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Keywords = in vivo fluorescence imaging

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24 pages, 12095 KB  
Article
Sarcosine-Based Pharmacokinetic Optimization and Fluorescent Dye Library Evaluation of Dual-Labeled PSMA Inhibitors for Fluorescence-Guided Surgery
by Paul Minges, Jessica Matthias, Lisa-Charlotte Domogalla, Björn Thomas, Nils Steinacker, Nawal Ayada Amgar, Holger Müller, Antje Dietzel-Schaarschmidt, Philipp T. Meyer, Matthias Eder and Ann-Christin Eder
Pharmaceuticals 2026, 19(8), 1187; https://doi.org/10.3390/ph19081187 - 29 Jul 2026
Viewed by 182
Abstract
Objectives: Fluorescence-guided surgery (FGS) targeting prostate-specific membrane antigen (PSMA) holds promise for improving surgical precision in prostate cancer. Since conjugation of fluorescent dyes to targeting vectors can substantially alter pharmacokinetic properties, we systematically evaluated a library of fluorescent dyes conjugated to a [...] Read more.
Objectives: Fluorescence-guided surgery (FGS) targeting prostate-specific membrane antigen (PSMA) holds promise for improving surgical precision in prostate cancer. Since conjugation of fluorescent dyes to targeting vectors can substantially alter pharmacokinetic properties, we systematically evaluated a library of fluorescent dyes conjugated to a PSMA-617-derived scaffold incorporating sarcosine-based spacers to identify candidates with favorable biodistribution and optical profiles for clinical translation. Methods: Nineteen fluorescent dyes spanning NIR, large Stokes shift, and STED-compatible categories were conjugated to a dual-labeled PSMA-617-derived precursor (Glu-urea-Lys-2Nal-TXA-Sar10-Lys(DOTA)-Sar5-βAla; hereafter DP). Compounds were radiolabeled with 68Ga or 177Lu and characterized for serum stability, lipophilicity, binding affinity, and internalization in LNCaPPSMA+ cells. In vivo pharmacokinetics were assessed in LNCaP xenograft-bearing BALB/c nu/nu mice by µPET/MRI (1 and 2 h p.i., 500 pmol 68Ga), organ distribution (0.5, 1, and 2 h p.i., 60 pmol 177Lu), and clinical-grade endoscopic fluorescence imaging. Results: All conjugates retained hydrophilic character (logD: −3.72 to −1.79), low nanomolar binding affinity (Ki: 18–87 nM), and high serum stability (94–100% intact at 24 h). Despite comparable in vitro properties, dye conjugation markedly influenced in vivo pharmacokinetics: tumor uptake at 2 h p.i. ranged from 1 to 23%ID/g and kidney accumulation from 3 to 82%ID/g. Visible-range dyes exhibited faster renal washout within the imaging window and higher tumor-to-background contrast than NIR fluorophores. Fluorescence signal intensity did not correlate with radiotracer-derived uptake, underscoring the importance of dye-specific photophysical properties. Conclusions: DP-12 (SulfoCy5), DP-15 (Alexa Fluor 647), and DP-18 (Tide Fluor 5WS) were identified as lead candidates combining favorable pharmacokinetics with strong fluorescence contrast, warranting further evaluation toward fluorescence-guided prostate cancer surgery. Full article
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21 pages, 4557 KB  
Article
Repurposed Aripiprazole-Loaded Hyaluronic Acid/Ceramide/Terpene Nanosponge as a Bioadhesive Topical Delivery System for Cutaneous Candida albicans Infection
by Rofida Albash, Anroop B. Nair, Mohamed A. Morsy, Katharigatta N. Venugopala, Pottathil Shinu, Mariam Hassan, Azza A. K. El-Sheikh and Amira B. Kassem
Pharmaceuticals 2026, 19(8), 1135; https://doi.org/10.3390/ph19081135 - 23 Jul 2026
Viewed by 270
Abstract
Objectives: The present study was designed to repurpose aripiprazole (AR) as an antifungal drug for the management of topical candidiasis using a bioadhesive sponge incorporating a hyaluronic acid (HA)-, ceramide-, and terpene-based vesicular nanosystem (HCT-NS). Methods: AR-loaded HCT-NS were formulated by the modified [...] Read more.
Objectives: The present study was designed to repurpose aripiprazole (AR) as an antifungal drug for the management of topical candidiasis using a bioadhesive sponge incorporating a hyaluronic acid (HA)-, ceramide-, and terpene-based vesicular nanosystem (HCT-NS). Methods: AR-loaded HCT-NS were formulated by the modified ethanol injection method with varying amounts of HA, ceramide, and two types of terpenes. The formulation optimization of AR-loaded HCT-NS was carried out by a full factorial design. The responses evaluated were zeta potential (ZP), particle size (PS), and entrapment efficiency (EE). Results: The optimized AR-loaded HCT-NS has 5 mg of HA, 10 mg of ceramide, and fenchone, which showed spherical vesicles with EE of 81.21 ± 0.01%, PS of 223.25 ± 11.25 nm, polydispersity index (PDI) of 0.492 ± 0.003, and ZP of −27.74 ± 0.04 mV. The optimum HCT-NS showed a greater drug release in comparison to the AR suspension. In addition, the selected HCT-NS exhibited good bioadhesive characteristics and stayed stable during storage. Confocal laser scanning microscopy confirmed the penetration of the fluorescently optimized HCT-NS via the skin. Further, the scanning electron microscope image indicates the porous structure of the formed sponge. In vivo evaluations for the optimum HCT-NS sponge showed a good antifungal impact against Candida albicans. The safety of topical treatment was confirmed by histopathological examination. Conclusions: Taken together, the results here suggest that the AR-loaded HCT-NS sponge showed potent antifungal activity against Candida albicans fungal infection. Full article
(This article belongs to the Special Issue Application of Nanotechnology in Drug Delivery)
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15 pages, 11627 KB  
Article
Spectrofluorimetric Analysis of Amyloid Degradation Using Shankhapushpi Extract/Zinc Oxide Nanoflower—An In Vitro Study
by Tharun Asaithambi, Naga Snigdha Syamala Bandhakavi, Pavithra Arikrishnan, Sarvesh Sridharan, Sania Ullas, Saranya Udayakumar, Agnishwar Girigoswami and Koyeli Girigoswami
Chemistry 2026, 8(7), 98; https://doi.org/10.3390/chemistry8070098 - 15 Jul 2026
Viewed by 474
Abstract
Amyloidosis encompasses a spectrum of diseases in which insoluble protein aggregates are deposited in various parts of the body, including the brain, giving rise to Alzheimer’s disease, prion disease, and Parkinson’s disease, and also being a manifestation of Type II diabetes. The soluble [...] Read more.
Amyloidosis encompasses a spectrum of diseases in which insoluble protein aggregates are deposited in various parts of the body, including the brain, giving rise to Alzheimer’s disease, prion disease, and Parkinson’s disease, and also being a manifestation of Type II diabetes. The soluble protein gets aggregated as insoluble plaques by an unknown phenomenon, leading to the disease. If an agent is developed that can dissociate or disintegrate these plaques, it can be proposed as a lead molecule for amyloid dissociation. In the present study, we have taken the aqueous extract of a herb, Shankhapushpi (Convolvulus pluricaulis), and synthesized zinc oxide nanoflowers (ZnO-NFs-Skp). The plant extract was characterized using phytochemical analysis, and the ZnO-NFs-Skp were characterized using various photophysical tools like dynamic light scattering, zeta potential, XRD, FTIR, and scanning electron microscopy (SEM). The in vitro cytotoxicity of the ZnO-NFs-Skp was assessed in the PC12 cell line using an MTT assay and a fluorescent dual-staining assay. The effect of ZnO-NFs-Skp on zebrafish embryos was evaluated for in vivo biocompatibility. Finally, the amyloid degradation of the ZnO-NFs, after incubation with preformed insulin amyloids, the model amyloid protein used for the amyloid study, was evaluated at different time intervals using the Thioflavin T fluorescence assay. The results indicated that the Shankhapushpi extract had alkaloids, coumarins, and glycosides. The hydrodynamic diameter of ZnO-NF-Skp was found to be 181 nm, and the zeta potential was −17.7 mV. SEM imaging showed a carnation flower-like morphology with a petal thickness of 30 ± 5 nm. The ZnO-NFs-Skp did not induce any toxicity up to a dose of 160 μg/mL, both in vitro and in vivo. The amyloid degradation study revealed 38% degradation of the IA, 24 h after incubation at 37 °C. SEM analysis also evidenced the degradation of IA. Compared to ZnO nanoparticles (18%), ZnO-NFs-Skp could degrade almost double (35%) the amount of IA after 12 h incubation, as shown by the ThT assay. Overall, the data suggested that Shankhapushpi-mediated ZnO-NFs (ZnO-NFs-Skp) are biocompatible and have a good capacity to degrade amyloids. In the future, amyloid degradation using Aβ-42 and the prion protein needs to be investigated. Full article
(This article belongs to the Special Issue Fluorescent Chemosensors and Probes for Detection and Imaging)
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14 pages, 14083 KB  
Article
Construction of a Near-Infrared Viscosity Fluorescent Probe Targeting Mitochondria and Study on Its pH-Coordinated Effect
by Xu Tang, Yuxuan Jiang, Yaqin Li, Yunlong Han and Zhi Zhu
Molecules 2026, 31(13), 2324; https://doi.org/10.3390/molecules31132324 - 2 Jul 2026
Viewed by 364
Abstract
In this study, a mitochondria-targeting near-infrared (NIR) fluorescent probe, Mito-V, based on an oxanthrene-like hybrid structure was designed and synthesized, for detecting viscosity with pH-cooperative response characteristics. Upon increasing viscosity, Mito-V exhibits a significant NIR fluorescence enhancement with a high signal-to-noise ratio and [...] Read more.
In this study, a mitochondria-targeting near-infrared (NIR) fluorescent probe, Mito-V, based on an oxanthrene-like hybrid structure was designed and synthesized, for detecting viscosity with pH-cooperative response characteristics. Upon increasing viscosity, Mito-V exhibits a significant NIR fluorescence enhancement with a high signal-to-noise ratio and excellent selectivity. Under weakly acidic conditions, the viscosity response is further enhanced, demonstrating a pH-cooperative effect that improves detection sensitivity. Cellular imaging experiments confirmed that Mito-V can effectively monitor fluctuations in intracellular viscosity, and co-localization studies revealed its high specificity for mitochondria, with a Pearson’s coefficient of 0.89. Furthermore, the pH-cooperative effect on viscosity detection was verified at the cellular level. In vivo imaging in zebrafish successfully visualized viscosity variations, demonstrating the probe’s applicability and biosafety for monitoring viscosity in biological systems. These findings indicate that Mito-V holds great potential for studying viscosity-related processes in live cells and organisms. Full article
(This article belongs to the Section Analytical Chemistry)
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16 pages, 2210 KB  
Article
Dynamics of Extracellular Traps in Vaginal Dysbiosis Associated with Gardnerella vaginalis: Ex Vivo Evidence from Neutrophils and Monocytes
by Aurora Prado-Sanhueza, Angélica Melo, Isabel Iturrieta-González, Pablo Navarro and Fabiola Zambrano
Int. J. Mol. Sci. 2026, 27(13), 5932; https://doi.org/10.3390/ijms27135932 - 1 Jul 2026
Viewed by 354
Abstract
Vaginal dysbiosis, particularly bacterial vaginosis (BV), is associated with altered immune responses that may influence the formation of extracellular traps (ETs). This study aimed to characterize neutrophil and macrophage extracellular traps (NETs and METs) in vaginal discharge samples obtained from women with normal [...] Read more.
Vaginal dysbiosis, particularly bacterial vaginosis (BV), is associated with altered immune responses that may influence the formation of extracellular traps (ETs). This study aimed to characterize neutrophil and macrophage extracellular traps (NETs and METs) in vaginal discharge samples obtained from women with normal microbiota (NM) and BV, with particular emphasis on Gardnerella vaginalis (GV) detection. An ex vivo analysis was performed using vaginal smears from 14 patients previously classified according to the Nugent criteria. Immunofluorescence assays targeting neutrophil elastase (NE), citrullinated histone H3 (Citr-H3), CD15, and CD68 were conducted, and quantitative image analysis was performed using the TissueFAXS and StrataQuest platforms. NETs were classified into three morphotypes: spread (spr), diffuse (diff), and aggregated (agg). BV samples exhibited a substantially higher mean NET count than NM samples (842.43 vs. 91.86). The number of diffNETs was significantly higher in BV samples than in NM samples (p = 0.004), whereas GV-positive samples showed increased sprNET abundance compared with that in negative samples (248 vs. 8; p < 0.05). CD68+ cell counts were significantly higher in BV samples (p = 0.026), whereas no significant differences in NE or Citr-H3 fluorescence intensity were observed between groups. MET structures were also identified, suggesting macrophage involvement in the local immune response. Collectively, these findings indicate that vaginal dysbiosis and GV presence are associated with enhanced NET formation and distinct morphotype distributions, supporting a role for ETs in the immunopathology of BV. Full article
(This article belongs to the Special Issue Molecular Aspects of Reproductive Medicine)
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17 pages, 11164 KB  
Article
pIgR Stem Zone-Targeted Nanobodies as Apical-to-Basolateral Carriers for Inhaled Biologic Delivery Across Mucosal Barriers
by Aidong Qiu, Ruiyuan Wang, Yangyingjie Bai, Bowen Zhang, Xinyu He, Jiani Xie and Jianghai Liu
Antibodies 2026, 15(4), 53; https://doi.org/10.3390/antib15040053 - 23 Jun 2026
Viewed by 680
Abstract
Background: The mucosal barrier presents a significant challenge for non-invasive delivery of macromolecular therapeutics, often requiring administration with poor bioavailability and increased toxicity risks. The polymeric immunoglobulin receptor (pIgR) contains an extracellular secretory component (SC) for immunoglobulin binding and a membrane-anchored stem domain [...] Read more.
Background: The mucosal barrier presents a significant challenge for non-invasive delivery of macromolecular therapeutics, often requiring administration with poor bioavailability and increased toxicity risks. The polymeric immunoglobulin receptor (pIgR) contains an extracellular secretory component (SC) for immunoglobulin binding and a membrane-anchored stem domain capable of apical-to-basolateral transcytosis. We hypothesized that targeting the stem domain could enable active drug transport across mucosal barriers. Methods: Using phage display, we identified four high-affinity nanobodies against human and murine pIgR. Two lead candidates (3LTHMP-4 and 3LTHMP-5) demonstrated efficient apical-to-basolateral transport in vitro (Transwell assays) and in vivo (fluorescence imaging). Engineered bispecific antibodies fusing these nanobodies with anti-IL-5 mAb reslizumab were administered via inhalation in a murine asthma model at one-tenth the intraperitoneal reslizumab dose. Resluts: The bispecific antibodies showed significant therapeutic efficacy, while reslizumab alone at equivalent concentrations failed to demonstrate efficacy. Hydrogen–Deuterium Exchange Mass Spectrometry (HDX-MS) revealed that both 3LTHMP-4 and 3LTHMP-5 specifically bind to the pIgR stem domain (residues 578–612), a region distinct from the dimeric IgA binding site. Conclusions: These findings suggest that stem domain-specific binding may facilitate transport across the mucosal barrier while preserving native receptor physiology, offering a potential strategy for effective transmucosal delivery of biologics. Full article
(This article belongs to the Section Antibody Discovery and Engineering)
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20 pages, 2714 KB  
Review
Photonic Methods for the Assessment of Lesion Activity
by Daniel Fried
Diagnostics 2026, 16(12), 1908; https://doi.org/10.3390/diagnostics16121908 - 19 Jun 2026
Viewed by 387
Abstract
Background/Objectives: This review describes the advantages of new photonic-based approaches for assessing the activity of caries lesions. Many lesions have been arrested or are non-carious developmental defects, such as fluorosis, which do not require intervention. New methods are needed to assess lesion activity [...] Read more.
Background/Objectives: This review describes the advantages of new photonic-based approaches for assessing the activity of caries lesions. Many lesions have been arrested or are non-carious developmental defects, such as fluorosis, which do not require intervention. New methods are needed to assess lesion activity and avoid unnecessary removal of the tooth structure. Methods: At present, there are no reliable methods for assessing lesion activity in vivo. Nondestructive optical monitoring of lesion structure and the changes in light scattering that occur during drying offer the potential for lesion activity assessment during a single examination. Since optical diagnostic instruments exploit changes in the porosity and the permeability of the lesion, they have the potential to assess whether lesions are active and expanding or arrested and undergoing remineralization. Optical coherence tomography (OCT), Raman imaging and fluorescence loss, thermal and short-wavelength infrared (SWIR) reflectance measurements during lesion dehydration with forced air are presented. Results: Clinical studies have shown that optical coherence tomography is capable of showing distinct structural differences between active and arrested lesions on coronal and root surfaces. Differences in the kinetics of dehydration measured using reflectance measurements at SWIR wavelengths coincident with water absorption bands also show great potential. Conclusions: OCT and dehydration imaging at SWIR wavelengths have great potential for assessing lesion activity since they can also be used for caries screening, are safe for frequent monitoring and do not require the application of external agents. Full article
(This article belongs to the Special Issue Advances in Dental Imaging)
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22 pages, 3989 KB  
Article
Precipitation-Based Encapsulation of Fibrinogen in Calcium Carbonate for Non-Compressible Hemorrhage Control
by Henry T. Peng, Tristan Bonnici, Catherine Tenn, Christian J. Kastrup and Andrew Beckett
Pharmaceuticals 2026, 19(6), 923; https://doi.org/10.3390/ph19060923 - 11 Jun 2026
Viewed by 453
Abstract
Background: Uncontrolled hemorrhage, especially at non-compressible sites, remains a major cause of preventable trauma deaths. This study reports the development of fibrinogen-loaded calcium carbonate (CaCO3) microparticles that combine hemostatic activity with self-propelling capability for targeted delivery against blood flow, with [...] Read more.
Background: Uncontrolled hemorrhage, especially at non-compressible sites, remains a major cause of preventable trauma deaths. This study reports the development of fibrinogen-loaded calcium carbonate (CaCO3) microparticles that combine hemostatic activity with self-propelling capability for targeted delivery against blood flow, with a focus on understanding formulation-dependent trade-offs among particle yield, protein loading, clotting performance, and transport behavior. Methods: Microparticles were synthesized via a precipitation method using different carbonate sources and characterized for yield, morphology, size, and fibrinogen encapsulation. Hemostatic function was assessed using rotational thromboelastometry (ROTEM) in fibrinogen-deficient plasma. Propulsion behavior was evaluated following exposure to protonated tranexamic acid (TXA+), which triggers CO2 generation. Particle size and encapsulation were examined by microscopy and fluorescence imaging. Results: The precipitation method produced spherical micrometer-sized particles, with fibrinogen inclusion reducing yield and particle size relative to unload controls. Fluorescence microscopy confirmed successful encapsulation. Encapsulation efficiency varied with formulation, with sodium carbonate-based particles showing higher relative fibrinogen loading. ROTEM analysis demonstrated that fibrinogen-loaded particles significantly improved clot formation, increasing maximum clot firmness compared to fibrinogen-free particles, although performance remained formulation-dependent. TXA+-triggered propulsion achieved maximum speeds up to 4.221 cm/s. Fibrinogen-loaded particles exhibited longer activation lag times than unloaded particles, indicating a trade-off between hemostatic functionality and propulsion kinetics. Conclusions: Fibrinogen-loaded CaCO3 microparticles exhibit both hemostatic activity and chemically triggered motion in vitro. The study identifies key formulation-dependent trade-offs between particle yield, fibrinogen loading, clotting performance, and propulsion behavior. While these findings support the feasibility of combining localization and clot stabilization mechanisms, further studies under physiologically relevant flow conditions and in vivo models are required to evaluate their potential for active delivery in non-compressible hemorrhage. Full article
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14 pages, 2617 KB  
Article
Assessing Intraoperative Tumor-to-Background Ratios Across Different Subsites of the Oral Cavity Using an Integrin-Specific Fluorescent Tracer
by Bo E. Zweedijk, Martha F. A. D. Osei-Agyeman, Lorraine J. Lauwerends, Dominic J. Robinson, Hamed Abbasi, Jens F. de Gijsel, Hetty Mast, Brend P. Jonker, José A. U. Hardillo, Dominiek A. Monserez, Aniel Sewnaik, Robert J. Baatenburg de Jong, Cornelis Verhoef, John V. Frangioni, Sjors A. Koppes, Denise E. Hilling, Alexander L. Vahrmeijer and Stijn Keereweer
Cancers 2026, 18(12), 1910; https://doi.org/10.3390/cancers18121910 - 11 Jun 2026
Viewed by 530
Abstract
Background/Objectives: Intraoperative fluorescence imaging (FI) with tumor-targeted tracers offers a promising approach to improve surgical precision in cancer surgery. cRGD-ZW800-1, an integrin-targeted fluorescent tracer, has previously demonstrated safety, tumor specificity, and utility in detecting inadequate margins in oral cancer. During this study, we [...] Read more.
Background/Objectives: Intraoperative fluorescence imaging (FI) with tumor-targeted tracers offers a promising approach to improve surgical precision in cancer surgery. cRGD-ZW800-1, an integrin-targeted fluorescent tracer, has previously demonstrated safety, tumor specificity, and utility in detecting inadequate margins in oral cancer. During this study, we observed variability in background fluorescence between different subsites of the oral cavity. Therefore, this study aimed to systematically evaluate intraoperative in vivo and ex vivo mucosal contrast ratios across various oral cavity subsites using FI with cRGD-ZW800-1. Methods: Thirty-one patients with oral squamous cell carcinoma underwent intraoperative FI following intravenous injection of cRGD-ZW800-1 at least 18 h preoperatively. In vivo imaging was performed using the Quest Spectrum platform. In addition, ex vivo FI of the resected specimen was performed using the Pearl Trilogy Small Animal Imaging System. As these ex vivo images were obtained under uniform and controlled acquisition conditions, they allow for direct comparison with the intraoperative fluorescence signals. Fluorescence intensities and tumor-to-background ratios (TBRs) were assessed per oral subsite using manually drawn regions of interest (ROIs) on the tumor and adjacent healthy mucosa using Quest’s Spectrum Software, version 4.8.2, (in vivo images) and the Pearl’s integrated software ImageStudio version 6.2 (ex vivo images). A TBR ≥ 1.5 was considered sufficient. Results: Under uniform imaging settings, all samples exhibited adequate contrast (TBR ≥ 2.3), allowing clear tumor visualization and precise evaluation of mucosal margins on final histopathology. Notably, intraoperative in vivo contrast in the posterior located maxillary alveolar process was comparatively lower, which was attributable to suboptimal imaging conditions and subsite-specific background fluorescence. Conclusions: Our findings indicate that, although contrast varies across different oral subsites, all specimens exhibited sufficient ex vivo mucosal contrast to allow reliable tumor delineation. As in vivo imaging may be affected by subsite-specific background fluorescence and inherent limitations of intraoperative imaging geometry, fluorescence signals should be interpreted in conjunction with standard visual and tactile assessment. Due to anatomical constraints, different oral subsites may appear within the same field of view, which can influence perceived signal intensity. Therefore, intraoperative ex vivo fluorescence evaluation is recommended for signal interpretation. Full article
(This article belongs to the Special Issue Advancements in Head and Neck Cancer Surgery (2nd Edition))
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16 pages, 2791 KB  
Article
Platelet-Rich Plasma Enhances Adhesion and Short-Term Retention of Bone Marrow-Derived Mesenchymal Stromal Cells to Articular Cartilage
by Sung Yong Ahn and Chris Hyunchul Jo
Cells 2026, 15(11), 1024; https://doi.org/10.3390/cells15111024 - 2 Jun 2026
Viewed by 484
Abstract
Mesenchymal stromal cell (MSC) adhesion and retention at sites of cartilage degeneration are critical for improving cartilage repair. This study investigated whether platelet-rich plasma (PRP) enhances the adhesion and short-term retention of bone marrow-derived MSCs (BM-MSCs) and chondrocytes under in vitro and ex [...] Read more.
Mesenchymal stromal cell (MSC) adhesion and retention at sites of cartilage degeneration are critical for improving cartilage repair. This study investigated whether platelet-rich plasma (PRP) enhances the adhesion and short-term retention of bone marrow-derived MSCs (BM-MSCs) and chondrocytes under in vitro and ex vivo conditions. BM-MSCs and chondrocytes were treated with PRP or pretreated with PRP for 10 or 30 min, and cell adhesion to collagen-coated surfaces was evaluated using a cell viability assay. Ex vivo adhesion and short-term retention of BM-MSCs on osteochondral discs with varying lesion severity were assessed by fluorescence imaging analysis. PRP significantly enhanced the adhesion of both BM-MSCs and chondrocytes in a time-dependent manner, with the 30 min PRP pretreatment group showing the greatest effect. BM-MSC attachment in the 30 min PRP pretreatment group was significantly higher than that in the untreated control group after 30 min of incubation (p < 0.001), whereas chondrocyte attachment was also significantly increased following PRP pretreatment. In addition, PRP pretreatment significantly enhanced BM-MSC attachment compared with PRP treatment alone at 20 and 30 min of incubation (both p < 0.001). In ex vivo experiments, adhesion and short-term retention increased significantly with increasing lesion severity from G1 to G3 (p < 0.05 and p < 0.01, respectively). In G2 and G3 lesions, PRP pretreatment for 30 min significantly enhanced BM-MSC adhesion and short-term retention compared with the control group (both p < 0.01). These findings suggest that PRP may improve the early adhesion and retention of MSCs on damaged cartilage and support the potential use of PRP as a biological adjunct for MSC-based cartilage repair strategies. Full article
(This article belongs to the Special Issue Study on Human Mesenchymal Stem Cells—2nd Edition)
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32 pages, 17226 KB  
Article
Dynamic Physical Distortions of Butterfly Pupal Wings: Potential Mechanical Signals from Eyespot Organizers for Color Pattern Determination
by Yugo Nakazato, Euichi Hirose and Joji M. Otaki
Biology 2026, 15(11), 856; https://doi.org/10.3390/biology15110856 - 29 May 2026
Viewed by 466
Abstract
Butterfly wing color patterns are determined in pupal wing tissues, in which the prospective eyespot focus functions as a developmental organizer. Here, we investigated the microscopic structures of pupal wing tissues containing an eyespot organizer in line with the physical distortion hypothesis. Histochemical [...] Read more.
Butterfly wing color patterns are determined in pupal wing tissues, in which the prospective eyespot focus functions as a developmental organizer. Here, we investigated the microscopic structures of pupal wing tissues containing an eyespot organizer in line with the physical distortion hypothesis. Histochemical staining revealed that the pupal cuticle and epidermis were wavy and thin at 6 h but smooth and thick at 12 h postpupation. The eyespot organizer was associated with the thickest cuticle layer, called the cuticle focal spot. Transmission election microscopy (TEM) revealed that the intervening space (IVS) between the cuticle layer and the cellular apical end was wide at 6 h but narrow at 12 h postpupation. The spatial relationship between cuticle thickness and IVS width was indicative of mechanical buckling of the region adjacent to the cuticle focal spot. Live in vivo imaging revealed that the IVS at and near the eyespot organizer trapped orange fluorescent protein (OFP) injected into hemolymph. Dynamic distortions of the pupal wing epidermis and cuticular surface were detected in live individuals over time. These results suggest that physical distortions of the wing tissue induced by differential cuticle synthesis and subsequent buckling may function as mechanical morphogenic signals from eyespot organizers. Full article
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18 pages, 3548 KB  
Article
Ion-Triggered In Situ Gel Combined with Melatonin Liposomes: Breaking Through the Dual Barriers of Nasal and Brain Delivery to Treat Insomnia
by Zhewen Dong, Xinxin Dong, He Wang, Yujie Pan, Meiqi Yang, Sihan Zhao, Wanxian Deng, Mengshan Han, Tiantian Ye and Shujun Wang
Pharmaceutics 2026, 18(6), 656; https://doi.org/10.3390/pharmaceutics18060656 - 27 May 2026
Viewed by 563
Abstract
Background/Objectives: Insomnia severely impairs quality of life. Oral melatonin (MEL) suffers from poor brain delivery. Intranasal administration bypasses the blood–brain barrier, but rapid mucociliary clearance shortens drug retention, and MEL poor water solubility limits its nasal dissolution. Traditional in situ gels have “gelation-first, [...] Read more.
Background/Objectives: Insomnia severely impairs quality of life. Oral melatonin (MEL) suffers from poor brain delivery. Intranasal administration bypasses the blood–brain barrier, but rapid mucociliary clearance shortens drug retention, and MEL poor water solubility limits its nasal dissolution. Traditional in situ gels have “gelation-first, spreading-second” defects, causing uneven distribution. Herein, we developed a two-step sequential ion-triggered in situ gel combined with MEL liposomes (MEL-Lips-Gel) to enhance solubility, achieve instant uniform coating, and prolong retention for efficient nose-to-brain delivery. Methods: MEL-Lips were dispersed in alginate (first component) and calcium gluconate served as the second component. After sequential spray, the two components mix and form an ion-crosslinked gel. Rheology, in vivo fluorescence imaging, in vitro release, open-field/sucrose preference tests, and H&E staining were performed. Results: MEL-Lips showed uniform size and good encapsulation. The sequential system achieved instant widespread spreading and rapid gelation, significantly prolonged nasal retention, enabled sustained brain delivery, and reversed insomnia-induced hyperactivity and anxiety-like behaviors more effectively than oral MEL, intranasal MEL solution, liposomes alone, or non-liposomal gel, with good nasal safety. Conclusions: This sequential ion-triggered liposome-in-gel strategy synergistically overcomes rapid clearance (via gel) and poor solubility (via liposomes), enhancing nose-to-brain delivery of melatonin and providing a promising platform for insomnia therapy. Full article
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22 pages, 4265 KB  
Article
Renal Accumulation and Hemocyte-Mediated Internalization After Acute Exposure to Injected Polyethylene Terephthalate Nanoplastics (PET-NPs) in the Freshwater Gastropod Pomacea canaliculata
by Anita Ferri, Sandro Sacchi, Chiara Losi, Martina Amico, Nicola Franchi and Davide Malagoli
J. Xenobiot. 2026, 16(3), 88; https://doi.org/10.3390/jox16030088 - 19 May 2026
Cited by 1 | Viewed by 708
Abstract
The increasing fragmentation of plastic debris into nanosized particles represents a threat to freshwater ecosystems, yet the biological effects of nanoplastics (NPs) on freshwater invertebrates remain poorly understood. This study investigated tissue distribution, cellular effects and immune responses following acute exposure to polyethylene [...] Read more.
The increasing fragmentation of plastic debris into nanosized particles represents a threat to freshwater ecosystems, yet the biological effects of nanoplastics (NPs) on freshwater invertebrates remain poorly understood. This study investigated tissue distribution, cellular effects and immune responses following acute exposure to polyethylene terephthalate nanoplastics (PET-NPs) in the freshwater gastropod Pomacea canaliculata, a species of high ecological relevance and physiological resilience. Adult snails were injected with PET-NPs at 5 or 10 mg/L and sampled after 24 and 72 h. PET-NPs accumulation in the anterior and posterior kidneys was assessed by fluorescence imaging and tissue morphology was evaluated. Stress- and inflammation-related genes (Pc-Heat Shock Protein (HSP)70, Pc-HSP90 and Pc-Allograft inflammatory factor 1) expression was quantified by RT-qPCR. PET-NPs uptake and phagocytic activity were analyzed in circulating hemocytes in vivo and ex vivo. PET-NPs were accumulated in renal tissues, persisting up to 72 h without histopathological alterations. Gene expression analyses revealed non-linear and dose/time-dependent responses. Hemocytes of different morphologies internalized PET-NPs in a dose-dependent manner and showed intercellular particle transfer. Overall, acute PET-NP exposure determines rapid immune handling and tissue sequestration with limited short-term physiological impact, underscoring the potential involvement of immune processes in NPs fate and highlighting the need for chronic exposure studies. Full article
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21 pages, 4157 KB  
Article
Optimizing Sequential Targeted Therapies in Advanced Renal Cell Carcinoma Using Patient-Derived Orthotopic Xenograft Mouse Avatars
by Amita Bhattarai, Ravan Moret, Xin Zhang, Grace Maresh, Henry Yip, Carl Haupt, Rachel Graham, Maria Latsis, Marc Matrana, Kyle Rose, Stephen Bardot and Li Li
Cancers 2026, 18(10), 1615; https://doi.org/10.3390/cancers18101615 - 16 May 2026
Viewed by 668
Abstract
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 [...] Read more.
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
(This article belongs to the Section Cancer Therapy)
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Article
A Transgenic Mouse Model to Track MRC1-High Macrophages Using In Vivo Optical Imaging
by Chintan Chawda, Giorgia Zambito, Natasa Gaspar, Christopher Schliehe, Pieter J. M. Leenen, Clemens Löwik and Laura Mezzanotte
Int. J. Mol. Sci. 2026, 27(10), 4305; https://doi.org/10.3390/ijms27104305 - 12 May 2026
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Abstract
Macrophages play a crucial role in health and disease. Currently, reporter mice for tracking alternatively activated macrophages in vivo are lacking. We designed a transgenic mouse model in which luminescence and fluorescence proteins, click beetle red luciferase (CBRED2) and mKate2, report on the [...] Read more.
Macrophages play a crucial role in health and disease. Currently, reporter mice for tracking alternatively activated macrophages in vivo are lacking. We designed a transgenic mouse model in which luminescence and fluorescence proteins, click beetle red luciferase (CBRED2) and mKate2, report on the expression of the Mrc1/Cd206 promoter, active in the monocyte/macrophage population. The mouse line was named B6Mrc1-mKate2-CBRED2. Using this novel mouse model, we were able to develop in vitro assays to validate transgenic macrophage polarization and test them with compounds of repolarization potency. Furthermore, in the in vivo assays, we exploited the migratory and infiltrative potency of macrophages for detecting tumor locations via optical imaging. In fact, macrophages can act as universal cancer markers, as they infiltrate primary and secondary tumors, stimulating or suppressing tumor growth. We first characterized transgenic mice for reporter expression ex vivo, followed by the generation of luminescence-based assays to reflect the polarity of differentiated macrophages, and lastly, we visualized reporter macrophages accumulating and infiltrating the tumor microenvironment (TME) of murine pancreatic ductal adenocarcinoma (PDAC) at multiple time points. We found that the extent of macrophage recruitment and retention was dependent on the infiltrative T-cell and dendritic cell populations present in the TME, reflecting the immunologically hot or cold nature of the PDAC clones, respectively. In conclusion, the ability to optically detect light-emitting macrophages can be applied not only for cancer studies but also in the context of inflammatory diseases. Full article
(This article belongs to the Special Issue The Role of Macrophages in Tumors)
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