Fig. 3: MNPs display diverse staining and uptake in the small intestinal organoids.

a Scheme of experimental workflow. b Representative confocal fluorescence images and corresponding phasor plots of the pig small intestinal organoid incubated with NP A-D (10 μg/ mL, 18 h), co-stained with Nile Red. NP A, B and D displayed signals on both fluorescent intensity images and phasor plots, whereas type C showed no signal, similar to control. c Different types of uptake of NP type D uptake (10 μg/mL NPD, 20% laser power) into organoids, co-stained with WGA, with respect to the topology and size. Left: partial NP D uptake in AO, showing high pixel signal on a phasor plot. Middle: organoid size-dependent NP D uptake in AO. ROI 1: enhanced NP D pixel signal in a small AO, ROI 2: reduced NP D pixel signal in larger organoid. Right: Homogeneous NP D distribution in BO with strong signal on a phasor plot. d Topology-dependent uptake of NP D (magenta) in apical-basal organoid (AB), co-stained with WGA (green) and Nile Red (yellow). Left: 3D reconstruction shows distinct NP D distribution in AO and BO regions. Right: representative fluorescence image of AB organoid taken from 3D reconstruction. AO and BO regions defined by WGA and Nile Red signals, with corresponding NP type D phasor FLIM plots of these regions (bottom right). Phasor plots correspond to individual plane images