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Separation of PEGylated protein mixtures into individual species is a challenging procedure, and many efforts have been focused on creating novel chromatographic supports for this purpose. In this study, a new monolithic stationary phase with hyperbranched nanostructures was chemically synthesized. For this, monoliths with a support matrix of poly (glycidyl methacrylate-co-ethylene dimethacrylate) and ethylenediamine chemistry were modified with third-generation dendrons with butyl-end groups. The new monolith was analyzed by infrared spectroscopy, confirming the dendron with butyl ligands and exhibited low mass transfer resistance as observed by breakthrough frontal analysis. This support was able to separate mono-PEG ribonuclease A from the PEGylation mixture, indicated by a single band (∼30 kDa) in the electrophoretic analysis. Moreover, the separation of mono-PEGylated positional isomers was probably observed, as the protein with ∼30 kDa was found in two separate peaks. Interestingly, the dendronized monolith allowed the separation of the reaction mixture into individual PEGylated species when using high ammonium sulfate concentrations (2 M). A correlation between the PEGylation degree and the strength of the hydrophobic interactions on the monolith was observed. This chromatographic approach combines the natural branched architecture of dendrons and the higher capabilities of the monoliths enhancing the hydrophobic surface area, and therefore the interaction between the PEGylated proteins and ligands. Thus, the novel support represents a novel platform for the purification of PEGylated from non-PEGylated proteins with biotechnological applications., (© 2023 Wiley-VCH GmbH.)

Two families of phosphorhydrazone dendrons having either an azide or an alkyne linked to the core and diverse types of pyridine derivatives as terminal functions have been synthesized and characterized. These dendrons were grafted via click reaction to graphene oxide (GO) functionalized with either alkyne or azide functions, respectively. The resulting modified-GO and GO-dendrons materials have been characterized by Fourier Transform Infrared (FTIR), Raman spectroscopy (RS), and Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) analyses. In addition, the free dendrons and the dendrons grafted to GO were tested toward cancerous (HCT116) and non-cancerous (RPE1) cell lines., (© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

The Staudinger reaction between a phosphine and an azide, applied to phosphorus azides, has been used for the synthesis of a large variety of dendritic structures, incorporating P=N-P=X moieties (X = mainly S, but also O and N-R). Conjugation of the P=N bond with the P=X bond greatly stabilizes the P=N bond. Highly branched structures such as dendrons, dendrimers, Janus dendrimers, layered dendrimers, surface-block dendrimers, and diverse other dendritic structures incorporating such linkage have been elaborated. Accelerated methods of synthesis of dendrimers are also based on the Staudinger reaction. A versatile reactivity was observed exclusively on the sulfur atom of P=N-P=S linkages, such as alkylation or complexation. Alkylation on S induces a weakening of the strength of the P=S bond, which can be easily cleaved to generate phosphines able to react in Staudinger reactions inside the structure of dendrimers, thus affording highly sophisticated dendritic structures., (© 2023 Wiley-VCH GmbH.)

Functional supramolecular gel materials have potential applications in sensors, optical switches, artificial antennae, drug delivery and so on. In this paper, quinoline-cored poly(aryl ether) dendritic organogelators were designed, synthesized and fully characterized. The gelation behaviour of the dendritic organogelator was tested in organic solvents, mixed solvents and ionic liquids. The dendron Q-G1 was found to be an efficient and versatile organogelator toward various apolar and polar organic solvents with the critical gelation concentrations (CGCs) approaching 1.2×10 -2  mol/L, indicating one dendritic organogelator could immobilize 1.2×10 3 solvent molecules in the organogel network. Interestingly, these dendrons exhibited excellent gel formation in ionic liquids. Notably, these dendritic organogels were found to display multiple stimuli-responsive properties toward external stimuli including heat, ultrasound and shear stress, with a reversible sol-gel phase transition. In addition, the dendritic organogel could effectively adsorb heavy metals and organic dyes. The removal rate of Pb 2+ was up to 20% and the adsorption rate for Rhodamine B was as high as 89%., (© 2021 Wiley-VCH GmbH.)

The construction of fullerene (C 60 ) hierarchical nanostructures with the help of amphiphilic molecules remains a challenging task in nanoscience and nanotechnology. Utilizing the host-guest complex concept, sub-10 nm layered superstructures are constructed from a monofunctionalized C 60 dendron (C 60 D, guest) and tweezer-like pyrene dendron (PD, host). Since C 60 D and PD are asymmetric shape amphiphiles having liquid crystal (LC) dendrons, both C 60 D and PD construct head-to-head bilayer superstructures by themselves. From fluorescence titration experiments, it is realized that the host-guest complex shows 1:1 stoichiometric binding with a binding constant (K sv = 2.45 × 10 5 m -1 ). Based on the morphological observations and scattering analyses, it is found that buckle-like asymmetric building blocks (C 60 D·PD) are self-assembled by the host-guest complex and construct multilayer hybrid nanostructures. The hierarchical hybrid nanostructures consist of the self-assembled C 60 D·PD bilayer with a 2D C 60 ·P nanoarray sandwiched between LC dendrons. This advanced strategy is expected to be a practicable and rational guideline for the fabrication of programmed hierarchical hybrid nanostructures., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)