Elucidating the mechanism of cellular uptake
Two different monomers, butyl cyanoacrylate (BCA) and octyl cyanoacrylate (OCA), were used to produce PBCA, POCA and P(BCA/OCA) NPs.PBCA NPs are reported to degrade faster than POCA, and their copolymer could potentially have a tunable, intermediate degradation rate that could be used to achieve required drug release kinetics .Endocytosis inhibition in RBE4 cells had a greater effect than in PC3 cells as inhibition of CME and Cav ME reduced POCA NP uptake by 73 and 43 %, respectively, and PBCA NP uptake by 83 and 56 %, respectively.Endocytosis is an energy-dependent process and is strongly inhibited at low temperatures [ The effect of inhibition of endocytosis by genistein and chlorpromazine on the uptake of PBCA and POCA NPs in a PC3 cells and b in RBE4 cells. The median fluorescence intensity is expressed relative to autofluorescence.Both its emission spectrum and fluorescence lifetime depend on the local environment and can be used to locate the dye intracellularly.
Inhibiting Cav ME did not affect PBCA NP uptake in PC3 cells, whereas inhibiting CME reduced PBCA NP uptake by approximately 40 %.
Degradation rates under different extracellular conditions were compared to intracellular model drug release.
Nile Red 668 (NR668), a novel hydrophobic dye with the emission spectrum depending on the hydrophobicity of the local environment, was chosen due to its high hydrophobicity and unique spectral properties [: Figure S1), which is required to avoid false interpretation of results based on fluorescence signals.
In most target organs, cellular uptake of NPs occurs primarily through clathrin-mediated endocytosis (CME), although caveolin-mediated endocytosis (Cav ME) and other mechanisms can also play a role .
Among various nanoparticles currently investigated for their potential in cancer treatment, polymeric NPs have emerged as promising drug carriers.