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The intrinsic correlation between depression and serotonin (5‐HT) is a highly debated topic, with significant implications for the diagnosis, treatment, and advancement of drugs targeting neurological disorders. To address this important question, it is of utmost priority to understand the action mechanism of serotonin in depression through fluorescence imaging studies. However, the development of efficient molecular probes for serotonin is hindered by the lack of responsive sites with high selectivity for serotonin at the present time. Herein, we developed the first highly selective serotonin responsive site, 3‐mercaptopropionate, utilizing thiol‐ene click cascade nucleophilic reactions. The novel responsive site was then employed to construct the powerful molecular probe SJ‐5‐HT for imaging the serotonin level changes in the depression cells and brain tissues. Importantly, the imaging studies reveal that the level of serotonin in patients with depression may not be the primary factor, while the ability of neurons in patients with depression to release serotonin appears to be more critical. Additionally, this serotonin release capability correlates strongly with the levels of mTOR (intracellular mammalian target of rapamycin). These discoveries could offer valuable insights into the molecular mechanisms underpinning depression and furnish mTOR as a novel direction for the advancement of antidepressant therapies. [ABSTRACT FROM AUTHOR]

Accurate visualization of tumor microenvironment is of great significance for personalized medicine. Here, we develop a near‐infrared (NIR) fluorescence/photoacoustic (FL/PA) dual‐mode molecular probe (denoted as NIR−CE) for distinguishing tumors based on carboxylesterase (CE) level by an analyte‐induced molecular transformation (AIMT) strategy. The recognition moiety for CE activity is the acetyl unit of NIR−CE, generating the pre‐product, NIR−CE−OH, which undergoes spontaneous hydrogen atom exchange between the nitrogen atoms in the indole group and the phenol hydroxyl group, eventually transforming into NIR−CE−H. In cellular experiments and in vivo blind studies, the human hepatoma cells and tumors with high level of CE were successfully distinguished by both NIR FL and PA imaging. Our findings provide a new molecular imaging strategy for personalized treatment guidance. [ABSTRACT FROM AUTHOR]

We revisit one of the most used techniques for quantifying the aqueous OH radicals (OHaq) in plasma–liquid systems, the molecular probe method which obtains the [OHaq] by measuring a stable material formed through a rapid reaction between the molecular probe and the OHaq. In this study, we used disodium terephthalate (NaTA) as the molecular probe; the experimental results with a theoretical analysis suggest that to obtain the correct OHaq concentration, the concentration of the molecular probe should be greater than a certain value, which depends on the types of the plasma–liquid systems. However, this is not the case in most of the existing reports in which the NaTA is often much less than the requisite value. [ABSTRACT FROM AUTHOR]

The hydroxyl radical (•OH) is shown to play a crucial role in the occurrence and progression of acute kidney injury (AKI). Therefore, the development of a robust •OH probe holds great promise for the early diagnosis of AKI, high‐throughput screening (HTS) of natural protectants, and elucidating the molecular mechanism of intervention in AKI. Herein, the design and synthesis of an activatable fluorescent/photoacoustic (PA) probe (CDIA) for sensitive and selective imaging of •OH in AKI is reported. CDIA has near‐infrared fluorescence/PA channels and fast activation kinetics, enabling the detection of the onset of •OH in an AKI model. The positive detection time of 12 h using this probe is superior to the 48‐hour detection time for typical clinical assays, such as blood urea nitrogen and serum creatinine detection. Furthermore, a method is established using CDIA for HTS of natural •OH inhibitors from herbal medicines. Puerarin is screened out by activating the Sirt1/Nrf2/Keap1 signaling pathway to protect renal cells in AKI. Overall, this work provides a versatile and dual‐mode tool for illuminating the •OH‐related pathological process in AKI and screening additional compounds to prevent and treat AKI. [ABSTRACT FROM AUTHOR]

Introduction: Drug development has been challenged by the dual drawbacks involving unpredictable disease outcomes and drug resistance, which has placed greater demands on pharmacology education. Molecular pharmacology, as a frontier crossover field of pharmacology, focuses on the research of new drugs and targets. However, due to the lack of a systematic experimental training system, molecular pharmacology has not made a corresponding contribution in promoting the training of innovative talent in pharmacology. We aim to establish an experimental training program suitable for molecular pharmacology to improve students' ability to engage in drug development in future. Methods: Based on the feasibility of drug–target projects, a comprehensive training program containing molecular docking, target stability experiment, and fluorescent probe detection of protein expression in living cells and mice was conducted among 20 pharmacy graduate students. The experimental training was assessed by the experimental training report and the student recognition questionnaires. Results: All 20 students mastered the experimental principles and operations required for the training program. The experimental reports proved that the students were in good command of the experimental principles, operations and applications. The results of the Likert questionnaire indicated that the training program promoted the understanding of the drug research process and increased motivation to learn. Conclusion: The designed experimental training program has a positive effect on the training of pharmacology talents, and can be implemented as a part of molecular pharmacology education. [ABSTRACT FROM AUTHOR]

The surface area of anisotropic polymeric assemblies is a critical parameter concerning their properties. However, it is still a grand challenge for traditional techniques to determine the surface area. Here, a molecular probe loading (MPL) method is developed to measure the surface area of anisotropic polymersomes in the shape of tube, disc, and stomatocyte. This method uses an amphiphilic molecular probe, comprising hydrophobic pyrene as the anchor and hydrophilic tetraethylene glycol (EG4) as the float. The surface area of spherical polymersomes determined by dynamic light scattering is quantitatively correlated with the loading amount of probes, allowing the calculation of the average separation distance between the loaded probes. With the separation distance, we successfully determine the surface area of anisotropic polymersomes by measuring the loading amount. We envision that the MPL method will assist in the real‐time surface area characterization, enabling the customization of functions. [ABSTRACT FROM AUTHOR]

Activity assays are indispensable for studying biochemical properties of enzymes. The purposes of measuring activity are wide ranging from a simple detection of the presence of an enzyme to kinetic experiments evaluating the substrate specificity, reaction mechanisms, and susceptibility to inhibitors. Common activity assay methods include spectroscopy, electrochemical sensors, or liquid chromatography coupled with various detection techniques. This review focuses on the use of matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) as a growing and modern alternative, which offers high speed of analysis, sensitivity, versatility, possibility of automation, and cost‐effectiveness. It may reveal reaction intermediates, side products or measure more enzymes at once. The addition of an internal standard or calculating the ratios of the substrate and product peak intensities and areas overcome the inherent inhomogeneous distribution of analyte and matrix in the sample spot, which otherwise results in a poor reproducibility. Examples of the application of MALDI‐TOF MS for assaying hydrolases (including peptidases and β‐lactamases for antibiotic resistance tests) and other enzymes are provided. Concluding remarks summarize advantages and challenges coming from the present experience, and draw future perspectives such as a screening of large libraries of chemical compounds for their substrate or inhibitory properties towards enzymes. [ABSTRACT FROM AUTHOR]

Here, we disclose a new turn‐on type fluorescent probe (named BCB‐1) for the detection of Aβ plaques, which is an essential biomarker in Alzheimer's disease (AD). BCB‐1 has a hybrid structure of benzo[g]coumarin and benzothiazole, and it showed significant emission enhancement at the near‐infrared (NIR) region when sensing Aβ plaques. BCB‐1 also showed high selectivity and sensitivity toward Aβ plaques, and its bio‐imaging applicability was confirmed within an AD mouse (5XFAD) brain. We expect our superb AD diagnosis fluorescent probe to be broadly applied in Aβ plaques related clinical and biological studies. [ABSTRACT FROM AUTHOR]

Glutathione (GSH), the most common and abundant antioxidant in the body, is particularly concentrated in cancer cells (2–10 mM). This concentration is approximately 1000 times that of normal cells, making GSH a specific tumor marker. Overexpression of GSH is critical for mapping the redox state of cancer cells. However, there are few probes and detection methods responsive to GSH that can quantitatively visualize GSH in vivo in two‐photon excitation fluorescence (TPEF) imaging mode. The experimental results show that TPEF‐GSH could not only target GSH in tumors, but also establish the quantitative relationship between TPEF signal and GSH concentration. We explored the optimal two‐photon excitation wavelength of TPEF‐GSH, the optimal cell incubation duration with TPEF‐GSH, the best imaging time point for GSH in cells, and the quantitative relationship between the TPEF signal and the changes in GSH concentrations. In zebrafish embryo and zebrafish experiments, the ratiometric value of TPEF‐GSH increased with the decrease of GSH concentration. Microinjection and co‐incubation were used to verify whether the ratiometric value could quantify endogenous GSH in tumor‐bearing zebrafish, and the obtained GSH levels were 4.66 mM and 5.16 mM, respectively. The ratio TPEF probe could accurately visualize and quantify GSH in vivo, reflecting the redox status of the tumor. The design of the ratiometric molecular probe provides a reliable strategy for the development of TPEF nanoprobe in vivo. In this article, a new GSH sensitive molecular probe, TPEF‐GSH, has been developed with good specificity and sensitivity. TPEF‐GSH was successfully used to image cancer cells in vitro and tumor‐bearing zebrafish in vivo, and to further detect GSH levels. [ABSTRACT FROM AUTHOR]

Inflammation usually results in high‐level reactive oxygen species (ROS) and reactive nitrogen species (RNS) not only in acidic tissue but also in alkaline tissue. However, noninvasively in vivo monitoring reactive species specifically within alkaline tissue remains a huge challenge. Here we introduce a dual activatable fluorescent probe PN910 located in the second near‐infrared window (NIR‐II, 900–1700 nm), which shows high selectivity toward H2O2 and OONO− at pH beyond 7.4. Then we verified that PN910 could be used for the real‐time, specific and accurate monitoring of cystitis and colitis for living animals. This report presents a unique approach to the development of dual activatable probe for in vivo biosensing. [ABSTRACT FROM AUTHOR]

Optical endoscopy is the primary diagnostic and therapeutic tool for management of gastrointestinal (GI) malignancies. Most GI neoplasms arise from precancerous lesions; thus, technical innovations to improve detection and diagnosis of precancerous lesions and early cancers play a pivotal role in improving outcomes. Over the last few decades, the field of GI endoscopy has witnessed enormous and focused efforts to develop and translate accurate, user-friendly, and minimally invasive optical imaging modalities. From a technical point of view, a wide range of novel optical techniques is now available to probe different aspects of light-tissue interaction at macroscopic and microscopic scales, complementing white light endoscopy. Most of these new modalities have been successfully validated and translated to routine clinical practice. Herein, we provide a technical review of the current status of existing and promising new optical endoscopic imaging technologies for GI cancer screening and surveillance. We summarize the underlying principles of light-tissue interaction, the imaging performance at different scales, and highlight what is known about clinical applicability and effectiveness. Furthermore, we discuss recent discovery and translation of novel molecular probes that have shown promise to augment endoscopists' ability to diagnose GI lesions with high specificity. We also review and discuss the role and potential clinical integration of artificial intelligence-based algorithms to provide decision support in real time. Finally, we provide perspectives on future technology development and its potential to transform endoscopic GI cancer detection and diagnosis. [ABSTRACT FROM AUTHOR]

Kita‐kyushu lung cancer antigen 1 (KK‐LC‐1) is a kind of cancer‐testis antigen with anti‐tumor potential for clinical application. As a class of small‐molecule antigen conjugate, tumor‐targeting peptides have broad application prospects in gastric cancer diagnosis, imaging, and biological treatment. Here, we screened specific cyclic nonapeptides from a phage‐display library. The targeting peptide with the best affinity was selected and further verified in ex vivo tissue sections. Finally, enrichment of targeting peptides in tumor tissues was observed in vivo, and the dynamic biodistribution process was also observed with micro‐positron emission tomography (micro‐PET)/computed tomography (CT) imaging. Studies showed that the specific cyclic nonapeptide had a high binding capacity for KK‐LC‐1 protein. It has a strong affinity and specificity for KK‐LC‐1‐expressing positive tumor cells. Targeting peptides were significantly enriched at tumor sites in vivo, with very low normal tissue background. These findings demonstrated that the KK‐LC‐1 targeting peptide has high clinical potential. [ABSTRACT FROM AUTHOR]

Biosynthesis of (1R,4aS,7S,7aR)‐nepetalactol (1) and (4aS,7S,7aR)‐nepetalactone (2) in plants involves iridoid synthase (ISY), an atypical reductive cyclase that catalyses the reduction of 8‐oxogeranial into the reactive enol of (S)‐8‐oxocitronellal, and cyclization of this enol intermediate, either non‐enzymatically or by a nepetalactol‐related short chain dehydrogenase enzyme (NEPS) that yields the nepetalactols. In this study, we investigated the biosynthesis in vivo of 1 and 2 in the pea aphid, Acyrthosiphon pisum, using a library of isotopically‐labelled monoterpenoids as molecular probes. Topical application of deuterium‐labelled probes synthesized from geraniol and nerol resulted in production of 2H4−lactol 1 and 2H4−lactone 2. However, deuterium incorporation was not evident using labelled probes synthesized from (S)‐citronellol. These results suggest that iridoid biosynthesis in animals, specifically aphids, may follow a broadly similar route to that characterised for plants. [ABSTRACT FROM AUTHOR]

Understanding the complex interplay among gasotransmitters is of great significance but remains technically challenging. In this study, we present the design and synthesis of a dually responsive BOD‐NH‐SC reporter for probing the dynamic and alternating existence of NO and H2S in living cells. This designed reporter can repeatedly cycle S‐nitrosation and transnitrosation reactions when successively treated with NO and H2S, thus affording the interchange of NIR fluorescence at 645 nm (NO) and NIR II fluorescence at 936 nm (H2S). In light of this unique fluorescence alternation between two colors, we synthesized water‐soluble BOD‐NH‐SC dots to visualize the intracellular dynamics of NO and H2S. These molecular probes thus provide a toolbox to elucidate the interplaying roles of NO and H2S in the complex interaction networks of various signal transduction pathways. [ABSTRACT FROM AUTHOR]

The beginning of the 21st century was marked by the intensive development of fiber‐optic sensors. New functional materials with excellent sensory properties are required to design such sensors. Fluorescent probes for neutral and charged molecules are constantly developing. However, only a small part of the reported probes was successfully converted into functional sensing polymers and found real‐world applications. A great challenge is to retain the sensing properties of a probe in a polymer matrix. The purpose of this review is to understand how properties of a probe are changed upon incorporation into a polymer and to reveal successful approaches. The review focuses on the use of the naphthalimide‐based probes in the construction of sensing polymers. The literature overview is presented according to the nature of the guest molecules targeted for the quantitative detection: cations, anions, and small organic molecules. [ABSTRACT FROM AUTHOR]

The importance of London dispersion interactions in solution is an ongoing debate. Although the significance of dispersion for structure and stability is widely accepted, the degree of its attenuation in solution is still not properly understood. Quantitative evaluations are derived mostly from computations. Experimental data provide guidelines to include London dispersion in solution phase design. Herein, dispersive interactions were examined with an azobenzene probe. Alkyl substituents in meta positions of the azobenzene core were systematically varied and the effect on the half‐lives for the thermally induced Z to E isomerization in several alkane solvents was determined. The results show that intramolecular dispersion is only marginally influenced. In solvents with low surface tension, reduced destabilizing solvent‐solvent interactions increase the half‐life up to 20 %. Specific individual interactions between alkyl chains on the azobenzene and those of the solvent lead to additional fluctuations of the half‐lives. These presumably result from structural changes of the conformer ensemble. [ABSTRACT FROM AUTHOR]

Pyropheophorbide‐a (Pyro) is a promising multifunctional molecule for multimodal tumour imaging and photodynamic therapy, but its clinical applications are seriously restricted by the limited tumour accumulation capability. Here, we designed and synthesized a small‐molecule probe that achieved specific dual‐modal tumour imaging based on Pyro. Briefly, a novel molecule combining Pyro, an RGD dimer peptide (3PRGD2) and 64Cu, was designed and synthesized, and the obtained molecule, 64Cu‐Pyro‐3PRGD2, exhibited high tumour specificity in both positron emission tomography and optical imaging in vivo. c (RGDfk) peptide blocking significantly reduced the efficacy of the probe, which confirmed the integrin αVβ3 targeting of this molecular probe. 64Cu‐Pyro‐3PRGD2 had very low accumulation in normal organs and could be rapidly cleared through kidney metabolism, which prevented the potential damage to adjacent normal tissues. Overall, combining tumour targeting, dual‐modal imaging, and biosafety, 64Cu‐Pyro‐3PRGD2 has the potential for clinical use as a molecular imaging probe for tumour diagnosis. [ABSTRACT FROM AUTHOR]

Activatable (turn‐on) probes that permit the rapid, sensitive, selective, and accurate identification of cancer‐associated biomarkers can help drive advances in cancer research. Herein, a NAD(P)H:quinone oxidoreductase‐1 (NQO1)‐specific chemiluminescent probe 1 is reported that allows the differentiation between cancer subtypes. Probe 1 incorporates an NQO1‐specific trimethyl‐locked quinone trigger moiety covalently tethered to a phenoxy‐dioxetane moiety through a para‐aminobenzyl alcohol linker. Bio‐reduction of the quinone to the corresponding hydroquinone results in a chemiluminescent signal. As inferred from a combination of in vitro cell culture analyses and in vivo mice studies, the probe is safe, cell permeable, and capable of producing a "turn‐on" luminescence response in an NQO1‐positive A549 lung cancer model. On this basis, probe 1 can be used to identify cancerous cells and tissues characterized by elevated NQO1 levels. An activatable chemiluminescence probe was developed for imaging endogenous NOQ1 in cells and mice without the requirement of additional components. The advantages of this probe include rapid response, good selectivity, and high signal‐to‐noise ratio. [ABSTRACT FROM AUTHOR]

Fluorescence‐guided surgery (FGS) and other interventions are rapidly evolving as a class of technologically driven interventional approaches in which many surgical specialties visualize fluorescent molecular tracers or biomarkers through associated cameras or oculars to guide clinical decisions on pathological lesion detection and excision/ablation. The technology has been commercialized for some specific applications, but also presents technical challenges unique to optical imaging that could confound the utility of some interventional procedures where real‐time decisions must be made. Accordingly, the AAPM has initiated the publication of this Blue Paper of The Emerging Technology Working Group (TETAWG) and the creation of a Task Group from the Therapy Physics Committee within the Treatment Delivery Subcommittee. In describing the relevant issues, this document outlines the key parameters, stakeholders, impacts, and outcomes of clinical FGS technology and its applications. The presentation is not intended to be conclusive, but rather to inform the field of medical physics and stimulate the discussions needed in the field with respect to a seemingly low‐risk imaging technology that has high potential for significant therapeutic impact. This AAPM Task Group is working toward consensus around guidelines and standards for advancing the field safely and effectively. [ABSTRACT FROM AUTHOR]

Rapid detection of multifocal cancer without the use of complex imaging schemes will improve treatment outcomes. In this study, dynamic fluorescence imaging was used to harness differences in the perfusion kinetics of near‐infrared (NIR) fluorescent dyes to visualize structural characteristics of different tissues. Using the hydrophobic nontumor‐selective NIR dye cypate, and the hydrophilic dye LS288, a high tumor‐to‐background contrast was achieved, allowing the delineation of diverse tissue types while maintaining short imaging times. By clustering tissue types with similar perfusion properties, the dynamic fluorescence imaging method identified secondary tumor locations when only the primary tumor position was known, with a respective sensitivity and specificity of 0.97 and 0.75 for cypate, and 0.85 and 0.81 for LS288. Histological analysis suggests that the vasculature in the connective tissue that directly surrounds the tumor was a major factor for tumor identification through perfusion imaging. Although the hydrophobic dye showed higher specificity than the hydrophilic probe, use of other dyes with different physical and biological properties could further improve the accuracy of the dynamic imaging platform to identify multifocal tumors for potential use in real‐time intraoperative procedures. [ABSTRACT FROM AUTHOR]

We report the design and synthesis of several 4-phenylpiperidine-4-carbonitrile derivatives as σ1 receptor ligands. In vitro radioligand competition binding assays showed that all the ligands exhibited low nanomolar affinity for σ1 receptors ( Ki(σ1) = 1.22-2.14 nM) and extremely high subtype selectivity ( Ki(σ2) = 830-1710 nM; Ki(σ2)/ Ki(σ1) = 680-887). [18F]9 was prepared in 42-46% isolated radiochemical yield, with a radiochemical purity of >99% by HPLC analysis after purification, via nucleophilic 18F- substitution of the corresponding tosylate precursor. Biodistribution studies in mice demonstrated high initial brain uptakes and high brain-to-blood ratios. Administration of SA4503 or haloperidol 5 min prior to injection of [18F]9 significantly reduced the accumulation of radiotracers in organs known to contain σ1 receptors. Two radioactive metabolites were observed in the brain at 30 min after radiotracer injection. [18F]9 may serve as a lead compound to develop suitable radiotracers for σ1 receptor imaging with positron emission tomography. [ABSTRACT FROM AUTHOR]

Surgical guidance with fluorescence has been demonstrated in individual clinical trials for decades, but the scientific and commercial conditions exist today for a dramatic increase in clinical value. In the past decade, increased use of indocyanine green based visualization of vascular flow, biliary function, and tissue perfusion has spawned a robust growth in commercial systems that have near-infrared emission imaging and video display capabilities. This recent history combined with major preclinical innovations in fluorescent-labeled molecular probes, has the potential for a shift in surgical practice toward resection guidance based upon molecular information in addition to conventional visual and palpable cues. Most surgical subspecialties already have treatment management decisions partially based upon the immunohistochemical phenotype of the cancer, as assessed from molecular pathology of the biopsy tissue. This phenotyping can inform the surgical resection process by spatial mapping of these features. Further integration of the diagnostic and therapeutic value of tumor metabolism sensing molecules or immune binding agents directly into the surgical process can help this field mature. Maximal value to the patient would come from identifying the spatial patterns of molecular expression in vivo that are well known to exist. However, as each molecular agent is advanced into trials, the performance of the imaging system can have a critical impact on the success. For example, use of pre-existing commercial imaging systems are not well suited to image receptor targeted fluorophores because of the lower concentrations expected, requiring orders of magnitude more sensitivity. Additionally the imaging system needs the appropriate dynamic range and image processing features to view molecular probes or therapeutics that may have nonspecific uptake or pharmacokinetic issues which lead to limitations in contrast. Imaging systems need to be chosen based upon objective performance criteria, and issues around calibration, validation, and interpretation need to be established before a clinical trial starts. Finally, as early phase trials become more established, the costs associated with failures can be crippling to the field, and so judicious use of phase 0 trials with microdose levels of agents is one viable paradigm to help the field advance, but this places high sensitivity requirements on the imaging systems used. Molecular-guided surgery has truly transformative potential, and several key challenges are outlined here with the goal of seeing efficient advancement with ideal choices. The focus of this vision 20/20 paper is on the technological aspects that are needed to be paired with these agents. [ABSTRACT FROM AUTHOR]

3-18F- l-α-methyl-tyrosine ([18F] FAMT), a PET probe for tumor imaging, has advantages of high cancer-specificity and lower physiologic background. FAMT- PET has been proved useful in clinical studies for the prediction of prognosis, the assessment of therapy response and the differentiation of malignant tumors from inflammation and benign lesions. The tumor uptake of [18F] FAMT in PET is strongly correlated with the expression of L-type amino acid transporter 1 ( LAT1), an isoform of system L upregulated in cancers. In this study, to assess the transporter-mediated mechanisms in FAMT uptake by tumors, we examined amino acid transporters for FAMT transport. We synthesized [14C] FAMT and measured its transport by human amino acid transporters expressed in Xenopus oocytes. The transport of FAMT was compared with that of l-methionine, a well-studied amino acid PET probe. The significance of LAT1 in FAMT uptake by tumor cells was confirmed by si RNA knockdown. Among amino acid transporters, [14C] FAMT was specifically transported by LAT1, whereas l-[14C]methionine was taken up by most of the transporters. Km of LAT1-mediated [14C] FAMT transport was 72.7 μM, similar to that for endogenous substrates. Knockdown of LAT1 resulted in the marked reduction of [14C] FAMT transport in HeLa S3 cells, confirming the contribution of LAT1 in FAMT uptake by tumor cells. FAMT is highly specific to cancer-type amino acid transporter LAT1, which explains the cancer-specific accumulation of [18F] FAMT in PET. This, vice versa, further supports the cancer-specific expression of LAT1. This study has established FAMT as a LAT1-specific molecular probe to monitor the expression of a potential tumor biomarker LAT1. [ABSTRACT FROM AUTHOR]

To screen and identify the novel probe markers binding hepatocellular carcinoma specifically and sensitively, a phage-displayed 12-mer peptide library was used to make biopanning with the modified protocols on HepG2 cells. After four rounds of panning, the consensus sequences were obtained, and the PC28, a phage clone with most specific and sensitive binding to HepG2 cells, was identified as the best positive clone. The peptide probe HCSP4 (sequence SLDSTHTHAPWP) was synthesized based on the sequencing result of PC28. The specificity and sensitivity of HCSP4 were primarily analyzed using immunofluorescence, flow cytometry, and other methods. The results show that HCSP4 can bind to hepatocellular carcinoma cells with satisfactory specificity and sensitivity. It may be a promising lead candidate for molecular imaging and targeted drug delivery in the diagnosis and therapy of hepatocellular carcinoma. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The increasing number of health issues caused by obesity and lack of healthy and efficient fat substitutes require development on new fat substitute. This study proposes a new potential reduced-calorie structured triacylglycerol (TAG) of '1,3-medium-chain, 2-short-chain triglycerides (MSM)' configuration, and the fat substitution method is based on the suppression of 2-monoacylglycerol absorption into intestinal cells, which would decrease the recombination of TAG and reduce lipid absorption in the digestive tract. A molecular probe, 1,3-dicapryloyl-2-acetylglycerol, is offered for nutritionists to conduct further study on its metabolism in human body. The synthesis method for this structured TAG starts from the lipase-catalyzed esterification between glycerol and caprylic acid, yielding 1,3-dicapryloylglycerol, and is followed by direct esterification with acetic anhydride to form 1,3-dicapryloyl-2-acetylglycerol. Its structure is characterized by FTIR,1H NMR,13C NMR, and LC-ESI-MS. Practical application: This kind of pure structured triglyceride can function as a molecular probe for nutritionists to test its metabolism in human body and conduct further evaluation on their fat substitute potential. The synthesis method can also be easily adopted by food industry since it involves only two simple reaction steps. [ABSTRACT FROM AUTHOR]

SUMMARY A detection technique with a DNA probe was developed for the bloom-forming alga Alexandrium affine harvested in Japan. The design of this probe was based on the sequence polymorphism within the 28S ribosomal DNA (rDNA) of this strain using the BIAcoreTM 2000 biosensor, which determines surface plasmon resonance. The specific DNA sequence in 28S rDNA for A. affine was determined by sequence data analysis, and a probe was designed for the detection of A. affine . A fragment of the 28S rDNA from A. affine was amplified by polymerase chain reaction and applied to the BIAcoreTM sensor system, and the target DNA was selectively recognized by species-specific hybridization using two DNA probes: a fluorescein isothiocyanate (FITC)-labeled probe and a biotin-labeled DNA probe. Using FITC-labeled anti-immunogloblin G antibody, enhancement of the response for the target DNA can be detected directly as a resonant unit change. In this detection method, a difference within only 20 base pairs of the target could be detected, and specific detection of A. affine was achieved intraspecifically. [ABSTRACT FROM AUTHOR]

Abstract: β-Amyloid peptides (Aβ) are the main protein components of neuritic plaques and are important in the pathogenesis of Alzheimer's disease. It is reported that Aβ itself is not toxic; however, it becomes toxic to neuronal cells once it has aggregated into amyloid fibrils by peptide–peptide interactions. In this study, to specify the molecular mechanism of aggregation, a novel fluorescence assay was designed. For this purpose, possible partial peptides (38 types of 5-mer) were synthesized on solid-phase. The molecular interactions were examined by a fluorescence probe possessing Lys-Leu-Val-Phe-Phe (KLVFF) as a molecular recognition site. KLVFF is known to be a minimum sequence for formation of the Aβ aggregate. A specific interaction was observed between labeled and immobilized KLVFF. It suggests that the aggregation of Aβ was controlled by the recognition of KLVFF itself by hydrophobic and electrostatic interactions. [ABSTRACT FROM AUTHOR]