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The development of near-infrared (NIR) J-aggregates has received increasing attention due to their broad applications. Here, we report the nitrosation of an amine-containing aza-BODIPY precursor (BDP-NH

Carbon monoxide (CO) has emerged as a potential therapeutic agent for the treatment of many diseases. However, the therapeutic outcome is highly dependent on the dosages and administration sites. Hence, there is mounting interest in the development of CO-releasing materials to accomplish site-specific and dose-controlled delivery of CO. Herein, a micellar nanoparticle platform for the photo-mediated release of CO by using amphiphilic triblock copolymers bearing CO-releasing moieties of 3-hydroxylflavone (3-HF) derivatives within the middle blocks is developed. These micelles are relatively stable without CO leakage but undergo visible light-mediated CO release and simultaneous main chain scission. Moreover, these micellar nanoparticles are cytocompatible regardless of light irradiation, which shows unique anti-inflammatory performance only after light irradiation as a result of photo-triggered CO release. This work may represent the first example of main-chain degradable micellar nanocarriers with controlled CO-releasing performance for potential anti-inflammatory applications.

The development of portable and inexpensive detection methods can significantly contribute to the prevention of water-borne infectious diseases caused by pathogenic bacteria. Here we designed a nanosystem capable of both bacterial detection and inhibition, where polyion complex (PIC) micelles are constructed from negatively-charged tetraphenylethylene (TPE) sulfonate derivatives, which exhibit the aggregation-induced emission (AIE) feature, and cationic diblock copolymers, poly(ethylene oxide)-b-quaternized poly(2-(dimethylamino)ethyl methacrylate) (PEO-b-PQDMA). Upon contacting with bacteria, the PIC nanosystem disintegrates presumably due to competitive binding of polycation blocks with negatively-charged bacterial surfaces. This process is accompanied by a conspicuous quenching of TPE fluorescence emission, serving as a real-time module for microbial detection. Furthermore, the sharp decrease in CFU is indicative of prominent anti-microbial activities. Thus, PIC micelles possess dual functions of fluorometric detection and inhibition for bacteria in aqueous media. By tuning the charge density of TPE sulfonate derivatives and chain length of cationic PQDMA blocks, optimal performance against Gram-negative Escherichia coli has been achieved with a detection limit of 5.5 × 10(4) CFU/mL and minimum inhibitory concentration (MIC) of 19.7 μg/mL. Tests against Gram-positive Staphylococcus aureus were also conducted to demonstrate versatility of the nanosystem.

Endosomal escape is of crucial importance to increase the therapeutic efficacy for nanoparticle-based drug and gene delivery. It has been long presumed that pH-responsive polymeric nanocarriers are potent in aiding endosomal escape due to the "proton sponge" effect; however, the intracellular pH (pHi) gradients subjected by pH-responsive nanocarriers during endocytic and endosomal escaping processes remain to be quantified and elucidated. We herein report the fabrication of ultrasensitive ratiometric fluorescent pHi imaging probes with robust endosomal escaping capability derived from dual dye-labeled pH-responsive block copolymers, which can directly monitor endosomal escape in living cells and quantitatively measure pHi variations during the entire endocytic and endosomolytic processes. Micellar nanoparticle-based pHi sensors could be efficiently internalized into cells via endocytosis where micelle-to-unimer transition occurs, followed by endosomal escape into the cytosol. This process is accompanied by deactivation of blue coumarin emission within acidic organelles and restored blue/red dual emissions within the neutral cytosolic milieu, allowing for ratiometric fluorescent imaging of entire pHi gradients subjected by micellar nanoparticles following the endocytic transport pathway.

Core cross-linked (CCL) polymeric micelles covalently labeled with DOTA(Gd) and green- emitting NBD fluorophores within pH-responsive cores are fabricated, which can serve as a dual-modality MR/fluorescence imaging system and exhibit mildly acidic pH-triggered turn-on or enhancement of signal intensities for both imaging modalities. Compared to non-crosslinked diblock precursor, CCL micelles demonstrate better MR and fluorescence imaging performance due to structural stability and integrity endowed by the core cross-linking procedure. Furthermore, selective enhancement of MR/fluorescence imaging signal intensities of the dual-modality imaging system can also be actuated under specific intracellular microenvironments such as mildly acidic organelles.

We report on the fabrication of pH-disintegrable polyelectrolyte multilayer-coated mesoporous silica nanoparticles (MSN) capable of triggered co-release of cisplatin and model drug molecules. The outer polyelectrolyte multilayer was assembled from permanently cationic polyelectrolyte, poly(allyl amine hydrochloride) (PAH), and negatively charged polyelectrolyte, P(DMA-co-TPAMA), consisting of N,N-dimethylacrylamide (DMA) and 3,4,5,6-tetrahydrophthalic anhydride-functionalized N-(3-aminopropyl)methacrylamide (TPAMA) monomer units, which exhibits pH-induced charge conversion characteristics. Thus, the subtle alteration of solution pH from 7.4 to ≈5-6 can lead to the disintegration of outer polyelectrolyte multilayers, accompanied with the co-release of cisplatin and RhB.