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Summary. Platelet-derived growth factor (PDGF) is a major mitogen for connective tissue cells. In this study, we investigated the effects and mechanism of PDGF on the ex vivo expansion of cord blood CD34+ cells. Our data demonstrated that among various cytokine combinations of thrombopoietin (TPO), interleukin 1 beta (IL-1β), IL-3, IL-6 and Flt-3 ligand (Flt-3L), TPO + IL-6 + Flt-3L was most efficient in promoting the expansion of CD34+ cells, CD34+ CD38– cells, mixed-lineage colony-forming units (CFU-GEMM) and long-term culture-initiating cells (LTC-IC) by 21·7 ± 5·00-, 103 ± 27·9-, 10·7 ± 7·94- and 6·52 ± 1·51-fold, respectively, after 12–14 d of culture. The addition of PDGF increased the yield of these early progenitors by 45·0%, 66·5%, 45·1% and 79·8% respectively. More significantly, PDGF enhanced the engraftment of human CD45+ cells and their myeloid subsets (CD33+ , CD14+ cells) in non-obese diabetic (NOD)/severe-combined immunodeficient (SCID) mice. The expression of PDGF receptor (PDGFR)-β was not detectable in fresh CD34+ cells but was upregulated after culture for 3 d. PDGF also enhanced the development of adherent cells/clusters that expressed the endothelial markers VE-cadherin and CD31. These findings suggest that PDGF is an effective cytokine for the ex vivo expansion of early stem and progenitor cells. The mechanism could be mediated by PDGFR-β on committed CD34+ progenitor cells and/or secondary to the stimulation of autologous, stromal feeder cells. [ABSTRACT FROM AUTHOR]

The synthesis of a dimer of porphyrin linked by flexible alkoxyl chains and its application as neutral ionophore for a berberine-sensitive potentiometric sensor were described. The porphyrin dimer based sensor shows a linear response towards berberine in the range 1.2 × 10[SUP-7] -5.0 × 10[SUP-3] mol L[SUP-1], with a pH range from 3.7 to 11.2, a fast response time of 10s and a slope of 65.5 ± 2.5mV/dec. The proposed electrode exhibits different selectivity behavior compared with the electrode based on classical cation exchanger. As an electroactive material, porphyrin dimer shows better potentiometric response characteristics comparing to porphyrin monomer or metalloporphyrin. The effects of solvent mediator have been studied and the experimental conditions optimized. The interaction between BE[SUP+] and porphyrin dimer was investigated using UV-VIS spectrophotometry. The electrode can be used in the direct assay of BE in pharmaceutical preparations with satisfactory results. [ABSTRACT FROM AUTHOR]

In this paper, based on our recent work (Zhang and Zhang, 2021), we introduce multiple perturbations in an SIS epidemic model with isolation and varying total population size. We present the threshold R s of the model. When R s is less than 1, we prove that the disease will die out. When R s is greater than 1, we construct an appropriate stochastic Lyapunov function and using the well-known Khasminskii's theory, prove the existence of the stationary distribution. This has important significance to obtain the statistical characteristics of the infectious disease such as the mean, variance and so on. [ABSTRACT FROM AUTHOR]

The potential for off-target mutations is a critical concern for the therapeutic application of CRISPR-Cas9 gene editing. Current detection methodologies, such as GUIDE-seq, exhibit limitations in oligonucleotide integration efficiency and sensitivity, which could hinder their utility in clinical settings. To address these issues, we introduce OliTag-seq, an in-cellulo assay specifically engineered to enhance the detection of off-target events. OliTag-seq employs a stable oligonucleotide for precise break tagging and an innovative triple-priming amplification strategy, significantly improving the scope and accuracy of off-target site identification. This method surpasses traditional assays by providing comprehensive coverage across various sgRNAs and genomic targets. Our research particularly highlights the superior sensitivity of induced pluripotent stem cells (iPSCs) in detecting off-target mutations, advocating for using patient-derived iPSCs for refined off-target analysis in therapeutic gene editing. Furthermore, we provide evidence that prolonged Cas9 expression and transient HDAC inhibitor treatments enhance the assay's ability to uncover off-target events. OliTag-seq merges the high sensitivity typical of in vitro assays with the practical application of cellular contexts. This approach significantly improves the safety and efficacy profiles of CRISPR-Cas9 interventions in research and clinical environments, positioning it as an essential tool for the precise assessment and refinement of genome editing applications. OliTag-seq, a specific and reproducible in-cellulo assay for CRISPR/Cas9 off-target analysis, can improve site cleavage efficiency and the identification of off-target sites. [ABSTRACT FROM AUTHOR]

Clear delineation of tumor margins is essential for accurate resection and decreased recurrence rate in the clinic. Fluorescence imaging is emerging as a promising alternative to traditional visual inspection by surgeons for intraoperative imaging. However, traditional probes lack accuracy in tumor diagnosis, making it difficult to depict tumor boundaries accurately. Herein, we proposed an offensive and defensive integration (ODI) strategy based on the “attack systems (invasive peptidase) and defense systems (reductive microenvironment)” of multi‐dimensional tumor characteristics to design activatable fluorescent probes for imaging tumor boundaries precisely. Screened out from a series of ODI strategy‐based probes, ANQ performed better than traditional probes based on tumor unilateral correlation by distinguishing between tumor cells and normal cells and minimizing false‐positive signals from living metabolic organs. To further improve the signal‐to‐background ratio in vivo, derivatized FANQ, was prepared and successfully applied to distinguish orthotopic hepatocellular carcinoma tissues from adjacent tissues in mice models and clinical samples. This work highlights an innovative strategy to develop activatable probes for rapid diagnosis of tumors and high‐precision imaging of tumor boundaries, providing more efficient tools for future clinical applications in intraoperative assisted resection. [ABSTRACT FROM AUTHOR]

A novel coumarin-based fluorescent probe, P-CM, for quantitative detection of nitroxyl (HNO) was developed. P-CM exhibits a selective response to HNO over other biological reductants and was also applied for quantitative detection of HNO in bovine serum with satisfactory results. [ABSTRACT FROM AUTHOR]

A highly selective electrochemical biosensor for the ultrasensitive detection of Hg2+in aqueous solution has been developed based on the strong and specific binding of Hg2+by two DNA thymine bases (T–Hg2+–T) and the use of AuNP-functionalized reporter DNA to achieve signal amplification. [ABSTRACT FROM AUTHOR]

Abnormal physiological processes and diseases can lead to content or activity fluctuations of biocomponents in organelles and whole blood. However, precise monitoring of these abnormalities remains extremely challenging due to the insufficient sensitivity and accuracy of available fluorescence probes, which can be attributed to the background fluorescence arising from two sources, 1) biocomponent autofluorescence (BCAF) and 2) probe intrinsic fluorescence (PIF). To overcome these obstacles, we have re‐engineered far‐red to NIR II rhodol derivatives that possess weak BCAF interference. And a series of "zero" PIF sensing‐platforms were created by systematically regulating the open‐loop/spirocyclic forms. Leveraging these advancements, we devised various ultra‐sensitive NIR indicators, achieving substantial fluorescence boosts (190 to 1300‐fold). Among these indicators, 8‐LAP demonstrated accurate tracking and quantifying of leucine aminopeptidase (LAP) in whole blood at various stages of tumor metastasis. Furthermore, coupling 8‐LAP with an endoplasmic reticulum‐targeting element enabled the detection of ERAP1 activity in HCT116 cells with p53 abnormalities. This delicate design of eliminating PIF provides insights into enhancing the sensitivity and accuracy of existing fluorescence probes toward the detection and imaging of biocomponents in abnormal physiological processes and diseases. [ABSTRACT FROM AUTHOR]

Abnormal physiological processes and diseases can lead to content or activity fluctuations of biocomponents in organelles and whole blood. However, precise monitoring of these abnormalities remains extremely challenging due to the insufficient sensitivity and accuracy of available fluorescence probes, which can be attributed to the background fluorescence arising from two sources, 1) biocomponent autofluorescence (BCAF) and 2) probe intrinsic fluorescence (PIF). To overcome these obstacles, we have re‐engineered far‐red to NIR II rhodol derivatives that possess weak BCAF interference. And a series of "zero" PIF sensing‐platforms were created by systematically regulating the open‐loop/spirocyclic forms. Leveraging these advancements, we devised various ultra‐sensitive NIR indicators, achieving substantial fluorescence boosts (190 to 1300‐fold). Among these indicators, 8‐LAP demonstrated accurate tracking and quantifying of leucine aminopeptidase (LAP) in whole blood at various stages of tumor metastasis. Furthermore, coupling 8‐LAP with an endoplasmic reticulum‐targeting element enabled the detection of ERAP1 activity in HCT116 cells with p53 abnormalities. This delicate design of eliminating PIF provides insights into enhancing the sensitivity and accuracy of existing fluorescence probes toward the detection and imaging of biocomponents in abnormal physiological processes and diseases. [ABSTRACT FROM AUTHOR]

High-Sr/Y granitoids in continental settings are sometimes erroneously regarded as the products derived from partial melting of thickened/delaminated mafic lower curst under relatively higher pressures (>1.5 GPa) in a collisional orogenic setting. In fact, multiple magmatic processes in the trans-crustal magma system, such as recycling of antecrysts, crustal assimilation, and fractional crystallization, can create or modify the primary "adakitic" signature. As a result, the generation of adakitic magmas in continental settings remains controversial from a bulk-rock perspective. Here, we address the origin of adakitic plutonic rocks through geochemical and textural characterization of rock-forming minerals in the pyroxene-bearing Zhuyuan granodiorite, West Qinling, China. The Zhuyuan granodiorite formed in a post-collisional setting and primarily consists of resorbed orthopyroxene, three types of clinopyroxene, amphibole, two types of plagioclases, K-feldspar, biotite, and quartz. Type-1 Cpx has high XMg (70.0–81.7). Type-2 Cpx displays normal zoning and decreasing XMg (80.9 to 71.5) from the core to rim. Type-3 Cpx is reversely zoned, where the rims have higher XMg (75.5–86.9), Ni, Cr, suggesting a recharge event. Orthopyroxene has high-Ni and -Cr contents, as well as high XMg (80.9–82.8), indicative of antecrysts that grew in mafic magma reservoirs. The injection of magmas from different sources is supported by sieve-textured plagioclase and crystal size distributions of non-poikilitic amphibole. Finally, non-sieve textured plagioclase, biotite, K-feldspar, and quartz are late-crystallized phases, indicative of an orthocrystic origin. The melts in equilibrium with these orthocrysts display significantly higher Sr/Y values than the magma batches that crystallized other mafic phases (i.e., amphibole, clinopyroxene, and orthopyroxene). Thus, we propose that the system involved an initial high-Sr/Y melts in equilibrium with the orthocryst assemblage was generated by water-fluxed melting of intermediate to felsic sources. The addition of low Sr/Y non-orthocrysts (e.g., amphibole and pyroxene) and associated melt diluted the original "adakitic signal" in the magma reservoir and drove the bulk composition to more mafic values. Consequently, the Zhuyuan pyroxene-bearing granodiorite represents a mixture of crystals with diverse origins and distinct magma batches of various compositions (from felsic to mafic compositions). Our study emphasizes that the origin of adakitic granitoids cannot be clearly deciphered without geochemical analysis of the constituent minerals. We also suggest that Sr/Y values in plutons should be cautiously used in paleo-crustal thickness estimates in collisional settings because of possible open system scenarios as described here. [ABSTRACT FROM AUTHOR]

We introduced the radical chain transfer reaction into the LPO process to target the propagation step and overcome the sluggish rate of lipid peroxidation, thereby promoting endogenous lipid peroxidation and enhancing therapeutic outcomes. [Display omitted] Lipid peroxidation (LPO), the process of membrane lipid oxidation, is a potential new form of cell death for cancer treatment. However, the radical chain reaction involved in LPO is comprised of the initiation, propagation (the slowest step), and termination stages, limiting its effectiveness in vivo. To address this limitation, we introduce the radical chain transfer reaction into the LPO process to target the propagation step and overcome the sluggish rate of lipid peroxidation, thereby promoting endogenous lipid peroxidation and enhancing therapeutic outcomes. Firstly, radical chain transfer agent (CTA-1)/Fe nanoparticles (CTA-Fe NPs-1) was synthesized. Notably, CTA-1 convert low activity peroxyl radicals (ROO·) into high activity alkoxyl radicals (RO·), creating the cycle of free radical oxidation and increasing the propagation of lipid peroxidation. Additionally, CTA-1/Fe ions enhance reactive oxygen species (ROS) generation, consume glutathione (GSH), and thereby inactivate GPX-4, promoting the initiation stage and reducing termination of free radical reaction. CTA-Fe NPs-1 induce a higher level of peroxidation of polyunsaturated fatty acids in lipid membranes, leading to highly effective treatment in cancer cells. In addition, CTA-Fe NPs-1 could be enriched in tumors inducing potent tumor inhibition and exhibit activatable T 1 -MRI contrast of magnetic resonance imaging (MRI). In summary, CTA-Fe NPs-1 can enhance intracellular lipid peroxidation by accelerating initiation, propagation, and inhibiting termination step, promoting the cycle of free radical reaction, resulting in effective anticancer outcomes in tumor-bearing mice. [ABSTRACT FROM AUTHOR]

Organic fluorophores are indispensable tools in cells, tissue and in vivo imaging, and have enabled much progress in the wide range of biological and biomedical fields. However, many available dyes suffer from insufficient performances, such as short absorption and emission wavelength, low brightness, poor stability, small Stokes shift, and unsuitable permeability, restricting their application in advanced imaging technology and complex imaging. Over the past two decades, many efforts have been made to improve these performances of fluorophores. Starting with the luminescence principle of fluorophores, this review clarifies the mechanisms of the insufficient performance for traditional fluorophores to a certain extent, systematically summarizes the modified approaches of optimizing properties, highlights the typical applications of the improved fluorophores in imaging and sensing, and indicates existing problems and challenges in this area. This progress not only proves the significance of improving fluorophores properties, but also provide a theoretical guidance for the development of high‐performance fluorophores. [ABSTRACT FROM AUTHOR]

Organic fluorophores are indispensable tools in cells, tissue and in vivo imaging, and have enabled much progress in the wide range of biological and biomedical fields. However, many available dyes suffer from insufficient performances, such as short absorption and emission wavelength, low brightness, poor stability, small Stokes shift, and unsuitable permeability, restricting their application in advanced imaging technology and complex imaging. Over the past two decades, many efforts have been made to improve these performances of fluorophores. Starting with the luminescence principle of fluorophores, this review clarifies the mechanisms of the insufficient performance for traditional fluorophores to a certain extent, systematically summarizes the modified approaches of optimizing properties, highlights the typical applications of the improved fluorophores in imaging and sensing, and indicates existing problems and challenges in this area. This progress not only proves the significance of improving fluorophores properties, but also provide a theoretical guidance for the development of high‐performance fluorophores. [ABSTRACT FROM AUTHOR]

Background: CRISPR-Cas9 technology has advanced in vivo gene therapy for disorders like hemophilia A, notably through the successful targeted incorporation of the F8 gene into the Alb locus in hepatocytes, effectively curing this disorder in mice. However, thoroughly evaluating the safety and specificity of this therapy is essential. Our study introduces a novel methodology to analyze complex insertion sequences at the on-target edited locus, utilizing barcoded long-range PCR, CRISPR RNP-mediated deletion of unedited alleles, magnetic bead-based long amplicon enrichment, and nanopore sequencing. Results: We identified the expected F8 insertions and various fragment combinations resulting from the in vivo linearization of the double-cut plasmid donor. Notably, our research is the first to document insertions exceeding ten kbp. We also found that a small proportion of these insertions were derived from sources other than donor plasmids, including Cas9-sgRNA plasmids, genomic DNA fragments, and LINE-1 elements. Conclusions: Our study presents a robust method for analyzing the complexity of on-target editing, particularly for in vivo long insertions, where donor template integration can be challenging. This work offers a new tool for quality control in gene editing outcomes and underscores the importance of detailed characterization of edited genomic sequences. Our findings have significant implications for enhancing the safety and effectiveness of CRISPR-Cas9 gene therapy in treating various disorders, including hemophilia A. [ABSTRACT FROM AUTHOR]

To compare how OCT4A proteins interact with and regulate multiple OCT4A-octamer motifs (OMs) in different regions of the FOS gene expressed in somatic cancer cells versus pluripotent stem cells. Two FOS reporter gene systems harboring predicted OMs or their mutational counterparts were introduced into HeLa and NCCIT cells with varying OCT4A protein levels. The transcription of dsGFP reflecting FOS expression was quantitated by RT-qPCR, the OCT4A-OMs binding and the correlation between OCT4A and FOS transcription was determined by ChIP-PCR and RNA-Seq, respectively. In NCCIT cells, abundant OCT4A proteins bound to and inhibited OM1 and OM2 at the promoter of the FOS gene. RA-induced OCT4A down-regulation transiently increased FOS transcription. In contrast, in HeLa cells that contain much lower levels of endogenous OCT4A proteins, OCT4A primarily bound to and activate OM1 thereby promoting FOS transcription. OCT4A KO significantly reduced FOS expression. Ectopically introduced OCT4A, at its leaked or induced expression level, promoted FOS transcription by binding to OM2/OM3 or OM1/OM3, respectively. Thus, the interaction of OCT4A proteins with different OMs is cellular context- and protein level-dependent, and such complicated OCT4A binding mode can only be reflected by a dsGFP-based reporter harboring the full-length FOS gene but not by that merely having the FOS promoter. Our findings unravel an additional layer of regulatory mechanisms that account for the cellular context- and dose-related versatile functions of OCT4A protein, and further underscore the importance of precise modulation of OCT4A in the regenerative medicine and anticancer therapies. 1) Both two reporter gene assays revealed that OCT4A-OMs interaction patterns and the corresponding regulatory effects on c-FOS transcription vary in SCCs and PSCs with multiple OCT4A protein levels. 2) The reporter system harboring the full-length FOS gene but not by that merely having the FOS promoter reflects physiological conditions. (Numbered round corner boxes: OMs, blue/red arrow: negative/positive regulatory effect, respectively, blue-red mixed arrow: either negative or regulatory effect depending on OCT4A protein level). Unlabelled Image [ABSTRACT FROM AUTHOR]

In this study, we show that changes in electricity prices in China have significant environmental consequences through its effect on industrial pollution emissions concentrations. To investigate this relationship, we pair a novel dataset of hourly smokestack-level pollutant emissions of industrial plants in Anhui, China with changes in hourly electricity prices. Using a difference-in-differences (DID) regression model, we find that pollution emissions from these plants have an inverse relationship with electricity prices. This relationship is most prominent for firms in the highly competitive and energy-intensive sectors of metals and cement production. On average, we find that a 1% decrease in electricity price leads to around 1%–5.8% increase in sulfur dioxide and particulate matters emissions concentrations. Similarly, we also found impacts on the number of hours in which emissions were observed. These results suggest that electricity prices could be an effective policy tool for managing air pollution – a challenge currently faced by many low- and middle-income countries. More generally, policymakers need to be cognizant that electricity sector-related policies could generate unintended consequences for the environment. • Exploit changes in electricity prices in Anhui (China) to show that electricity price affects pollution emissions. • Statistical inferences are greatly aided by hourly data on smokestack level emissions and the unique policy change scenario. • Analyses are conducted along dimensions of three sectors, two air pollutants, and two measures of pollution emissions. • We implemented numerous robustness checks to ensure our results are not confounded. [ABSTRACT FROM AUTHOR]

In this paper, a stochastic SIRS model with standard incidence rate and partial temporary immunity is proposed. The sufficient conditions of the extinction and the existence of a stationary probability measure for the disease are established. Our results reveal that random perturbations in the environment can restrain the spread of disease. That is, the deterministic model neglecting random perturbations overestimates the ability of the disease to spread. The numerical simulations are carried out to demonstrate the analytical results. [ABSTRACT FROM AUTHOR]

Liver kinase B1 (LKB1), a serine/threonine protein, is a key regulator in stem cell function and energy metabolism. Herein, we describe the role of LKB1 in modulating the differentiation of synovium‐derived stem cells (SDSCs) toward chondrogenic, adipogenic, and osteogenic lineages. Human fetal SDSCs were transduced with CRISPR associated protein 9 (Cas9)‐single‐guide RNA vectors to knockout or lentiviral vectors to overexpress the LKB1 gene. Analyses including ICE (Inference of CRISPR Edits) data from Sanger sequencing and quantitative polymerase chain reaction (qPCR) as well as Western blot demonstrated successful knockout (KO) or overexpression (OE) of LKB1 in human fetal SDSCs without any detectable side effects in morphology, proliferation rate, and cell cycle. LKB1 KO increased CD146 expression; interestingly, LKB1 OE increased SSEA4 level. The qPCR data showed that LKB1 KO upregulated the levels of SOX2 and NANOG while LKB1 OE lowered the expression of POU5F1 and KLF4. Furthermore, LKB1 KO enhanced, and LKB1 OE inhibited, chondrogenic and adipogenic differentiation potential. However, perhaps due to the inherent inability to achieve osteogenesis, LKB1 did not obviously affect osteogenic differentiation. These data demonstrate that LKB1 plays a significant role in determining human SDSCs' adipogenic and chondrogenic differentiation, which might provide an approach for fine‐tuning the direction of stem cell differentiation in tissue engineering and regeneration. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:258‐268, 2020 [ABSTRACT FROM AUTHOR]

An integrated engineering strategy is conducted to develop the cyanine-based activatable NIR-II nanoplatforms with bright, stable emission and high specificity. [Display omitted] High-quality second near-infrared (NIR-II) nanoprobes are of great significance for real-time bioimaging and medical diagnosis. Cyanine is an important class of fluorophores to construct activatable probes; however, there are still significant challenges hindering their biological applications, including weak fluorescence in aqueous solution, instability, and insufficient specificity. Herein, an integrated engineering strategy is conducted to develop the cyanine-based activatable NIR-II nanoplatforms with bright, stable emission and high specificity. Specifically, poly(styrene- co -maleic anhydride) (PSMA) is employed to encapsulate NIR-II fluorescent molecules (IR1048) to render the stable and bright NIR-II nanoparticles (PSMA@IR1048 NPs). By charge-modulated strategy, a series of cyanine-fluorophores are loaded on the surface of PSMA@IR1048 NPs and exhibit tunable response toward reactive species. Combing those two strategies, NIR-II ratiometric fluorescent nanoprobes (RNPs, including RNP1, RNP2, and RNP3) are constructed; among them, RNP2 displays hypochlorous acid (HClO) responsive performance and generates a higher NIR-II fluorescent ratio (FL2/FL1) signal. Such nanoprobe can reliably report the pathological HClO level in models of diabetic liver injury and lower limb ischemia–reperfusion (I/R) injury mice. Our study paves an engineering strategy to construct cyanine-based stable, bright, and specific NIR-II probes for bioimaging. [ABSTRACT FROM AUTHOR]

The accurate, rapid, and sensitive identification of cancer cells in complex physiological environments is significant in biological studies, personalized medicine, and biomedical engineering. Inspired by the naturally confined enzymes on fluid cell membranes, a fluidly confined CRISPR‐based DNA reporter (FINDER) was developed on living cell membranes, which was successfully applied for rapid and sensitive cancer cell identification in clinical blood samples. Benefiting from the spatial confinement effect for improved local concentration, and membrane fluidity for higher collision efficiency, the activity of CRISPR‐Cas12a was, for the first time, found to be significantly enhanced on living cell membranes. This new phenomenon was then combined with multiple aptamer‐based DNA logic gate for cell recognition, thus a FINDER system capable of accurate, rapid and sensitive cancer cell identification was constructed. The FINDER rapidly identified target cells in only 20 min, and achieved over 80 % recognition efficiency with only 0.1 % of target cells presented in clinical blood samples, indicating its potential application in biological studies, personalized medicine, and biomedical engineering. [ABSTRACT FROM AUTHOR]

The accurate, rapid, and sensitive identification of cancer cells in complex physiological environments is significant in biological studies, personalized medicine, and biomedical engineering. Inspired by the naturally confined enzymes on fluid cell membranes, a fluidly confined CRISPR‐based DNA reporter (FINDER) was developed on living cell membranes, which was successfully applied for rapid and sensitive cancer cell identification in clinical blood samples. Benefiting from the spatial confinement effect for improved local concentration, and membrane fluidity for higher collision efficiency, the activity of CRISPR‐Cas12a was, for the first time, found to be significantly enhanced on living cell membranes. This new phenomenon was then combined with multiple aptamer‐based DNA logic gate for cell recognition, thus a FINDER system capable of accurate, rapid and sensitive cancer cell identification was constructed. The FINDER rapidly identified target cells in only 20 min, and achieved over 80 % recognition efficiency with only 0.1 % of target cells presented in clinical blood samples, indicating its potential application in biological studies, personalized medicine, and biomedical engineering. [ABSTRACT FROM AUTHOR]

Background: Natural killer (NK) cells hold great promise in treating diverse hematopoietic and solid tumors. Despite their availability from peripheral blood and cord blood, stem cell-derived NK cells offer an 'off-the-shelf' solution. Hematopoietic stem and progenitor cells (HSPCs) derived from cord blood pose no risk to the newborn or mother and are virtually ideal sources for NK cell differentiation. Methods: We developed a modified protocol to differentiate HSPCs to NK cells under serum-free conditions using defined factors. The HSPC-derived NK (HSC-NK) cells could be expanded in a K562 feeder cell-dependent manner. Furthermore, using lentivirus transduction, chimeric antigen receptor (CAR)-modified HSPCs could be differentiated into NK cells, leading to the establishment of CAR-NK cells. Results: The efficiency of NK cell differentiation from HSPCs was increased through the simple modulation of osmotic pressure by the addition of sodium chloride or glucose. Furthermore, the hyperosmosis-primed HSC-NK cells exhibited enhanced proliferation capacity and maintained normal functional characteristics, including transcriptome and antitumor efficacy. The optimized protocol yielded approximately 1.8 million NK cells from a single CD34-positive cell within a 28-day cycle, which signifies more than a ten-fold increase in efficiency relative to the conventional methods. This optimized protocol was also suitable for generating CAR-NK cells with high yields compared to standard conditions. Conclusions: The results of this study establish high osmotic pressure as a simple yet powerful adjustment that significantly enhances the efficiency and functionality of HSC-NK cells, including CAR-NK cells. This optimized protocol could lead to cost-effective, high-yield NK cell therapies, potentially revolutionizing cancer immunotherapy strategies. [ABSTRACT FROM AUTHOR]

DNA‐based probes have gained significant attention as versatile tools for biochemical analysis, benefiting from their programmability and biocompatibility. However, most existing DNA‐based probes rely on fluorescence as the signal output, which can be problematic due to issues like autofluorescence and scattering when applied in complex biological materials such as living cells or tissues. Herein, we report the development of bioluminescent nucleic acid (bioLUNA) sensors that offer laser excitation‐independent and ratiometric imaging of the target in vivo. The system is based on computational modelling and mutagenesis investigations of a genetic fusion between circular permutated Nano‐luciferase (NLuc) and HaloTag, enabling the conjugation of the protein with a DNAzyme. In the presence of Zn2+, the DNAzyme sensor releases the fluorophore‐labelled strand, leading to a reduction in bioluminescent resonance energy transfer (BRET) between the luciferase and fluorophore. Consequently, this process induces ratiometric changes in the bioluminescent signal. We demonstrated that this bioLUNA sensor enabled imaging of both exogenous Zn2+in vivo and endogenous Zn2+ efflux in normal epithelial prostate and prostate tumors. This work expands the DNAzyme sensors to using bioluminescence and thus has enriched the toolbox of nucleic acid sensors for a broad range of biomedical applications. [ABSTRACT FROM AUTHOR]

Fluorescence imaging utilizing traditional organic fluorophores is extensively applied in both cellular and in vivo studies. However, it faces significant obstacles, such as low signal‐to‐background ratio (SBR) and spurious positive/negative signals, primarily due to the facile diffusion of these fluorophores. To cope with this challenge, orderly self‐assembled functionalized organic fluorophores have gained significant attention in the past decades. These fluorophores can create nanoaggregates via a well‐ordered self‐assembly process, thus prolonging their residency time within cells and in vivo settings. The development of self‐assembled‐based fluorophores is an emerging field, and as such, in this review, we present a summary of the progress and challenges of self‐assembly fluorophores, focusing on their development history, self‐assembly mechanisms, and biomedical applications. We hope that the insights provided herein will assist scientists in further developing functionalized organic fluorophores for in situ imaging, sensing, and therapy. [ABSTRACT FROM AUTHOR]

DNA‐based probes have gained significant attention as versatile tools for biochemical analysis, benefiting from their programmability and biocompatibility. However, most existing DNA‐based probes rely on fluorescence as the signal output, which can be problematic due to issues like autofluorescence and scattering when applied in complex biological materials such as living cells or tissues. Herein, we report the development of bioluminescent nucleic acid (bioLUNA) sensors that offer laser excitation‐independent and ratiometric imaging of the target in vivo. The system is based on computational modelling and mutagenesis investigations of a genetic fusion between circular permutated Nano‐luciferase (NLuc) and HaloTag, enabling the conjugation of the protein with a DNAzyme. In the presence of Zn2+, the DNAzyme sensor releases the fluorophore‐labelled strand, leading to a reduction in bioluminescent resonance energy transfer (BRET) between the luciferase and fluorophore. Consequently, this process induces ratiometric changes in the bioluminescent signal. We demonstrated that this bioLUNA sensor enabled imaging of both exogenous Zn2+in vivo and endogenous Zn2+ efflux in normal epithelial prostate and prostate tumors. This work expands the DNAzyme sensors to using bioluminescence and thus has enriched the toolbox of nucleic acid sensors for a broad range of biomedical applications. [ABSTRACT FROM AUTHOR]

Fluorescence imaging utilizing traditional organic fluorophores is extensively applied in both cellular and in vivo studies. However, it faces significant obstacles, such as low signal‐to‐background ratio (SBR) and spurious positive/negative signals, primarily due to the facile diffusion of these fluorophores. To cope with this challenge, orderly self‐assembled functionalized organic fluorophores have gained significant attention in the past decades. These fluorophores can create nanoaggregates via a well‐ordered self‐assembly process, thus prolonging their residency time within cells and in vivo settings. The development of self‐assembled‐based fluorophores is an emerging field, and as such, in this review, we present a summary of the progress and challenges of self‐assembly fluorophores, focusing on their development history, self‐assembly mechanisms, and biomedical applications. We hope that the insights provided herein will assist scientists in further developing functionalized organic fluorophores for in situ imaging, sensing, and therapy. [ABSTRACT FROM AUTHOR]

Carboxylesterase (CE) is crucial in metabolizing ester-containing biomolecules and is particularly significant in liver metabolic diseases. Herein, we present the first activatable NIRF/PA dual-mode imaging probe QHD-CE for detection of CE in vitro and in vivo. QHD-CE displays excellent sensitivity and selectivity for CE with a high reaction efficiency (∼90 min). By utilizing QHD-CE, the dynamic changes of CE in drug-induced liver injury and diabetic mice models were monitored. [ABSTRACT FROM AUTHOR]

While fluorescent sensors have been developed for monitoring metal ions in health and diseases, they are limited by the requirement of an excitation light source that can lead to photobleaching and a high autofluorescence background. To address these issues, bioluminescence resonance energy transfer (BRET)-based protein or small molecule sensors have been developed; however, most of them are not highly selective nor generalizable to different metal ions. Taking advantage of the high selectivity and generalizability of DNAzymes, we report herein DNAzyme-based ratiometric sensors for Zn2+ based on BRET. The 8-17 DNAzyme was labeled with luciferase and Cy3. The proximity between luciferase and Cy3 permitted BRET when coelenterazine, the substrate for luciferase, was introduced. Adding samples containing Zn2+ resulted in a cleavage of the substrate strand, causing dehybridization of the DNAzyme construct, thus increasing the distance between Cy3 and luciferase and changing the BRET signals. Using these sensors, we detected Zn2+ in serum samples and achieved Zn2+ detection with a smartphone camera. Moreover, since the BRET pair is not the component that determines the selectivity of the sensors, this sensing platform has the potential to be adapted for the detection of other metal ions with other metal-dependent DNAzymes. [ABSTRACT FROM AUTHOR]

We investigate a stochastic heroin epidemic model with bilinear incidence and varying population size. Sufficient criteria for the extinction of the drug abusers and the existence of ergodic stationary distribution for the model are established by constructing suitable stochastic Lyapunov functions. By analyzing the sensitivity of the threshold of spread, we obtain that prevention is better than cure. Numerical simulations are carried out to confirm the analytical results. [ABSTRACT FROM AUTHOR]

Although preconditioning strategies are growing areas of interest for therapies targeting intervertebral discs (IVDs), it is unknown whether the Wnt signals previously implicated in chondrogenesis, Wnt3A, Wnt5A, and Wnt11, play key roles in the promotion of human nucleus pulposus (NP) cell redifferentiation. In this study, NP cells isolated from herniated disc patients were transduced with lentiviral vectors to overexpress the WNT3A, WNT5A, or WNT11 genes, or CRISPR associated protein 9 (Cas9)/single‐guide RNA (sgRNA) vectors to knock out these genes. Following expansion, transduced NP cells were induced for redifferentiation toward the NP phenotype. The overexpression of specific WNT factors led to increases in both glycosaminoglycan (GAG) deposition and expression of redifferentiation genes. These effects were attenuated by knockout of the same WNT genes. These results indicate that specific WNT signals can regulate the expression of redifferentiation genes, unequally impact GAG deposition, and contribute to the redifferentiation of human NP cells. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:3196–3207, 2018. Nucleus pulposus (NP) cells isolated from herniated disc patients were transduced with lentiviral vectors to overexpress the WNT3A, WNT5A, or WNT11 genes, or CRISPR associated protein 9 (Cas9)/single‐guide RNA (sgRNA) vectors to knock out these genes. Following expansion, transduced NP cells were induced for redifferentiation toward the NP phenotype. The overexpression of specific WNT factors led to increases in both glycosaminoglycan deposition and expression of redifferentiation genes, which were attenuated by knockout of the same WNT genes. [ABSTRACT FROM AUTHOR]

Organic afterglow nanoparticles are unique optical materials that emit light long after cessation of excitation. Due to their advantages of no need for real‐time light excitation, avoiding autofluorescence, low imaging background, high signal‐to‐background ratio, deep tissue penetration, and high sensitivity, afterglow imaging technology has been widely used in cell tracking, biosensing, cancer diagnosis, and cancer therapy, which provides an effective technical method for the acquisition of molecular information with high sensitivity, specificity and real‐time at the cellular and living level. In this review, we summarize and illustrate the recent progress of organic afterglow imaging, focusing on the mechanism of organic afterglow materials and their biological application. Furthermore, we also discuss the potential challenges and the further directions of this field. [ABSTRACT FROM AUTHOR]

Mature microRNAs (miRNAs) in extracellular vesicles (EVs) are involved in different stages of cancer progression, yet it remains challenging to precisely detect mature miRNAs in EVs due to the presence of interfering RNAs (such as longer precursor miRNAs, pre‐miRNAs) and the low abundance of tumor‐associated miRNAs. By leveraging the size‐selective ability of DNA cages and polyethylene glycol (PEG)‐enhanced thermophoretic accumulation of EVs, we devised a DNA cage‐based thermophoretic assay for highly sensitive, selective, and in situ detection of mature miRNAs in EVs with a low limit of detection (LoD) of 2.05 fM. Our assay can profile EV mature miRNAs directly in serum samples without the interference of pre‐miRNAs and the need for ultracentrifugation. A clinical study showed that EV miR‐21 or miR‐155 had an overall accuracy of 90 % for discrimination between breast cancer patients and healthy donors, which outperformed conventional molecular probes detecting both mature miRNAs and pre‐miRNAs. We envision that our assay can advance EV miRNA‐based diagnosis of cancer. [ABSTRACT FROM AUTHOR]

Mature microRNAs (miRNAs) in extracellular vesicles (EVs) are involved in different stages of cancer progression, yet it remains challenging to precisely detect mature miRNAs in EVs due to the presence of interfering RNAs (such as longer precursor miRNAs, pre‐miRNAs) and the low abundance of tumor‐associated miRNAs. By leveraging the size‐selective ability of DNA cages and polyethylene glycol (PEG)‐enhanced thermophoretic accumulation of EVs, we devised a DNA cage‐based thermophoretic assay for highly sensitive, selective, and in situ detection of mature miRNAs in EVs with a low limit of detection (LoD) of 2.05 fM. Our assay can profile EV mature miRNAs directly in serum samples without the interference of pre‐miRNAs and the need for ultracentrifugation. A clinical study showed that EV miR‐21 or miR‐155 had an overall accuracy of 90 % for discrimination between breast cancer patients and healthy donors, which outperformed conventional molecular probes detecting both mature miRNAs and pre‐miRNAs. We envision that our assay can advance EV miRNA‐based diagnosis of cancer. [ABSTRACT FROM AUTHOR]

Probes allowing high‐contrast discrimination of cancer cells and effective retention are powerful tools for the early diagnosis and treatment of cancer. However, conventional small‐molecule probes often show limited performance in both aspects. Herein, we report an ingenious molecular engineering strategy for tuning the cellular uptake and retention of rhodamine dyes. Introduction of polar aminoethyl leads to the increased brightness and reduced cellular uptake of dyes, and this change can be reversed by amino acetylation. Moreover, these modifications allow cancer cells to take up more dyes than normal cells (16‐fold) through active transport. Specifically, we further improve the signal contrast (56‐fold) between cancer and normal cells by constructing activatable probes and confirm that the released fluorophore can remain in cancer cells with extended time, enabling long‐term and specific tumor imaging. [ABSTRACT FROM AUTHOR]

Probes allowing high‐contrast discrimination of cancer cells and effective retention are powerful tools for the early diagnosis and treatment of cancer. However, conventional small‐molecule probes often show limited performance in both aspects. Herein, we report an ingenious molecular engineering strategy for tuning the cellular uptake and retention of rhodamine dyes. Introduction of polar aminoethyl leads to the increased brightness and reduced cellular uptake of dyes, and this change can be reversed by amino acetylation. Moreover, these modifications allow cancer cells to take up more dyes than normal cells (16‐fold) through active transport. Specifically, we further improve the signal contrast (56‐fold) between cancer and normal cells by constructing activatable probes and confirm that the released fluorophore can remain in cancer cells with extended time, enabling long‐term and specific tumor imaging. [ABSTRACT FROM AUTHOR]

Mesenchymal stromal cells (MSCs) have great value in cell therapies. The MSC therapies have many challenges due to its inconsistent potency and limited quantity. Here, we report a strategy to generate induced MSCs (iMSCs) by directly reprogramming human peripheral blood mononuclear cells (PBMCs) with OCT4, SOX9, MYC, KLF4, and BCL-XL using a nonintegrating episomal vector system. While OCT4 was not required to reprogram PBMCs into iMSCs, omission of OCT4 significantly impaired iMSC functionality. The omission of OCT4 resulted in significantly downregulating MSC lineage specific and mesoderm-regulating genes, including SRPX, COL5A1, SOX4, SALL4, TWIST1. When reprogramming PBMCs in the absence of OCT4, 67 genes were significantly hypermethylated with reduced transcriptional expression. These data indicate that transient expression of OCT4 may serve as a universal reprogramming factor by increasing chromatin accessibility and promoting demethylation. Our findings represent an approach to produce functional MSCs, and aid in identifying putative function associated MSC markers. Induced MSCs (iMSCs) are generated by direct reprogramming of human PBMCs using 5 factor transfection, including OCT4, SOX9, MYC, KLF4, and BCL-XL. [ABSTRACT FROM AUTHOR]

The development of photothermal agents (PTAs) with robust photostability and high photothermal conversion efficiency is of great importance for cancer photothermal therapy. Herein, a novel PTA was created using two‐dimensional intermetallic PtSnBi nanoplates (NPs), which demonstrated excellent photostability and biocompatibility with a high photothermal conversion efficiency of ∼61 % after PEGylation. More importantly, PtSnBi NPs could be employed as photoacoustic imaging contrast agents for tumor visualization due to their strong absorbance in the NIR range. In addition, both in vitro and in vivo experiments confirmed that PtSnBi NPs had a good photothermal efficacy under NIR laser irradiation. Therefore, the remarkable therapeutic characteristics of PtSnBi NPs make them a most promising candidate for cancer theranostics. [ABSTRACT FROM AUTHOR]

Recently, supramolecular chemistry with its unique properties has received considerable attention in many fields. Supramolecular fluorescent systems constructed on the basis of macrocyclic hosts are not only effective in overcoming the limitations of imaging and diagnostic reagents, but also in enhancing their performances. This paper summarizes the recent advances in supramolecular fluorescent systems based on host–guest interactions and their application in bioimaging and therapy as well as the challenges and prospects in developing novel supramolecular fluorescent systems. [ABSTRACT FROM AUTHOR]

Probes allowing high‐contrast discrimination of cancer cells and effective retention are powerful tools for the early diagnosis and treatment of cancer. However, conventional small‐molecule probes often show limited performance in both aspects. Herein, we report an ingenious molecular engineering strategy for tuning the cellular uptake and retention of rhodamine dyes. Introduction of polar aminoethyl leads to the increased brightness and reduced cellular uptake of dyes, and this change can be reversed by amino acetylation. Moreover, these modifications allow cancer cells to take up more dyes than normal cells (16‐fold) through active transport. Specifically, we further improve the signal contrast (56‐fold) between cancer and normal cells by constructing activatable probes and confirm that the released fluorophore can remain in cancer cells with extended time, enabling long‐term and specific tumor imaging. [ABSTRACT FROM AUTHOR]

The second near‐infrared (NIR‐II) fluorescent imaging shows great potential for deep tissue analysis at high resolution in living body owing to low background autofluorescence and photon scattering. However, reversible monitoring of redox homeostasis using NIR‐II fluorescent imaging remains a challenge due to the lack of appropriate probes. In this study, a series of stable and multifunctional NIR‐II dyes (NIR‐II Cy3s) were constructed based on trimethine skeleton. Significantly, introducing the 1,4‐diethyl‐decahydroquinoxaline group to the NIR‐II Cy3s not only effectively increased the wavelength, but also served as an effective response site for HClO, which can be restored by reactive sulfur species (RSS). Based on this, NIR‐II Cy3s were used for reversible monitoring of HClO/RSS‐mediated redox processes in the pathophysiology environment. Finally, NIR‐II Cy3‐988 was successfully utilized for assessment of the redox environments and drug treatment effects in acute inflammation model. [ABSTRACT FROM AUTHOR]

The second near‐infrared (NIR‐II) fluorescent imaging shows great potential for deep tissue analysis at high resolution in living body owing to low background autofluorescence and photon scattering. However, reversible monitoring of redox homeostasis using NIR‐II fluorescent imaging remains a challenge due to the lack of appropriate probes. In this study, a series of stable and multifunctional NIR‐II dyes (NIR‐II Cy3s) were constructed based on trimethine skeleton. Significantly, introducing the 1,4‐diethyl‐decahydroquinoxaline group to the NIR‐II Cy3s not only effectively increased the wavelength, but also served as an effective response site for HClO, which can be restored by reactive sulfur species (RSS). Based on this, NIR‐II Cy3s were used for reversible monitoring of HClO/RSS‐mediated redox processes in the pathophysiology environment. Finally, NIR‐II Cy3‐988 was successfully utilized for assessment of the redox environments and drug treatment effects in acute inflammation model. [ABSTRACT FROM AUTHOR]

An abstract of the article "HOXB4 Overexpression Expands Short-Term Repopulating Cells in Nonhuman Primates and Dogs," by Xiao-Bing Zhang, Laura J. Peterson, Alixandra A. Knapp, Brian C. Beard, R. Keith Humphries and Hans-Peter Kiem is presented.

Herein, we report a new click-activated prodrug, CA4V, and a bioorthogonal nanoreactor, CA4V/ZIF-90@TzCOF@Apt, which consists of a ZIF-90 core, tetrazine-based covalent organic framework (COF) shells and an aptamer polymer coating. When targeting a tumor, the acid-causing collapse of ZIF-90 initiates a nanoconfined bioorthogonal reaction in defined COF cages, which boosts the click efficiency of CA4V activation and therapeutic effects in vivo. [ABSTRACT FROM AUTHOR]

Disease signaling molecules and biomarkers are important in biosensing and biomedicine, and their ultra‐sensitive detection and imaging are critical in medical diagnosis. However, most biomarkers have low levels of expression in cells and are easily degraded; therefore, they cannot be accurately detected in real time by conventional amplification methods, which are typically confined to cell lysates. To achieve highly sensitive detection of intracellular low‐abundance molecules, extensive efforts have been devoted to the development of in situ signal amplification techniques. This review tracks the development of recent advances in in situ signal amplification strategies, and systematically summarizes the advantages and disadvantages of enzymatic and non‐enzymatic amplification techniques for detecting and tracing intracellular targets. Further, perspectives, challenges, and opportunities for intracellular signal amplification are discussed to promote its adoption for in situ signal amplification in clinical settings and to provide new insights into signaling molecules and biomarkers in cellular functions and associated diseases. [ABSTRACT FROM AUTHOR]

Tumor‐specific, hypoxia‐activated prodrugs have been developed to alleviate the side effects of chemotherapy drugs. However, the release efficiency of hypoxia‐activated prodrugs is restricted by the degree of tumor hypoxia, which further leads to poor cancer treatment effects. On the other hand, oxygen is consumed gradually in photodynamic therapy (PDT), which aggravates hypoxia at the tumor site. In this study, we combined hypoxia‐activated prodrugs with PDT agents to promote the prodrugs release, thereby improving their bioavailability and therapeutic effects. As a proof of concept, a mitochondria‐targeted molecular prodrug, CS‐P, was designed and synthesized. It can be selectively activated by tumor hypoxia to release chemotherapeutic drugs and photosensitizers, and then further discharge drugs after light irradiation. The design strategy proposed in this paper provides a new idea for enhancing hypoxia‐activated prodrug release and real‐time monitoring prodrug release. [ABSTRACT FROM AUTHOR]

Tumor‐specific, hypoxia‐activated prodrugs have been developed to alleviate the side effects of chemotherapy drugs. However, the release efficiency of hypoxia‐activated prodrugs is restricted by the degree of tumor hypoxia, which further leads to poor cancer treatment effects. On the other hand, oxygen is consumed gradually in photodynamic therapy (PDT), which aggravates hypoxia at the tumor site. In this study, we combined hypoxia‐activated prodrugs with PDT agents to promote the prodrugs release, thereby improving their bioavailability and therapeutic effects. As a proof of concept, a mitochondria‐targeted molecular prodrug, CS‐P, was designed and synthesized. It can be selectively activated by tumor hypoxia to release chemotherapeutic drugs and photosensitizers, and then further discharge drugs after light irradiation. The design strategy proposed in this paper provides a new idea for enhancing hypoxia‐activated prodrug release and real‐time monitoring prodrug release. [ABSTRACT FROM AUTHOR]

Ferroptosis exhibits potential to damage drug‐resistant cancer cells. However, it is still restricted with the "off‐target" toxicity from the undesirable leakage of metal ions from ferroptosis agents, and the lack of reliable imaging for monitoring the ferroptosis process in living systems. Herein, we develop a novel ternary alloy PtWMn nanocube as a Mn reservoir, and further design a microenvironment‐triggered nanoplatform that can accurately release Mn ions within the tumor to increase reactive oxygen species (ROS) generation, produce O2 and consume excess glutathione for synergistically enhancing nonferrous ferroptosis. Moreover, this nanoplatform exerts a responsive signal in high‐field magnetic resonance imaging (MRI), which enables the real‐time report of Mn release and the monitoring of ferroptosis initiation through the signal changes of T1‐/T2‐MRI. Thus, our nanoplatform provides a novel strategy to store, deliver and precisely release Mn ions for MRI‐guided high‐specificity ferroptosis therapy. [ABSTRACT FROM AUTHOR]

Ferroptosis exhibits potential to damage drug‐resistant cancer cells. However, it is still restricted with the "off‐target" toxicity from the undesirable leakage of metal ions from ferroptosis agents, and the lack of reliable imaging for monitoring the ferroptosis process in living systems. Herein, we develop a novel ternary alloy PtWMn nanocube as a Mn reservoir, and further design a microenvironment‐triggered nanoplatform that can accurately release Mn ions within the tumor to increase reactive oxygen species (ROS) generation, produce O2 and consume excess glutathione for synergistically enhancing nonferrous ferroptosis. Moreover, this nanoplatform exerts a responsive signal in high‐field magnetic resonance imaging (MRI), which enables the real‐time report of Mn release and the monitoring of ferroptosis initiation through the signal changes of T1‐/T2‐MRI. Thus, our nanoplatform provides a novel strategy to store, deliver and precisely release Mn ions for MRI‐guided high‐specificity ferroptosis therapy. [ABSTRACT FROM AUTHOR]