Search Results (273)

Alzheimer’s disease (AD) is characterized by cognitive decline and amyloid-β (Aβ)-related pathology. Non-rodent models that capture selected aspects of human AD remain limited. We established and characterized a human APP-driven, Aβ-related AD-like tree shrew model following AAV-mediated delivery of triple-mutant human amyloid precursor protein (hAPP-SLA) carrying the Swedish, Austrian, and London mutations by bilateral stereotaxic injection directed at CA1 coordinates. Adult tree shrews received bilateral AAV-hAPP-SLA injections directed at CA1 coordinates and were evaluated by bioluminescence imaging, behavioral testing, PCR, RT-qPCR, Western blotting, ELISA, and histopathology. Vector-associated reporter signals remained detectable for 6 months. The experimental group showed exogenous hAPP expression and reduced endogenous tsAPP expression, increased relative hippocampal Aβ₄₂ protein level, enhanced 4G8-reactive APP/Aβ-related signals, elevated total Aβ immunoreactivity, increased serum Aβ₄₂/Aβ₄₀ ratio, cytoarchitectural alterations, reduced Nissl staining, and Thioflavin S-reactive aggregate-associated signals. AT8 (Ser202/Thr205), GFAP, and Iba-1 immunoreactivity increased, whereas Synaptophysin and PSD-95 immunoreactivity was reduced. These changes were accompanied by reduced short-delay recognition-related performance and reduced social approach and social novelty preference. Aged tree shrews showed partly overlapping alterations. This model provides a non-rodent platform for studying human APP-driven Aβ-related pathology. Full article

In medicine, nanoparticles are used for various purposes, including theranostics, imaging, diagnostics, drug delivery, tissue regeneration and targeted cancer treatments, and to minimize the harmful side effects associated with conventional therapies. Target-specific biomolecules, such as silica nanoparticles (SiNPs) labeled with metallic radionuclides, are becoming increasingly popular. The choice of radionuclide is based on its nuclear properties. Silica has several advantages for nanoparticle synthesis, including high biocompatibility, the capacity for drug encapsulation due to its porous structure, and the potential for extensive surface functionalization, including radiolabeling for imaging and therapeutic applications. A radionuclide can be attached to a silica nanoparticle either directly or through the use of chelators or polymers. Additionally, the capability to encapsulate therapeutic agents within such systems offers significant potential for the development of targeted therapies. This study aims to provide a comprehensive overview of recent developments in the radiolabeling of silica-based nanoparticles, with a focus on their application in nuclear medicine, particularly in diagnostic imaging and targeted radionuclide therapy. Theranostics employs a range of imaging modalities to guide and monitor therapeutic interventions. Principal techniques include positron emission tomography (PET), single-photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), and Optical Imaging (such as fluorescence and bioluminescence). These imaging methods enable precise visualization of pathological sites, facilitate tracking of therapeutic agent distribution, and permit real-time assessment of treatment efficacy. Full article

Background: Healthcare-associated infections (HAIs) remain a critical patient safety challenge. Hand hygiene is considered the most effective preventive measure, yet traditional monitoring captures only compliance, not technique quality. This prospective before–after study evaluated whether real-time visual feedback via the Semmelweis UV-fluorescence system is associated with improved hand hygiene quality, measured by ATP bioluminescence and microbiological culture. Methods: Three clinical departments (the Intensive Care Unit, Hematology, and Gynecology) at a Romanian tertiary hospital were purposively selected. Seventy-one healthcare workers (HCWs) were enrolled. The 12-week study comprised Phase 1 (baseline, weeks 1–4), Phase 2 (active intervention with Semmelweis feedback, weeks 5–8), a one-week washout (week 9), and Phase 3 (sustainability assessment, weeks 10–12). Paired ATP-CFU samples were collected weekly. Within-group comparisons used Kruskal–Wallis H tests with post hoc Dunn’s tests and Bonferroni correction. Secondary outcomes included Semmelweis global and zone-specific coverage and the correlation between subject-level Semmelweis coverage and ATP bioluminescence (Spearman’s rho). Results: A total of 781 paired ATP-CFU samples and 497 Semmelweis evaluations were analyzed. Mean ATP declined from 195.9 RLU at baseline to 148.2 RLU in Phase 2 (−24.4%) and 154.8 RLU in Phase 3 (−21.0%; Kruskal–Wallis H = 102.73, p < 0.001). CFU/mL declined from 84.8 to 66.2 (−21.9%) and 70.7 (−16.6%; H = 22.48, p < 0.001). Post hoc comparisons confirmed significant Phase 1 versus Phase 2 and Phase 1 versus Phase 3 differences for both markers (all p < 0.01), while Phase 2 versus Phase 3 was non-significant, indicating stabilization at an improved level. Subject-level Semmelweis coverage correlated negatively with ATP (rho = −0.665, 95% CI −0.778 to −0.510, p < 0.001), supporting construct validity at the operator level. Semmelweis global coverage was 93.1% (Phase 2) and 90.6% (Phase 3); interdigital spaces showed the highest inadequacy rate (73.9% protocol-based, 92.5% targeted). Conclusions: Real-time visual feedback via UV-fluorescence imaging was associated with significant and sustained improvements in hand hygiene quality beyond baseline. ATP, CFU, and Semmelweis assessments captured complementary, non-redundant dimensions, supporting multimodal evaluation. Interdigital spaces and fingertips remained persistent failure points requiring targeted educational reinforcement. Full article

Immature testicular tissue transplantation is a promising strategy for restoring fertility in prepubertal boys undergoing gonadotoxic treatments, yet it faces challenges such as significant germ cell loss and poor graft survival due to the initial period without a blood supply. This study utilized an in vivo tissue-engineering platform involving decellularized testicular extracellular matrix to enhance graft stability and maturation. Immature testicular tissue from three-week-old transgenic mice was transplanted into age-matched recipient mice across four experimental groups: tissue co-transplanted with young decellularized matrix into a cleared testicular cavity, tissue with adult matrix in a cleared cavity, tissue transplanted alone in a cleared cavity, and tissue injected directly into an intact recipient testis. Graft growth was monitored longitudinally using bioluminescence imaging, and spermatogenesis was evaluated via histology and immunohistochemistry sixty-five days post-transplantation. The decellularization protocol successfully removed more than 98 percent of host deoxyribonucleic acid while preserving key matrix components. Grafts injected into intact testes showed the earliest bioluminescence peak but subsequently declined. Conversely, tissue co-transplanted with young decellularized matrix in a cleared cavity exhibited a delayed but significantly higher and more sustained peak compared to the group without a scaffold. The young matrix group appeared to provide more sustained support for spermatogenic progression, as reflected by a more stable increase and a prolonged spermatogenic peak over time. Evidence of advanced spermatogenic stages, including spermatids and sperm-like cells, was observed in all groups by day sixty-five. In conclusion, decellularized testicular matrix serves as a supportive bioactive scaffold that improves long-term graft stability, with outcomes significantly influenced by the age of the scaffold’s donor and the transplantation microenvironment. Full article

Background: Tumor–stroma interactions play a critical role in renal cell carcinoma (RCC) progression. Cancer-associated fibroblasts (CAFs) are considered key components of the tumor microenvironment; however, their origin remains controversial. This study aimed to determine whether bone marrow-derived mesenchymal stem cells (MSCs) contribute to CAF-like stromal changes and RCC progression. Methods: An orthotopic xenograft mouse model was established using luciferase- and GFP-labeled Caki-1 cells. MSCs labeled with PKH26 were administered intravenously. Tumor growth was evaluated using an in vivo imaging system and tumor volume measurements. Immunohistochemical analyses were performed to assess MSC localization and α-smooth muscle actin (α-SMA) expression. In vitro proliferation and migration assays were conducted using direct and indirect co-culture systems. Results: The intravenous administration of MSCs significantly increased tumor growth and bioluminescence intensity in an orthotopic model. The tumor volumes were significantly larger in the MSC-treated versus control group. An immunofluorescence analysis demonstrated partial co-localization of PKH26-labeled MSCs with α-SMA-positive fibroblast-like cells, suggesting acquisition of CAF-like features. Direct co-culture with MSCs significantly enhanced RCC cell proliferation and migration in vitro, whereas culturing in conditioned medium alone did not produce similar effects. Conclusions: Exogenously administered bone marrow-derived MSCs may be recruited into RCC tissues and acquire CAF-like features through interactions with tumor cells. These findings suggest that stromal–tumor cell interactions within the tumor microenvironment may contribute to RCC progression and represent a potential therapeutic target. Full article

Background/Objectives: Advanced renal cell carcinoma (aRCC) remains incurable, with no established optimal sequence of targeted therapies due to interpatient heterogeneity and acquired resistance. We developed a luciferase-enabled patient-derived orthotopic xenograft (PDOX) avatar platform to evaluate sequential targeted therapies in individualized aRCC models that recapitulate tumor architecture, proliferation, angiogenesis, metastasis, and PD-L1 expression. Methods: Tumor specimens from two renal cell carcinoma (RCC) patients were expanded subcutaneously in NOD/SCID mice, transduced with luciferase/red fluorescent protein (Luc/RFP), and orthotopically implanted into mouse kidneys (KiCa-Pt58: sarcomatoid RCC, pT3aN1M1, Fuhrman grade 4; KiCa-Pt118: clear cell RCC with sarcomatoid component, pT3aNxM0, Fuhrman grade 4, respectively). Tumor growth and metastasis were monitored weekly by bioluminescence imaging (BLI). Mice were randomized into vehicle control or four sequential treatment groups (Everolimus→Sunitinib [E→S], Sunitinib→Everolimus [S→E], Pazopanib→Sunitinib [P→S], Pazopanib→Everolimus [P→E]). Drugs were administered orally three times weekly until resistance (>200% BLI increase), with one switch. At necropsy, tumor burden, ex vivo BLI metastasis, weights, H&E histology, and immunohistochemistry (Ki67, CD44, CD31, PD-L1) were assessed. Results: Two independent experiments were performed. In dosing optimization, PDOX tumors recapitulated parental histology and proliferative indices, mirroring patient trajectories. KiCa-Pt58 (metastatic sarcomatoid RCC; deceased 1-month post-nephrectomy) showed aggressive features: rapid engraftment at low doses, early growth (week 2), and lung metastases in 78% of mice (sacrifice day 34), reflecting a fulminant course. KiCa-Pt118 (non-metastatic; patient recurrence-free >8 years post nephrectomy) exhibited indolent behavior: delayed engraftment requiring higher doses plus lymph node stromal (HK) support, slower growth (week 4), no metastases, and later sacrifice (day 78), consistent with remission. In sequential therapy evaluation, for KiCa-Pt58, P→E yielded greatest reductions in tumor weight (p < 0.01), lung metastases (p < 0.01), Ki67+ proliferation, CD31+ angiogenesis, and PD-L1 expression versus control; E→S and S→E were also effective. For KiCa-Pt118, S→E and P→E reduced tumor burden (p < 0.01) and Ki67⁺ proliferation; S→E lowered CD31 and PD-L1. Conclusions: This RCC PDOX platform faithfully preserves patient-specific biology—including metastatic propensity, engraftment efficiency, growth kinetics, and stromal dependency—while enabling real-time evaluation of sequential targeted therapies. Given the limited number of models tested, these findings provide proof-of-concept for individualized treatment exploration in advanced RCC and support future investigation of rational combinations with immune checkpoint blockade in humanized or immunocompetent systems. Full article

Glioblastoma (GBM) remains the most aggressive primary malignant brain tumor in adults, with poor survival largely driven by diffuse cellular infiltration, profound heterogeneity, and near-universal recurrence following standard therapy. Although maximizing the extent of resection is a key determinant of patient outcome, current clinical imaging modalities lack the spatial resolution necessary to detect microscopic tumor invasion and therapy-resistant cell populations. Emerging in vivo imaging technologies capable of cellular and near-single-cell resolution have therefore become a major focus in preclinical neuro-oncology research, with growing relevance for surgical guidance, treatment adaptation, and translational discovery. This review evaluates multiple optical imaging modalities, including multi-photon microscopy, near-infrared II fluorescence imaging, bioluminescence imaging, photoacoustic imaging, optical coherence tomography, confocal laser endomicroscopy, Raman spectroscopy, autofluorescence microscopy, and fluorescence macroscopy with a focus on their ability to detect residual GBM cells. Despite significant advances, these approaches remain constrained by limitations in molecular target availability, probe delivery across the blood–brain barrier, and signal variability within heterogeneous tumor regions. The biological complexity of GBM further challenges detection, as residual tumor cells are spatially dispersed and phenotypically diverse, limiting the effectiveness of single-marker or single-modality strategies. Together, these findings highlight the need for integrated, biologically informed imaging approaches to improve detection of residual disease and guide surgical decision making. Full article

Background: Breast cancer brain metastases (BCBM) lack effective treatments, contributing to breast cancer-related morbidity and mortality. Integrating translational animal models and advanced non-invasive imaging can accelerate the development of urgently needed therapies. Method: In this study, we developed an intracarotid method mimicking BCBM and compared it to the stereotactic model in terms of animal welfare, tumour establishment, and blood–brain barrier (BBB) permeability. BCBM was established through intracarotid or stereotactic inoculation of BT474 and MDA-MB-231.Luc2 cells in NMRI nude mice. We utilised magnetic resonance imaging (MRI) and bioluminescence imaging (BLI) to monitor tumour growth and BBB permeability, supported by fluorescent immunohistochemistry for validation. Finally, light sheet microscopy (LSM) was employed to visualise tumour establishment in intact brains. Results: Both inoculation methods achieved a survival rate > 70%, with animals recovering within a week post-surgery. MRI and BLI effectively visualised tumour growth with stereotactic implantation, resulting in single tumours, while intracarotid inoculation led to micro-seeding of up to seven tumours in one brain. Tumour growth was rapid and homogenous in the stereotactic model, whereas the intracarotid model exhibited slower, heterogenous growth. Notably, BBB permeability was significantly higher in small tumours in the stereotactic model when compared to the intracarotid model (p = 0.003). Ex vivo analyses validated these findings with the identification of multiple metastasis in the intracarotid model and single tumours in the stereotactic model. Conclusions: We developed an animal model that closely mimics BCBM, highlighting extravasation and micro-seeding while maintaining animal welfare. Our established imaging protocols enable longitudinal evaluations of BBB permeability and treatment response, creating a translational platform for testing novel anti-cancer therapies. Full article

Rationale: Radium-223 dichloride (²²³RaCl₂) is an FDA-approved alpha-emitting radiopharmaceutical that targets bone metastases in metastatic castration-resistant prostate cancer (mCRPC). This study investigates the therapeutic and immunological effects of combining ²²³RaCl₂ with immune checkpoint inhibitors (ICIs) in a clinically relevant, immunocompetent murine model of prostate cancer bone metastasis. Methods: Luciferase-expressing MyC-CaP prostate cancer cells were implanted intratibially into FVB mice to establish bone metastases. Mice were treated with escalating doses of ²²³RaCl₂ (0.04–0.27 µCi) alone or a single dose combined with anti-CTLA-4 and anti-PD-L1 ICIs. Tumor growth was monitored using bioluminescence imaging. Micro-CT, alpha camera imaging, histology, and qPCR were used to assess bone remodeling, radiopharmaceutical distribution, immune infiltration, and gene expression. Ex vivo biodistribution and blood analyses quantified tissue uptake and toxicity. Results: Escalating doses of ²²³RaCl₂ did not significantly inhibit tumor growth or improve survival. Biodistribution and imaging showed preferential localization of ²²³RaCl₂ to tumor-adjacent bone, with minimal signal in isolated tumor tissue. Immunohistochemistry revealed increased CD4⁺ and CD8α⁺ T-cell infiltration in regions of high γH2AX expression, indicating localized immune modulation. However, combination therapy with ICIs did not enhance tumor control or immune infiltration beyond monotherapy. qPCR demonstrated significant upregulation of Mhc1 only in the combination group, suggesting localized immune activation. Toxicity profiles remained acceptable. Conclusions: ²²³RaCl₂ localizes primarily to bone surfaces, limiting direct cytotoxic and immunomodulatory effects within the tumor microenvironment. While combination with ICIs did not improve efficacy, these findings provide a platform for studying spatial dose distribution and support future development of tumor-targeted alpha therapies to potentiate immunotherapy in mCRPC. Full article

Acute and chronic kidney diseases remain significant challenges in regenerative medicine, with few therapies capable of reversing tissue injury or preventing progression. Bone marrow mesenchymal stem cell-derived exosomes (BM-MSC-Exos) are nanosized vesicles (30–150 nm) that have emerged as multifunctional nanotheranostic platforms, combining targeted therapeutic activity with imaging-enabled monitoring. In renal pathophysiology, BM-MSC-Exos exert anti-inflammatory, anti-fibrotic, angiogenic, and pro-regenerative effects. These actions are mediated by microRNAs, messenger RNAs, mitochondrial regulators, and bioactive proteins that modulate epithelial repair and immune responses. Recent bioengineering advances enable more precise BM-MSC-Exos design, including enrichment with synthetic RNAs or gene-editing components and membrane functionalization to enhance kidney tropism. In parallel, fluorescence, bioluminescence, and nanoparticle-based approaches support in vivo tracking. These tools allow real-time assessment of biodistribution and tubular uptake, strengthening evidence for target engagement. This review synthesizes current knowledge on BM-MSC-Exos in renal repair. We summarize contemporary strategies for cargo and surface engineering, outline imaging methodologies for in vivo tracking, and discuss how administration routes influence renal targeting. We also provide an updated overview of clinical trials evaluating exosomes as therapeutic agents or biomarkers in nephrology. Collectively, engineered BM-MSC-Exos represent a promising and increasingly sophisticated platform for precision-guided kidney therapy, supported by monitoring tools that facilitate preclinical evaluation of biodistribution and efficacy. Full article

Background/Objectives: A key disadvantage of DNA vaccines is ineffective uptake of plasmid DNA, resulting in low immunogenicity. A way to overcome it is forced DNA delivery, which requires specialized equipment and/or reagents. Effective delivery of plasmids without specialized devices or using commonly available ones would significantly increase DNA vaccine applicability. Here, we delivered DNA by intradermal injections, facilitating them by optimized sonoporation (SP) or electroporation (EP), and we compared these methods by their capacity to support the production of foreign proteins in mice. Methods: DNA delivery was optimized using the plasmid encoding firefly luciferase (Luc) (pVaxLuc). Luc production was assessed by bioluminescence imaging (BLI) (IVIS, PerkinElmer, Shelton, CT, USA; LumoTrace Fluo, Abisense, Dolgoprudny, Russia). Female BALB/c mice were injected intradermally (id) with pVaxLuc in phosphate buffers of varying ionic strengths. Injection sites were subjected to SP (Intelect Mobile, Chattanooga, UK) or EP (CUY21EDITII, BEX Co., Tokyo, Japan) or left untreated. Optimal delivery protocols were selected based on the highest in vivo levels of photon flux according to BLI. Optimal protocols for id injections with/without EP were applied to DNA-immunized mice with HIV-1 clade A reverse transcriptase. Antibody response induced by DNA immunization was assessed by ELISA. Results: The optimal phosphate buffers for id delivery had ionic strengths from 81 to 163 mmol/L. The optimal SP regimen included an acoustic pressure of 2.4 W/cm² applied in a duty cycle of 2%. The optimal EP regimen included bipolar driving pulses of 100 V, a pulse duration of 10 ms, and an interval between the pulses of 20 ms. Optimized DNA delivery by id/SP injection was inferior to both id/EP and id alone. DNA immunization with HIV-1 RT by id injections induced anti-RT antibodies in a titer of 10⁴ and by id/EP in a titer of 10⁵. Conclusions: Electroporation of the sites of id DNA injection provided the highest levels of production of luciferase reporters and induced a strong antibody response against HIV-1 RT. Full article

Background/Objectives: Colorectal cancer (CRC) remains a leading cause of cancer-related mortality worldwide, and the development of effective therapies with improved safety profiles is urgently needed. The hydrodistillation residue extract of Syzygium aromaticum (SA) is rich in phenolic compounds, including ellagic acid and gallic acid, which are known for their antioxidant and anticancer properties. This study aimed to evaluate the anticancer efficacy, safety, and metabolic effects of SA extract in CRC models. Methods: The anticancer activity of SA was investigated using in vitro and in vivo approaches. Human colorectal cancer HCT116-Red-FLuc cells were used to assess cytotoxicity, selectivity, and dose- and time-dependent effects. In vivo efficacy was evaluated in a CRC xenograft mouse model using tumor volume measurement, micro-ultrasound imaging, and bioluminescence analysis. Hematological and blood biochemical parameters were analyzed to assess systemic safety. Untargeted metabolomic profiling was performed to explore metabolic alterations associated with SA treatment. Results: SA inhibited HCT116-Red-FLuc cell proliferation in a dose- and time-dependent manner and demonstrated selective cytotoxicity toward cancer cells, with a selectivity index of 4.41 at 24 h, although selectivity declined with prolonged exposure. In xenograft mice, SA significantly suppressed tumor growth and reduced metastatic incidence. The 500 mg/kg dose (SA500) showed the greatest antitumor efficacy while maintaining normal hematological and biochemical profiles, indicating a favorable safety margin compared with 5-fluorouracil (5FU). The 1000 mg/kg dose (SA1000) induced marked suppression of Ki-67, Bcl-2, and CD31 expression and enhanced apoptosis. Metabolomic analysis identified 44 differential metabolites related to fatty acid, amino acid, and nucleotide metabolism. Conclusions: These findings suggest that SA extract exerts significant antitumor activity against CRC with improved tolerability compared with conventional chemotherapy, supporting its potential as a complementary natural therapeutic candidate. Full article

Background: We investigated whether EphA2 inhibition can attenuate the progression of renal cell carcinoma (RCC) in an orthotopic mouse model of kidney tumor cells (Renca). Materials and Methods: 16 BALB/c mice were divided into two groups and implanted with either control or shRNA-mediated, EphA2-knockdown Renca–Luciferase cells via injection under the right renal capsule. Tumor progression was followed by in vivo bioluminescence imaging (BLI). Tumor growth was evaluated via ex vivo BLI and the wet weight of harvested orthotopic kidneys on day 18. Tumor apoptosis was evaluated using the TUNEL assay. Changes in FAK/RhoA signaling, a mediator of malignant cellular behavior, were determined using Western blotting and RT-PCR. Results: The TUNEL assay showed increased apoptosis of tumor cells in the EphA2-knockdown group compared to that in the control group (p = 0.021). Tumor wet weight (1569.9 ± 595.5 vs. 636.5 ± 288.9 mg, p = 0.009) and activation of RhoA and FAK were decreased in the EphA2-knockdown group (p < 0.05 for all). Tumor burden was reduced in the EphA2-knockdown group according to in vivo BLI on days 14 and 18 and an ex vivo test (p = 0.021, p = 0.043, p = 0.021). Conclusions: EphA2 knockdown significantly reduced the progression of RCC by inducing tumor apoptosis and suppressing FAK/RhoA signaling in an orthotopic mouse model. The EphA2/FAK/RhoA pathway might constitute a potential target to suppress the progression of RCC. Full article

Neutrophils, key effector cells of the innate immune system, combat pathogens through mechanisms including the production of reactive oxygen species (ROS) and the release of neutrophil extracellular traps (NETs). While these responses are critical for host defense, prolonged elevation of ROS and dysregulated NETosis mediated by neutrophils have been implicated in autoimmune diseases, chronic inflammation, and cancer. In pancreatic ductal adenocarcinoma (PDAC), a highly aggressive and inflammatory malignancy, an increase in neutrophils infiltrating the tumor microenvironment promotes cancer progression and metastasis through increased ROS production and NET release. Using bioluminescence imaging with the reporter L-012 and NET assays, we assessed ROS and NET release, respectively, induced by phorbol myristate acetate and platelet-activating factor in bone-marrow-isolated neutrophils from wild-type and syngeneic myeloperoxidase (MPO)-deficient mice ex vivo. MPO deficiency impaired both ROS generation and NET release, establishing a positive correlation between these processes. In vivo analyses using subcutaneous and spontaneous murine PDAC models revealed elevated ROS in tumors, which were significantly reduced upon genetic deletion of host MPO or peptidyl arginine deiminase 4, an essential enzyme for NET formation, or after treatment with hydroxychloroquine, a NET inhibitor. Furthermore, luminol and 4-[¹⁸F]fluoro-1-naphthol ([¹⁸F]4FN), functional L-012 analogs, also enabled non-invasive detection of intratumoral ROS by bioluminescence and PET imaging in vivo, respectively; [¹⁸F]4FN PET showed a three-fold increased uptake in PDAC tumors versus muscle. PDAC tissues and blood-isolated neutrophils obtained from PDAC patients exhibited elevated ROS compared to controls ex vivo. Importantly, ROS levels correlated strongly with NET formation in patient samples. These findings reveal a bidirectional relationship between ROS and NETs and highlight the potential utility of L-012- and [¹⁸F]4FN-based PET imaging for monitoring NET-associated inflammation in PDAC in vivo. Full article

This article is devoted to the synthesis and investigation of a family of new benzimidazole compounds with a propylsulfonate moiety, synthesized by condensation of salicylic aldehyde or its 5-substituted derivatives with 3-(2,3-dimethylbenzimidazol-1-ium-1-yl)propane-1-sulfonate. The structure of the obtained dyes was confirmed using NMR, FT-IR, and HRMS. Absorption and photoluminescence properties were studied in phosphate buffers over a wide pH range, and changes in the absorption and fluorescence spectra of DMSO solutions upon titration with DIPEA and HCl were also studied. It was found that all the target compounds possess pH-sensitive optical properties and can be used as fluorescent probes, while methoxycarbonyl-substituted derivative 3c demonstrated the most prominent optical and fluorescent response starting from pH ~ 4.5. The toxicity of the compounds was studied using whole-cell bioluminescent bacterial sensors. The effect on the biomass and metabolic activity of strains Staphylococcus aureus ATCC 6538-P FDA 209-P and Escherichia CDC F-50 bacterial biofilms was also investigated. In the final stage of the study, bioimaging experiments were carried out using the selected most promising dye 3c and biofilms. It was demonstrated that the dye can be excited by light with wavelengths of 458 nm or 750 nm in multiphoton mode. Importantly, when biofilms are incubated in the dye solution for 3 h, only the extracellular matrix is stained. However, if the staining time is increased to 24 h, dye penetration into bacterial cells is observed, resulting in a second photoluminescence maximum during sample analysis. It is important to note that when biofilms are incubated in a dye solution for 3 h, only the extracellular matrix is stained, while with longer staining, penetration of the dye into bacterial cells is observed, and a second photoluminescence maximum appears during sample analysis. The results obtained demonstrate a high potential of using benzimidazole-based compounds as pH-sensitive fluorescent probes operating in a biologically relevant pH range, which can be used for imaging of bacterial biofilms. Full article