Dendritic cell internalization of foam-structured fluorescent mesoporous silica nanoparticles

In this paper, foam-structured fluorescent mesoporous silica nanoparticles (FMSNs) are produced in a sol–gel method with the introduction of a phosphonate functional group. It is found that the phosphonate functionalized FMSNs with the foam structure minimizes the aggregation of FMSNs in solution. The average particle size of the FMSNs without and with phosphonate functionalization is 46.3 ± 5 nm and 60.5 ± 8 nm in diameter, respectively. The latter one exhibits higher fluorophore loading capacity (∼67 ± 2.5%). The excitation wavelength (λex) of FMSNs is observed at 526 nm, approximate 12 nm larger in the Stoke-shift compared to the free organic dye at 494/514 nm. Furthermore, the photostability of the hydrophobic fluorophore is greatly improved by the FMSNs with the foam structure. In addition, the dose-dependent nature of FMSN uptake is assessed for the immune cells, the bone marrow-derived dendritic immune cells (BMDCs). Our results indicate that approximately 42% of BMDCs are able to take up foam-structured FMSNs (>5 μg/ml) without decreasing the viability of BMDCs. Thus, the phosphonate functionalized FMSNs with the foam structure are suitable to be used for many biomedical applications, especially in cell tracking.

The primary mouse bone marrow-derived dendritic cells (BMDC) have been cultured to assess the cell uptake of the fluorescent mesoporous silica nanoparticles with the foam structure functionalized with phosphonate group.Figure optionsDownload high-quality image (130 K)Download as PowerPoint slideResearch highlights
► A new foam-like nanostructure of fluorescent mesoporous silica nanoparticles.
► A one-step synthesis method for the foam-structured fluorescent nanoparticles.
► High loading capacity to the foam-structured mesoporous silica nanoparticles for encapsulation of hydrophobic fluorophor.
► A bio-compatible fluorescent nanoparticles assessed by the immune cell, i.e. the bone marrow-derived dendritic immune cells (BMDCs).
► Enhanced cell uptake of the foam-structured nanoparticles enables to be used for the cell tracking.