AIE-Active and Thermoresponsive Alternating Polyurethanes of Bile Acid and PEG for Cell Imaging

Abstract

Alternating polyurethanes (PUs) of poly­(ethylene glycol) (PEG) and bile acids were synthesized through a single step condensation and then conjugated with a tetraphenylethene (TPE) derivative, a typical aggregation-induced emission (AIE) molecule, as chain ends. These degradable PUs showed thermo-sensitivity in water, and the phase transition temperatures can be adjusted through varying the ratios of hydrophilicity–hydrophobicity and the concentrations of the polymers. In aqueous solutions, these PUs emitted strong fluorescence, which gradually declined in intensity with increasing temperature. In the presence of γ-cyclodextrins, due to host–guest complexation of TPE units with γ-cyclodextrins, fluorescence exhibited a small decrease and then a significant increase upon heating. These PUs exhibited excellent cytocompatibility and were used for A375 cells imaging. Gradual enhancement of the green fluorescence was found mainly in the cytoplasm with increasing temperature assisted by γ-cyclodextrin. These alternating PUs provide a design for photofunctional biomaterials, such as injectable in situ drug carriers. The in vivo biocompatibility will be further evaluated.

Recent Progress in Macromolecular Design and Synthesis of Bile Acid‐Based Polymeric Architectures

“…Similarly, they have also synthesized CA and LCA derived polyurethane-based linear polymer end-locked with tetraphenylethylene (TPE). [59] The BA-based main chain polymer displayed aggregation induced emission (AIE)-and thermo-responsive behavior using 𝛾-cyclodextrin (𝛾-CD) as tuneable activity handle. Apart from pH and inclusion-based CAP crosslinking, the same research group has also reported the photo-crosslinking module of CAPs.…”

Aggregation-induced emission luminogen based self-healing hydrogels fluorescent sensors for α-amylase

“…24,25 Since Tang et al reported the aggregation-induced emission luminogens (AIEgens) in 2001, 26 the unique characteristics of AIEgens have overcome the drawbacks of ACQ, ultimately yielding high levels of fluorescence emission in the aggregated state 27–29 and making modulated fluorescence, with a high fluorescent intensity, possible. Among the AIEgens, especially the most studied tetraphenylethylene (TPE) derivatives, which as a guest could form a stable host–guest complex with γ-CD, 30,31 providing excellent convenience for preparing self-healing hydrogels with AIE behaviors. For example, the host–guest recognition between β-CD and α-bromonaphthalene was successfully incorporated into a supramolecular polymeric hydrogel to realize the emitting phosphorescence.…”

Facile Construction of Bio-Based Supramolecular Hydrogels from Dehydroabietic Acid with a Tricyclic Hydrophenanthrene Skeleton and Stabilized Gel Emulsions

“…In other words, the phase change process between the gel-sol can be controlled by heating, chemicals, ultrasound, light, electricity, oxidation/reduction, and shear stimulation, etc. [5][6][7][8][9]. These properties mean that such gels exhibit potential applications in sensing [10,11], controlled drug release [12][13][14], removal of toxic dyes [6,[15][16][17], and micro-and nanomaterial preparation [18,19].…”