Fig. 3.

a Illustration of drug loading and the release process in multifunctional mesoporous TiO₂ nanocarriers conjugated with PEI and folic acid. b The photocatalytic degradation of folic acid-PEI on the surface of mesoporous TiO₂ nanocarriers through the use of UV light irradiation. c The improved cellular internalization of the nanocarriers into KB and A549 cells after 5 h (I) and the number of internalized nanocarriers with and without folic acid conjugation (II). FCM: Flow cytometry measurements. d Fluorescence images of treated KB cells after incubation (I) with and (II) without folic acid-conjugated nanocarriers. The punctuated green colors indicate the nanocarriers and blue (color) shows the cell nuclei. e In vivo fluorescence images of tissue collected at different times (post-injection).

Adapted from Ref. [8] with permission from the Elsevier. (Color figure online)