A portable smartphone platform utilizing dual-sensing signals for visual determination of semicarbazide in food samples.

Semicarbazide (SEM) is a metabolite of antibiotic nitrofurazone and a food contaminant in food production, showing potential carcinogenic, mutagenic, teratogenic, and toxic effects on human health. It is urgent to develop a highly efficient and sensitive assay for visual detection of SEM. In this paper, a pyrrolopyrrole cyanine fluorescent probe (PPCy-1) was reported for visualization and quantitative analysis of SEM through a chromophore reaction sensing mechanism for the first time. The probe towards SEM exhibited a fast response (10 min), a low detection limit (0.18 µM), high selectivity, and distinct dual ratiometric fluorescence turn-on and colorimetric modes. Its practicability was further verified by detecting SEM in meat, water, and honey samples with satisfactory recovery values. More importantly, a smartphone-assisted portable testing platform was constructed based on a PPCy-1-immobilized test paper or a polyamide thin film with a color scanning APP for real-time and on-site detection of SEM. This work provides low-cost, convenient, and rapid assays for visual SEM detection, which have potential applications in food safety monitoring.

Sorafenib-Based Drug Delivery Systems: Applications and Perspectives.

As a Food and Drug Administration (FDA)-approved molecular-targeted chemotherapeutic drug, sorafenib (SF) can inhibit angiogenesis and tumor cell proliferation, leading to improved patient overall survival of hepatocellular carcinoma (HCC). In addition, SF is an oral multikinase inhibitor as a single-agent therapy in renal cell carcinoma. However, the poor aqueous solubility, low bioavailability, unfavorable pharmacokinetic properties and undesirable side effects (anorexia, gastrointestinal bleeding, and severe skin toxicity, etc.) seriously limit its clinical application. To overcome these drawbacks, the entrapment of SF into nanocarriers by nanoformulations is an effective strategy, which delivers SF in a target tumor with decreased adverse effects and improved treatment efficacy. In this review, significant advances and design strategies of SF nanodelivery systems from 2012 to 2023 are summarized. The review is organized by type of carriers including natural biomacromolecule (lipid, chitosan, cyclodextrin, etc.); synthetic polymer (poly(lactic-co-glycolic acid), polyethyleneimine, brush copolymer, etc.); mesoporous silica; gold nanoparticles; and others. Co-delivery of SF and other active agents (glypican-3, hyaluronic acid, apolipoprotein peptide, folate, and superparamagnetic iron oxide nanoparticles) for targeted SF nanosystems and synergistic drug combinations are also highlighted. All these studies showed promising results for targeted treatment of HCC and other cancers by SF-based nanomedicines. The outlook, challenges and future opportunities for the development of SF-based drug delivery are presented.

Recent Advances of Diketopyrrolopyrrole Derivatives in Cancer Therapy and Imaging Applications.

Cancer is threatening the survival of human beings all over the world. Phototherapy (including photothermal therapy (PTT) and photodynamic therapy (PDT)) and bioimaging are important tools for imaging-mediated cancer theranostics. Diketopyrrolopyrrole (DPP) dyes have received more attention due to their high thermal and photochemical stability, efficient reactive oxygen species (ROS) generation and thermal effects, easy functionalization, and tunable photophysical properties. In this review, we outline the latest achievements of DPP derivatives in cancer therapy and imaging over the past three years. DPP-based conjugated polymers and small molecules for detection, bioimaging, PTT, photoacoustic imaging (PAI)-guided PTT, and PDT/PTT combination therapy are summarized. Their design principles and chemical structures are highlighted. The outlook, challenges, and future opportunities for the development of DPP derivatives are also presented, which will give a future perspective for cancer treatment.

Green, Efficient Detection and Removal of Hg2+ by Water-Soluble Fluorescent Pillar[5]arene Supramolecular Self-Assembly.

Developing a water-soluble supramolecular system for the detection and removal of Hg2+ is extremely needed but remains challenging. Herein, we reported the facile construction of a fluorescent supramolecular system (H⊃G) in 100% water through the self-assembly of carboxylatopillar[5]arene sodium salts (H) and diketopyrrolopyrrole-bridged bis(quaternary ammonium) guest (G) by host-guest interaction. With the addition of Hg2+, the fluorescence of H⊃G could be efficiently quenched. Since Hg2+ showed synergistic interactions (coordination and Hg2+- cavity interactions with G and H, respectively), crosslinked networks of H⊃G@Hg2+ were formed. A sensitive response to Hg2+ with excellent selectivity and a low limit of detection (LOD) of 7.17 × 10-7 M was obtained. Significantly, the quenching fluorescence of H⊃G@Hg2+ can be recovered after a simple treatment with Na2S. The reusability of H⊃G for the detection of Hg2+ ions was retained for four cycles, indicating the H⊃G could be efficiently used in a reversible manner. In addition, the H⊃G could efficiently detect Hg2+ concentration in real samples (tap water and lake water). The developed supramolecular system in 100% water provides great potential in the treatment of Hg2+ detection and removal for environmental sustainability.

Recent Advances in Fluorescent Methods for Polyamine Detection and the Polyamine Suppressing Strategy in Tumor Treatment.

The biogenic aliphatic polyamines (spermine, spermidine, and putrescine) are responsible for numerous cell functions, including cell proliferation, the stabilization of nucleic acid conformations, cell division, homeostasis, gene expression, and protein synthesis in living organisms. The change of polyamine concentrations in the urine or blood is usually related to the presence of malignant tumors and is regarded as a biomarker for the early diagnosis of cancer. Therefore, the detection of polyamine levels in physiological fluids can provide valuable information in terms of cancer diagnosis and in monitoring therapeutic effects. In this review, we summarize the recent advances in fluorescent methods for polyamine detection (supramolecular fluorescent sensing systems, fluorescent probes based on the chromophore reaction, fluorescent small molecules, and fluorescent nanoparticles). In addition, tumor polyamine-suppressing strategies (such as polyamine conjugate, polyamine analogs, combinations that target multiple components, spermine-responsive supramolecular chemotherapy, a combination of polyamine consumption and photodynamic therapy, etc.) are highlighted. We hope that this review promotes the development of more efficient polyamine detection methods and provides a comprehensive understanding of polyamine-based tumor suppressor strategies.

Design, synthesis and applications of NIR-emissive scaffolds of diketopyrrolopyrrole-aza-BODIPY hybrids.

Herein, we report a facile synthetic method towards diketopyrrolopyrrole-aza-BODIPY hybrids by a two-step strategy. The three resulting fluorophores (LAB-TH4 ∼ LAB-TH6) showed absorption maxima up to 637 nm with molar extinction coefficients (ε) up to 32 300 M-1 cm-1 and emission maxima at 661 nm with a fluorescence quantum yield of 25.2% in solution. Due to good biocompatibility and strong ROS generation ability, they are useful fluorophores for bioimaging and photodynamic therapy (PDT). In addition, as a useful scaffold, a novel NIR-emissive conjugated polymer can be constructed by further bromination and Suzuki coupling polymerization.

Development of a novel chromophore reaction-based fluorescent probe for biogenic amines detection.

Biogenic amines (BAs) are important biomarkers to monitor meat spoilage. However, the design of efficient BA fluorescent probes with distinct colorimetric and ratiometric fluorescent dual-channels is still a critical challenge because of similar chemical properties and basicity between BAs and other amines. Herein, pyrrolopyrrole cyanine (PPCy-1) is reported to display distinctly high reactivity toward BAs through an ultrasensitive irreversible chromophore reaction for the first time. The reaction mechanism is ascribed to synergistic aza-Michael addition and B-N detachment, followed by hydrolysis to produce low-conjugated diketopyrrolopyrrole and heteroaromatic acetonitrile compounds. As a result, colorimetric and ratiometric fluorescent dual-channel (Δλab = 188 nm and Δλem = 151 nm) signals and a limit of detection up to 62.1 nM level for BA solution are acquired. In addition, the colorimetric detection of volatile amine vapor using the PPCy-1-loaded filter paper, showing a color change from green to yellow, is feasible. A simple and cost-effective fluorescence "turn on" method using the filter paper or the CAD-40 resin loaded with PPCy-1 to detect TVB (total volatile bases) originating from shrimp spoilage is further demonstrated.

A novel and efficient chromophore reaction based on a lactam-fused aza-BODIPY for polyamine detection.

Polyamines (such as spermine, spermidine) play important roles in biomedical and food field. The elevated polyamines have been proposed to serve as target analytes for monitoring meat spoilage. Because of structural similarity and low concentration of polyamines in real samples, it is exceedingly challenging to design and develop sensitive probes for visual detection of polyamines. To address this issue, a highly efficient probe was reported based on a newly developed chromophore reaction between lactam-fused aza-BODIPY (abbreviation: LAB) and polyamines by virtue of unique multiple amino groups character of polyamines. This chromophore reaction includes a kinetic-controllable reaction of a B-N bond cleavage by polyamines followed by a fast hydrolysis reaction to yield much smaller conjugated molecules. With 130 nm hypsochromic shift of the absorption peak and up to 99% fluorescence quenching within 1 min, LAB can be used as a highly sensitive fluorescent probe for detection of polyamines solution and monitoring fish spoilage with synchronous colorimetric and fluorescent changes.

A highly efficient, colorimetric and fluorescent probe for recognition of aliphatic primary amines based on a unique cascade chromophore reaction.

Pyrrolopyrrole aza-BODIPY based nanoaggregates were reported as a highly selective and sensitive probe for recognition of aliphatic primary amines with a novel cascade chromophore reaction. Due to its distinct reaction characteristics, this probe loaded test strip can conveniently detect n-hexylamine vapor and monitor the freshness of shrimp.

Use of ultrasonic and pepsin treatment in tandem for collagen extraction from meat industry by-products.

BACKGROUND: Relatively little attention is paid to collagen-rich cattle short tendons (musculus extensor communis, musculus flexor digitorum, musculus digitorum profundis) as a source of high content and relatively pure collagen, a meat-processing by-product that is used to a minimal extent. Thus, suitable extraction processes from a meat production by-product to gain intact collagen is promising, which thus become interesting from an economic and environmental point of view. RESULTS: Two extraction methods were compared: a 48 h pepsin treatment using 0.5 mol L⁻¹ acetic acid and an extraction using pepsin treatment after ultrasonic treatment in a 0.5 mol L⁻¹ acetic acid solution (the total ultrasonic and pepsin treatment time was 48 h). The results indicated that the optimal conditions for the extraction of collagen from cattle tendon with the ultrasonic-pepsin tandem method is: 4°C, tendon pre-swollen for 12 h in 0.5 mol L⁻¹ acetic acid, pepsin amount: 50 U mg⁻¹ of sample, ultrasonic-pepsin tandem treatment time for 18 h and 30 h, respectively. Extracted cattle tendon collagen using ultrasonic and pepsin treatment in tandem was characterised by amino acid analysis, SDS-PAGE, FT-IR, solubility and thermal denaturation temperature. The results show that the ultrasonic-pepsin tandem method can effectively improve the efficiency of pepsin extraction of natural collagen without any compromise of the resultant collagen quality. CONCLUSION: This study provides a favourable process to deal with poorly extractable residue by use of ultrasonic and pepsin treatment in tandem. Extracted collagen possesses an intact molecular structure, which is useful and particularly important for its biomedical applications, such as drug delivery systems, wound dressings, and scaffolds.