Loading and Release of Charged and Neutral Fluorescent Dyes into and from Mesoporous Materials: A Key Role for Sensing Applications

The aim of this study is to determine the efficiency of loading and release of several zwitterionic, neutral, anionic and cationic dyes into/from mesoporous nanoparticles to find the optimum loading and release conditions for their application in detection protocols. The loading is carried out for MCM-41 type silica supports suspended in phosphate-buffered saline (PBS) buffer (pH 7.4) or in acetonitrile, involving the dyes (rhodamine B chloride, rhodamine 101 chloride, rhodamine 101 perchlorate, rhodamine 101 inner salt, meso-(4-hydroxyphenyl)-boron–dipyrromethene (BODIPY), sulforhodamine B sodium salt and fluorescein 27). As a general trend, rhodamine-based dyes are loaded with higher efficiency, when compared with BODIPY and fluorescein dyes. Between the rhodamine-based dyes, their charge and the solvent in which the loading process is carried out play important roles for the amount of cargo that can be loaded into the materials. The delivery experiments carried out in PBS buffer at pH 7.4 reveal for all the materials that anionic dyes are more efficiently released compared to their neutral or cationic counterparts. The overall best performance is achieved with the negatively charged sulforhodamine B dye in acetonitrile. This material also shows a high delivery degree in PBS buffer.

Photoredox Halogenation of Quinolones: Dual Role of Halo-fluorescein Dyes

An efficient C-3 halogenation of quinolin-4-ones is reported with halogenated fluorescein dyes which serve both as halogen source and photocatalyst. The reaction shows broad substrate scope and gives good to...

Persistent Prolate Polymersomes for Enhanced Co-Delivery of Hydrophilic and Hydrophobic Drugs

Self-assembled polymersomes encapsulate, protect, and deliver hydrophobic and hydrophilic drugs. Though spherical polymersomes are effective, early studies suggest that non-spherical structures may enhance specificity of delivery and uptake due to similarity to endogenous uptake targets. Here we describe a method to obtain persistent non-spherical shapes, prolates, via osmotic pressure and the effect of prolates on uptake behavior. Polyethylene glycol-b-poly(lactic acid) polymersomes change in diameter from 175 ± 5nm to 200 ± 5nm and increase in polydispersity from 0.06 ± 0.02 to 0.122 ± 0.01 nm after addition of 50 mM salt. Transmission and scanning electron microscopy confirm changes from spheres to prolates. Prolate-like polymersomes maintain their shape in 50 mM NaCl for seven days. Nile Red and bovine serum albumin(BSA)-Fluorescein dyes are taken up in greater amounts by SH-SY5Y neural cells when encapsulated in polymersomes. Prolate polymersomes may be taken up more efficiently in neural cells than spherical polymersomes.

Near-infrared fluorescein dyes containing a tricoordinate boron atom

Tricoordinate boron imparts near-infrared absorption/emission and unusual multi-stage changes in the photophysical properties to fluorescein dyes.

Phosphinate-containing rhodol and fluorescein scaffolds for the development of bioprobes

A series of phosphinate-containing rhodol and fluorescein dyes are disclosed.

Hyperbranched poly(ether amine) nanomicelles as nanoreactors for the unexpected ultrafast photolysis of fluorescein dyes

hPEA nanomicelles can encapsulate fluorescein dyes as a nanoreactor, leading to the fast photobleaching of dyes.

Synthesis of seminaphtho-phospha-fluorescein dyes based on the consecutive arylation of aryldichlorophosphines

Seminaphtho-phospha-fluorescein, a phosphine oxide-containing unsymmetric fluorescein dye with NIR fluorescence, was synthesized based on the consecutive arylation of PhPCl2.