Examples of SER drug delivery nanoformulations for cancer treatment. a1 Schematic representation of the construction of the pH-sensitive charge-reversal system based on curcumin (Cur) loaded fluorinated graphene oxide (FGO) modified with polyethyleneimine anchored to sericin-polypeptide (FPS); a2 Apoptotic morphology study using cell nuclei stained by DAPI dye in PC-3 (a2) and HeLa cells (a3) treated with PBS (control), free curcumin (Cur), FPS-Cur for 6 h treatment. Reproduced with permission from Jahanshahi et al. ; b1 Schematic illustration of the synthesis procedure of doxorubicin (DOX) loaded sericin-coated mesoporous silica nanoparticles (SMSNs); b2 Cellular uptake of free DOX (left) and DOX-loaded SMSNs (right) for 1, 2 and 4 h; b3 The relative tumor volume of MCF-7/ADR tumor-bearing mice over 21 days; b4 Representative tumors isolated from the mice after the treatment. Reproduced with permission from Liu et al.