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Abstract As the field of theranostics expands, an imminent need arises for multifaceted polymer‐based nanotechnologies for clinical application. In this work, reversible addition‐fragmentation chain transfer (RAFT) aqueous emulsion polymerization is used to form¹⁹F‐containing amphiphilic hybrid block copolymers (HBCs). Employing a cationic dendritic macromolecular chain transfer agent (mCTA), polymer frameworks comprised of chemically distinctive blocks of differing architectures (i.e., dendritic and grafted/linear) are strategically designed and synthesized. In aqueous media, self‐assembled polymer nanoparticles (PNPs) are formed. Their physicochemical properties and their potential as biomaterials for MRI applications are assessed. By showcasing a newly established mCTA and using these resulting PNPs as imaging probes, the work expands the design space of RAFT polymerization in biomedical research, paving the way for the development of more effective and versatile MRI imaging tools. 

Abstract Ionic liquids (ILs) have emerged as promising biomaterials for enhancing drug delivery by functionalizing polymeric nanoparticles (NPs). Despite the biocompatibility and biofunctionalization they confer upon the NPs, little is understood regarding the degree in which non‐covalent interactions, particularly hydrogen bonding and electrostatic interactions, govern IL‐NP supramolecular assembly. Herein, we use salt (0‐1 M sodium sulfate) and acid (0.25 M hydrochloric acid at pH 4.8) titrations to disrupt IL‐functionalized nanoassembly for four different polymeric platforms during synthesis. Through quantitative¹H‐nuclear magnetic resonance spectroscopy and dynamic light scattering, we demonstrate that the driving force of choline trans‐2‐hexenoate (CA2HA 1:1) IL assembly varies with either hydrogen bonding or electrostatics dominating, depending on the structure of the polymeric platform. In particular, the covalently bound or branched 50:50 block co‐polymer systems (diblock PEG‐PLGA [DPP] and polycaprolactone [PCl]‐poly[amidoamine] amine‐based linear‐dendritic block co‐polymer) are predominantly affected by hydrogen bonding disruption. In contrast, a purely linear block co‐polymer system (carboxylic acid terminated poly[lactic‐co‐glycolic acid]) necessitates both electrostatics and hydrogen bonding to assemble with IL and a two‐component electrostatically bound system (electrostatic PEG‐PLGA [EPP]) favors hydrogen‐bonding with electrostatics serving as a secondary role. 

Herein, we focus on the design, synthesis, and characterization of thienothiadiazole (TTD)-based near-infrared II (NIR-II) theranostic fluorophores and their nanoparticles. 

In this work, we have taken a donor–acceptor–donor (D–A–D) fluorophore ( II-EDOT-TPA ) and encapsulated it using a linear dendritic block copolymer (LDBC). In parallel, a polyethylene glycol derivative ( PEG-II-EDOT-TPA ) was synthesized. The self-assembly and colloidal properties of both nanoaggregates were comparatively assessed. Photophysical and morphological characterization of the LDBC encapsulated II-EDOT-TPA and PEG-II-EDOT-TPA nanoaggregates was performed, which showed the photophysical and morphological properties differed greatly when comparing the two. Both nanoaggregate types were incubated with HEK-293 cells in order to measure cell viability and perform confocal fluorescence microscopy. Minimal cytotoxicity values (<20%) were seen with the two nanoaggregate forms, while both types of nanoaggregates were found to accumulate into the lysosomes of the HEK-293 cells. This work provides fascinating insights into NIR fluorophore design and methods to effectively alter the photophysical and morphological properties of the nanoaggregates for bio-imaging purposes.