Assembly of Fluorescent Polymer Nanoparticles Using Different Microfluidic Mixers.

Nanoprecipitation is a facile and efficient approach to the assembly of loaded polymer nanoparticles (NPs) for applications in bioimaging and targeted drug delivery. Their successful use in clinics requires reproducible and scalable synthesis, for which microfluidics appears as an attractive technique. However, in the case of nanoprecipitation, particle formation depends strongly on mixing.

Size-Dependent Electroporation of Dye-Loaded Polymer Nanoparticles for Efficient and Safe Intracellular Delivery.

Efficient and safe delivery of nanoparticles (NPs) into the cytosol of living cells constitutes a major methodological challenge in bio-nanotechnology. Electroporation allows direct transfer of NPs into the cytosol by forming transient pores in the cell membrane, but it is criticized for invasiveness, and the applicable particle sizes are not well defined. Here, in order to establish principles for efficient delivery of NPs into the cytosol with minimal cytotoxicity, the influence of the size of NPs on their electroporation and intracellular behavior is investigated.

An Optimized and Standardized Rapid Flow Cytometry Functional Method for Heparin-Induced Thrombocytopenia.

Heparin-induced thrombocytopenia (HIT) is a thrombocytopenia caused by heparin and mediated by an atypical immune mechanism leading to a paradoxical high thrombotic risk, associated with severe morbidity or death. The diagnosis of HIT combines a clinical scoring of pretest probability and laboratory testing. First-line routine tests are antigen binding assays detecting specific antibodies.

Light-Harvesting Nanoparticle Probes for FRET-Based Detection of Oligonucleotides with Single-Molecule Sensitivity.

Controlling the emission of bright luminescent nanoparticles by a single molecular recognition event remains a challenge in the design of ultrasensitive probes for biomolecules. Herein, we developed 20-nm light-harvesting nanoantenna particles, built of a tailor-made hydrophobic charged polymer poly(ethyl methacrylate-co-methacrylic acid), encapsulating circa 1000 strongly coupled and highly emissive rhodamine dyes with their bulky counterion. Being 87-fold brighter than quantum dots QDots 605 in single-particle microscopy (with 550-nm excitation), these DNA-functionalized nanoparticles exhibit over 50 % total FRET efficiency to a single hybridized FRET acceptor, a highly photostable dye (ATTO665), leading to circa 250-fold signal amplification.

Zwitterionic Stealth Dye-Loaded Polymer Nanoparticles for Intracellular Imaging.

Intracellular applications of fluorescent nanoparticles (NPs) as probes and labels are currently limited by significant molecular crowding and the high level of complexity encountered inside living cells. The solution is to develop very small, bright, and noninteracting (stealth) NPs. Combining these properties requires implementing the stealth behavior through the thinnest possible hydrophilic shell.

Controlling Size and Fluorescence of Dye-Loaded Polymer Nanoparticles through Polymer Design.

Nanoprecipitation is a straightforward yet powerful technique to synthesize polymer nanoparticles loaded with various biologically active compounds or contrast agents. Particle formation in this approach is kinetically controlled, and various assembly parameters have been used to control the size distribution and properties of the formed nanoparticles. Here, the influence of the nature of the polymer on the formation of nanoparticles in nanoprecipitation is studied systematically by varying its hydrophobicity and charge over a broad range.

Tailoring Fluorescence Brightness and Switching of Nanoparticles through Dye Organization in the Polymer Matrix.

Fluorescent nanoparticles (NPs) help to increase spatial and temporal resolution in bioimaging. Advanced microscopy techniques require very bright NPs that exhibit either stable emission for single-particle tracking or complete on/off switching (blinking) for super-resolution imaging. Here, ultrabright dye-loaded polymer NPs with controlled switching properties are developed.

Charge-controlled nanoprecipitation as a modular approach to ultrasmall polymer nanocarriers: making bright and stable nanoparticles.

Ultrasmall polymer nanoparticles are rapidly gaining importance as nanocarriers for drugs and contrast agents. Here, a straightforward modular approach to efficiently loaded and stable sub-20-nm polymer particles is developed. In order to obtain ultrasmall polymer nanoparticles, we investigated the influence of one to two charged groups per polymer chain on the size of particles obtained by nanoprecipitation.