Edmondo Benetti: God Made the Bulk: the Surface was invented by the Devil - Topological Evolution of Polymer Interfaces

The application of distinctive polymer topologies, beyond the simple linear chain, to yield cyclic and loops-forming surface-grafted assemblies, enables a broad modulation of highly relevant, interfacial physicochemical properties. This is especially valid on flat surfaces, where the ultra-dense and highly compact character of cyclic polymer "brushes" provide an enhanced steric stabilization and a superlubricious behavior [1]. The improvement in interfacial properties granted by cyclic polymer grafts can be thus exploited to molecularly design copolymers capable of passivating the surface of articular cartilage and restoring its natural lubricating functions, in order to halt degenerative diseases such as osteoarthritis (OA) [2,3].

Alternatively, when cyclic brushes form shells on inorganic nanoparticles (NPs), their exceptional structural properties make them impenetrable and long-lasting shields, which extend the stability of NP dispersions and hinder any interaction with serum proteins [4].

Polymer topology effects, typically observed in bulk or in solution are amplified by adding an additional boundary such as a grafting surface. Their precise tuning translates into materials with unprecedented properties and extremely high applicability.