0000000000725243
AUTHOR
Roland H. Staff
Fluorescence Correlation Spectroscopy in Dilute Polymer Solutions: Effects of Molar Mass Dispersity and the Type of Fluorescent Labeling
Fluorescence correlation spectroscopy (FCS) has become an important tool in polymer science. Among various other applications the method is often applied to measure the hydrodynamic radius and the degree of fluorescent labeling of polymers in dilute solutions. Here we show that such measurements can be strongly affected by the molar mass dispersity of the studied polymers and the way of labeling. As model systems we used polystyrene and poly(methyl methacrylate) synthesized by atom transfer radical polymerization or free-radical polymerization. Thus, the polymers were either end-labeled bearing one fluorophore per chain or side-labeled with a number of fluorophores per chain proportional to…
Chemical Routes Toward Multicompartment Colloids
The search for mimicking natural living and non-living systems with synthetic products leads to the fabrication of advanced colloidal morphologies with hierarchical micro- and nanostructures. Different chemical routes toward the synthesis of colloids with complex morphologies are presented and a tentative analogy between these routes and the four basic arithmetic operations is proposed.
HPMA-based block copolymers promote differential drug delivery kinetics for hydrophobic and amphiphilic molecules.
Abstract We describe a method how polymeric nanoparticles stabilized with (2-hydroxypropyl)methacrylamide (HPMA)-based block copolymers are used as drug delivery systems for a fast release of hydrophobic and a controlled release of an amphiphilic molecule. The versatile method of the miniemulsion solvent-evaporation technique was used to prepare polystyrene (PS) as well as poly-d/l-lactide (PDLLA) nanoparticles. Covalently bound or physically adsorbed fluorescent dyes labeled the particles’ core and their block copolymer corona. Confocal laser scanning microscopy (CLSM) in combination with flow cytometry measurements were applied to demonstrate the burst release of a fluorescent hydrophobic…