Fig. 4

Penetration of mTHPC-loaded NPs in co-culture spheroids. The typical fluorescence images of cryosections of FaDu monoculture (F5) and FaDu:MeWo (5:2 and 5:5) co-culture spheroids at day 5 post-seeding after incubation with (a) Foslip^®, (b) mTHPC-DCL and (c) mTHPC-EVs for 3, 6 and 24 h. MeWo cells were pre-stained with PKH67 membrane dye (green color). mTHPC fluorescence is displayed in red color (merged images) and pseudo-colors (mTHPC images). The concentration of mTHPC was 4.5 µM. Serum concentration – 6%. Scale bar – 100 µm