Real‐Time In Vivo Detection of Cellular Senescence through the Controlled Release of the NIR Fluorescent Dye Nile Blue

In vivo detection of cellular senescence is accomplished by using mesoporous silica nanoparticles loaded with the NIR‐FDA approved Nile blue (NB) dye and capped with a galactohexasaccharide (S3). NB emission at 672 nm is highly quenched inside S3, yet a remarkable emission enhancement is observed upon cap hydrolysis in the presence of β‐galactosidase and dye release. The efficacy of the probe to detect cellular senescence is tested in vitro in melanoma SK‐Mel‐103 and breast cancer 4T1 cells and in vivo in palbociclib‐treated BALB/cByJ mice bearing breast cancer tumor. I got the Nile blues: Mesoporous silica nanoparticles loaded with Nile blue and capped with a galacto‐hexasaccharide are used for in vivo imaging of cellular senescence. Fluorescence dye emission is quenched inside nanoparticles, yet a remarkable fluorescence is observed upon cap hydrolysis by β‐galactosidase. The probe detects cellular senescence in vitro and in vivo in palbociclib‐treated BALB/cByJ mice bearing breast tumors.