The generation of dendrimers is a powerful tool in the control of the size and biodistribution of polyion complexes (PIC). Using a combinatorial screening of six dendrimers (18-243 terminal groups) and five oppositely charged PEGylated copolymers, a dendrimer-to-PIC hierarchical transfer of structural information was revealed with PIC diameters that increased from 80 to 500 nm on decreasing the dendrimer generation. This rise in size, which was also accompanied by a micelle-to-vesicle transition, is interpreted according to a cone- to rod-shaped progression in the architecture of the unit PIC (uPIC). This precise size tuning enabled dendritic PICs to act as nanorulers for controlled biodistribution. Overall, a domino-like control of the size and biological properties of PIC that is not attainable with linear polymers is feasible through dendrimer generation.

The interaction of two anthocyaninsw ith aw atersoluble polyanionic dendrimerw as studied through UV/Vis, stopped-flow,a nd NMR spectroscopy. Cyanidin-3-glucoside (cy3glc)r evealed as tronger interactiont han malvidin-3-glucoside (mv3glc) at pH 1a ccording to their apparent association constants. Ah igher color increased was also obtained for cy3glca tp H3.5 as ar esult of this strongeri nteraction.A high-frequency chemical shift of the cy3glc aromatic protons suggest the formation of ionic pairs. The interaction parame-ters (K % 700 m À1 , n % 295) indicated the binding of approximately two anthocyanin molecules by each sulfate group. The equilibriuma nd ratec onstantso fc y3glc in the presence of dendrimer showed an increased stability of the flavylium cationand ahigher protectiono fthis speciesf rom hydration (pK' a and pK h increased almost one pH unit).T he tuning and color stabilizationo fa nthocyanins by using this dendrimer allow novel applications as colorimetric sensors for food packaging.[a] L. Cruz, N. Mateus,V .d eFreitas Supporting Information and the ORCID identification number(s) for the author(s) of this articlecan be found under: https://doi.

Multivalency is a widely occurring natural phenomenon often exploited in nanotechnology to enhance biorecognition. We report the preparation and characterization of versatile, multivalent Affitin-dendrimer conjugates (Affidendrons) showcased by a set targeting Staphylococcus aureus (S. aureus), an opportunistic pathogen causing numerous hospital-and community-acquired infections. Affitins are small affinity proteins characterized by higher stability and lower cost-effective production than antibodies. The strategy presented provides a platform for the rational design of multivalent nanodevices that, retaining the ability of Affitins to recognize their target with high specificity, achieve a largely enhanced affinity. Affidendrons with precisely designed size and valency have been exploited to modulate complex multicellular behaviors of S. aureus, such as agglutination and biofilm formation. Agglutination assays showed that Affidendrons rapidly cross-link S. aureus strains with high bacterial cell selectivity. Moreover, remarkably low concentrations of Affidendrons were able to effectively prevent biofilm formation. Overall, Affidendrons represent a promising platform for the rapid and selective pathogen identification, infection imaging, and theranostic applications.