L-Cysteine (Cys) and glutathione (GSH) are closely related biological species that widely exist in food and living cells. To simultaneously detect Cys and GSH from different emission channels, we developed a fluorescent probe (BDP-NBD) based on near-infrared BODIPY and 7-nitrobenzofurazan (NBD). Upon nucleophilic substitution reaction with GSH, BDP-NBD generated an emission band at 713 nm, which can be used to determine GSH (0-100 μM) with a low detection limit (34 nM). Different from GSH, BDP-NBD underwent a nucleophilic substitution-rearrangement reaction with Cys, affording two emission bands at 550 nm and 713 nm, respectively. BDP-NBD was successfully employed to quantify Cys and GSH in various food samples with good recoveries (86.6%-104.6%). Besides, BDP-NBD can image Cys and GSH in living cells from two emission channels. Therefore, this work developed a tool for the simultaneous determination of Cys and GSH in both food and living cells so as to ensure food safety and human health.

Amphiphilic rod-coil compounds have excellent photophysical properties and can be assembled into supramolecular nanostructures of different sizes in water or polar solvents. Herein, we synthesized the amphiphilic compounds 2N-DSA, 4N-DSA, and 6N-DSA with 9,10-distyrylanthracene (DSA) as the core and a naphthalene unit as the terminal group that connected DSA through a tetraethylene glycol chain. These compounds have excellent aggregation-induced emission (AIE) properties in aqueous solution and are assembled into worm-like fragments or different sizes of spherical assemblies, defending the volume ratio of the rod to coil segments. Notably, the donor-acceptor interaction between DSA and electron- deficient compounds 2,4,6-trinitrophenol (TNP), 2,4,5,7-tetranitrofluorenone (TNF), and tetraethylene glycol dinitrobenzoate (TGDNB) forms a charge transfer complex, which can be used as a nanoreactor to improve the yield of the Suzuki coupling reaction about 8-10 times. The experimental results reveal that the synergy effect of the donor-acceptor, intermolecular π-π stacking, and hydrophobic-hydrophilic interactions significantly influences the morphology of aggregates and the efficiency of the nanoreactor.

Mechanochromic (MC) luminescence of organic molecules has been emerging as a promising smart material for optical recording and memory devices. At the same time, pressure-induced blue-shifted and enhanced luminescence are rarely reported now. Herein, a series of cyanostilbene-based AIEgens with different substituents were synthesized to evaluate the influence of morphology transformation and push-pull electronic effect on the MC luminescence. Among these luminophores, compound 1 with one cyano group and diethylamino group was more susceptible to mechanical stimuli and obtained blue-shifted and enhanced fluorescence in response to anisotropic grinding. Powder X-ray diffraction patterns indicated that the MC behaviors were ascribed to the solid-state morphology transition from crystal-to-crystal. Analysis of crystal structures revealed that loose molecular packing is a key factor for high high-contrast MC luminescence. The smart molecular design, together with the excellent performance, verified that luminophores with twisted structures are ideal candidates for MC luminogens.

In the present work, we described the preparation and characterization of the micelles based on amphiphilic poly(ε-caprolactone-block-ethylene glycol) block copolymer (PCL-b-PEG) loaded with non-symmetric [Pt(C^N*N'^C')] complex (Pt1) (where C^N*N'^C': 6-(phenyl(6-(thiophene-2-yl)pyridin-2-yl)amino)-2-(tyophene-2-yl)nicotinate). The obtained nanospecies displayed the ignition of near-infrared (NIR) phosphorescence upon an increase in the content of the platinum complexes in the micelles, which acted as the major emission component at 12 wt.% of Pt1. Emergence of the NIR band at 780 nm was also accompanied by a 3-fold growth of the quantum yield and an increase in the two-photon absorption cross-section that reached the value of 450 GM. Both effects are believed to be the result of progressive platinum complex aggregation inside hydrophobic poly(caprolactone) cores of block copolymer micelles, which has been ascribed to aggregation induced emission (AIE). The resulting phosphorescent (Pt1@PCL-b-PEG) micelles demonstrated pronounced sensitivity towards molecular oxygen, the key intracellular bioanalyte. The detailed photophysical analysis of the AIE phenomena revealed that the NIR emission most probably occurred due to the excimeric excited state of the 3MMLCT character. Evaluation of the Pt1@PCL-b-PEG efficacy as a lifetime intracellular oxygen biosensor carried out in CHO-K1 live cells demonstrated the linear response of the probe emission lifetime towards this analyte accompanied by a pronounced influence of serum albumin on the lifetime response. Nevertheless, Pt1@PCL-b-PEG can serve as a semi-quantitative lifetime oxygen nanosensor. The key result of this study consists of the demonstration of an alternative approach for the preparation of NIR biosensors by taking advantage of in situ generation of NIR emission due to the nanoconfined aggregation of Pt (II) complexes inside the micellar nanocarriers.

Recent years have witnessed increasingly rapid advances in nanocarrier-based biomedicine aimed at improving treatment paradigms for cancer. Nanogels serve as multipurpose and constructed vectors formed via intramolecular cross-linking to generate drug delivery systems, which is attributed predominantly to their satisfactory biocompatibility, bio-responsiveness, high stability, and low toxicity. Recently, immunotherapy has experienced unprecedented growth and has become the preferred strategy for cancer treatment, and mainly involves the mobilisation of the immune system and an enhanced anti-tumour immunity of the tumour microenvironment. Despite the inspiring success, immunotherapeutic strategies are limited due to the low response rates and immune-related adverse events. Like other nanomedicines, nanogels are comparably limited by lower focal enrichment rates upon introduction into the organism via injection. Because nanogels are three-dimensional cross-linked aqueous materials that exhibit similar properties to natural tissues and are structurally stable, they can comfortably cope with shear forces and serum proteins in the bloodstream, and the longer circulation life increases the chance of nanogel accumulation in the tumour, conferring deep tumour penetration. The large specific surface area can reduce or eliminate off-target effects by introducing stimuli-responsive functional groups, allowing multiple physical and chemical modifications for specific purposes to improve targeting to specific immune cell subpopulations or immune organs, increasing the bioavailability of the drug, and conferring a low immune-related adverse events on nanogel therapies. The slow release upon reaching the tumour site facilitates long-term awakening of the host's immune system, ultimately achieving enhanced therapeutic effects. As an effective candidate for cancer immunotherapy, nanogel-based immunotherapy has been widely used. In this review, we mainly summarize the recent advances of nanogel-based immunotherapy to deliver immunomodulatory small molecule drugs, antibodies, genes and cytokines, to target antigen presenting cells, form cancer vaccines, and enable chimeric antigen receptor (CAR)-T cell therapy. Future challenges as well as expected and feasible prospects for clinical treatment are also highlighted.

Photo-driven theranostics, also known as phototheranostics, relying on the diverse excited-state energy conversions of theranostic agents upon photoexcitation represents a significant branch of theranostics, which ingeniously integrate diagnostic imaging and therapeutic interventions into a single formulation. The combined merits of photoexcitation and theranostics endow photo-driven theranostics with numerous superior features. The applications of aggregation-induced emission luminogens (AIEgens), a particular category of fluorophores, in the field of photo-driven theranostics have been intensively studied by virtue of their versatile advantageous merits of favorable biocompatibility, tuneable photophysical properties, unique aggregation-enhanced theranostic (AET) features, ideal AET-favored on-site activation ability and ready construction of one-for-all multimodal theranostics. This review summarised the significant achievements of photo-driven theranostics based on AIEgens, which were detailedly elaborated and classified by their diverse theranostic modalities into three groups: fluorescence imaging-guided photodynamic therapy, photoacoustic imaging-guided photothermal therapy, and multi-modality theranostics. Particularly, the tremendous advantages and individual design strategies of AIEgens in pursuit of high-performance photosensitizing output, high photothermal conversion and multimodal function capability by adjusting the excited-state energy dissipation pathways are emphasized in each section. In addition to highlighting AIEgens as promising templates for modulating energy dissipation in the application of photo-driven theranostics, current challenges and opportunities in this field are also discussed.