Facile Peptide Macrocyclization and Multifunctionalization via Cyclen Installation.

Cyclen-peptide bioconjugates are usually prepared in multiple steps that require individual preparation and purification of the cyclic peptide and hydrophilic cyclen derivatives. An efficient strategy is discovered for peptide cyclization and functionalization toward lanthanide probe via three components intermolecular crosslinking on solid-phase peptide synthesis with high conversion yield. Multifunctionality can be conferred by introducing different modular parts or/and metal ions on the cyclen-embedded cyclopeptide.

MSOT-Guided Nanotheranostics for Synergistic Mild Photothermal Therapy and Chemotherapy to Boost Necroptosis/Apoptosis.

The development of nanotheranostics for precision imaging-guided regulated cell death-mediated synergistic tumor therapy is still challenging. Herein, a novel multifunctional nanotheranostic agent, iRGD-coated maleimide-poly(ethylene glycol)-poly(lactic acid/glycolic acid)-encapsulated hydrophobic gold nanocages (AuNCs) and hydrophilic epigallocatechin gallate (EGCG) (PAuE) is developed for multispectral optoacoustic tomography (MSOT)-guided photothermal therapy (PTT) and chemotherapy. The portions of necroptotic and apoptotic tumor cells were 52.

pH-Triggered Poly(ethylene glycol)-Poly(lactic acid/glycolic acid)/Croconaine Nanoparticles-Assisted Multiplexed Photoacoustic Imaging and Enhanced Photothermal Cancer Therapy.

The most advantageous and attractive property of photoacoustic imaging is its capability to visualize and differentiate multiple species according to their unique absorbance profiles simultaneously in a single mixture. We here report the pH-sensitive near-infrared (NIR) croconaine (Croc) dyes-loaded copolymeric PEG-PLGA nanoparticles (NPs) for multiplexed PA imaging and pH-responsive photothermal therapy (PTT) in an orthotopic xenograft model. PEG chains on the polymeric NPs shell were conjugated with iRGD in another set of NPs to realize efficient tumor targeting.

Nitroreductase-Induced Aggregation of Gold Nanoparticles for "Off-On" Photoacoustic Imaging of Tumor Hypoxia.

Hypoxia is an important phenomenon due to insufficient oxygen supply in tumor tissue, and nitroreductase (NTR) is a characteristic enzyme used for evaluating hypoxia level in tumors. In this work, we designed a smart gold nanoparticle (AuNPs), modified by 16-mercaptoundecanoic acid (MHDA) and hypoxia-responsive 11-(2-nitro-1H-imidazol-1-yl)undecane-1-thiol (NI) ligand, that responds to the hypoxic environment in tumor sites. With proper surface ligand composition, the responsive nanoprobe exhibited aggregation through the bioreduction of the nitro group on NI ligands under hypoxic conditions and the UV-vis absorption peak maximum would shift to 630 nm from 530 nm, which acts as an "off-on" contrast agent for tumor hypoxic photoacoustic (PA) imaging.

Lanthanide-tetrapyrrole complexes: synthesis, redox chemistry, photophysical properties, and photonic applications.

Tetrapyrrole derivatives such as porphyrins, phthalocyanines, naphthalocyanines, and porpholactones, are highly stable macrocyclic compounds that play important roles in many phenomena linked to the development of life. Their complexes with lanthanides are known for more than 60 years and present breath-taking properties such as a range of easily accessible redox states leading to photo- and electro-chromism, paramagnetism, large non-linear optical parameters, and remarkable light emission in the visible and near-infrared (NIR) ranges. They are at the centre of many applications with an increasing focus on their ability to generate singlet oxygen for photodynamic therapy coupled with bioimaging and biosensing properties.

photoacoustic imaging for monitoring treatment outcome of corneal neovascularization with metformin eye drops.

Corneal neovascularization (CNV) compromises corneal avascularity and visual acuity. Current clinical visualization approaches are subjective and unable to provide molecular information. Photoacoustic (PA) imaging offers an objective and non-invasive way for angiogenesis investigation through hemodynamic and oxygen saturation level (sO) quantification.

Biomimetic Anti-PD-1 Peptide-Loaded 2D FePSe Nanosheets for Efficient Photothermal and Enhanced Immune Therapy with Multimodal MR/PA/Thermal Imaging.

Metal phosphorous trichalcogenides (MPX) are novel 2D nanomaterials that have recently been exploited as efficient photothermal-chemodynamic agents for cancer therapy. As a representative MPX, FePSe has the potential to be developed as magnetic resonance imaging (MRI) and photoacoustic imaging (PAI) agents due to the composition of Fe and the previously revealed PA signal. Here, a FePSe-based theranostic agent, FePSe@APP@CCM, loaded with anti-PD-1 peptide (APP) as the inner component and CT26 cancer cell membrane (CCM) as the outer shell is reported, which acts as a multifunctional agent for MR and PA imaging and photothermal and immunotherapy against cancer.

Multifunctional Nanotheranostic Gold Nanocage/Selenium Core-Shell for PAI-Guided Chemo-Photothermal Synergistic Therapy in vivo.

Introduction: Cancer theragnosis involving cancer diagnosis and targeted therapy simultaneously in one integrated system would be a promising solution of cancer treatment. Herein, a convenient and practical cancer theragnosis agent was constructed by combining gold nanocages (AuNCs) covered with selenium and a chitosan (CS) shell (AuNCs/Se) to incorporate the anti-cancer drug doxorubicin (DOX) as a multifunctional targeting nanocomposite (AuNCs/DOX@Se-iRGD) for photoacoustic imaging (PAI)-guided chemo-photothermal synergistic therapy that contributes to enhanced anti-cancer efficacy. The novel design of AuNCs/DOX@Se-iRGD gives the nanocomposite two outstanding properties: (1) AuNCs, with excellent LSPR property in the NIR region, act as a contrast agent for enhanced PAI and photothermal therapy (PTT); (2) Se acts as an anti-cancer nanoagent and drug delivery cargo.

Catalytic asymmetric oxo-Diels-Alder reactions with chiral atropisomeric biphenyl diols.

New chiral atropisomeric biphenyl diols , and containing additional peripheral chiral centers with different steric bulkiness and/or electronic properties were synthesized. The X-ray crystal structure of shows the formation of a supramolecular structure whereas that of , containing additional CF substituents, shows the formation of a monomeric structure. Diols - were found to be active organocatalysts in oxo-Diels-Alder reactions in which recorded a 72% ee with trimethylacetaldehyde as a substrate.

Breaking the 1,2-HOPO barrier with a cyclen backbone for more efficient sensitization of Eu(iii) luminescence and unprecedented two-photon excitation properties.

A cyclen backbone was utilized to study the effect of backbone rigidity on Eu(iii) luminescence sensitization using a 1,2-HOPO derivative and 2-thenoyltrifluoroacetonate (TTA) as chromophores. The restriction of molecular movement of brought about by the increased rigidity provided a tightly packed coordination environment for the octadentate Eu(iii) center which resulted in the highest overall quantum yield (30.2%) and sensitization efficiency (64.

Synthesis of a Conformationally Stable Atropisomeric Pair of Biphenyl Scaffold Containing Additional Stereogenic Centers.

The synthesis of a new CF₃-containing stereogenic atropisomeric pair of ortho-disubstituted biphenyl scaffold is presented. The atropisomers are surprisingly conformationally stable for isolation. X-ray structures show that their stability comes from an intramolecular hydrogen bond formation from their two hydroxyl groups and renders the spatial arrangement of their peripheral CF₃ and CH₃ groups very different.

pH-responsive targeted gold nanoparticles for photoacoustic imaging of tumor microenvironments.

The acidic microenvironment of tumor tissues has been proven to be a major characteristic for differentiation from normal tissues, thereby providing a desirable target for both disease diagnosis and functional imaging. We herein introduce a way to endow gold nanoparticles with aggregation behaviour induced by pH tuning. The nanoparticle surface was modified with two thiol conjugate molecules, which could smartly stabilize it at the pH of blood and normal tissues but induce aggregation in response to the acidic extracellular pH in tumor.

808 nm excited energy migration upconversion nanoparticles driven by a Nd-Trinity system with color-tunability and superior luminescence properties.

We have developed energy migration upconversion (EMU) nanoparticles (UCNPs) with optimal Nd-sensitization under excitation of an 808 nm laser to avoid over-heating effects caused by a 980 nm laser while maximizing the excitation efficiency. To realize efficient 808 nm sensitization, a "Nd-Trinity system" was implemented in the energy migration upconversion (EMU) cores (NaGdF:Yb,Tm@NaGdF:Yb,X, X = Eu/Tb), resulting in a core-multishell structure of EMU cores (accumulation layer@activation layer)@transition layer@harvest layer@activation layer. The spatially separated dopants and optimized Yb/Nd content effectively prevented severe quenching events in the UCNPs and their Nd-sensitized EMU-based photoluminescence mechanism was studied under 808 nm excitation.

Gadolinium and Platinum in Tandem: Real-time Multi-Modal Monitoring of Drug Delivery by MRI and Fluorescence Imaging.

A novel dual-imaging cisplatin-carrying molecular cargo capable of performing simultaneous optical and MR imaging is reported herein. This long-lasting MRI contrast agent (r relaxivity of 23.4 mMs at 3T, 25 C) is a photo-activated cisplatin prodrug () which enables real-time monitoring of anti-cancer efficacy.

Chiral transcription in self-assembled tetrahedral EuL chiral cages displaying sizable circularly polarized luminescence.

Predictable stereoselective formation of supramolecular assembly is generally believed to be an important but complicated process. Here, we show that point chirality of a ligand decisively influences its supramolecular assembly behavior. We designed three closely related chiral ligands with different point chiralities, and observe their self-assembly into europium (Eu) tetrametallic tetrahedral cages.

Study of the Aggregation of DNA-Capped Gold Nanoparticles: A Smart and Flexible Aptasensor for Spermine Sensing.

A smart gold nanoparticle based aptasensor is developed for the sensing of this biomarker in a convenient and fast manner. A comprehensive study was performed to elucidate the driving force of DNA adsorption, different factors' effects, such as gold nanoparticle size, DNA length, concentration, and working pH towards spermine sensing by using UV/Vis absorption spectroscopy and isothermal titration calorimetry. It was found that the developed aptasensor could detect spermine by two different sensing mechanisms simply by adjusting the DNA concentration without complicated procedures.

Mechanistic Investigation of Inducing Triboluminescence in Lanthanide(III) β-Diketonate Complexes.

In this work, we synthesized a series of lanthanide(III) β-diketonate complexes to investigate the induction of triboluminescence. Triboluminescence (TL) spectra, solid-state emission spectra, and luminescence lifetimes of the complexes were obtained to prove consistent emitting species for steady-state and triboluminescence measurements. Detailed analyses of the crystal lattice packing were conducted in an attempt to correlate crystal symmetry, gas discharge, and structural arrangements with "triboexcitation", and it is found that either noncentrosymmetric or centrosymmetic compounds can be TL-active.

New Class of Bright and Highly Stable Chiral Cyclen Europium Complexes for Circularly Polarized Luminescence Applications.

High glum values of +0.30 (ΔJ = 1, 591 nm, in DMSO) and -0.23 (ΔJ = 1, 589 nm, in H2O) were recorded in our series of newly designed macrocyclic europium(III) complexes.

Photo-reactive charge trapping memory based on lanthanide complex.

Traditional utilization of photo-induced excitons is popularly but restricted in the fields of photovoltaic devices as well as photodetectors, and efforts on broadening its function have always been attempted. However, rare reports are available on organic field effect transistor (OFET) memory employing photo-induced charges. Here, we demonstrate an OFET memory containing a novel organic lanthanide complex Eu(tta)3ppta (Eu(tta)3 = Europium(III) thenoyltrifluoroacetonate, ppta = 2-phenyl-4,6-bis(pyrazol-1-yl)-1,3,5-triazine), in which the photo-induced charges can be successfully trapped and detrapped.

Highly luminescent Sm(III) complexes with intraligand charge-transfer sensitization and the effect of solvent polarity on their luminescent properties.

Samarium complexes with the highest quantum yields to date have been synthesized, and their luminescence properties were studied in 12 solvents. Sensitization via a nontriplet intraligand charge-transfer pathway was also successfully demonstrated in solution states with good quantum yields.

In vitro imaging and human serum albumin responsive dimeric lanthanide DO3A complex.

Two series of dimeric DO3A (1,4,7,10-tetraazacyclodecane-1,4,7-triacetate) lanthanide complexes (LnL(1)-LnL(2), Ln = Eu, Gd, and Tb) have been synthesized with two different bridged chromophores. The X-ray structures of dimeric LnL(1) (Ln = Gd and Tb) complexes show that each metal ion has nine coordination numbers with eight directly bound donor atoms of the ligand and one oxygen donor from the water molecule. Photophysical measurements indicate that the bridged antenna in LnL(2) gives a higher efficiency than that of LnL(1) and is responsive to the protein Human Serum Albumin (HSA), giving an f-f luminescence signal enhancement with a binding constant log K = 4.

Impressive europium red emission induced by two-photon excitation for biological applications.

Three triazine-based europium(III) complexes were synthesized that demonstrated strong two-photon induced europium emission with a high two-photon absorption cross-section. The modified triazine ligand of complex 3 initiated over 100% enhancement of the two-photon absorption cross-section (σ(2): 320 GM) when compared with complex 1 (σ(2): 128 GM) in a solution of DMSO. Europium complex 3 is also stable in vitro, and power-dependence curves were obtained in vitro to confirm the two-photon-induced f-f emission in HeLa cells.