Smart Magnetic Nanosensors Synthesized through Layer-by-Layer Deposition of Molecular Beacons for Noninvasive and Longitudinal Monitoring of Cellular mRNA

Abstract

Noninvasive and longitudinal monitoring of gene expression in living cells is essential for understanding and monitoring cellular activities. Herein, a smart magnetic nanosensor is constructed for the real-time, noninvasive, and longitudinal monitoring of cellular mRNA expression through the layer-by-layer deposition of molecular beacons (MBs) and polyethylenimine on the iron oxide nanoparticles. The loading of MBs, responsible for the signal intensity and the tracking time, was easily tuned with the number of layers incorporated. The idea was first demonstrated with the magnetic nanosensors for glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA, which was efficiently internalized into the cells under the influence of magnetic field. This nanosensor allowed the continuous monitoring of the cellular GAPDH mRNA expression for 1 month. Then this platform was further utilized to incorporate two kinds of MBs for alkaline phosphatase (ALP) and GAPDH mRNAs, respectively. The multifunctional nanosensors permitted the simultaneous monitoring of the reference gene (GAPDH mRNA) and the early osteogenic differentiation marker (ALP mRNA) expression. When the fluorescence signal ratio between ALP mRNA MBs and GAPDH mRNA MBs was taken, the dynamic osteogenic differentiation process of MSCs was accurately monitored.

Non-invasive monitoring of the osteogenic differentiation of human mesenchymal stem cells on a polycaprolactone scaffold using Raman imaging

“…9 Fluorescence based nanosensors were developed to monitor the osteogenesis of hMSCs. 10,11 However, the inuences on cellular viability and bone functionality generated from the uorescent dye are still not well understood. Therefore, it is highly desired to have a label-free imaging methodology which can noninvasively detect the osteogenic differentiation of MSCs, visualize the ne structure of mineralized nodules, and acquire the chemical information during the osteogenic differentiation on the scaffolds.…”

Functional Imaging with Nucleic‐Acid‐Based Sensors: Technology, Application and Future Healthcare Prospects

“…Alternatively, NA probes can be loaded on nanoparticles (NPs) to mediate more efficient cellular entry, such as in the case of a liposome‐mediated transfection agent (i.e., lipofectamine). Similarly, NA probes could be encapsulated inside biodegradable NPs [e.g., poly(lactic‐co‐glycolic acid), PLGA] or attached to the surfaces of solid NPs (e.g., silica, IONPs, carbon‐based) through electrostatic layer‐by‐layer assembly or exploitation of π–π interactions . Upon cellular entry, the nanosensor assembly starts to disintegrate and to release functional NA probes into the intracellular compartments, where they report the presence of target molecules.…”

“…Similarly,N Ap robes could be encapsulated inside biodegradable NPs [e.g.,p oly(lactic-co-glycolica cid), PLGA] [9] or attachedt ot he surfaceso fs olid NPs (e.g.,s ilica, IONPs, carbon-based)t hrough electrostatic layer-by-layer assembly or exploitation of p-p interactions. [19] Upon cellular entry,t he nanosensor assembly starts to disintegrate and to releasef unctional NA probesi nto the intracellular compartments, where they report the presence of target molecules. Here, the rate of intracellular probe introduction is highlyv ariable, being based on the nanosensor disintegration kinetics.…”

Oligonucleotide Molecular Sprinkler for Intracellular Detection and Spontaneous Regulation of mRNA for Theranostics of Scar Fibroblasts

“…Abnormal expression of mRNA tends to precede the cutaneous features of scars and can provide a target for earlier treatment, potentially averting the permanent sequelae . Providing specific and sensitive probes, the temporal and spatial distribution of mRNA at the cellular level can be monitored in a quantitative and non‐invasive way, which would allow us to identify the abnormal fibroblasts in the skin of live mice and rabbits, and to ex vivo human skin models …”