Optical Imaging and High‐Accuracy Quantification of Intracellular Iron Contents

Abstract

Precise quantification of intracellular iron contents is important to biomedical applications of magnetic nanoparticles. Current approaches for iron quantification rely on specialized instruments while most only yield iron quantities averaged over plenty of cells. Here, a simple and robust approach, combining digital optical microscopy with the Beer–Lambert's law, that allows for imaging stainable iron distribution in individual cells and the quantification of stainable iron contents with an unprecedented accuracy of femtogram per pixel, is presented. It is further shown that this approach enables studying of the internalization and reduction dynamics of super‐paramagnetic iron oxide nanoparticles (SPIONs) by stem cells in single cell level.

Temperature‐Dependent CAT‐Like RGD‐BPNS@SMFN Nanoplatform for PTT‐PDT Self‐Synergetic Tumor Phototherapy

“…Moreover, Perl's staining was carried out for intracellular iron content detection. [ 41 ] In brief, BPNS@SMFN and RGD‐BPNS@SMFN (100 µg mL −1 Fe) were coincubated with HeLa cells for 6 h respectively, then paraformaldehyde was used to fix the cells for 30 min. After removing the excessive paraformaldehyde, the Perl's staining reagent was added.…”

A Self-Homing and Traceable Cardiac Patch Leveraging Ferumoxytol for Spatiotemporal Therapeutic Delivery

“…Before internalization into the MSCs, ferumoxytol was subjected to pretreatment with poly-L-lysine, following established protocols. 69 Specifically, 167 μL of ferumoxytol (30 mg/mL Fe concentration) was combined with 100 μL of 10% poly-L-lysine solution (w/v) (Sigma, USA) in 733 μL of ddH 2 O, resulting in a final concentration of 5 mg/ mL. Subsequently, an ultrasonic ice bath was utilized to facilitate the wrapping of poly-L-lysine around the nanoparticles for 3 h.…”

“…Ferumoxytol (γ-Fe 2 O 3 @PSC) was characterized by high homogeneity and monodispersity. Before internalization into the MSCs, ferumoxytol was subjected to pretreatment with poly- l -lysine, following established protocols . Specifically, 167 μL of ferumoxytol (30 mg/mL Fe concentration) was combined with 100 μL of 10% poly- l -lysine solution (w/v) (Sigma, USA) in 733 μL of ddH 2 O, resulting in a final concentration of 5 mg/mL.…”

Magnetic Characterization of Human Intrinsically Magnetic Monocytes Through a Novel Optical Tracking‐Based Magnetic Sensor

“…Cell labeling method employed here has been validated in earlier studies. [ 29,30 ] Briefly, SPIONs were mixed with ploy‐L‐lysine (PLL, Sigma‐Aldrich, St. Louis, MO, USA) solution with a final concentration of 5 mg (Fe concentration): 100 µg(PLL)/mL in an ultrasonic bath for 3 h. The solution was then diluted with complete medium into different iron concentrations (50, 100, 200 µg mL −1 ) and replaced the cell culture medium with another 24 h incubation. Then the cells were washed with 0.01 M phosphate buffer saline (PBS) and collected for further measurement.…”