Search Results (397)

Background/Objective: Intraoperative local photodynamic therapy (PDT) using talaporfin sodium (TS) and photodynamic diagnosis (PDD) with 5-aminolevulinic acid (5-ALA) are valuable adjuncts in the treatment of malignant brain tumors. Although their concomitant use was previously contraindicated due to photosensitivity concerns, a 2022 regulatory revision permitted their combined application. Transient postoperative hyperintensity on diffusion-weighted imaging (DWI) at the irradiation site serves as a biomarker for PDT effects, but the radiological and clinical impact of combining 5-ALA and TS remains unclarified. To compare and evaluate postoperative DWI findings and clinical outcomes in patients undergoing TS-PDT with or without concomitant 5-ALA-guided PDD. Methods: This retrospective study analyzed 34 patients with recurrent primary malignant brain tumors who underwent TS-PDT between January 2019 and November 2025. Patients were divided into a TS alone group (n = 19) and a TS + 5-ALA group (n = 15). Postoperative DWI hyperintensity thickness and minimum apparent diffusion coefficient (ADC) values at the laser irradiation site were measured. Adverse events including photosensitivity were also compared. Results: No significant differences were observed between the TS alone and TS + 5-ALA groups in DWI hyperintensity thickness (3.71 mm vs. 3.90 mm; p = 0.703 or median ADC values (601.0 × 10⁻⁶ mm²/s vs. 527.0 × 10⁻⁶ mm²/s; p = 0.205). Furthermore, there were no significant differences in the incidence of photosensitivity and liver enzyme elevation. Conclusion: Concomitant use of 5-ALA-PDD and TS-PDT can be used without worsening DWI findings at the PD laser irradiation site. Full article

Technological advances in optical imaging and artificial light technologies have substantially transformed modern neurosurgical practice by improving intraoperative visualization and surgical precision. This narrative review evaluates current applications of fluorescence-guided surgery, optical navigation systems, near-infrared imaging, augmented visualization platforms, and artificial intelligence-assisted intraoperative imaging in neurosurgery. Particular attention is given to clinically established fluorophores, including 5-aminolevulinic acid, fluorescein sodium, and indocyanine green, which are increasingly used for tumor delineation, vascular assessment, and real-time tissue perfusion analysis. Emerging technologies such as Raman spectroscopy, multispectral imaging, holographic navigation, and nerve-specific fluorescent probes are also discussed in the context of precision and minimally invasive neurosurgery. Current evidence demonstrates that advanced optical systems improve surgical orientation, maximize extent of resection, and support preservation of critical neurovascular structures, particularly in neuro-oncology, vascular neurosurgery, and skull base surgery. However, limitations related to fluorescence specificity, standardization, cost, and technological accessibility remain significant challenges. The continued integration of multimodal optical imaging, computational navigation, and AI-assisted visualization is expected to further enhance intraoperative decision-making, surgical safety, and postoperative outcomes, contributing to the future development of precision image-guided neurosurgery. Full article

Experimental macromolecular structures are foundational for elucidating molecular mechanisms and guiding drug design and protein engineering. However, inaccurate structural models are occasionally deposited in the Protein Data Bank (PDB), potentially confounding structural analyses and misleading subsequent studies. Although the integration of artificial intelligence (AI)-predicted models to improve experimentally determined structures has been proposed, the impact of AI-guided rebuilding on functional interpretation remains largely uncharacterized. Here, AI-predicted models of δ-aminolevulinic acid dehydratase (ALAD) were analyzed, and a misinterpreted region in its original crystal structure was rebuilt using an AlphaFold3 (AF3) model as a template. The incorrectly modeled region between Cys122 and Leu142 was corrected utilizing the AF3 main-chain conformation. This rebuilding decreased the R_free value and improved structural geometry compared to the experimental structure. Notably, the initially deposited ALAD structure exhibited an inactive conformation characterized by a disrupted substrate-binding A-site. In contrast, the AI-rebuilt ALAD model restored a biologically relevant active-site conformation, featuring a coordinated zinc-binding pocket, mediated by Cys122, Cys124, and Cys132, and an intact substrate-binding configuration at the A-site. These results demonstrate the feasibility of AI-predicted model-guided rebuilding in the present ALAD case and may provide a basis for future studies evaluating its applicability to other protein systems. Full article

Glioblastoma (GBM) remains a highly lethal malignancy characterized by profound treatment resistance and metabolic plasticity. While photodynamic therapy (PDT) and the mitochondrial complex I inhibitor carboxyamidotriazole orotate (CTO) have individually shown promise, their combined potential requires further exploration and optimization. This study systematically investigated the interaction between 5-aminolevulinic acid (5-ALA)-mediated PDT and CTO in U87 GBM models. Intriguingly, we discovered a sequence-dependent interaction under the tested treatment schedules: CTO pre-incubation before PDT resulted in attenuated PDT-induced cytotoxicity, possibly due to CTO-mediated suppression of reactive oxygen species (ROS) accumulation. In contrast, a sequential “PDT→CTO” regimen enhanced anti-tumor efficacy both in vitro and in vivo. Mechanistically, the sequential approach was associated with enhanced mitochondrial depolarization and reduced expression of glycolysis-related genes, suggesting a potential metabolic “dual-hit” involving disturbance of mitochondrial function and compensatory glycolytic adaptation. These results highlight treatment sequence as a critical determinant of PDT-CTO interaction and provide a basis for further preclinical investigation of PDT followed by metabolic intervention as a combination strategy with potential translational relevance. Full article

Glioblastoma multiforme (GBM), isocitrate dehydrogenase (IDH)-wildtype, is the most aggressive primary malignant tumor of the central nervous system, characterized by poor prognosis and high recurrence rates despite standard multimodal treatment. This study investigates the molecular response of glioblastoma cells to 5-aminolevulinic acid (5-ALA)-based photodynamic therapy (PDT), focusing on gene expression changes associated with apoptosis, ferroptosis, and oxidative stress. Human glioblastoma T98G cells were treated with 5-ALA followed by light irradiation, and gene expression was analyzed using RT-qPCR. PDT induced moderate upregulation of pro-apoptotic genes (BAX, CASP3, FAS) alongside increased expression of the anti-apoptotic gene BCL2, indicating simultaneous activation of cell death and survival pathways. Ferroptosis-related genes showed mixed responses, with slight upregulation of ACSL4 and downregulation of GPX4, suggesting increased susceptibility to lipid peroxidation. The most significant change was observed in GCH1 expression, reflecting activation of oxidative stress response mechanisms. However, none of the observed changes reached statistical significance, likely due to the limited sample size. These findings demonstrate that PDT induces a complex and dual biological response in glioblastoma cells, involving both cytotoxic and adaptive mechanisms. This may limit therapeutic efficacy and contribute to treatment resistance. The results support the rationale for combining PDT with targeted molecular therapies aimed at inhibiting antioxidant defenses and anti-apoptotic pathways. Additionally, personalized therapeutic strategies based on tumor molecular profiles may enhance treatment outcomes. Further studies with larger sample sizes and functional validation are required to confirm these preliminary observations. Full article

Background/Objectives: Glioblastoma multiforme (GBM) treatment is limited by tumor hypoxia and poor specificity of therapeutic agents. To address these challenges, we developed brain-targeted liposomes co-encapsulating 5-aminolevulinic acid (5-ALA) and catalase (CAT), termed brain-targeted 5-ALA-CAT liposomes (BACL), which were surface-modified with the Angiopep-2 ligand to enhance blood–brain barrier penetration and achieve multimodal therapy combining targeted delivery and oxygen generation. Methods: BACL was prepared and characterized. Tumor targeting was verified by flow cytometry and in vivo imaging. In vitro antitumor activity was evaluated by wound-healing assay, colony formation assay, live/dead staining, MTT assay, and Western blotting. In vivo efficacy, apoptosis, and safety were assessed in a subcutaneous xenograft model. Transcriptome sequencing and qRT-PCR were employed to identify molecular mechanisms and novel targets. Results: BACL exhibited favorable physicochemical properties (size: 122.4 nm, PDI: 0.189, zeta potential: −12.3 mV) and spherical morphology as observed by TEM, with encapsulation efficiencies of 51.2% for 5-ALA and 43.8% for CAT. Compared with unmodified 5-ALA, BACL increased the cellular uptake efficiency by 1.6-fold in glioma cells while maintaining catalytic stability for sustained oxygen generation. In vitro experiments demonstrated that BACL significantly inhibited glioma cell migration, colony formation, and cell viability, and induced apoptosis. In a subcutaneous xenograft tumor model, BACL-mediated photodynamic therapy (PDT) achieved a tumor growth inhibition rate of 52%, with apoptosis induction via regulation of Bcl-2, Bax, and p53 expression, and no obvious toxicity to major organs was observed. Transcriptomic analysis combined with qRT-PCR validation revealed that BACL activates multiple antitumor signaling pathways, including targeted inhibition of IL-10 and CXCL13 to disrupt cytokine–receptor interactions, as well as coordinated regulation of S100A3 and IGSF-9 expression to suppress glioma progression. Conclusions: These multimodal actions enhanced PDT efficacy while remodeling the tumor microenvironment. Our findings position BACL as a promising therapeutic platform integrating targeted delivery, hypoxia alleviation, and immunomodulation for GBM therapy. Full article

Plant cytochrome P450 monooxygenases (CYPs) are valuable biocatalysts for the regioselective hydroxylation of aromatic compounds. However, their expression in bacterial hosts is hampered by poor solubility, membrane anchoring and the requirement for redox partners. In this work, we report the design and characterization of modular expression systems that enable the functional production of SbCYP82D1.1 from Scutellaria baicalensis (SbF6H) in Escherichia coli. Both independent expression and synthetic fusion systems were evaluated by combining a CYP with a compatible reductase (ATR2_tr from Arabidopsis thaliana) to catalyze the conversion of chrysin into baicalein. A combinatorial library of N-terminal variants, host strains, media, and induction strategies was constructed and screened. Among the tested host, E. coli DH 10-beta provided the highest product titers, particularly when cultures were supplemented with 5-aminolevulinic acid. Truncation of the native transmembrane anchor significantly improved catalytic performance, whereas the addition of the heterologous MALLLAVF tag decreased activity. Fusion systems outperformed separate expression formats, showing approximately two-fold higher activity, with the flexible glycine–serine linker (L_GS) supporting the highest hydroxylation product formation. The corresponding fusion construct showed an apparent conversion of 0.1 mM chrysin to baicalein of up to 90% under the applied whole-cell reaction and analytical conditions, although this value should be interpreted with caution due to the concurrent instability of baicalein observed in all reactions and culture conditions. This result nevertheless indicates a marked improvement in whole-cell baicalein formation compared with previously reported bacterial systems. Together, these results demonstrate that rational N-terminal engineering combined with fusion protein design can enable efficient bacterial expression of plant CYPs, representing a promising step toward scalable production of hydroxylated flavonoids. Full article

5-Aminolevulinic acid (5-ALA) has emerged as an important theranostic agent in oncology due to its selective intracellular conversion to protoporphyrin IX (PpIX), enabling both photodynamic diagnosis (PDD) and photodynamic therapy (PDT). This narrative review summarizes current knowledge regarding the biological mechanisms underlying 5-ALA metabolism, selective tumor accumulation, and the clinical applications of 5-ALA-based approaches across multiple oncological indications. Particular emphasis is placed on glioblastoma, head and neck lesions, dermatological malignancies, urological cancers, gynecological lesions, and emerging translational applications. The review also discusses key biological and technical limitations, including tumor hypoxia, restricted light penetration, heterogeneous PpIX accumulation, resistance mechanisms, and tumor-specific variability. Recent advances in drug delivery systems, nanotechnology, sonodynamic therapy, radiodynamic strategies, and combination immunotherapeutic approaches are also highlighted. Collectively, current evidence indicates that while 5-ALA has established clinical utility in selected indications, many applications remain preclinical or early translational, underscoring the need for further well-designed clinical studies. Full article

Gliomas remain among the most treatment-resistant malignancies of the central nervous system. Glioblastoma (GBM), the most aggressive adult-type diffuse glioma, is associated with persistently poor survival despite maximal safe resection followed by chemoradiation. Gliomas do not grow in isolation. Work over the past twenty years has dismantled the older tumor-centric view of glioma biology, replacing it with a model in which malignant cells operate within a tumor microenvironment (TME) composed of immune, vascular, stromal, and neural elements that together govern disease behavior. What makes the glioma TME so difficult to treat is not just its composition of immune cells, vasculature, stroma, and neurons, but the fact that these elements are arranged unevenly across the tumor. Different regions harbor different cellular mixtures and signaling environments, and, as a result, different vulnerabilities to therapy. Cytoreduction has not lost its importance, far from it. However, the same surgical window now also serves a different purpose; it lets the surgeon see which tissue is biologically dangerous rather than just visually abnormal, locate the true edge of infiltration, and get therapeutics past a blood–brain barrier (BBB) that has historically locked them out of the brain. This review examines two technology domains, including: (1) optical theranostics (5-aminolevulinic acid fluorescence-guided surgery, fluorescein-guided visualization, Raman spectroscopy, and stimulated Raman histology); and (2) blood–brain barrier disrupting technologies. The direction they collectively point toward is a version of glioma surgery that is guided less by anatomy and more by the biology of the tumor itself. Full article

Tear staining is a common yet often underestimated condition in dogs that affects appearance and may reflect underlying disease. This study evaluated dietary supplementation with the traditional Chinese herbs Chrysanthemum morifolium (CM), Cassia semen (CS), and Poria cocos (PC) in dogs predisposed to tear staining and investigated potential mechanisms. Forty Poodle and Bichon dogs were fed diets supplemented with 0.5% CM, CS, or PC. Tear staining indices were measured biweekly, together with blood indicators of iron status, immune and inflammatory markers, and antioxidant capacity. All three supplements reduced tear staining (p < 0.05), as shown by lower scores and shorter stain length versus control. CM and PC improved iron status and porphyrin metabolism by increasing serum iron and ferritin and modulating δ-aminolevulinic acid and porphobilinogen deaminase. They also enhanced humoral immunity and antioxidant status by increasing serum immunoglobulins, reducing pro-inflammatory cytokines, and moderately improving antioxidant activities. CM and PC increased fecal Allobaculum abundance, which correlated with tear staining indices and porphyrin-related measures. In conclusion, CM, CS, and PC are promising dietary strategies for reducing tear staining in dogs, with CM and PC possibly acting via Allobaculum-associated modulation of iron and porphyrin metabolism, while improving iron status, immunity, and antioxidant defense. Full article

Intraoperative fluorescence-guided surgery is an important adjunct to brain tumor resection. However, fluorescent probe performance varies across molecularly and histopathologically distinct entities, including IDH-wildtype glioblastoma, metastatic brain tumors (MBTs), and primary central nervous system lymphoma (PCNSL), and the mechanisms underlying this variability remain poorly understood. We propose a mechanistic framework integrating biomechanical constraints, molecular barrier heterogeneity, and probe-specific pharmacokinetics to explain cross-tumor differences in fluorescence signal. Probe performance is conceptualized through three sequential bottlenecks: extravasation (blood–brain barrier/blood–tumor barrier permeability and transcytosis), interstitial penetration (extracellular matrix density and hydraulic resistance), and retention/clearance (efflux transporters and metabolic processing). An overlying optical layer, including tissue absorption, scattering, and autofluorescence, further modulates the detected signal. Tumor-specific molecular heterogeneity critically shapes these processes. In IDH-wildtype glioblastoma and legacy high-grade glioma cohorts, heterogeneous expression of ATP-binding cassette transporters has been associated with reduced intracellular accumulation of protoporphyrin IX after 5-aminolevulinic acid administration and may contribute to false-negative fluorescence in selected tumor regions. In MBTs, stage-dependent blood–tumor barrier integrity and vascular programs influence probe delivery, whereas in PCNSL, corticosteroid-sensitive restoration of endothelial barrier function may compromise the performance of leakage-dependent tracers. Together, this framework highlights how tumor biology, barrier function, and probe pharmacology jointly shape fluorescence contrast. Rational probe selection informed by tumor-specific transport and barrier constraints may improve intraoperative visualization of brain tumors and optimize surgical decision-making. Full article

Chromochloris zofingiensis, a photosynthetic microalga, has attracted considerable attention due to its ability to simultaneously accumulate lipids and astaxanthin. However, the induction of lipid and secondary metabolite biosynthesis by abiotic stress is typically accompanied by growth inhibition, resulting in a trade-off between metabolite accumulation and biomass production. In recent years, phytohormones have emerged as an effective strategy for regulating microalgal metabolism, owing to their high specificity and low effective dosage. In this study, 5-aminolevulinic acid (5-ALA) was applied under nitrogen-deficient conditions, and its effects on growth, photosynthesis, lipid metabolism, and carotenoid biosynthesis were systematically evaluated through integrated physiological, biochemical, and transcriptomic analyses. The results showed that 5-ALA had no significant effect on biomass accumulation or photosynthetic performance. However, at 2 μM, 5-ALA exhibited the strongest promotive effect on lipid and astaxanthin accumulation, with total fatty acids (TFA) and triacylglycerol (TAG) contents increasing by 13.3% and 25.7%, respectively, and total carotenoids and astaxanthin contents increasing by 15.6% and 17.2%, respectively. Under semi-continuous cultivation, TAG and astaxanthin productivities were enhanced by 13.9% and 22.9%, reaching 164 mg L⁻¹ d⁻¹ and 2.15 mg L⁻¹ d⁻¹, respectively. Transcriptomic analysis revealed that 5-ALA induced only limited transcriptional changes but enhanced glycolysis, central carbon metabolism, and nitrogen recycling, thereby increasing the supply of carbon precursors and energy. Notably, no significant transcriptional changes were observed in the carotenoid biosynthesis pathway, indicating that the enhanced accumulation of total carotenoids and astaxanthin was likely driven by increased metabolic flux. In terms of lipid metabolism, the upregulation of pathways involved in the conversion of membrane lipids into TAG, together with the downregulation of TAG degradation pathways and enhanced carbon flux, collectively promoted TAG accumulation. Overall, this study demonstrates that supplementation with 2 μM 5-ALA provides a practical and cost-effective strategy for the efficient co-production of lipids and astaxanthin in C. zofingiensis. Full article

Background/Objectives: Bladder cancer remains one of the most frequently diagnosed malignancies worldwide and is characterized by high recurrence rates requiring long-term surveillance. Conventional white-light cystoscopy (WLC) remains the standard diagnostic method; however, it may fail to detect flat lesions such as carcinoma in situ or small papillary tumors. In recent years, enhanced imaging techniques, including fluorescence cystoscopy and autofluorescence-based systems, have been introduced to improve diagnostic accuracy. The aim of this study is to evaluate the usefulness of fluorescence-based diagnostic techniques and autofluorescence imaging supported by numerical color value (NCV) analysis in the detection and assessment of bladder lesions. Methods: The study was conducted at the Center of Photodynamic Diagnostics and Therapy, Department of Internal Medicine, Angiology and Physical Medicine, Medical University of Silesia in Bytom. Bladder mucosa was assessed using the Onco-LIFE optical imaging system, which enables visualization under both white-light and autofluorescence conditions. The study included 30 patients diagnosed with non-muscle-invasive bladder cancer or suspected bladder lesions, who underwent cystoscopic evaluation using white-light cystoscopy and autofluorescence imaging. From this cohort, three representative cases were selected for detailed qualitative presentation to illustrate different pathological conditions of the bladder mucosa. In selected cases, photodynamic diagnosis (PDD) using intravesical administration of 5-aminolevulinic acid (ALA) was performed prior to cystoscopic examination. Autofluorescence signals were analyzed using red and green fluorescence channels, and tissue characteristics were evaluated using the numerical color value parameter. Results: Representative cases of non-muscle-invasive bladder lesions were analyzed and compared using conventional white-light cystoscopy and autofluorescence imaging. The use of fluorescence-based imaging enabled improved visualization of suspicious mucosal changes compared with standard WLC. Differences in fluorescence patterns were observed between malignant lesions, inflammatory changes, and carcinoma in situ. NCV analysis allowed quantitative assessment of fluorescence signals and supported differentiation of pathological tissue from normal bladder mucosa. Conclusions: Fluorescence cystoscopy and autofluorescence-based imaging systems represent valuable tools for improving the detection of bladder lesions during endoscopic examination. The integration of enhanced optical imaging techniques with quantitative fluorescence analysis may increase diagnostic sensitivity and support targeted biopsy and tumor resection. Continued technological development and clinical experience may further expand the role of fluorescence diagnostics in the early detection and management of bladder cancer. Full article

This study evaluated changes in blood pressure and hypotension-related adverse drug reactions (ADRs) following oral administration of 5-aminolevulinic acid hydrochloride (5-ALA) in patients undergoing transurethral resection of bladder tumor (TURBT). Photodynamic diagnosis under blue light has demonstrated superior sensitivity compared with that of white light when 5-ALA is administered 4 to 8 h before TURBT (95.3% vs. 61.1%, p < 0.001); however, data regarding associated blood pressure change remain limited. In this study, blood pressure changes were monitored for 24 h after 5-ALA administration (20 mg/kg) and hypotension-related ADRs were assessed within 14 days post-dose. Both systolic and diastolic blood pressures reached their nadir at 2 h after 5-ALA administration. Absolute blood pressure values were lower in patients with ADRs, whereas the magnitude of blood pressure changes was not different between patients with and without ADRs. The incidence of hypotension, defined as systolic blood pressure ≤ 80 mmHg, was 2.1%, which was lower than that reported in previous retrospective studies (40.0–75.6%). Although hypotension-related ADRs occurred in 25.5% of patients, all events were non-serious and resolved without clinical sequelae. The lower incidence may partly reflect the exclusion criteria and medication restrictions applied in this protocol-controlled trial. Full article

Chlorophylls are the major light-harvesting pigments in photosynthetic organisms. Their biosynthesis requires the coordinated supply of metabolic intermediates from two independent upstream branches: the methylerythritol 4-phosphate (MEP)-derived terpenoid pathway, which supplies the phytyl side chain via geranylgeranyl diphosphate (GGPP), and the tetrapyrrole biosynthesis pathway (TBP), which provides the porphyrin ring. How flux through these two branches is coordinated remains poorly understood. In this study, we report the identification of a direct protein–protein interaction between δ-aminolevulinic acid dehydratase (ALAD), the second enzyme of the TBP, positioned immediately upstream of the first metabolic branch point, and the Type II small subunit of GGPP synthase (SSUII), a key regulator of terpenoid flux toward chlorophyll biosynthesis. ALAD was identified as a candidate SSUII-interacting protein by co-immunoprecipitation coupled with LC-MS analysis of rice leaf tissue, with a sequence coverage of 57.04%. The interactions between OsALAD1 and OsSSUII in rice, and between AtALAD1 and AtSSUII in Arabidopsis thaliana, were validated by yeast two-hybrid assay and bimolecular fluorescence complementation (BiFC) in Arabidopsis protoplasts. BiFC imaging demonstrated that the interaction is localized to the chloroplast. Sequence analysis revealed that plant ALAD proteins are highly conserved, with 92% similarity between OsALAD1 and AtALAD1, and 76.9% similarity between OsALAD1 and the green alga Chlamydomonas reinhardtii CrALAD1, indicating cross-species conservation of the ALAD–SSUII interaction. In vitro enzyme activity assays showed that AtSSUII does not directly alter AtALAD1 catalytic activity, suggesting the interaction operates through post-translational rather than direct catalytic mechanisms. Overexpression of AtALAD1 caused severe chlorosis and seedling lethality, while AtSSUII overexpression produced no distinct phenotype; neither transgene altered the transcript level of the other. Together, our results reveal a conserved cross-pathway protein–protein interaction linking the terpenoid regulatory machinery to the early TBP, suggesting a molecular possibility for the coordinated regulation of chlorophyll biosynthesis. Full article