1 research outputs found
A Selective and Purification-Free Strategy for Labeling Adherent Cells with Inorganic Nanoparticles
Cellular labeling with inorganic
nanoparticles such as magnetic
iron oxide nanoparticles, quantum dots, and fluorescent silica nanoparticles
is an important method for the noninvasive visualization of cells
using various imaging modalities. Currently, this is mainly achieved
through the incubation of cultured cells with the nanoparticles that
eventually reach the intracellular compartment through specific or
nonspecific internalization. This classic method is advantageous in
terms of simplicity and convenience, but it suffers from issues such
as difficulties in fully removing free nanoparticles (suspended in
solution) and the lack of selectivity on cell types. This article
reports an innovative strategy for the specific labeling of adherent
cells without the concern of freely suspended nanoparticles. This
method relies on a nanocomposite film that is prepared by homogeneously
dispersing nanoparticles within a biodegradable polymeric film. When
adherent cells are seeded on the film, they adhere, spread, and filtrate
into the film through the micropores formed during the film fabrication.
The pre-embedded nanoparticles are thus internalized by the cells
during this infiltration process. As an example, fluorescent silica
nanoparticles were homogeneously distributed within a polycaprolactone
film by utilizing cryomilling and heat pressing. Upon incubation within
physiological buffer, no silica nanoparticles were released from the
nanocomposite film even after 20 d of incubation. However, when adherent
cells (e.g., human mesenchymal stem cells) were grown on the film,
they became fluorescent after 3 d, which suggests internalization
of silica nanoparticles by cells. In comparison, the suspension cells
(e.g., monocytes) in the medium remained nonfluorescent no matter
whether there was the presence of adherent cells or not. This strategy
eventually allowed the selective and concomitant labeling of mesenchymal
stem cells during their harvest from bone marrow aspiration