Fig. 3From: Magnetic resonance imaging with upconversion nanoprobes capable of crossing the blood-cerebrospinal fluid barrierIn vitro viability of (a) Z310 cells and (b) BCECs cultured with PEG-UCNP or ANG-PEG-UCNP for 24 h. (c) An illustration of the Z310 transwell assay used to assess whether nanoprobes crossed the blood cerebrospinal fluid barrier. (d) Corresponding transcytosis of PEG-UCNP and ANG-PEG-UCNP without or with ANG blockage. (**p < 0.01)Back to article page