A coumarin-based fluorescent probe for NIR imaging-guided photodynamic therapy against S. aureus-induced infection in mouse models.

A coumarin-based viscosity-responsive fluorescent probe (HZAU800) was designed and synthesized. The probe, containing a strong electron-donating and rigid group on the 7-position of coumarin and a rhodamine derivative containing an oxonium ion on 3-position, could not only shift the emission wavelength to near-infrared region (NIR, λem = 800 nm) but also deliver a good PDT effect due to its high rigid planarity. The NIR fluorescence of HZAU800 can be lighted up in the S. aureus-infected region due to its high viscous environment. Under the laser's irradiation at 690 nm, the PDT effect was effectively triggered up, and the antibacterial evaluation in vitro and in vivo was successfully carried out. This study not only offers a new strategy for constructing coumarin-based phototherapy agents but also facilitates the exploration of the next generation of antibacterial materials based on coumarin architectures.

Construction of a Smart Nanofluidic Sensor through a Redox Reaction Strategy for High-Performance Carbon Monoxide Sensing.

Carbon monoxide (CO), an important gas signaling molecule, demonstrated various physiological and pathological functions by regulating the ion flux of biological channels. Herein, inspired by the CO-regulated K+ channel in vivo, we propose a smart CO-responsive nanosensor through the redox reaction strategy. Such nanosensor demonstrated an outstanding CO specificity and selectivity with high ion rectification (∼9) as well as excellent stability and recyclability. Therefore, these results will provide a new direction for the design of nanochannel-based sensors for future practical and biological applications.

A nano-cocktail of an NIR-II emissive fluorophore and organoplatinum(ii) metallacycle for efficient cancer imaging and therapy.

The scarcity of efficient imaging technologies for precise cancer treatment greatly drives the development of new nanotheranostic based platforms that enable both diagnostic and therapeutic functions, together in a single formulation. Owing to the complicated physiological microenvironment, nanosystems designed with the possibility of noninvasive real-time monitoring of therapeutic progression in the second near-infrared channel (NIR-II, 1000-1700 nm) could substantially improve the current cancer therapies. Herein, we design a novel NIR-II theranostic nanoprobe, PSY (size ∼110 nm), by incorporating organoplatinum(ii) metallacycles P1 and an organic NIR-II molecular dye, SY1030, into the FDA-approved polymer Pluronic F127. Preliminary in vitro and in vivo studies suggest that PSY is capable of being internalized into glioma U87MG-cells with no significant internalization in non-cancerous tissues. In addition, it shows excellent photostability and minimal background for real-time monitoring the process of therapy in the NIR-II region. Furthermore, in U87MG xenografts and orthotopic breast tumor, PSY demonstrat significantly improved anticancer efficacy compared to a clinically approved Pt(ii)-based anticancer drug, cisplatin. The engineered nano-cocktail PSY offers a simple strategy for delivering the organoplatinum(ii) macrocycle P1 and NIR-II fluorophore SY1030 as a cocktail of diagnostic and therapeutic functions and highlights its promising capacity for future cancer treatment.

Fabrication of a Tyrosine-Responsive Liquid Quantum Dots Based Biosensor through Host-Guest Chemistry.

Design and fabrication of smart liquid quantum dots (LQDs) with high biomolecule selectivity and specificity remains a challenge. Herein, a multifunctional calix[4]arene derivative (PCAD) was rationally designed and applied to fabricate a Tyr-responsive CdSe-LQD system through host-guest chemistry. Such a biosensor displays an outstanding fluorescence/macroscopic response for Tyr and reversible fluidic features due to the hydrogen interaction between the PCAD of CdSe-LQDs and Tyr. These excellent results highlighted CdSe-LQDs as a promising platform for biological molecule recognition and separation in the future.

A highly selective and recyclable NO-responsive nanochannel based on a spiroring opening-closing reaction strategy.

Endogenous nitric oxide (NO) is an important messenger molecule, which can directly activate K+ transmission and cause relaxation of vascular smooth muscle. Here, inspired by the K+ channel of smooth muscle cells, we report, a novel NO-regulated artificial nanochannel based on a spiro ring opening-closing reaction strategy. This nanofluidic diode system shows an outstanding NO selective response owing to the specific reaction between o-phenylenediamine (OPD) and NO on the channel surface with high ion rectification ratio (~6.7) and ion gating ratio (~4). Moreover, this NO gating system exhibits excellent reversibility and stability as well as high selectivity response. This system not only helps us understand the process of NO directly regulating biological ion channels, but also has potential application value in the field of biosensors.