The internalization of both analogs was rapid and rsst2A-mediated, as shown by the significant decrease of internalization levels manifested in the presence of excess Tate (Figure 4A,B).
Model siRNA-polyplexes, based on chitosan as a 'classical' condensing agent, were applied to a panel of lung epithelial cell lines, H1299, A549 and Calu-3 and cell internalization levels, trafficking pathways and gene silencing assessed on exposure to pharmacological inhibitors.
Altogether these data indicate that cav-1 transfection did not affect the internalization levels or kinetics of PrPC that we had observed in the absence of caveolae demonstrating that although PrPC can be found in caveolae it is not endocytosed via those structures.
The internalization levels for polyplexes formed with the PMAG- b-PDMAPMA polymer series generally improved by increasing the N/ P ratio from 5 to 10 in HeLa cells.
However, the polyplexes formulated with glycopolymers containing the DMAPMA blocks exhibited lower cellular internalization levels than that observed with the PMAG- b-PAEMA series at N/ P ratios of 5 in HeLa cells.
The authors supposed that the size-dependent immunomodulatory effects of gold nanoparticles could be attributed to different mechanisms of their internalization, levels of accumulation, and intracellular distribution within DCs, leading to different modulation of maturational signaling.
Similar to internalization, pERK level was measured 30 min later since the stimulation started regardless of agonist exposure time.
It is possible that a similar competition is taking place on the M2 receptor with low levels of RACK1 allowing increased beta-arrestin binding and increased internalization, while high levels of RACK1 prevent beta-arrestin from acting on the M2 receptor.
