Janus-Type Dendrimers Based on Highly Branched Fluorinated Chains with Tunable Self-Assembly and ¹⁹F Nuclear Magnetic Resonance Properties

Abstract

Tuning the self-assembly of dendritic amphiphiles represents a major challenge for the design of advanced nanomaterials for biomimetic applications. The morphology of the final aggregates, in fact, critically depends on the primary structure of the dendritic building blocks as well as the environmental conditions. Here we report a new family of fluorinated Janus-type dendrimers (FJDs), based on a short-chain and branched fluorinated synthon with 27 magnetically equivalent fluorine atoms, linked to bis-MPA polyester dendrons of different generations. Increasing size, flexibility, and number of peripheral hydroxyl groups, we observed a peculiar self-assembly behavior in bulk and in aqueous media as a consequence of the subtle balance between their fluorinated and hydrophilic portions. The lowest generation FJDs formed spherical nanoparticles in water, e.g., micelles, showing a single 19 F NMR peak with good signal-to-noise ratio and over time stability, making them promising as 19 F-MRI traceable probes. The highest generation FJD, instead, presented an interesting morphological transition from multilamellar dendrimersomes to tubules as a consequence of a subtle balance of intraand intermolecular forces that compete at the interface. Interestingly, a reduction of the local mobility of CF 3 groups passing from dendrimersomes to tubules switches off the 19 F NMR signal. The transition mechanism has been rationalized by coarse-grain simulations as well as demonstrated by using cosolvents of different nature (e.g., fluorinated) that promote conformational changes, ultimately reflected in the self-assembly behavior. Short and branched fluorinated chains have here been demonstrated as new moieties for the design of FJDs with tunable self-assembly behavior for potential applications as biocompatible 19 F MRI probes in the construction of theranostic platforms.

Triazine Dendrimers: An Excellent Drug Carrier for Improving the Solubility of Glyburide an Antidiabetic Agent

“…For NMR studies, 5 mg of dendrimers were pipetted out using pasture pipette in NMR tube and mixed with 1ml of D2O solvent. The 1 H NMR studies was performed at 500 MHz, whereas 13 C NMR at 125 MHz using Bruker Avence NEO [40].…”

“…NMR is one of the most preferred technique for complete structural elucidation of organic molecules[40]. The carbon NMR spectroscopic patterns of G1, G2 and G3 dendrimers are depicted in Fig.2.6 -2.8.…”

Synthesis and Linker‐Controlled Self‐Assembly of Dendritic Amphiphiles with Branched Fluorinated Tails

“…As an additional benefit, this building block exhibits lower lipophilicity and lower bioaccumulation. [ 33–40 ]…”

“…As an additional benefit, this building block exhibits lower lipophilicity and lower bioaccumulation. [33][34][35][36][37][38][39][40] In this work, we attempt to use the branched perfluoroalkyl group F27 in studies of the supramolecular self-assembling behavior of dendritic amphiphiles with oligoglycerol head group (G2). We wanted to learn if the bulky F27 block could impose diverging nanostructures as compared to the linear perfluoroalkyls reported previously.…”

Multibranched-Based Fluorinated Materials: Tailor-Made Design of 19F-MRI Probes

“…PERFECTA can easily be dispersed in physiological media through formulation with biocompatible additives, and the presence of ethereal bonds may hasten for enhanced biodegradability . Moreover, PERFECTA’s scaffold can be modified for producing partially fluorinated macromolecules with different topologies and features , (such as biodegradable polyesters and dendrimers), increasing system functionality (such as nanoparticles and surfaces functionalization), and producing novel derivatives with improved features such as solubility and degradation (Figure ).…”