In vitrocell-based characterization
methods of
nanoparticles are generally static and require the use of secondary
analysis techniques and labeling agents. In this study, bare niosomes
and chitosan-coated niosomes (chitosomes) and their interactions with
intestinal cells are studied under dynamic conditions and without
fluorescent probes, using surface plasmon resonance (SPR)-based cell
sensing. Niosomes and chitosomes were synthesized by using Tween 20
and cholesterol in a 15 mM:15 mM ratio and then characterized by dynamic
light scattering (DLS). DLS analysis demonstrated that bare niosomes
had average sizes of ∼125 nm, polydispersity index (PDI) below
0.2, and a negative zeta (ζ)-potential of −35.6 mV. In
turn, chitosomes had increased sizes up to ∼180 nm, with a
PDI of 0.2–0.3 and a highly positive ζ-potential of +57.9
mV. The viability of HT29-MTX, Caco-2, and Caco-2/HT29-MTX cocultured
cells showed that both niosomes and chitosomes are cytocompatible
up to concentrations of 31.6 μg/mL for at least 240 min. SPR
analysis demonstrated that chitosomes interact more efficiently with
HT29-MTX, Caco-2, and Caco-2/HT29-MTX cocultures compared to bare
niosomes. The resulting SPR measurements were further supported by
confocal microscopy and flow cytometry studies, which demonstrated
that this method is a useful complementary or even alternative tool
to directly characterize the interactions between niosomes andin vitrocell models in label-free and real-time conditions.