ATRP can be performed in untreated water without addition of halide salts, with no deleterious effect on the polymerization control.

Thiourea dioxide, a green and inexpensive compound used at industrial scale, was employed as reducing agent for the controlled polymerization of a wide range of monomer families, namely, acrylates (methyl acrylate, 2-hydroxyethyl acrylate, butyl acrylate, methacrylates (2-(dimethylamino)­ethyl methacrylate, 2-aminoethyl methacrylate hydrochloride, and methyl methacrylate), styrene, acrylonitrile, and vinyl chloride (nonactivated monomer) by ATRP. Mechanistic studies confirmed that the polymerizations are ruled by the activators regenerated by electron transfer (ARGET) mechanism. It is worth noting that vinyl chloride has never been polymerized by ARGET ATRP. The system proved to be very versatile and robust, working in organic solvents, organic/water mixtures, and aqueous medium at near room temperature with low metal catalyst concentration. Chain extension experiments confirmed the high chain-end functionality of the polymers, allowing the preparation of several well-defined block copolymers.

The cellular surface contains specific proteins, also known as lectins, that are carbohydrates receptors involved in different biological events, such as cell–cell adhesion, cell recognition and cell differentiation. The synthesis of well-defined polymers containing carbohydrate units, known as glycopolymers, by reversible deactivation radical polymerization (RDRP) methods allows the development of tailor-made materials with high affinity for lectins because of their multivalent interaction. These polymers are promising candidates for the biomedical field, namely as novel diagnostic disease markers, biosensors, or carriers for tumor-targeted therapy. Although linear glycopolymers are extensively studied for lectin recognition, branched glycopolymeric structures, such as polymer brushes can establish stronger interactions with lectins. This specific glycopolymer topology can be synthesized in a bottlebrush form or grafted to/from surfaces by using RDRP methods, allowing a precise control over molecular weight, grafting density, and brush thickness. Here, the preparation and application of glycopolymer brushes is critically discussed and future research directions on this topic are suggested.

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