AIE-Active Tetraphenylethylene Cross-Linked N-Isopropylacrylamide Polymer: A Long-Term Fluorescent Cellular Tracker

Abstract

There is a great demand to understand cell transplantation, migration, division, fusion, and lysis. Correspondingly, illuminant object-labeled bioprobes have been employed as long-term cellular tracers, which could provide valuable insights into detecting these biological processes. In this work, we designed and synthesized a fluorescent polymer, which was comprised of hydrophilic N-isopropylacrylamide polymers as matrix and a hydrophobic tetraphenylethene (TPE) unit as AIE-active cross-linkers (DDBV). It was found that when the feed molar ratio of N-isopropylacrylamides to cross-linkers was 22:1, the produced polymers demonstrated the desirable LCST at 37.5 °C. And also, the temperature sensitivity of polymers could induce phase transfer within a narrow window (32-38 °C). Meanwhile, phase transfer was able to lead the florescent response. And thus, we concluded that two responses occur when one stimulus is input. Therefore, the new cross-linker of DDBV rendered a new performance from PNIPAm and a new chance to create new materials. Moreover, the resulted polymers demonstrated very good biocompatibility with living A549 human lung adenocarcinoma cells and L929 mouse fibroblast cells, respectively. Both of these cells retained very active viabilities in the concentration range of 7.8-125 μL/mg of polymers. Notably, P[(NIPAm)22-(DDBV)1] (P6) could be readily internalized by living cells with a noninvasive manner. The cellular staining by the fluorescent polymer is so indelible that it enables cell tracing for at least 10 passages.

Aggregation‐Induced Emission: Lighting up Cells, Revealing Life!

“…This suggests that TPE‐CS is an excellent candidate for long‐term cell tracing. In addition, based on the temperature‐sensitive characteristics of polymers, two kinds of temperature‐sensitive AIE‐based fluorescent probes, TPE‐PNIPAM and TPE‐PNIPAm, have been developed and applied for long‐term cell tracing. For example, Zhang et al have reported temperature‐sensitive NPs made from self‐assembly of TPE‐PNIPAM in water (Figure d) .…”

Novel AIEgen-Functionalized Diselenide-Crosslinked Polymer Gels as Fluorescent Probes and Drug Release Carriers

“…In 2016, Ishiwari et al introduced TPE molecules into polyacrylic acid hydrogels, showing enhanced fluorescence emission after adding Ca 2+ due to significant chain folding thereof [22]. Later, in the same Polymers 2020, 12, 551 2 of 12 year, Lei et al designed temperature-responsive polymer gels, whose fluorescence switch was driven by a combination of poly(N-isopropylacrylamide) (PNIPAm) and the AIE effect [23].…”

Synthesis of π-conjugated network polymers based on triphenylamine (TPA) and tetraphenylethylene (TPE) as building blocks via direct Pd-catalyzed reactions and their application in CO2 capture and explosive detection

“…18,19 As a result, molecular rotations can be restrained to some extent; this leads to more emissive polymers not only in the powder but also in the solution state. 20,21 Therefore, polymerization-promoted AIE systems have been designed and developed in recent years. [22][23][24][25] By integrating the desirable AIE feature with conjugated polymer characteristics, attractive materials could be generated.…”