Jump to main content
Jump to site search

Labelling primary immune cells using bright blue fluorescent nanoparticles

Author affiliations


Tracking cell movements is an important aspect of many biological studies. Reagents for cell tracking must not alter the biological state of the cell and must be bright enough to be visualized above background autofluorescence, a particular concern when imaging in tissue. Currently there are few reagents compatible with standard UV excitation filter sets (e.g. DAPI) that fulfill those requirements, despite the development of many dyes optimized for violet excitation (405 nm). A family of boron-based fluorescent dyes, difluoroboron β-diketonates, has previously served as bio-imaging reagents with UV excitation, offering high quantum yields and wide excitation peaks. In this study, we investigated the use of one such dye as a potential cell tracking reagent. A library of difluoroboron dibenzoylmethane (BF2dbm) conjugates were synthesized with biocompatible polymers including: poly(L-lactic acid) (PLLA), poly(ε-caprolactone) (PCL), and block copolymers with poly(ethylene glycol) (PEG). Dye–polymer conjugates were fabricated into nanoparticles, which were stable for a week at 37 °C in water and cell culture media, but quickly aggregated in saline. Nanoparticles were used to label primary splenocytes; phagocytic cell types were more effectively labelled. Labelling with nanoparticles did not affect cellular viability, nor basic immune responses. Labelled cells were more easily distinguished when imaged on a live tissue background than those labelled with a commercially available UV-excitable cytoplasmic labelling reagent. The high efficiency in terms of both fluorescence and cellular labelling may allow these nanoparticles to act as a short-term cell labelling strategy while wide excitation peaks offer utility across imaging and analysis platforms.

Graphical abstract: Labelling primary immune cells using bright blue fluorescent nanoparticles

Back to tab navigation

Supplementary files

Article information

27 Sep 2019
27 Jan 2020
First published
06 Feb 2020

Biomater. Sci., 2020, Advance Article
Article type

Labelling primary immune cells using bright blue fluorescent nanoparticles

M. C. Belanger, M. Zhuang, A. G. Ball, K. H. Richey, C. A. DeRosa, C. L. Fraser and R. R. Pompano, Biomater. Sci., 2020, Advance Article , DOI: 10.1039/C9BM01572H

Social activity

Search articles by author