Stimuli-responsive Magnetic Nanohybrids for Triggered Drug Release and Potential Tumor Treatment via Hyperthermia

Poster (2012, September 13)

see attachment

Synthetic and mechanistic advances in the cobalt-mediated radical polymerization of N-vinyl amides

Conference (2012, May 28)

see the pdf file

Stimuli-responsive magnetic nanohybrids designed for controlled drug release application

Conference (2012, May 10)

Stimuli-responsive organic/inorganic nanohybrids, with an inorganic core and a polymer coating, have been frequently suggested as a promising vehicle for drug or gene delivery and also controlled release ... [more ▼]

Stimuli-responsive organic/inorganic nanohybrids, with an inorganic core and a polymer coating, have been frequently suggested as a promising vehicle for drug or gene delivery and also controlled release, due to their outstanding biocompatibility, versatile surface modification, specific responsive properties to external stimuli, and so on. Magnetic nanoparticles have various applications in biomedical filed, such as magnetic resonance imaging, biosensors, magnetic separation, drug release, hyperthermia therapy and so on. Poly (acrylic acid) copolymers exhibit a sharp conformation transition when exposed to external change in pH. The PAA copolymer was used to form a polymer shell outside the magnetic core, a cationic dye was uploaded by electro-static interaction. The controlled release was achieved by tuning the external pH value. Magnetic/SiO2 mesoporous nanoparticles were prepared as another drug vehicle, in order to obtain a higher drug loading amount. Crystalline molecules were utilized as a gate keeper to control the release of drugs uploaded. [less ▲]

Synthesis of thermo-responsive poly(N-vinylcaprolactam)-containing block copolymers by cobalt-mediated radical polymerization

in Journal of Polymer Science. Part A, Polymer Chemistry (2012), 50(2), 400-408

Thermo-responsive block copolymers based on poly(N-vinylcaprolactam) (PNVCL) have been prepared by cobalt-mediated radical polymerization (CMRP) for the first time. The homopolymerization of NVCL was ... [more ▼]

Thermo-responsive block copolymers based on poly(N-vinylcaprolactam) (PNVCL) have been prepared by cobalt-mediated radical polymerization (CMRP) for the first time. The homopolymerization of NVCL was controlled by bis(acetylacetonato)cobalt(II) and a molecular weight as high as 46,000 g/mol could be reached with a low polydispersity. The polymerization of NVCL was also initiated from a poly(vinyl acetate)-Co(acac)2 (PVAc-Co(acac)2) macroinitiator to yield well-defined PVAc-b-PNVCL block copolymers with a low polydispersity (Mw/Mn = 1.1) up to high molecular weights (Mn = 87,000 g/mol), which constitutes a significant improvement over other techniques. The amphiphilic PVAc-b-PNVCL copolymers were hydrolyzed into unprecedented double hydrophilic poly(vinyl alcohol)-b-PNVCL (PVOH-b-PNVCL) copolymers and their temperature-dependent solution behavior was studied by turbidimetry and dynamic light scattering. Finally, the so-called cobalt-mediated radical coupling (CMRC) reaction was implemented to PVAc-b-PNVCL-Co(acac)2 precursors to yield novel PVAc-b-PNVCL-b-PVAc symmetrical triblock copolymers. [less ▲]

Preparation and characterization of thermo-responsive gold nanohybrids

Poster (2011, October 25)

Stimuli-responsive nano-materials have been playing increasingly important roles in the biomedical field due to their ability to alter the physico-chemical properties in response to external stimuli, such ... [more ▼]

Stimuli-responsive nano-materials have been playing increasingly important roles in the biomedical field due to their ability to alter the physico-chemical properties in response to external stimuli, such as temperature, pH, ionic strength, magnetic field, etc. Nanohybrids bearing an inorganic core and thermo-responsive polymer shell are particularly applicable in target delivery and controlled drug release. Poly (N-vinylcaprolactam) (PNVCL) and its copolymers, exhibiting lower critical solution temperature (LCST) where the transition between hydrophilic and hydrophobic state happens, is one of the optimal choices for this core/shell structure. Here we present the in-situ fabrication of thermo-responsive gold nanohybrids coated with a novel poly(vinyl alcohol)-b-poly(N-vinylcaprolactam) (PVOH-b-PNVCL) block copolymer prepared by the cobalt-mediated radical polymerization (CMRP). The interaction between both PVOH and PNVCL segments and gold nanoparticles was confirmed by FT-IR spectra. A sharp thermo-induced phase transition with a good reversibility upon change in temperature was detected by DLS and UV/vis spectrometer. Furthermore, the presence of hydrophilic PVOH moieties endows the gold nanohybrids with improved colloidal stability above LCST without any flocculation detected, compared with the gold nanoparticles stabilized with PNVCL homopolymer. This kind of gold nanohybrids can be envisaged as a new drug delivery vehicle. [less ▲]

Magnetic hybrid materials for triggered drug delivery and optical properties of intraocular lens

Conference (2011, March 15)