Synthesis of Dendronized Poly(l-Glutamate) via Azide-Alkyne Click Chemistry

Novel Amphiphilic Dendronized Copolymers Formed by Enzyme-Mediated "Green" Polymerization

This study reports the first enzyme-mediated polymerization of dendritic macromonomers. The enzyme substrates are prepared by "click" conjugation between tyrosine and hydrophilic triethylene glycol (TrEG)-based dendrons of three generations (G1, G2, and G3). The resulting enzyme-polymerizable dendrons are defect-free as revealed by mass spectrometry, size-exclusion chromatography, and spectroscopic techniques. The phenol-containing macromonomers are water soluble and their polymerizations into dendronized polymers (denpols) are catalyzed by laccase (an oxidoreductase) under benign conditions (45 °C and aqueous medium at pH = 4.0) with copolymer yields between 30 and 40%. The resulting denpols consist of unnatural poly(tyrosine) backbones and dendritic poly(ether-ester) side chains and have molecular masses up to ∼13 000 Da (generation 1), ∼20 000 Da (generation 2), and ∼36 000 Da (generation 3) determined by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) analyses. They display amphiphilic properties and self-assemble in aqueous solutions to form aggregates with generation-dependent morphologies.

Multifunctional Nanomaterials: Design, Synthesis and Application Properties

The immense scope of variation in dendritic molecules (hyper-branching, nano-sized, hydrophobicity/hydrophilicity, rigidity/flexibility balance, etc.) and their versatile functionalization, with the possibility of multivalent binding, permit the design of highly improved, novel materials. Dendritic-based materials are therefore viable alternatives to conventional polymers. The overall aim of this work is to show the advantages of dendronization processes by presenting the synthesis and characterization of three different dendronized systems: (I) microbeads of functionalized chitosan; (II) nanostructuration of polypropylene surfaces; and (III) smart dendritic nanogels. The particular properties yielded by these systems could only be achieved thanks to the dendronization process.