An acrylate AIE-active dye with a two-photon fluorescent switch for fluorescent nanoparticles by RAFT polymerization: synthesis, molecular structure and application in cell imaging

Visualization and correlation of drug release of risperidone/clozapine microspheres in vitro and in vivo based on FRET mechanism

This study addresses the challenging task of quantitatively investigating drug release from PLGA microspheres after in vivo administration. The objective is to employ Förster resonance energy transfer (FRET) to visualize drug-encapsulated microspheres in both in vitro and in vivo settings. The primary goal is to establish a quantitative correlation between FRET fluorescence changes and microsphere drug release. The study selects drugs with diverse structures and lipid solubility to explore release mechanisms, using PLGA as the matrix material. Clozapine and risperidone serve as model drugs. FRET molecules, Cy5 and Cy5.5, along with Cy7 derivatives, create FRET donor-acceptor pairs. In vitro results show that FRET fluorescence changes align closely with microsphere drug release, particularly for the Cy5.5-Cy7 pair. In vivo experiments involve subcutaneous administration of microspheres to rats, tracking FRET fluorescence changes while collecting blood samples. Pharmacokinetic studies on clozapine and risperidone reveal in vivo absorption fractions using the Loo-Riegelman method. Correlating FRET and in vivo absorption data establishes an in vitro-in vivo relationship (IVIVR). The study demonstrates that FRET-based fluorescence changes quantitatively link to microsphere drug release, offering an innovative method for visualizing and monitoring release in both in vitro and in vivo settings, potentially advancing clinical applications of such formulations.

AIE-active macromolecules: designs, performances, and applications

Aggregation-induced emission (AIE) macromolecules as emerging luminescent materials gained increasing attention owing to their good processability, high brightness, wide functionality, and smart responsiveness, with great potential in many fields.

Investigation on dyeing mechanism of modified cotton fiber

Cotton fabrics have been chemically modified with two cationic compounds. They were 3-chloro-2-hydroxypropyltrimethylammonium chloride and the copolymer of dimethyl diallyl ammonium chloride and allyl glycidyl ether, respectively. Under the conditions of no inorganic salt, two modified cotton fabrics were dyed with reactive dyes. The dyeing mechanism of two modified cotton fabrics was investigated in comparison with traditional dyeing of untreated cotton fabrics. It involved the adsorption type, adsorption thermodynamics, and adsorption kinetics between reactive dyes and modified cotton fabrics in the dyeing process. The color-fixing process of modified cotton fibers was also studied in detail. The results showed that there were obvious distinctions between the salt-free dyeing mechanism of modified cotton fabrics and traditional dyeing of untreated cotton fabrics. The adsorption isotherm model of the two modified cotton fabrics conformed to the Langmuir-model. The kinetic model of two modified cotton fabrics conformed to the pseudo-second-order kinetic model. The adsorption of modified cotton fabrics was an endothermic process. The adsorption of unmodified cotton fabrics was an exothermic process. These will serve as a theoretical basis of the industrial production of salt-free dyeing of modified cotton fiber.

In this investigation, the dyeing mechanism of cotton fibers was investigated through adsorption isotherm, adsorption thermodynamics, adsorption kinetics, activation energy, diffusion coefficient, half-dyeing time and process of fixation.

Fabrication and characterization of structurally stable pH-responsive polymeric vesicles by polymerization-induced self-assembly

Smart polymeric vesicles with both tertiary amine and epoxy functional groups were fabricated for the first time via a reversible addition–fragmentation chain transfer dispersion polymerization approach, using (2-(diisopropylamino)ethyl methacrylate (DIPEMA) and glycidyl methacrylate (GlyMA) in an ethanol–water mixture. Monitoring of the in situ polymerization revealed the low molecular weight distributions and the intermediate structures of spheres and worms, indicating an evolution in particle morphology. A phase diagram was constructed for reproducible fabrication of the vesicles, and copolymer composition was found to be more related to particle morphology. The vesicles exhibited superior structural stability for the cross-linking of the core through epoxydiamine chemistry, and intelligent pH responsibility due to the presence of the tertiary amine groups. The cross-linked vesicles showed good stability and reversibility during the swelling and shrinking cycles by switching the pH values, which endowed them with potential cell-like transmission functions. This research thus provides a method for producing structurally stable pH-responsive polymeric vesicles, and the reported vesicles are based on commercially available starting materials for possible industrial scale-up.

Smart polymeric vesicles with both tertiary amine and epoxy functional groups were fabricated for the first time via a reversible addition–fragmentation chain transfer dispersion polymerization approach.