A Novel Water-Soluble Fluorescence Probe with Wash-Free Cellular Imaging Capacity Based on AIE Characteristics

Triphenylamine-equipped 1,8-naphthaolactam: a versatile scaffold for the custom design of efficient subcellular imaging agents

Fluorescence imaging has enabled much progress in biological fields, while the evolution of commercially available dyes has lagged behind their advanced applications. Herein, we launch triphenylamine-equipped 1,8-naphthaolactam (NP-TPA) as a versatile scaffold for the custom design of an efficient subcellular imaging agent (NP-TPA-Tar), given its bright and constant emissions in various states, significant Stokes shifts, and facile modifiability. The resultant four NP-TPA-Tars maintain excellent emission behavior with targeted modifications and can map the spatial distribution of lysosomes, mitochondria, endoplasmic reticulum, and plasma membrane in Hep G2 cells. Compared to its commercial counterpart, NP-TPA-Tar has a 2.8-25.2 fold increase in Stokes shift, a 1.2-1.9 fold increase in photostability, enhanced targeting capability, and comparable imaging efficiency even at low concentrations of 50 nM. This work will help to accelerate the update of current imaging agents and super-resolution and real-time imaging in biological applications.

Self-healing hydrogel with cross-linking induced thermo-response regulated light emission property

With increasing attention paid to smart materials, self-healing hydrogels with thermo-responses have been greatly developed in the past several years. At the same time, fluorescent or light emitting polymers have been studied for use as bioimaging tools and drug delivery vehicles. In this research, thermo-responsive self-healing hydrogels with aggregation-induced emission (AIE) property were prepared from tetraphenylethylene (TPE) containing TPE-poly(N,N-dimethylacrylamide-stat-Diacetone acrylamide) [TPE-P(DMA-stat-DAA)] cross-linked by diacylhydrazide. In addition to self-healing based on reversible acylhydrazone bond, the copolymer and hydrogels showed thermo-responses. The lower critical solution temperature (LCST) of the hydrogels was regulated to body temperature. Based on the AIE property of the TPE unit, the hydrogels showed an enhanced light emitting property above the LCST, which was regulated by temperature change. The in vitro cytotoxicity experiment showed that the hydrogels are not toxic, and the DOX release rate can be enhanced by low pH values, which endowed this kind of thermo-responsive light emitting hydrogel with great potential for applications in bio-diagnosis, drug delivery, artificial organs with light sensitive detection, etc.

Temperature-regulated aggregation-induced emissive self-healable hydrogels for controlled drug delivery

Thermoresponsive copolymers TPE-[P(DMA-stat-DAA)]₂ containing a tetraphenylethylene (TPE) moiety and a ketone group were synthesized.

Ca2+ Induced Crosslinking of AIE-Active Polyarylene Ether Nitrile into Fluorescent Polymeric Nanoparticles for Cellular Bioimaging

Biocompatible fluorescent polymeric nanoparticles (FPNs) are promising luminescent probes in cellular bioimaging, while the fabrication of high-quantum-yield FPN using nonconjugated heterochain polymers derived from step-growth polymerization is still in its infancy. Herein, the nonconjugated polyarylene ether nitrile (PEN) is endowed with aggregation-induced emission (AIE) feature by incorporation of an AIEgen named of 1,2-di(4-hydroxyphenyl)-1,2-diphenylethene into macromolecular backbone. Furthermore, the AIE-active PEN is crosslinked into water soluble fluorescent nanospheres showing good biocompatibility and strong emission ≈480 nm with a quantum yield of 21% in the presence of Ca²⁺ , which allows the successful bioimaging of cancer cells. Due to the facile fabrication of FPNs and their effective bioimaging performance, the current work will open the way for the biomedical applications of various high performance polyarylene ethers.