Confocal Fluorescence Imaging Research Articles

Comprehensive property combination for biomedical application achieved in a Ti35Zr35Nb15Mo5Fe5Cr5 complex concentrated alloy

A novel Ti35Zr35Nb15Mo5Fe5Cr5 complex concentrated alloy (CCA) with potential for biomedical application was developed by vacuum arc melting and its microstructural evolution, mechanical properties, corrosion and wear behavior, and cytocompatibility were systematically evaluated. The alloy has an experimentally measured density of 6.37 g/cm³, suitable to fulfill the requirement of light weight. XRD analysis revealed that the as-cast and annealed specimens contain two BCC solid solution phases and a TiCr2 type Laves phase. The average microhardness (H) and elastic modulus (E) of the as-cast CCA are 618.39 ± 9.26 HV and 97.32 ± 3.58 GPa, respectively. Moreover, the yield strength (YS) of the as-cast alloy, estimated from elastoplastic analysis of the microindentation data, is 1203.94 ± 30.28 MPa. However, the CCA annealed at 1100˚C exhibits a microhardness of 833.08 ± 7.58 HV and a YS of 1669.65 ± 24.79 MPa, with the elastoplastic stress-strain response revealing no significant loss of plasticity due to the increased hard Laves phase. Corrosion and wear tests conducted in simulated body fluid confirmed the alloy's excellent corrosion and wear resistance. Cell culture experiments with MG-63 and HEK-293 cells demonstrated superior cell viability and proliferation compared to CP-Ti and 316 L SS. Moreover, confocal fluorescence images of MG-63 cells stained with AO/EtBr, Rh-123, and DCFH-DA revealed that the present CCA exhibits good biocompatibility. Thus, a comprehensive combination of low density, compatible elastic modulus, good strength with adequate plasticity, and sufficient corrosion resistance and biocompatibility were successfully achieved, unraveling significant potential of the alloy for biomedical applications.

Betaine-Modified Green Carbon Dot for Cr(VI) Sensing, in Vivo Cr(VI) Imaging, and Growth Promotion in the Rice Plant.

Hexavalent chromium is a toxic environmental pollutant that damages plants due to disruption of nutrient uptake, photosynthesis metabolism, and oxidative stress, which suppresses the growth and development of the plant. In this work, we have developed a betaine-modified carbon dot (BT@CD) sensor for monitoring Cr(VI) in water and plants. Fluorescent carbon dots have been synthesized using jamun juice (Syzygium cumini) as the carbon source subjected to surface modification with betaine (BT@JCD). This BT@JCD exhibits strong blue fluorescence, which significantly decreases in the presence of Cr(VI) due to the inner filter effect in a range of 5-450 nM with a detection limit of 0.033 μM. Due to its easy translocation in the vascular bundles, these fluorescence nanosensors can be applied to detect Cr(VI) in rice plants Oryza sativa) through fluorescence confocal imaging. The treatment of rice plants with BT@JCDs in the concentration range of 0.2 to 1g/mL not only triggered photophysical parameters such as carbohydrates, chlorophyll, and carotenoids but also enhanced the antioxidant enzyme activity promoting plant growth.

Edwardsiella piscicida promotes mitophagy to escape autophagy-mediated antibacterial defense in teleost monocytes/macrophages

Edwardsiella piscicida is a Gram-negative intracellular pathogen. Currently, the immune evasion strategies of E. piscicida are not yet fully understood. In this study, we revealed that E. piscicida exploited mitophagy to enhance its intracellular survival in grass carp (Ctenopharyngodon idella) monocytes/macrophages. The results showed that in E. piscicida-infected cells, there was a significant loss of mitochondrial membrane potential and a marked increase in the production of mitochondrial reactive oxygen species (mtROS), indicating the damage to the mitochondria in the infected cells. Furthermore, fluorescence confocal images presented that E. piscicida infection elicited the colocalization of mitochondria with microtubule-associated protein 1 light chain 3 (LC3, a key marker molecule of autophagy) and lysosomes, suggesting the occurrence of mitophagy. This notion was supported by the findings that E. piscicida significantly stimulated LC3-II protein and damped Tom20 (a marker molecule of mitochondria) protein levels. Subsequently, a mitophagy inducer carbonyl cyanide m-chlorophenyl hydrazine (CCCP) and a mitophagy inhibitor mitochondrial division inhibitor 1 (Mdivi-1) were used to evaluate the role of mitophagy in modulating the intracellular survival of E. piscicida. The results revealed that CCCP significantly promoted intracellular survival of E. piscicida, whereas Mdivi-1 hindered the bacterial growth. Moreover, Mdivi-1 further increased the production of bacteria-induced mitochondrial ROS in an additive manner. In particular, CCCP suppressed and Mdivi-1 promoted the colocalization of LC3-II with E. piscicida, implying that E. piscicida-triggered mitophagy to facilitate its growth probably by subverting the autophagy targeting this bacterium, a previously known clearance pathway of E. piscicida. Overall, our findings suggest a new survival strategy employed by E. piscicida within fish monocytes/macrophages.

Supported Supramolecular Hydrogel Nanoarchitectonics for Tunable Biocatalytic Flow Activity.

Enzymatically-active polyelectrolyte multilayers containing n layers of phosphatase (APn-PEM) induce the formation of supported biocatalytic supramolecular hydrogels when brought in contact with the precursor tripeptide Fmoc-FFpY (Fmoc = N-fluorenylmethyloxycarbonyl; F = Phenylalanine; Y = Tyrosine; p = phosphate group). APn-PEM triggers the spatially-localized hydrogelation reaching 2, 17 and 350µm of thickness for n = 1, 2 and 3, respectively. As observed by cryo scanning electron microscopy, a dense nanofibrous network underpinning the hydrogel shows parallelly orientated Fmoc-FFY peptide-based fibrils, perpendicular to the substrate. For the gel generated by the AP3-PEM, fluorescence confocal microscopy images show that during the peptide self-assembly, some enzymes are distributed in the hydrogel, preferentially located in few dozens of micrometers above the substrate. In addition, a self-assembly growth rate of 5µmmin-1 is determined when the hydrogelation starts. Through transmission electron microscopy immuno-labelling experiments on self-assemblies generated in solution, we observe that AP are decorating the Fmoc-FFY nanofibers. It is observed both a long-term stability and a higher biocatalytic activity of the so AP-encapsulated hydrogel compared to the bare APn-PEM. This bioactivity can be tuned by the number n in batch and under continuous flow conditions. To illustrate the versatility of this enzyme-supported strategy, multi-catalytic transformations in continuous flow conditions have been successfully carried out using supported supramolecular hydrogel.

Mesoporous Silica Microparticle-Protein Complexes: Effects of Protein Size and Solvent Properties on Diffusion and Loading Efficiency.

Oral administration of protein-based therapeutics is highly desirable due to lower cost, enhanced patient compliance, and convenience. However, the harsh pH environment of the gastrointestinal tract poses significant challenges. Silica-based carriers have emerged as potential candidates for the delivery of protein molecules, owing to their tuneable surface area and pore volume. We explored the use of a commercial mesoporous silica carrier, SYLOID, for the delivery of octreotide and bovine serum albumin (BSA) using a solvent evaporation method in three different solvents. The loading of proteins into SYLOID was driven by diffusion, as described by the Stokes-Einstein equation. Various parameters were investigated, such as protein size, diffusion, and solubility. Additionally, 3D fluorescence confocal imaging was employed to identify fluorescence intensity and protein diffusion within the carrier. Our results indicated that the loading process was influenced by the molecular size of the protein as octreotide exhibited a higher recovery rate (71%) compared to BSA (32%). The methanol-based loading of octreotide showed uniform diffusion into the silica carrier, whereas water and ethanol loading resulted in the drug being concentrated on the surface, as shown by confocal imaging, and further confirmed by scanning electron microscopy (SEM). Pore volume assessment supported these findings, showing that octreotide loaded with methanol had a low pore volume (1.2cc/g). On the other hand, BSA loading was affected by its solubility in the three solvents, its tendency to aggregate, and its low solubility in ethanol and methanol, which resulted in dispersed particle sizes of 223 and 231μm, respectively. This reduced diffusion into the carrier, as confirmed by fluorescence intensity and diffusivity values. This study underscores the importance of protein size, solvent properties, and diffusion characteristics when using porous carriers for protein delivery. Understanding these factors allows for the development of more effective oral protein-based therapeutics by enhancing loading efficiency. This, in turn, will lead to advances in targeted drug delivery and improved patient outcomes.

Plant cell wall enzymatic deconstruction: Bridging the gap between micro and nano scales

Understanding lignocellulosic biomass resistance to enzymatic deconstruction is crucial for its sustainable conversion into bioproducts. Despite scientific advances, quantitative morphological analysis of plant deconstruction at cell and tissue scales remains under-explored. In this study, an original pipeline is devised, involving four-dimensional (space + time) fluorescence confocal imaging, and a novel computational tool, to track and quantify deconstruction at cell and tissue scales. By applying this pipeline to poplar wood, dynamics of cellular parameters was computed and cellulose conversion during enzymatic deconstruction was measured. Results showed that enzymatic deconstruction predominantly impacts cell wall volume rather than surface area. Additionally, a negative correlation was observed between pre-hydrolysis compactness measures and volumetric cell wall deconstruction rate, whose strength was modulated by enzymatic activity. Results also revealed a strong positive correlation between average volumetric cell wall deconstruction rate and cellulose conversion rate. These findings link key deconstruction parameters across nano and micro scales.

Novel High-Resolution Three-Dimensional Fluorescent Confocal Imaging Resolves Differences in Urinary Sediment

Novel High-Resolution Three-Dimensional Fluorescent Confocal Imaging Resolves Differences in Urinary Sediment

Sensitive Cancer Hypoxia Detection via a Dual-Locking Fluorescence Response System Using Two Hypoxia Indicators.

Hypoxia is intricately associated with various diseases, including ischemia, vascular disorders, and cancer. Particularly in cancer cells, hypoxia promotes tumor growth, cell proliferation, migration, and invasion and enhances treatment resistance, making its detection crucial for cancer diagnosis and therapy. However, methods for detecting hypoxia are limited, often relying on single-detection systems. In this study, we developed a dual-lock-based fluorescent probe that selectively exhibits strong green fluorescence under hypoxic conditions due to simultaneous activity of nitroreductases (NTRs) and hydrogen sulfide (H2S), with a high signal-to-background ratio. The biocompatibility and photophysical properties of the probes were thoroughly investigated through both extracellular and intracellular experimental analyses. Among the synthesized naphthalimide-based probes, the dual-detection probe DNNC demonstrated excellent selectivity and sensitivity to the simultaneous activity of NTR/H2S compared to other single-detection probes. The performance of DNNC was applied to various organ-derived cancer cells and tumor tissue models such as HeLa cell sparoids, enabling spatiotemporal confocal fluorescence imaging and quantitative analysis of hypoxic levels in cancer. Our development of DNNC is expected to significantly advance cancer diagnosis and treatment by molecularly detecting hypoxia associated with cancer aggressiveness, therapy resistance, and unfavorable prognosis.

Somatostatin modulation of initial fusion pores in Ca2+-triggered exocytosis from mouse chromaffin cells.

Somatostatin, a peptide hormone that activates G-protein-coupled receptors, inhibits the secretion of many hormones. This study investigated the mechanisms of this inhibition using amperometry recording of Ca2+-triggered catecholamine secretion from mouse chromaffin cells. Two distinct stimulation protocols, high-KCl depolarization and caffeine, were used to trigger exocytosis, and confocal fluorescence imaging was used to monitor the rise in intracellular free Ca2+. Analysis of single-vesicle fusion events (spikes) resolved the action of somatostatin on fusion pores at different stages. Somatostatin reduced spike frequency, and this reduction was accompanied by prolongation of pre-spike feet and slowing of spike rise times. This indicates that somatostatin stabilizes initial fusion pores and slows their expansion. This action on the initial fusion pore impacted the release mode to favour kiss-and-run over full-fusion. During a spike the permeability of a fusion pore peaks, declines and then settles into a plateau. Somatostatin had no effect on the plateau, suggesting no influence on late-stage fusion pores. These actions of somatostatin were indistinguishable between exocytosis triggered by high-KCl and caffeine, and fluorescence imaging showed that somatostatin had no effect on stimulus-induced rises in cytosolic Ca2+. Our findings thus demonstrate that the signalling cascades activated by somatostatin target the exocytotic machinery that controls the initial and expanding stages of fusion pores, while having no effect on late-stage fusion pores. As a result of its stronger inhibition of full-fusion compared to kiss-and-run, somatostatin will preferentially inhibit the secretion of large peptides over the secretion of small catecholamines. KEY POINTS: Somatostatin inhibits the secretion of various hormones by activating G-protein-coupled receptors. In this study, we used amperometry to investigate the mechanism by which somatostatin inhibits catecholamine release from mouse chromaffin cells. Somatostatin increased pre-spike foot lifetime and slowed fusion pore expansion. Somatostatin inhibited full-fusion more strongly than kiss-and-run. Our results suggest that the initial fusion pore is the target of somatostatin-mediated regulation of hormone release. The stronger inhibition of full-fusion by somatostatin will result in preferential inhibition of peptide release.

Characterizing thrombus adhesion strength on common cardiovascular device materials.

Thrombus formation in blood-contacting medical devices is a major concern in the medical device industry, limiting the clinical efficacy of these devices. Further, a locally formed clot within the device has the potential to detach from the surface, posing a risk of embolization. Clot embolization from blood-contacting cardiovascular devices can result in serious complications like acute ischemic stroke and myocardial infarction. Therefore, clot embolization associated with device-induced thrombosis can be life-threatening and requires an enhanced fundamental understanding of embolization characteristics to come up with advanced intervention strategies. Therefore, this work aims to investigate the adhesive characteristics of blood clots on common biocompatible materials used in various cardiovascular devices. This study focuses on characterizing the adhesion strength of blood clots on materials such as polytetrafluoroethylene (PTFE), polyurethane (PU), polyether ether ketone (PEEK), nitinol, and titanium, frequently used in medical devices. In addition, the effect of incubation time on clot adhesion is explored. Results from this work demonstrated strongest clot adhesion to titanium with 3h of incubation resulting in 1.06 ± 0.20kPa detachment stresses. The clot adhesion strength on titanium was 51.5% higher than PEEK, 35.9% higher than PTFE, 63.1% higher than PU, and 35.4% higher than nitinol. Further, adhesion strength increases with incubation time for all materials. The percentage increase in detachment stress over incubation time (ranging from 30min to 3h) for polymers ranged from at least 108.75% (PEEK), 140.74% (PU), to 151.61% (PTFE). Whereas, for metallic surfaces, the percentage rise ranged from 70.21% (nitinol) to 89.28% (titanium). Confocal fluorescence imaging of clot remnants on the material surfaces revealed a well-bounded platelet-fibrin network at the residual region, representing a comparatively higher adhesive region than the non-residual zone of the surface.

Dual-functional fluorescent probe for imaging ROS and hypoxia dynamic in cancer cells

Hypoxia is able to induce the overexpression of nitroreductase (NTR) in cancer cells. Moreover, there is still the controversy about reactive oxygen species (ROS) change under the hypoxic condition. Herein, we designed and synthesized a fluorescent probe WNO that could simultaneously visualize the fluctuation changes of NTR and ROS in hypoxic HeLa cells. WNO consists of 4-nitro-1,8-naphthalimide group and 2,3,3-trimethyl indolium salt. In buffer 4-nitro-1,8-naphthalimide group could selectively response to NTR in the presence of nicotinamide adenine dinucleotide phosphate (NADH), resulting in a strong green fluorescence. However, upon LED light irradiation 2,3,3-trimethyl indolium salt moiety could efficiently convert into Cy3 emitting a red fluorescence. Furthermore, the monitoring for NTR and photoconversion of WNO in hypoxic HeLa cells were investigated in detail by confocal fluorescence imaging through green and red channels, respectively. It was found that WNO could image the intracellular NTR or hypoxia level. Meanwhile, the WNO photoconversion was accelerated largely in hypoxic cells, which resulted from the production of excessive ROS. WNO and/or its photoconversion product mainly accumulated into the mitochondria. Moreover, MTT assay indicated that LED irradiation or hypoxia treatment made the cytotoxicity of WNO increase by 50 %. Additionally, based on ROS-stimulated the photoconversion of WNO, the intracellular ROS and NTR changes in mitochondrial dysfunction and oxidative stress were also investigated. It indicated that WNO was capable of sensitive and rapid imaging the intracellular ROS and NTR levels under both conditions. These findings would provide an excellent foundation for cancer diagnosis and therapy.

Tunneling nanotubes mediate KRas transport: Inducing tumor heterogeneity and altering cellular membrane mechanical properties

Mutation in oncogene KRas plays a crucial role in the occurrence and progression of numerous malignant tumors. Malignancy involves changes in cell mechanics for extensive cellular deformation during metastatic dissemination. We hypothesize that oncogene KRas mutations are intrinsic to alterations in cellular mechanics that promote malignant tumor generation and progression. Here, we demonstrate the use of optical tweezers coupled with a confocal fluorescence imaging system and gene interference technique to reveal that the mutant KRas protein can be transported between homogeneous and heterogeneous tumor cells by tunneling nanotubes (TNTs), resulting in a significant reduction of membrane tension and acceleration of membrane phospholipid flow in the recipient cells. Simultaneously, the changes in membrane mechanical properties of the tumor cells also enhance the metastatic and invasive ability of the tumors, which further contribute to the deterioration of the tumors. This finding helps to clarify the association between oncogene mutations and changes in the mechanical properties of tumor cells, which provides a theoretical basis for the development of cancer treatment strategies. Statement of significanceHere, we present a laser confocal fluorescence system integrated with optical tweezers to observe the transfer of mutant KRasG12D protein from mutant cells to wild-type cells through TNTs. Malignancy involves changes in cell mechanics for extensive cellular deformation during metastatic dissemination. Our results demonstrate a significant decrease in membrane tension and an increase in membrane phospholipid flow in recipient cells. These alterations in mechanical properties augment the migration and invasive capabilities of tumor cells, contributing to tumor malignancy. Our findings propose that cellular mechanical properties could serve as new markers for tumor development, and targeting membrane tension may hold potential as a therapeutic strategy.

A dual-response fluorescent probe to reveal the role of ferroptosis in drug-induced liver injury

Drug-induced liver injury (DILI) has already been recognized as a formidable obstacle in global health issues. Despite the proposed common cellular death types in DILI, exploration of alternative mechanisms such as ferroptosis for prevention and therapy remains limited. Visualization of the role of ferroptosis in DILI holds profound promise in advancing diagnostic and therapeutic strategies for DILI. To address this, herein, a unique multi-functional fluorescent probe, VIS-HNO, was elaborately built up and endowed with the extraordinary performance of excellent selectivity and high sensitivity toward HNO and viscosity. Employing the probe VIS-HNO with the confocal fluorescence imaging, the up-regulations of HNO and viscosity in the process of DILI and ferroptosis were disclosed. Then the remediation of DILI was achieved by VIS-HNO under the treatment of ferrostatin1 (Fer-1), indicating its therapeutic value for DILI. In addition, taking into account the significance of HNO in determining the role of ferroptosis in DILI, the pathway of HNO production in DILI was further explored, which presented essential insights into the role of ferroptosis in DILI. Overall, these findings demonstrated that VIS-HNO may be a potent tool to aid in diagnosing ferroptosis and DILI, more importantly, to understand the role of ferroptosis in DILI by evaluating HNO and viscosity level, which will facilitate the exploration of unique strategies for DILI treatment.

Smartphone-based sensing and in vivo and in vitro imaging of Mn(VII) based on nitrogen-doped red fluorescent carbon dots.

Smartphone-assisted visual assay platform provides novel insight for the real-time in-field quantitation of intended analytes in resource-insufficient areas. Herein, nitrogen-doped red fluorescent (FL) carbon dots (R-CDs) were developed for the timely on-site quantitation of Mn(VII) using the smartphone-assisted assay platform. R-CDs, possessing a desirable bright red FL at 616 nm under a 470 nm excitation, were fabricated through hydrothermal treatment adopting passion fruit and neutral red as precursors. Interestingly, bright red FL at 616 nm are gradually quenched upon introducing Mn(VII) based on the inner filter effect, concurrently accompanying with significant FL color variation from bright red to dark red. Inspired by the above-mentioned phenomena, hue-saturation-values (HSV) of real-time captured images could be precisely quantified through a color recognition APP within the smartphone, of which the V/S values could be employed to quantify Mn(VII) with a linear range of 50-400 μM. Furthermore, confocal fluorescence imaging of HeLa cells and zebrafish larvae demonstrates that R-CDs could be employed for the visual determination of Mn(VII) in vivo and in vitro, illustrating that R-CDs possess powerful practical application prospect in biosystem.

IR-780 Dye-based Targeting of Cancer-associated Fibroblasts Improves Cancer Immunotherapy by Increasing Intra-tumoral T Lymphocytes Infiltration.

Immune-checkpoint inhibitors (ICIs) against programmed death (PD)-1/PD-L1 pathway immunotherapy have been demonstrated to be effective in only a subset of patients with cancer, while the rest may exhibit low response or may develop drug resistance after initially responding. Previous studies have indicated that extensive collagen-rich stroma secreted by cancer-associated fibroblasts (CAFs) within the tumor microenvironment is one of the key obstructions of the immunotherapy for some tumors by decreasing the infiltrating cytotoxic T cells. However, there is still a lack of effective therapeutic strategies to control the extracellular matrix by targeting CAFs. The enhanced uptake of IR-780 by CAFs was assessed by using in vivo or ex vivo nearinfrared fluorescence imaging, confocal NIR fluorescent imaging, and CAFs isolation testing. The fibrotic phenotype down-regulation effects and in vitro CAFs killing effect of IR-780 were tested by qPCR, western blot, and flow cytometry. The in vivo therapeutic enhancement of anti-PD-L1 by IR-780 was evaluated on EMT6 and MC38 subcutaneous xenograft mice models. IR-780 has been demonstrated to be preferentially taken up by CAFs and accumulate in the mitochondria. Further results identified low-dose IR-780 to downregulate the fibrotic phenotype, while high-dose IR-780 could directly kill both CAFs and EMT6 cells in vitro. Moreover, IR-780 significantly inhibited extracellular matrix (ECM) protein deposition in the peri-tumoral stroma on subcutaneous EMT6 and MC38 xenografts, which increased the proportion of tumor-infiltrating lymphocytes (TILs) in the deep tumor and further promoted anti-PD-L1 therapeutic efficacy. This work provides a unique strategy for the inhibition of ECM protein deposition in the tumor microenvironment by targeted regulating of CAFs, which destroys the T cell barrier and further promotes tumor response to PD-L1 monoclonal antibody. IR-780 has been proposed as a potential therapeutic small-molecule adjuvant to promote the effect of immunotherapy.

Supported Biomembrane Systems Incorporating Multiarm Polymers and Bioorthogonal Tethering.

To functionalize interfaces with supported biomembranes and membrane proteins, the challenge is to build stabilized and supported systems that mimic the native lipid microenvironment. Our objective is to control substrate-to-biomembrane spacing and the tethering chemistry so proteoliposomes can be fused and conjugated without perturbation of membrane protein function. Furthermore, the substrates need to exhibit low protein and antibody nonspecific binding to use these systems in assays. We have employed protein orthogonal coupling schemes in concert with multiarm poly(ethylene glycol) (PEG) technology to build supported biomembranes on microspheres. The lipid bilayer structures and tailored substrates of the microsphere-supported biomembranes were analyzed via flow cytometry, confocal fluorescence, and super-resolution imaging microscopy, and the lateral fluidity was quantified using fluorescence recovery after photobleaching (FRAP) techniques. Under these conditions, the 4-arm-PEG20,000-NH2 based configuration gave the most desirable tethering system based on lateral diffusivity and coverage.

Inhibition of Lung Squamous Cancer Target HMGCS1 Promotes Cellular Ferroptosis

Targeted therapies are ineffective in lung squamous cancer (LUSC), and the low response rate of immunotherapy hampers its application in LUSC, so it is urgent to explore new strategies for LUSC treatment. Ferroptosis plays an important role in tumour suppression. The aim of this study was to investigate the role and mechanism of targeting 3-hydroxy-3-methylglutaryl-CoA synthase 1 (HMGCS1) in regulating ferroptosis in LUSC cells, in order to provide a new research direction for LUSC therapy. The expression of HMGCS1 in LUSC was analysed by The Cancer Genome Atlas (TCGA) and Clinical Proteomic Tumor Analysis Consortium (CPTAC) online databases; the relationship between HMGCS1 and survival time of lung cancer was analysed by the Kaplan-Meier Plotter online survival database; the expression level of HMGCS1 in LUSC tissues was verified by immunohistochemistry. After interfering with HMGCS1 expression by small interfering RNA (siRNA), cell activity and cell migration ability were detected by CCK8 and Transwell assay; apoptosis was detected by flow cytometry after interfering with HMGCS1 or after treatment with the HMGCS1 inhibitor of hymeglusin; Fe2+, reactive oxygen species (ROS) and lipid peroxidation levels were detected by flow cytometry and high-content confocal fluorescence imaging systems, respectively in SKMES cells after inhibition of HMGCS1; and Western blot was performed to detect the expression of ACSL4, GPX4 and SLC7A11, which are markers of the ferroptosis pathway after inhibition of HMGCS1. HMGCS1 mRNA and protein levels were significantly high in LUSC; siRNA interference with HMGCS1 expression inhibited the proliferative activity and migration ability of LUSC cells, but had no significant effect on apoptosis. Interference with HMGCS1 or treatment with the HMGCS1 inhibitor of hymeglusin significantly promoted intracellular Fe2+, ROS and lipid peroxidation levels in SKMES cells, and induced ferroptosis in LUSC cells; Western blot assay showed that inhibition of HMGCS1 significantly promoted the expression of ACSL4. Inhibition of HMGCS1, a target of LUSC, promotes ferroptosis in lung cancer cells and provides a research basis for screening new therapeutic targets for LUSC.

Ingenious designed a HER2-Specific macrophage biomimetic multifunctional nanoplatform for enhanced bio-photothermal synergistic therapy in HER2 positive breast cancer

Photothermal therapy (PTT) has garnered extensive attention as an efficient strategy for cancer therapy. Unfortunately, there are currently no suitable photothermal agents (PTAs) capable of effectively treating HER2-positive breast cancer (HER2+ BC) due to the challenges in addressing blood circulation and tumor accumulation. Here, we propose a HER2-specific macrophage biomimetic nanoplatform IR820@ZIF-8@EM (AMBP) for enhanced bio-photothermal therapy of HER2+ BC. An anti-HER2 antibody was expressed in engineered macrophages using the transmembrane expression technique. As an efficient PTAs, IR820 dyes were assembled into ZIF-8 as to develop a “nano-thermal-bomb”. Homology modeling methods support that the expressed anti-HER2 antibody can specifically recognize the HER2 receptor. Moreover, antibody-dependent cell-mediated cytotoxicity can also be induced in HER2+ BC cells by AMBP. In vitro fluorescence confocal imaging showed that AMBP promoted the uptake of HER2+ cancer cells while in vivo anti-tumor experiments demonstrated that AMBP efficiently accumulates in the tumor regions. Finally, under spatiotemporally controlled near-infrared (NIR) irradiation, three of the six tumors were eradicated in AMBP-treated mice, demonstrating a safe and effective strategy. In conclusion, our research opens a new paradigm for antibody-specific macrophage, and it is expected that these characteristics will have substantial clinical translation potential for BC treatment.

Particulate matter constituents trigger the formation of extracellular amyloid β and Tau -containing plaques and neurite shortening in vitro

Air pollution is an environmental factor associated with an increased risk of neurodegenerative diseases, such as Alzheimer’s and Parkinson’s, characterized by decreased cognitive abilities and memory. The limited models of sporadic Alzheimer’s disease fail to replicate all pathological hallmarks of the disease, making it challenging to uncover potential environmental causes. Environmentally driven models of Alzheimer’s disease are thus timely and necessary. We used live-cell confocal fluorescent imaging combined with high-resolution stimulated emission depletion (STED) microscopy to follow the response of retinoic acid-differentiated human neuroblastoma SH-SY5Y cells to nanomaterial exposure. Here, we report that exposure of the cells to some particulate matter constituents reproduces a neurodegenerative phenotype, including extracellular amyloid beta-containing plaques and decreased neurite length. Consistent with the existing in vivo research, we observed detrimental effects, specifically a substantial reduction in neurite length and formation of amyloid beta plaques, after exposure to iron oxide and diesel exhaust particles. Conversely, after exposure to engineered cerium oxide nanoparticles, the lengths of neurites were maintained, and almost no extracellular amyloid beta plaques were formed. Although the exact mechanism behind this effect remains to be explained, the retinoic acid differentiated SH-SY5Y cell in vitro model could serve as an alternative, environmentally driven model of neurodegenerative diseases, including Alzheimer’s disease.

A near-infrared fluorescent probe for the detection of Cu2+ in Chinese herbal medicine and imaging in living cells

Copper is one of the common among the heavy metal pollution in Chinese herbal medicine (CHM). So, it is essential to develop rapid and accurate testing method to quantify the Cu2+ content in CHM. Herein, we prepared a coordination-based near-infrared fluorescent probe (NRh6G-FA) by introducing a hemicyanine dye in rhodamine 6G scaffold. NRh6G-FA had a high sensitivity, anti-interference performance, fast response (within 60 s), visualization (from light yellow to green) for Cu2+ and excellent sensing performance for the detection of Cu2+ at low concentrations (LOD = 0.225 μM). The most likely mechanism was verified on the basis of Job’s plot, ESI-HRMS and DFT calculations. NRh6G-FA could be successfully applied for the detection and “naked eye” recognition of Cu2+ in CHM samples. Moreover, NRh6G-FA was used to visualize Cu2+ in living MCF-7 cells by confocal fluorescence imaging.