Elucidating the mechanism of cellular uptake Sexy chat rooms no membership needed
Approximately 90 % of RBE4 cells internalized NPs after 1 h, whereas PC3 cells reached this level after approximately 24 h (Fig. On the other hand, in PC3 cells the uptake of POCA NPs was eightfold higher than PBCA NPs already after 3 h (Fig. In PC3 cells, both inhibitors reduced POCA NP uptake by approximately 40 %.
Inhibiting Cav ME did not affect PBCA NP uptake in PC3 cells, whereas inhibiting CME reduced PBCA NP uptake by approximately 40 %.
Both its emission spectrum and fluorescence lifetime depend on the local environment and can be used to locate the dye intracellularly.
Emission spectrum analysis has previously been used by our group to locate Nile Red .
Poly(alkyl cyanoacrylate) (PACA) nanoparticles have shown promise as drug carriers both to solid tumors and across the blood–brain barrier.
Efficient drug delivery requires both high cellular uptake of the nanoparticles and release of the drug from the nanoparticles.
The cellular uptake and intracellular trafficking of PACA NPs were studied in two different cell lines using flow cytometry (FCM) and confocal laser scanning microscopy (CLSM).
Rat brain endothelial cells (RBE4) were chosen because of the reported ability of PACA NPs to cross the blood brain barrier , and human prostate cancer cells (PC3) were chosen to assess NP uptake and degradation in a common human tumor cell line.
Fluorescence lifetime imaging, emission spectra analysis and Förster resonance energy transfer indicated that the intracellular degradation was in line with the degradation found by direct methods such as gas chromatography and scanning electron microscopy, showing that PBCA has a faster degradation rate compared to POCA.Release of hydrophobic drugs from PACA nanoparticles is primarily governed by nanoparticle degradation, and this process has been poorly studied at the cellular level.Here we use the hydrophobic model drug Nile Red 668 (NR668) to investigate intracellular degradation of PACA nanoparticles by measuring changes in NR668 fluorescence emission and lifetime, as the spectral properties of NR668 depend on the hydrophobicity of the dye environment.The diameters of the three NPs were in the range of 148–177 nm with a relatively narrow size distribution [polydispersity index (PDI) ≤ 0.12].
All three NPs were slightly negatively charged with a zeta-potential of approximately −10 m V.The three complementary optical techniques showed that the intracellular degradation rates of the PBCA and POCA NPs are in line with the rates measured in solution.