Polymerizable Fluorescein Derivatives: Synthesis of Fluorescent Particles and Their Cellular Uptake

Abstract

Fluorescent particles are used for a diverse number of biochemical assays including intracellular imaging, cellular tracking, as well as detection of a variety of biomolecules. They are typically prepared by postpolymerization conjugations of dyes onto preformed particles. Herein we report the synthesis of aminomethyl-functionalized fluorescent particles via the synthesis and application of polymerizable fluorescein monomers. These monomers allowed high and controllable fluorophore loading into the particles, resulting in enhanced fluorescence properties in comparison with more commonly used carboxyfluorescein conjugated particles. Furthermore, the particles were rapidly taken up by cells with enhanced fluorescence. The herein presented results demonstrate the advantages of dye polymerization in contrast with more conventional conjugation strategies for fluorescent particle generation with applications in the life sciences.

Soft fluorescent nanomaterials for biological and biomedical imaging

“…Therefore, nonspecific in vitro imaging is an elementary step for showing cellular images labeled with soft fluorescent NPs. A lot of fluorescent organic NPs have been used to label cells, including fluorescent conjugated polymer NPs, 53, 75, 106 dye-doped polymeric NPs, 58, 66, 78, 129 AIE- 126 and DIE- 108 type small-molecule NPs, self-fluorescent biodegradable NPs 69 and phototunable NPs 110, 114 .…”

Fluorescein

“…In this study, fluorescein was modified with styryl monomers at different attachment points (xanthine and phthalic moiety) and converted into polymer particles. 9 Attachment on the phthalic moiety was advantageous with enhanced fluorescent properties, and demonstrated a five-fold increase in comparison to the commonly employed surface coupled fluorescein approach. …”

Biocompatible Polymer Nanoparticles for Intra-cellular Applications

“…2). [12] Covalent functionalization via amide bonds is one of the most common methods available to attach dyes and payloads to polymeric particles. [13] However, following such functionalization the number of surface groups available for attaching further cargos is greatly reduced.…”

“…This allowed the generation of highly fluorescent microspheres without compromising their cargo carrying capacity. [12] It is worth noting that this approach leads to higher emission intensity of backbone-incorporated fluorescein relative to the surface-conjugated fluorescein and a more even distribution of the fluorescent molecules throughout the particle. [12] The General Uptake of Microspheres into Cells…”