately, the reported YSNs always require complex multi-step synthesis processes and a harsh hard-template etching strategy. Herein, a facile “selective extraction” strategy is developed to synthesize yolk-shell structured polymer@void@mSiO2 nanoparticles (designated as YSPNs) comprising deformable and soft polystyrene-b-poly (acrylic acid) (PS-b-PAA) micellar cores and mesoporous silica shells. The YSPNs is formed by a morphological change and volume shrinkage of the PS-b-PAA aggregates from large compound vesicles to large compound micelles during the extraction process. As a multi-drug vehicle, both hydrophobic curcumin (Cur, 6.4 wt%) and hydrophilic doxorubicin hydrochloride (Dox, 19.4 wt%) can be co-loaded onto YSPNs through a successive impregnation method. Moreover, the result...