Folate and cell penetrating peptide modification effects on penetration behavior of nanostructured lipid carriers using multicellular tumor spheroids

Surface modification may have important influences on the penetration behavior of nanoscale drug delivery system. In the present study, we mainly focused on whether cell targeting or cell penetration could affect penetration abilities of nanostructured lipid carriers (NLC). Realtime penetration of folateor cell penetrating peptide (CPP)modified NLC was evaluated using a multicellular tumor spheroid (MTS) established by stacking culture method as an in vitro testing platform. The results suggested that CPP modification had a better penetration behavior both on penetration depth and intensity compared with folatemodified NLC at the early stage of penetration process.