Room Temperature Atom Transfer Radical Polymerization of Glycidyl Methacrylate Mediated by Copper(I)/N-Alkyl-2-pyridylmethanimine Complexes

Enzyme mimetic-catalyzed ATRP and its application in block copolymer synthesis combined with enzymatic ring-opening polymerization

Use of an enzyme mimetic (DhHP-6) as an ATRP catalyst for the synthesis of a series of functional polymers.

Zero valent metal/RAFT agent mediated CRP of functional monomers at room temperature: a promising catalyst system for CRP

A facile approach to synthesize GMA polymers using Fe(0)/RAFT agent mediated control radical polymerization.

Microspheres as therapeutic delivery agents: synthesis and biological evaluation of pH responsiveness

A soft template method was used for the synthesis of pH-responsive microcontainers with an inner cavity. Poly(glycidyl methacrylate) (PGMA) microspheres of narrow size distribution were synthesized by soap-free radical emulsion polymerization and the coating of the microspheres was carried out by the same procedure. The procedure consists of two steps. In the first step the sacrificial template is synthesized and in the second step the shell is formed. Acrylic acid was used as a coating monomer, with the aim of introducing pH sensitivity in the synthesized microcontainers. A loading and release study of the anthracycline drug doxorubicin (DOX) was also carried out. The toxicity evaluation of the drug was carried out using the MTT assay, and the necrotic effect was studied using trypan blue.

Surface-functionalized and surface-functionalizable poly(vinylidene fluoride) graft copolymer membranes via click chemistry and atom transfer radical polymerization

Poly(vinylidene fluoride) (PVDF) with azide-functionalized poly(glycidyl methacrylate) (PGMA) side chains (PVDF-g-P[GMA-(N3)(OH)]) were synthesized via free radical-initiated graft copolymerization of glycidyl methacrylate (GMA) from ozone-pretreated PVDF backbone (PVDF-g-PGMA), followed by reaction of the oxirane rings in the GMA side chains with sodium azide. Alkyne-functionalized poly(N-isopropylacrylamide) (alkynyl-PNIPAM), prepared a priori by atom transfer radical polymerization (ATRP), was used for the click reaction with the azido-containing PGMA side chains of the PVDF-g-P[GMA-(N3)(OH)] copolymer to give rise to the thermoresponsive PVDF-g-P[GMA-click-PNIPAM] copolymer. Both the PVDF-g-P[GMA-(N3)(OH)] and PVDF-g-P[GMA-click-PNIPAM] copolymers can be readily cast into microporous membranes by phase inversion in an aqueous medium. The PVDF-g-P[GMA-(N3)(OH)] microporous membranes with azido-containing surfaces could be further functionalized via surface click reaction with alkyne-terminated PNIPAM of controlled chain lengths to obtain the PVDF-g-P[GMA-click-PNIPAM]surface microporous membranes. The surface composition and morphology of the PVDF-g-P[GMA-click-PNIPAM] membranes can be adjusted by the temperature of casting medium, while the flux through both types of membranes exhibits thermoresponsive behavior.

Aminated linear and star-shape poly(glycerol methacrylate)s: synthesis and self-assembling properties

Over the past 10 years, polyglycerols and their structurally related analogs have received considerable attention in the biomedical field. Poly(glycidyl methacrylate) (PGMA) is a versatile polymer because its pendant epoxide groups can be opened with different functional groups to generate poly(glycerol methacrylate)s (PGOHMA) derivatives. In this work, linear and star-shape PGMAs were synthesized by atom transfer radical polymerization and then functionalized with four different amines by ring-opening addition. This resulted in the formation of polyglycerol-like polymers having both hydroxyl and amine moieties and different water-solubility. The water-insoluble polymers could form pH-sensitive nanoassemblies, while the soluble derivatives efficiently complexed a short strand polynucleotide. The aminated polyglycerol interacted more avidly with the oligonucleotide than the control poly(ethyleneimine), and high transfection efficacy could be obtained with the linear derivative. Such polymers could find practical applications for the delivery of drugs and nucleic acids.

Poly(oxazoline)s with telechelic antimicrobial functions

Poly(2-alkyl-1,3-oxazoline)s (alkyl = methyl, ethyl) with terminal quarternary ammonium groups were synthesized. It could be shown by NMR and ESI-MS that the termination of the living polymerization with N,N-dimethylalkyl(butyl to hexadecyl)amines was quantitative. The novel functions were investigated regarding their antimicrobial potential toward the bacterium Staphylococcus aureus revealing that only quarternary ammonium functions with 12 and more carbons are antibacterial. Using a novel bifunctional initiator, 3-[(tert-butoxycarbonyl)amino]benzyl-p-toluenesulfonate, poly(oxazoline) with a primary amino group at the starting end and an antimicrobial function at the terminal could be synthesized, as confirmed by NMR and ESI-MS measurements. Comparing the bioactivity of polymers with different functions at the starting end and terminated with dimethyldodecylamine revealed that the starting group has a great effect on the antibacterial properties of the distant terminal. The minimal inhibitory concentrations varied from 0.1 mM for polymer derivatives with a BOC-NH-phenyl starting group to 4 mM for poly(oxazoline)s with a free primary amine at the starting end.