Triphenylphosphonium Bromide Research Articles

Facile Functionalization of Charcoal by a Green Approach

The ability of charcoal, a low-cost material derived from biomass pyrolysis, to be functionalized via cation exchange in an aqueous solution, providing new interesting fillers with possible antimicrobial and flame-retardant properties, is discussed here. The adducts obtained through this sustainable procedure, show a significant uptake of close to 30% by weight of well-known quaternary phosphonium salts, tetraphenyl phosphonium bromide, and dodecyl triphenyl phosphonium bromide. The new functionalized materials were characterized by elemental analysis, wide-angle X-ray diffraction, infrared spectroscopy, and thermogravimetry. Additionally, a study of changing the ratio between the reagents for both adducts was performed to improve salt uptake and optimize the cationic exchange. Dispersibility tests showed the ability of functionalization to deeply change the polarities of the carbon materials to modify the compatibility and improve the possible interactions with different media, such as different polymer matrices.

Ester-stabilized phosphorus ylides as protonophores on bilayer lipid membranes, mitochondria and chloroplasts

Triphenylphosphonium ylides are commonly used as key intermediates in the Wittig reaction. Based on the known acidities of stabilized ylide precursors, we proposed that a methylene group adjacent to phosphorus in these compounds can ensure proton shuttling across lipid membranes. Here, we synthesized (decyloxycarbonylmethyl)triphenylphosphonium bromide (CMTPP-C10) by reaction of triphenylphosphine with decyl bromoacetate. This phosphonium salt precursor of the ester-stabilized phosphorus ylide along with its octyl (CMTPP-C8) and dodecyl (CMTPP-C12) analogues was found to be a carrier of protons in mitochondrial, chloroplast and artificial lipid membranes, suggesting that it can reversibly release hydrogen ions and diffuse through the membranes in both zwitterionic (ylide) and cationic forms. The CMTPP-C10-mediated electrical current across planar bilayer lipid membranes exhibited pronounced proton selectivity. Similar to conventional protonophores, known to uncouple electron transport and ATP synthesis, CMTPP-Cn (n = 8, 10, 12) stimulated mitochondrial respiration, while decreasing membrane potential, at micromolar concentrations, thereby showing the classical uncoupling activity in mitochondria. CMTPP-C12 also caused dissipation of transmembrane pH gradient on chloroplast membranes. Importantly, CMTPP-C10 exhibited substantially lower toxicity in cell culture, than C12TPP. Thus, we report the finding of a new class of ylide-type protonophores, which is of substantial interest due to promising therapeutic properties of uncouplers.

Tracking the super resolved structure of mitochondria using red emissive carbon nanodots as a fluorescent biomarker.

Herein, we report new red emissive highly photostable and water-soluble carbon nanodots (TPP CNDs) to visualize mitochondrial dynamics using super-resolution radial fluctuations (SRRF) microscopy. The TPP CNDs were synthesized in a one-step method, using 3-(carboxypropyl)triphenylphosphonium bromide (TPP) and o-phenylenediamine (OPDA) as precursors. The obtained crystal structure, NMR, and mass data suggested the presence of [3-(1H-benzimidazol-2-yl)propyl](triphenyl)phosphonium bromide (C28H26N2P+Br-) as a molecular fluorophore (MF) on the surface of the TPP CNDs. The TPP CNDs showed better photostability than the commercially available MitoTracker™ Green and were highly capable for long-term imaging of mitochondrial fission during hyperglycemic conditions and structural changes upon an antidiabetic drug treatment, without altering their fluorescence nature.

Orally deliverable sequence-targeted astaxanthin nanoparticles for colitis alleviation

Orally targeted strategy of anti-inflammatory agents has attracted tremendous attention for reducing highly health-care costs and enhancing the intervention efficiency of ulcerative colitis (UC). Herein, we developed a new kind of sequence-targeted astaxanthin nanoparticles for UC treatment. Astaxanthin nanoparticles were firstly designed by self-assembly method using (3-carboxypentyl) (triphenyl) phosphonium bromide (TPP)-modified whey protein isolate (WPI)-dextran (DX) conjugates. Subsequently, lipoic acid (LA) modified hyaluronic acid (HA) was coated on the surface of the nanoparticles by double emulsion evaporation method. Exhilaratingly, the constructed sequence-targeted astaxanthin nanoparticle exhibited excellent macrophages and mitochondria targeting ability, with a Pearson's correlation coefficient of 0.84 adstnd 0.92, respectively. In vivo imaging elucidated an obvious accumulation of the sequence-targeted nanoparticles in colon tissues in UC mice. Meanwhile, the reduction stimulus release features of astaxanthin were observed in the presence of 10 mM of glutathione (GSH) at pH 7.4. Most importantly, in vivo experiments indicated that sequence-targeted astaxanthin nanoparticles could markedly alleviate inflammation by moderating the TLR4/MyD88/NF-κB signaling pathway. What's more, the composition of gut microbiota and the production of short chain fatty acid were also improved upon the uptake of sequence-targeted astaxanthin nanoparticles. Our results suggested this novel astaxanthin nanoparticles, which showed sequence-targeted ability and reduction response feature, could be exploited as a promising strategy for effective UC treatment.

A Simple Cathode Interfacial Material Performs Well in Organic Solar Cells

A low‐cost perylene‐diimide diphosphonium bromide cathode interlayer material ((1,3,8,10‐tetraoxo‐1,3,8,10‐tetrahydroanthra[2,1,9‐def:6,5,10‐d'e’f']diisoquinoline‐2, 9‐diyl)bis(4,1‐phenylene))bis(triphenylphosphonium)bromide (named as CIL‐4), whose photovoltaic performance is comparable with recognized poly[(9,9‐bis(3′‐((N,N‐dimethyl)‐N‐ethylammonium)‐propyl)‐2,7‐fluorene)‐alt‐2,7‐(9,9‐dioctylfluor ene)] (PFN‐Br) is reported in this article. Unlike PFN‐Br, CIL‐4 is easy to prepare and well soluble in highly polarized solvents such as H2O, CH3OH, and DMF. An impressive power conversion efficiency (PCE) of 15.08% is demonstrated. In addition, CIL‐4 is very cost‐effective because of the one‐step synthesis and purification method. CIL‐4 also favorably tends to form a high‐quality amorphous films by a simple solution process. The femtosecond transient absorption (TA) experiment verified electron transfer occurs between n‐type electron acceptor Y6 and the CIL‐4 film interface. This work indicates that perylene‐diimide diphosphonium bromide can be a competent cathode‐adjusting material in the optoelectronic field.

Preparation and properties of quaternary phosphonium salt containing poly-acrylate emulsion

In this study, methacryloxyhexyl triphenylphosphonium bromide (Br-MHP), a quaternary phosphonium salt monomer, was synthesized and then poly-acrylate emulsion with various Br-MHP contents was prepared through seed emulsion polymerization. The chemical structure of Br-MHP and chemical composition of Br-MHP containing poly-acrylate emulsion were characterized by 1H NMR, 13C NMR, LC-MS and FT-IR, respectively. Effects of Br-MHP content on the stability of emulsion polymerization and micro-structure of the latex particles were investigated. The micro-morphology of the polymer film was observed by SEM. The film performances such as hardness, adhesive, water absorption ratio, thermal stability and antibacterial property were studied. The surface element composition of Br-MHP containing poly-acrylate film was characterized by XPS. The results show that Br-MHP monomer and poly-acrylate emulsion with various Br-MHP contents can be successfully prepared. With the increase of Br-MHP content, the emulsion polymerization stability increases while particle size of latex particles decreases. Besides, the prepared emulsions show excellent storage stability and mechanical stability. The prepared Br-MHP containing poly-acrylate films also present excellent film properties. As the content of Br-MHP increases, the water absorption ratio of the co-polymer film increases, while hardness and thermal stability decreases. Moreover, XPS result show that the quaternary phosphonium salt group is enrich on the polymer film surface, therefore, the Br-MHP containing poly-acrylate resin presents 99.99 % antibacterial efficiency against S. aureus and E. coli when Br-MHP content is only 1 wt% and 2 wt%, respectively.

Photophysical properties and aggregation behavior of diethylene glycol substituted pyropheophorbide-a in cationic surfactant solutions

The aggregation behavior of a novel amphiphilic photosensitizer - pyropheophorbide-[Formula: see text] 17-diethylene glycol ester 1 was studied in aqueous and aqueous-organic mixtures by means of steady-state absorption and fluorescence emission spectroscopy. The formation of [Formula: see text]-aggregates with a bathochromic shift of the absorption bands, weak fluorescence and resonance enhancement of the light scattering was observed in the mixed water-organic solvents. Solubilization studies in micellar cationic surfactant solutions of alkyl trimethylammonium bromides (C[Formula: see text]TAB) and alkyl triphenylphosphonium bromides (C[Formula: see text]TPPB) resulted in the most effective stabilization of the fluorescent monomolecular form of 1 in C[Formula: see text]TPPB micelles. It was shown that [Formula: see text]-aggregate formation in submicellar surfactant solutions is the initial stage of the solubilization process, which significantly increases in phosphate buffer medium at pH 7.4. Fluorescence lifetime ([Formula: see text] of 1 in DMSO was found to be 7.4 ns, fluorescence quantum yield - 34% and singlet oxygen quantum yield - 62%. The results obtained indicate the need for further studies of compound 1 solubilized in C[Formula: see text]TPPB micelles as the most promising prototype of the drug formulation for mitochondria-targeted photodynamic therapy of cancer.

Mitochondria-Targeting Polymer Micelles in Stepwise Response Releasing Gemcitabine and Destroying the Mitochondria and Nucleus for Combined Antitumor Chemotherapy.

Mitochondrial DNA and nuclear DNA are essential genetic material which play an important role in maintaining normal metabolism, survival, and proliferation of cells. Constructing a mitochondria-targeting stimuli-responsive nano-drug delivery system releasing chemotherapeutic agents in a stepwise response manner and destroying mitochondrial DNA and nuclear DNA simultaneously is an effective way to improve the anti-tumor effect of chemotherapeutic agents. In this study, a new mitochondria-targeting pH/ROS dual-responsive block copolymer TPP-PEG2k-b-(BS-AA)n (P1), untargeted pH/ROS dual-responsive copolymer mPEG2k-b-(BS-AA)n (P2), pH single-responsive copolymer (mPEG2k-b-(AH-AA)n (P3), ROS single-responsive copolymer mPEG2k-b-(SA-TG)n (P4), and non-responsive copolymer mPEG-b-PCL (P5) were constructed. pH/ROS-responsive properties were characterized by proton nuclear magnetic resonance (1H NMR) and dynamic light scattering (DLS). Anticancer chemotherapeutic agent gemcitabine (GEM) or fluorescent substance Nile Red (NR) were loaded in the polymer micelles. Results of the mitochondrial colocalization experiment indicate that (5-carboxypentyl)(triphenyl)phosphonium bromide (TPP)-functionalized P1 micelles could be efficiently targeted and located in mitochondria. Results of the cellular uptake experiment showed that pH/ROS dual-responsive GEM-loaded P1 and P2 micelles have faster internalized and entry nucleus rates than single-responsive or non-responsive GEM-loaded micelles. The in vitro release experiment suggests pH/ROS dual-responsive GEM/P1 and GEM/P2 micelles have higher cumulative release than single-responsive GEM/P3 and GEM/P4 micelles. The in vitro cytotoxic experiment shows that the mitochondria-targeted dual-responsive GEM/P1 micelles had the lowest IC50 values, and the cytotoxic effect of dual-responsive GEM/P2 micelles was superior to the single-responsive and non-responsive drug-loaded micelles.

Evoking tumor associated macrophages by mitochondria-targeted magnetothermal immunogenic cell death for cancer immunotherapy

Immunogenic cell death (ICD) based on endoplasmic reticulum (ER) stress has been widely studied as the fundamentals of cancer immunotherapy. However, the currently available ICD inducers are still very rare and mostly highly toxic chemotherapeutic drugs. Herein, a novel ICD modality based on mitochondrial heat stress by magnetic hyperthermia treatment (MHT), is proposed for effectively evoking tumor-associated macrophages (TAMs) against cancer cells. A monodisperse and biocompatible nanomedicine by grafting arginyl-glycyl-aspartic acid (RGD) and (3-carboxypropyl)triphenylphosphonium bromide (TPP) onto the surface of superparamagnetic ZnCoFe2O4@ZnMnFe2O4 nanoparticles (MNPs), named as MNPs-RGD-TPP (MRT), was synthesized for mitochondrial heat stress-induced oxidative damage of tumor cells under the magnetothermal manipulation. Such heat stress-damaged mitochondria can cause the immunogenic death of tumor cells to release damage-associated molecular patterns (DAMPs), including ATP and HSP 70, to M1-polarize TAMs, resulting in the reactivated immunoresponse of macrophages against cancer cells. The effectiveness and robustness of MRT nanomedicine in evoking TAMs-mediated extracellular killing or phagocytosis are verified both in vitro and in vivo. Such a therapeutic approach based on mitochondria-targeted magnetothermal ICD for activating TAMs may be instructive to future anticancer immunotherapy.

Nanocatalytic bacteria disintegration reverses immunosuppression of colorectal cancer.

Tumor-associated bacteria (TAB) play a critically important role in regulating the microenvironment of a tumor, which consequently greatly deteriorates the therapeutic effects by chemo- and radiotherapy deactivation and, more considerably, leads to substantial immunosuppression. On the contrary, herein we propose a nanocatalytic tumor-immunotherapeutic modality based on the bacteria disintegration by bacteria-specific oxidative damage under magnetic hyperthermia for highly effective immune response activation-promoted tumor regression. A monodispersed and superparamagnetic nanocatalytic medicine modified by arginyl-glycyl-aspartic acid (RGD) and (3-carboxypropyl)triphenylphosphonium bromide (TPP), named as MNP-RGD-TPP herein, has been synthesized, which features selective accumulation at the TAB by the electrostatic affinity, enabling effective TAB disintegration by the nanocatalytic Fenton reaction producing abundant cytotoxic hydroxyl radicals in situ under alternating magnetic field-induced hyperthermia. More importantly, the lipopolysaccharide has been metabolically secreted from the destructed TAB as pathogen-associated molecular patterns (PAMPs) to M1-polarize tumor-associated macrophages (TAMs) and promote the maturation of dendritic cells (DCs) for innate immuno-response activation of TAMs, followed by cytotoxic T lymphocytes awakening under the PAMPs presentation by the mature DCs against tumor cells. The integrated innate and adaptive immunity activations based on this TAB-promoted nanocatalytic immunomedicine, instead of magnetic heating-induced hyperthermia or the released Fe2+/Fe3+ Fenton agent, has been found to achieve excellent therapeutic efficacy in an orthotopic colorectal cancer model, demonstrating the great potential of such an integrated immunity strategy in clinical tumor immunotherapy.

Development and application of a sensitive phosphonium-hydrazide oligosaccharide labelling reagent in capillary electrophoresis- electrospray ionization- mass spectrometry

Glycosylation is one of the most ubiquitous post-translational modifications (PTM) of proteins. Although the ionization efficiency of native glycans is fairly low, with the assistance of chemical derivation strategies, mass spectrometry (MS) has been extensively used in glycomics because of its high sensitivity, accuracy, and speed. In this study, a novel glycan labelling reagent, (4-hydrazidebutyl) triphenylphosphonium bromide (P4HZD), with a permanent positive charge was developed. The comprehensive capabilities of P4HZD for MS analysis of oligosaccharides were evaluated in detail using maltodextrin as a standard. This labelling reagent can be used in common biological MS techniques such as matrix-assisted laser desorption ionization (MALDI) and electrospray ionization (ESI) mass spectrometry. The MS signal intensity of maltodextrin species could be enhanced up to 96-fold in MALDI-MS by labelling with P4HZD, making P4HZD favorable for MALDI-MS-based high-throughput screening of oligosaccharides. Moreover, P4HZD-labelled oligosaccharides with a degree of polymerization (DP) from 1 to 18 could be separated and analysed by capillary electrophoresis (CE) combined with positive ion mode ESI-MS. In comparison with a commercialized oligosaccharide tag, Girard's reagent P (GirP), P4HZD was more effective for enhancing the signal of oligosaccharides in the middle or higher mass range using both ESI and MALDI ion sources. Two biologics, immunoglobulin G 2 (IgG 2) and fusion protein (FP), were chosen as model complex biological samples to test the efficacy of detection and separation of oligosaccharides by MALDI-MS and CE-ESI-MS analysis with P4HZD labelling. The results indicated that P4HZD is a promising labelling reagent for the detection of oligosaccharides in complex biological samples. The tandem workflow combines the strengths of MALDI-MS and CE-ESI-MS to fulfil the analytical demands of high-throughput screening, while affording good separation.

Theoretical and Experimental Studies of Phosphonium Ionic Liquids as Potential Antibacterials of MDR Acinetobacter baumannii.

A previously developed model to predict antibacterial activity of ionic liquids against a resistant A. baumannii strain was used to assess activity of phosphonium ionic liquids. Their antioxidant potential was additionally evaluated with newly developed models, which were based on public data. The accuracy of the models was rigorously evaluated using cross-validation as well as test set prediction. Six alkyl triphenylphosphonium and alkyl tributylphosphonium bromides with the C8, C10, and C12 alkyl chain length were synthesized and tested in vitro. Experimental studies confirmed their activity against A. baumannii as well as showed pronounced antioxidant properties. These results suggest that phosphonium ionic liquids could be promising lead structures against A. baumannii.

Preparation and characterization of chitosan derivatives modified with quaternary ammonium salt and quaternary phosphate salt and its effect on tropical fruit preservation

In this paper, HACC modified with (5-Carboxypentyl) (triphenyl) phosphonium bromide (HA-CS-NP) was synthesized. Then, a multifunctional food packaging composite film with good thermal stability and antibacterial functions was fabricated by HA-CS-NP and poly (vinyl alcohol) (PVA). The tensile strength and elongation at break of HA-CS-NP/PVA composite film at the weight ratio of 3/7 were 20.32 ± 1.02 MPa and 65.73 ± 3.29%, respectively. And, the inhibition rates of HA-CS-NP (0.5%) on Mango C. lagenarium and Papaya C. gloeosporioides on day 6 were up to 80.92 ± 4.12%. Compared with CK group, the weight loss of experimental groups were 23.96 ± 2.46 g/206 ± 7.25 g (mangoes) and 59.45 ± 3.06 g/496 ± 6.37 g (papaya), reduced by 35.76 ± 1.15%. Moreover, the final hardness value of the fruits coated with composite films was 4.94 ± 0.23 kg/cm3 and increased by 20.79 ± 1.04%, and the rot index was reduced by 71.43 ± 3.24%. The multifunctional HA-CS-NP/PVA coating has broad prospects in the application of food packaging.

Mitochondrial targeted ROS Scavenger based on nitroxide for Treatment and MRI imaging of Acute Kidney Injury

Introduction Overproduction of reactive oxygen species (ROS) during oxidative stress is a hallmark of acute kidney injure (AKI), which induced the damage to the renal cells and mitochondrial injury. Purpose In this contribution, we prepared mitochondrial targeted nitroxide, which linked 3-carboxy-2,2,5,5-tetramethylpyrrolidine 1-oxyl (carboxy-PROXYL) with (2-aminoethyl)triphenylphosphonium bromide (TPP), named TPP-PROXYL to eliminate the ROS in situ and image the oxidative stress reaction by MRI. Methods 2,7-Dichlorodihydrofluorescein diacetate (DCFH-DA) staining, mitochondrial membrane potential assay (JC-1) staining and transmission electron microscope (TEM) experiments were processed to verify that TPP-PROXYL could target mitochondria, scavenge the ROS, and prevent damage to mitochondria in live cells. Contrast enhanced MRI also been used to monitor these redox reaction in AKI model. Results TPP-PROXYL demonstrated excellent ROS T1-weighted magnetic resonance imaging (MRI) enhancement in vitro and in vivo, with r1 value about 0.190 mM−1 ·s−1. In vivo AKI treatment experiments proved that TPP-PROXYL could improve the survival rate of mice and inhibit kidney damage. Moreover, the great ROS scavenging capability and the renal damage reduction during AKI treatment of TPP-PROXYL was verified via MR imaging technology. Conclusion Collectively, this research provides TPP-PROXYL would serve as a powerful platform to realize ROS scavenging, treatment and MR imaging of AKI.

Dual targeting procyanidin nanoparticles with glutathione response for colitis treatment

The purpose of this study is to design a cell membrane and mitochondrial targeting nanoparticle with glutathione stimulus response to deliver procyanidin for effective treatment of inflammatory bowel disease (IBD). The dual targeting procyanidin nanoparticles were prepared with amphiphilic stearic acid modified hyaluronic acid using cystamine dihydrochloride as a linker for encapsulation of (5-carboxypentyl) (triphenyl) phosphonium bromide conjugated procyanidins. As expected, the procyanidin nanoparticles showed good mitochondrial targeting ability, with a Pearson’s correlation coefficient of 0.91 at 4 h. In vivo imaging of IBD mice model demonstrated a remarkable colon accumulation of the targeting procyanidin nanoparticles. Significant glutathione stimulus release of procyanidin was found in the presence of 10 mM of glutathione at pH 7.4. In vivo experiments showed that the colon length of targeting procyanidin nanoparticle-treated IBD mice increased by 20.84% compared with the IBD mice. The weight loss, disease activity index score, oxidative stress level and the release of proinflammatory cytokines were significantly ameliorated. The composition and relative abundance of gut microbiota, and the number of short chain fatty acids were improved upon the uptake of targeting procyanidin nanoparticles. This study provided a dual targeting and glutathione response strategy to improve the bioavailability of procyanidin in IBD treatment.

Mitochondrial targeted melanin@mSiO2 yolk-shell nanostructures for NIR-Ⅱ-driven photo-thermal-dynamic/immunotherapy

The challenge of photothermal therapy (PTT) clinical transformation is the limited penetration depth of laser light and the general concern of using synthetic photothermal nanomaterials. Hence, it is of great significance to develop combined cancer therapies based on NIR-II photothermal agents from natural materials. Herein, natural melanin nanoparticles from cuttlefish ink coated with large pore mesoporous SiO2 were developed to load azodiisobutylimidazoline hydrochloride (AIPH@MS). After modification with (3-carboxypropyl) triphenylphosphonium bromide (CTPP), AIPH@MS-CTPP nanoparticles showed enhanced retention in the tumor site and were further delivered to thermally susceptible mitochondria. Under 1064 nm laser irradiation, hyperthermia produced by melanin not only directly leads to cell death but also promotes AIPH release to generate oxygen-independent alkyl free radicals, which could further attack tumor cells. The collaboration of the photothermal effect of melanin and thermodynamic therapy of AIPH could induce a local antitumor immune response and effectively reprogram tumor-associated macrophages from the M2 to M1 phenotype. In combination with anti-PD-1 immune checkpoint blockade, the paralyzed immune system was awakened to inhibit and eliminate secondary metastatic tumors. The NIR-II-driven treatment in this paper can achieve energy conversion processes from NIR-II light to thermal energy and then to chemical energy to perform photothermal-dynamic therapy and immunotherapy. This will overcome the high side effects and insufficient antitumor immune response of PTT and provide a strategy for effective and mild antitumor therapy with clinically approved laser power and safe nanotechnology.

Photo‐Induced Dynamic Room Temperature Phosphorescence Based on Triphenyl Phosphonium Containing Polymers

AbstractLong‐lived room temperature phosphorescence (RTP) systems have become a research focus in the field of functional materials due to their fascinating luminescence properties. However, it is still an enormous challenge to realize RTP under ambient conditions, since RTP can be quenched easily by molecular oxygen. Herein, two polymer acceptors containing triphenyl phosphonium bromide salt are designed and synthesized successfully. They are then doped into a poly(methyl methacrylate) matrix with donor molecules to form flexible films with long‐lived RTP. Interestingly, the long‐lived RTP performance is highly dependent on the grafting rate of the polymers. Upon increasing the grafting rate, the aggregation degree of polymer acceptors increases, further inhibiting the molecular movement in the aggregates and reducing nonradiative vibration deactivation of triplet excitons for achieving green long‐lived RTP. Meanwhile, the visualization of real information and complete pattern after 365 nm UV irradiation is demonstrated based on these long‐lived RTP systems, presenting application potential toward dynamic multilevel information encryption and display devices. This work provides an innovative principle for the activation of long‐lived RTP in the polymeric systems under ambient conditions.

Design, synthesis and imaging of a novel mitochondrial fluorescent nanoprobe based on distyreneanthracene-substituted triphenylphosphonium salt

Targeting and monitoring the dynamics of mitochondria are of great significance because mitochondria are involved in a variety of physiological and pathological processes. For achieving this purpose, highly sensitive, photostable, tolerance and specific fluorescent probe is necessary. To obtain a superior mitochondrial fluorescent probe, (4-distyreneanthracenoxybutyl) bis(triphenylphosphonium) bromide (DSA-TPP) with aggregation-induced emission (AIE) characteristic was designed and synthesized for mitochondrial targeting. DSA-TPP dots with high fluorescence quantum yield (Φ = 17.9) and small particle size (8 nm) can be easily prepared by self-assembly formation. DSA-TPP dots had the ability of lightning mitochondria in living cells with high brightness, superior photostability and strong tolerance to cell environment change.

Sensitive and Stable Thermometer Based on the Long Fluorescence Lifetime of Au Nanoclusters for Mitochondria

Detecting the temperature of intracellular mitochondria with high sensitivity and stability is crucial to understanding the cellular metabolism and revealing the processes of mitochondria-related physiology. In this paper, employing the long fluorescence lifetime of modified Au nanoclusters (mAuNCs) by 4-(carboxybutyl) triphenylphosphonium bromide, we developed a fluorescence lifetime thermometer with high sensitivity and stability for the temperature of the intracellular mitochondria. A high relative temperature sensitivity of 2.8% and excellent photostability were achieved from the present thermometer. After incubation with L929 cells, the mAuNCs could be endocytosed into the cells and targeted the mitochondria, and the temperature changes at the L929 cells' mitochondria, which were stimulated by carbonyl cyanide 3-chlorophenylhydrazone and Ca2+, were successfully detected via the fluorescence lifetime images of the mAuNCs. Furthermore, utilizing the mAuNCs, we clarified the effect of Mg2+ on the temperature of the intracellular mitochondria. The strategy of employing a material with a long fluorescence lifetime and remarkable stability to fabricate the fluorescence lifetime thermometer for mitochondria can be used to design various thermometers for other organelles.

Comparison between poly(azomethine)s and poly(p-phenylvinylene)s containing a di-R-diphenylsilane (R = methyl or phenyl) moiety. Optical, electronic and thermal properties

This work reported the preparation of new silicon-containing oligo (azomethine)s and silicon-containing oligo ( p -phenylvinylene)s. The materials were structurally characterized (FT-IR, NMR and elemental analysis). TGA analysis showed a high thermal stability (501–538 °C) and the absorption and emission obtained were closely related with the nature of the di-R-diphenylsilane moiety incorporated in the backbone. All samples showed wide-band gaps. • New silicon-based oligomaterials with potential optoelectronic applications. • Optical, electronic and thermal properties. • Comparison between silylated -azomethine and -vinylene materials. • Analysis of the effect promoted by the di-R-diphenylsilane (R = methyl/phenyl) moiety. Two new silicon-containing poly(azomethine)s (PAzM-Me and PAzM-Ph) and two new silicon-containing poly(p-phenylvinylene)s (PPVSi-Me and PPVSi-Ph) were obtained from 4′,4′''-(dimethylsilanediyl)bis([1,1′-biphenyl]-4-carbaldehyde) and 4′,4′''-(diphenyl silanediyl)bis([1,1′-biphenyl]-4-carbaldehyde) with p -phenylendiamine for PAzMs or phenylenebis(methylene))bis(triphenylphosphonium) bromide for PPVSis. All polymers were structurally characterized by FT-IR, NMR and elemental analysis. The materials showed a high thermal stability (501–538 °C) with the TPS-core increasing this parameter. The absorption and emission of PAzMs and PPVSis were closely related with the nature of the silane-core in the backbone. All samples showed wide-band gaps where the TPS-core-based materials evidenced the lower energy transitions; PAzM-Ph (2.83 eV) and PPVSi-Ph (2.81 eV). This work lay the groundwork for new architectures of silane-based poly(azomethine)s and poly( p -phenylvinylene)s derivatives for potential optoelectronic applications.