Search Results (397)

Background/Objectives: Carbon dots (CDs) are promising antimicrobial nanomaterials owing to their biocompatibility, environmental friendliness, and tunable surface chemistry. This study aimed to synthesize nitrogen-doped CDs (AS-CDs) and develop a light-responsive antibacterial system through conjugation with chlorin e6 (Ce6). Methods: AS-CDs were synthesized by a microwave-assisted method using L-ascorbic acid and spermidine, followed by conjugation with Ce6. The materials were characterized by transmission electron microscopy, zeta potential analysis, and spectroscopic methods, and their antibacterial activity was evaluated against Escherichia coli, Staphylococcus aureus, and methicillin-resistant S. aureus (MRSA) under both dark and visible-light conditions. Cytotoxicity was assessed using HaCaT cells. Results: The AS-CDs exhibited a uniform nanoscale morphology with an average diameter of 6.3 nm and a positive surface charge of +15.6 mV, together with intrinsic broad-spectrum antibacterial activity. Ce6 conjugation further enhanced antibacterial efficacy under light irradiation, with the CDs-Ce6 conjugate achieving complete eradication of S. aureus and MRSA and marked inhibition of E. coli at 2.5 μg/mL. Cytotoxicity studies demonstrated low toxicity in HaCaT cells within the effective antibacterial concentration range. Conclusions: These findings highlight the potential of microwave-synthesized, photosensitizer-conjugated CDs as next-generation antimicrobial agents. This platform offers a cost-effective, sustainable, eco-friendly, and efficient platform for combating bacterial infections, with broader potential in pharmaceutical and biomedical applications. Full article

Background: Photodynamic therapy (PDT) offers a promising complementary strategy for treating glioblastoma multiforme (GBM); however, limited control over photosensitizer activation and reduced efficacy under hypoxic conditions remain significant limitations. Methods: In this study, we present the synthesis and functional evaluation of Gal-SiX, an enzymatically activatable Si-xanthene-based activatable PDT agent designed to address these challenges. Prepared via an improved 10-step synthetic route, Gal-SiX exhibits clear turn-on fluorescence and absorbance responses upon β-galactosidase activation and efficiently generates reactive oxygen species in aqueous media. Results: Mechanistic studies revealed that Gal-SiX enables both Type I and Type II PDT pathways, a favorable feature for GBM environments characterized by restricted oxygen availability. In vitro assays conducted on U87MG glioblastoma cells and L929 healthy fibroblasts demonstrated light-dependent cytotoxicity, with IC₅₀ values of 3.30 μM and 7.19 μM, respectively. Gal-SiX also showed minimal dark toxicity (>80 μM) and potent light-induced cytotoxicity, yielding a phototoxicity index of 24.8 in glioblastoma cells. Confocal imaging and MTT assays consistently confirmed enzymatic activation and effective PDT response at the cellular level. Conclusions: Overall, this work introduces the first activatable Si-xanthene-based PDT agent for glioblastoma and provides the first evidence that the Si-xanthene scaffold can support dual Type I/II phototoxicity. These results underscore Gal-SiX’s potential as a PDT platform for addressing the unique constraints of GBM biology. Full article

Hepatocellular carcinoma (HCC) remains a major cause of cancer-related mortality in the world. Although there is an armamentarium of therapeutic options available for HCC therapy, current treatment modalities still face challenges, such as limited effectiveness and resistance to therapy due to inherent intratumoral heterogeneity. Hence, the development of novel therapeutics is an unmet need. Microalgae possess the ability to provide naturally derived compounds that are attractive for biomedical applications. The multifunctional nature of microalgae, with its unique combination of anticancer metabolites, oxygen-generating capability, and photosensitizing activity, make them a versatile platform for developing next-generation cancer therapeutics. In light of the above, this succinct narrative review highlights the potential biomedical applications of microalgae in cancer therapy, with a focus on HCC. Preclinical studies have shown the significant potential of microalgae as naturally occurring sources of chemopreventive and anticancer agents against HCC. Future directions include the use of biotechnology to enhance the production of microalgal-derived bioactive compounds and the formulation of biocompatible and biodegradable drug–microalgae embolic agents with prolonged release of anticancer drugs, thereby giving rise to synergistic antitumor effects, and their application for the delivery of immune checkpoint inhibitors for immunotherapy in HCC. Overall, microalgae hold considerable promise for advancing innovative therapeutic strategies against HCC. Full article

Nanotechnology combined with photodynamic therapy (PDT) has been explored to enhance antitumor and antimicrobial photobiological activity. Aluminum phthalocyanine chloride (Al-Pc-Cl), with or without magnetic nanoparticles (MagNPs), was incorporated into polymeric nanoparticles (PNPs) to improve the PDT for treating tumors and infectious diseases. Three batches of the nanoparticles (MagNPs, PNPs-PS and PNPs-PS-MagNPs) were developed and characterized in terms of size, PdI, morphology by TEM, release study, and antitumor (against A549 cells) and antimicrobial (against MRSA and C. albicans) photobiological activity. The developed nanoparticles were nanometric in size, with MagNPs, PNPs-PS, and PNPs-PS-MagNPs showing 33.6, 186.9, and 333.5 nm, respectively, maintained the magnetic properties (for MagNPs and PNPs-PS-MagNPs), and provided slow and sustained release of the photosensitizer. PNPs-PS and PNPs-PS-MagNPs showed excellent antitumor photobiological activity with cell viabilities of 42 and 34%, respectively, and were not cytotoxic in the dark, with cell viabilities above 70%. PNPs-PS showed strong antibacterial activity against MRSA with an IC₅₀ of 8.26 μg/mL, which was lower to free Al-Pc-Cl with an IC₅₀ of 14.22 μg/mL after I radiation. The results of the antifungal photobiological activity against C. albicans were excellent, with IC₅₀ values of 3.75 and 3.5 μg/mL for PNPs-PS and PNPs-PS-MagNPs, respectively, values which were significantly lower with p < 0.05 than free PS (IC₅₀ > 30 μg/mL) after irradiation with light and fluconazole (IC₅₀ > 30 μg/mL), the reference antifungal agent. PNPs-PS showed promising results regarding antitumor, antibacterial, and antifungal photobiological activity. However, PNPs-PS-MagNPs showed weak results for antibacterial photobiological activity against MRSA but with promising results for tumor cells and C. albicans. Full article

Polymer nanoparticles have been widely studied for tumor treatment due to their excellent biocompatibility, structural diversity, and multi-functionality. Among their various applications, combining polymer-based photosensitizers with photodynamic therapy (PDT) and immunotherapy has emerged as a promising strategy for treating solid tumors. This combination not only enhances local tumor ablation but also activates systemic antitumor immune responses. Polymer Nanoparticles, with their unique photodynamic properties and ability to integrate multiple therapeutic modalities, offer a powerful platform for photo-immunotherapy. This review systematically discusses recent advances in the design of polymer Nanoparticles and their synergistic mechanisms when combined with immunomodulatory agents such as Toll-like receptor (TLR) agonists, STING agonists, and immune checkpoint inhibitors (ICBs). Moreover, we highlight challenges faced in clinical translation and outline future perspectives for the development of these combination therapies. Full article

Central nervous system (CNS) tumors in children, though uncommon, pose distinct challenges due to their unique pathological and clinical features, which often differ from adult cases. Effective management of pediatric CNS tumors can be complicated, with complete surgical resection remaining a critical goal, in conditions like cerebra cavernous malformation (CCM), where it significantly impacts recurrence risk. However, achieving complete resection can be difficult, as preserving the surrounding healthy tissue is vital to avoid long-term neurological deficits, a particular concern in the developing brains of children. Photodynamic therapy (PDT) has emerged as a promising adjunctive treatment for pediatric CNS tumors due to its ability to selectively target tumor cells while sparing healthy tissue. PDT uses a photosensitizing agent. This targeted approach is advantageous in pediatric cases as it minimizes collateral damage, potentially reducing the long-term neurological and cognitive impacts seen with conventional treatments such as radiation. Despite its promise, the application of PDT for pediatric CNS tumors remains underexplored. Research is limited, primarily due to the rarity of these tumors in children and the ethical challenges involved in conducting pediatric trials. The current understanding of PDT’s effectiveness in CNS tumors largely stems from adult studies, which may not fully apply to children’s unique developmental and physiological characteristics, including differences in the tumor biology, metabolism, and pharmacokinetics of photosensitizers. To address this gap, our study conducted a comprehensive review of the available literature using PubMed, Google Scholar, and additional databases like Web of Science, aiming to summarize the existing knowledge on PDT for pediatric CNS tumors, incorporate recent advancements from the last years, and identify areas where further research is essential. The updated review includes new insights from ongoing sonodynamic therapy (SDT), which complements PDT by using ultrasound to enable deeper penetration. Full article

Prostate cancer (PCa) is the most common malignant tumor of the male genitourinary system, and its incidence and mortality have shown a marked global increase in recent years. Prostate-specific membrane antigen (PSMA), a type II transmembrane glycoprotein highly expressed in PCa cells, has emerged as a vital molecular target in the field of PCa precision diagnosis and therapy. In recent years, significant advances have been achieved in PSMA-based molecular imaging, radioligand therapy, and the development of novel targeted drugs. This review aims to summarize and critically discuss recent advances in PSMA-targeted molecular imaging, radioligand therapy, and emerging therapeutic strategies, highlighting their roles in precision diagnosis and personalized treatment of PCa. PSMA positron emission tomography/computed tomography (PET/CT) imaging using radionuclides such as ⁶⁸Ga and ¹⁸F has markedly improved the accuracy of primary tumor staging, localization of recurrent lesions, and therapeutic response assessment. Radioligand therapies, such as ¹⁷⁷Lu-PSMA-617 and ²²⁵Ac-PSMA-617, have prolonged survival and demonstrated symptomatic benefits in multiple clinical trials, and are now applied in early disease stages, including chemotherapy-naïve and hormone-sensitive settings. Meanwhile, PSMA-targeted antibodies and antibody–drug conjugates (PSMA-ADCs), as well as bispecific T-cell engagers (BiTEs) and chimeric antigen receptor T-cell (CAR-T) therapies, are constantly being optimized and show promising clinical potential. Furthermore, PSMA-targeted nanoplatforms enable precise delivery of chemotherapeutic agents, photosensitizers, or imaging probes, achieving integrated diagnosis and therapy with multimodal imaging guidance, and offering new strategies for individualized treatment. Taken together, the evidence summarized in this review highlights PSMA as a pivotal molecular target supporting precision diagnosis and personalized treatment across the continuum of prostate cancer management. Full article

Diabetic foot ulcer (DFU) infections frequently involve biofilm formation and exhibit limited responsiveness to conventional antibiotic therapy. In particular, Pseudomonas aeruginosa often participates in mono- and polymicrobial biofilms that display high tolerance to antimicrobial agents. This study evaluated the efficacy of methylene blue-mediated antimicrobial photodynamic therapy (aPDT), alone and in combination with antibiotics, against P. aeruginosa biofilms formed either as single-species or in mixed communities with Enterococcus faecalis, under conditions mimicking DFU infections. Macrocolony biofilms were challenged with amikacin alone (for single-species biofilms) or amikacin plus ampicillin (for mixed biofilms), aPDT, or sequential combinations of these treatments, and bacterial viability was quantified by colony-forming unit enumeration. Antibiotic treatment alone produced only modest reductions in P. aeruginosa viability, even at high concentrations, while aPDT using methylene blue was effective only at high photosensitizer concentrations. In contrast, sequential treatment with antibiotics followed by aPDT and a second antibiotic challenge resulted in a marked reduction in P. aeruginosa viability in both mono- and polymicrobial biofilms. Scanning electron microscopy revealed extensive structural damage in P. aeruginosa cells following combined treatments, whereas E. faecalis remained unaffected. Overall, our findings demonstrate that combining aPDT with antibiotics significantly enhances antibiofilm activity against P. aeruginosa, highlighting this approach as a promising alternative for the management of biofilm-associated DFU infections. Full article

Breast cancer remains the most common and leading cause of cancer deaths among women worldwide. The efficacy of conventional therapies is often hampered by off-target effects and multidrug resistance. Phototherapy, encompassing photodynamic therapy (PDT) and photothermal therapy (PTT), has gained significant attention due to its non-invasiveness, high spatiotemporal selectivity, and minimal side effects. However, its application is hindered by several obstacles, including the tumor hypoxic microenvironment, insufficient light penetration depth, and acquired heat resistance. Metal–organic frameworks (MOFs) have adjustable structures, enormous specific surfaces, and facile functionalization, providing an ideal platform to overcome these limitations. This review summarizes the latest research progress in the application of MOFs for precision phototherapy in breast cancer treatment. It emphasizes their role as a direct photosensitizer (PS), photothermal agent (PTA), or multifunctional nanocarrier for PDT, PTT, and synergistic phototherapy (including PDT/PTT, chemo/phototherapy, and immunotherapy/phototherapy). The design strategy and therapeutic effect of MOFs for phototherapy of breast cancer are critically discussed. In addition, the current bottlenecks and future perspectives are outlined to facilitate the clinical translation of MOF-based breast cancer treatment platforms. Full article

Background/Objectives: Indocyanine green (ICG) is an FDA-approved, near-infrared fluorescent dye widely used for tumor imaging. This study aimed to evaluate the photodynamic efficacy and selectivity of ICG as a photosensitizer in photodynamic therapy (PDT) against MCF-7 breast cancer cells in 2D monolayers and 3D collagen-embedded cell cultures that simulate ECM diffusion, and to confirm direct generation of singlet oxygen (¹O₂) as the primary cytotoxic species. Methods: MCF-7 breast adenocarcinoma cells and HMEC normal mammary epithelial cells were cultured in 2D monolayers, with MCF-7 cells additionally grown in 3D collagen type I matrices to mimic tumor environments. Cells were incubated with 50 µM ICG for 30 min, washed, and irradiated with a 780 nm diode laser at 39.8 mW/cm². Cell viability was quantified using the Muse^® Count & Viability assay at multiple time points, while ICG uptake and penetration were assessed via flow cytometry, fluorescence microscopy, and confocal imaging. Direct ¹O₂ production was measured through its characteristic 1270 nm phosphorescence using time-resolved near-infrared spectrometry. Results: ICG-PDT reduced MCF-7 viability to 58.3 ± 7.4% in 2D cultures (41.7% cell kill, p < 0.0001) and 70.2 ± 10.7% in 3D cultures (29.8% cell kill, p = 0.0002). In contrast, normal HMECs maintained 91.0 ± 1.3% viability (only 9% reduction, p = 0.08), resulting in a therapeutic index of approximately 4.6. IC₅₀ values in 2D MCF-7 cultures decreased over time from 51.4 ± 3.0 µM at 24 h to 27.3 ± 3.0 µM at 72 h. ICG uptake was higher in 2D (78%) than in 3D (65%) MCF-7 cultures, with diffusion in 3D collagen exhibiting linear depth-dependent penetration. Notably, the singlet-oxygen phosphorescence signal, though weak and requiring highly sensitive detectors, provided direct evidence of efficient ¹O₂ generation. Conclusions: ICG as a photosensitizer in photodynamic therapy using clinically compatible parameters is highly cytotoxic to MCF-7 breast cancer cells while largely sparing HMECs in 2D cell culture. Direct spectroscopic evidence confirms efficient ¹O₂ generation, which contributes significantly to the cytotoxicity. The reduced efficacy in 3D versus 2D models highlights the importance of penetration barriers also present in solid tumors. These results support further preclinical and clinical investigation of ICG as a dual imaging-and-therapy (theragnostic) agent for selective photodynamic treatment of breast cancer. Full article

In recent years, remarkable progress in nanomedicine has been achieved, leading to the development of several nanocarriers which aim to enhance the therapeutic efficacy in cancer treatment. Owing to their high versatility and highly tunable physicochemical properties, alumina (Al₂O₃) and silica (SiO₂) substrates represent promising and innovative nanoplatforms that are widely used in biomedical applications, such as drug-delivery, diagnosis, and biosensing in cancer. In particular, such platforms possess multiple advantageous properties, including mechanical stability, high loading capacity, tunable porosity, excellent biocompatibility, and in vitro and in vivo low toxicity. In this review article, we discuss their emerging role as biosensing platforms and drug delivery systems in oncology. As such, we describe how these substrates enable the incorporation of antibodies against various cancer biomarkers [e.g., cancer antigen 15-3 (CA15-3), serum amyloid A1 (SAA1), epithelial cell adhesion molecule (EpCAM), or human epidermal growth factor receptor 2 (HER2)] for the detection of multiple malignancies. Furthermore, we highlight the development of highly promising alumina- and silica-based platforms for drug delivery (e.g., chemotherapeutics, photosensitizers, or gene delivery agents) in cancer. Ultimately, by providing a comprehensive overview alongside a critical analysis, we demonstrate that such nanostructures represent promising platforms for potential clinical translation in cancer medicine, helping to mitigate the limitations of conventional cancer therapies. Full article

Multicomponent mixed lanthanide oxide (MMLO) nanoparticles possess considerable potential as multimodal imaging agents because they integrate diverse excellent optical and magnetic properties within a single nanoparticle. Herein, we present triply and quadruply mixed lanthanide oxide nanoparticles, namely, gadolinium (Gd)/dysprosium (Dy)/europium (Eu) oxide (GDEO), Gd/Dy/terbium (Tb) oxide (GDTO), and Gd/Dy/Eu/Tb oxide (GDETO) nanoparticles. Gd³⁺ can strongly induce positive (T₁) contrast in magnetic resonance imaging (MRI), Dy³⁺ and Tb³⁺ can generate negative (T₂) contrast in MRI, and Eu³⁺ and Tb³⁺ emit visible photons that are applicable to fluorescence imaging (FI). All the nanoparticles were grafted with hydrophilic, biocompatible polyacrylic acid (PAA) to enhance colloidal stability and biocompatibility and further grafted with small amounts of an organic photosensitizer, 2,6-pyridinedicarboxylic acid (PDA), to obtain a high absolute fluorescent quantum yield (QY) with an extended fluorescent lifetime (τ). All PAA-MMLO and PAA/PDA-MMLO nanoparticles exhibited nearly monodispersed particle-size distributions with average particle diameters of ~2 nm and displayed considerably higher longitudinal (r₁) and transverse (r₂) water proton spin relaxivities than commercial molecular MRI contrast agents. The PAA/PDA-GDEO, PAA/PDA-GDTO, and PAA/PDA-GDETO nanoparticles exhibited high absolute QYs of 45, 29, and 61%, respectively, and long τ values of 1–2 ms, making them suitable for time-delayed noise-free fluorescence signal detection. These findings confirm the high potential of PAA-MMLO nanoparticles as T₁ and/or T₂ MRI contrast agents and PAA/PDA-MMLO nanoparticles as both T₁ and/or T₂ MRI and FI agents. Full article

Background: Phototherapy utilizes targeted irradiation to inactivate bacteria or treat various medical conditions. Depending on the therapeutic goal, wavelengths from violet to infrared (IR) are applied. Within the visible and near-IR spectrum, photodynamic therapy (PDT) combines light with photosensitizers that generate reactive oxygen species (ROS), leading to bacterial inactivation. Optimizing photodynamic efficacy can involve either enhancing ROS formation through specific topical agents that modulate ROS generation or employing dual-wavelength light irradiation (DWLR) to achieve synergistic excitation. Established DWLR protocols typically combine blue and red light or IR to activate distinct photosensitizers. Materials and Methods: This study investigates whether a similar synergistic effect can be achieved within the green spectral range by simultaneously exciting a single photosensitizer—coproporphyrin III (CP III)—at 496 nm and 547 nm. Results: Convolution analysis and in vitro bacterial reduction experiments with Cutibacterium acnes subsp. elongatum revealed that cyan irradiation (496 nm) achieved the strongest photoreduction (2.31 log steps at 1620 J/cm²), whereas PC-lime irradiation (547 nm) produced a smaller effect (0.74 log steps). DWLR protocols (simultaneous and sequential irradiation) resulted in intermediate reductions (1.64 and 1.73 log steps, respectively), exceeding PC-lime but not surpassing cyan irradiation alone. Conclusions: These findings demonstrate that excitation efficiency at the local absorption maximum of CP III is the primary determinant of ROS generation, while spectral broadening through DWLR does not enhance bacterial inactivation within this wavelength range and in vitro setup. Full article

Heracleum sosnowskyi Manden., or H. sosnowskyi, of the Apiaceae was first cultivated in the USSR in 1947 as a potential fodder plant. Due to the development of cold-resistant cultivars and the characteristics of H. sosnowskyi, it quickly became feral. As a result, H. sosnowskyi began to spread as an aggressive invasive species in the 1970s and 1980s. By the 90s it had become an ecological disaster. As well as forming monocultures and displacing native species, H. sosnowskyi contains furanocoumarins, photosensitizing compounds that increase skin sensitivity to ultraviolet rays and cause severe burns. In addition, furanocoumarins have cytotoxic, genotoxic, mutagenic and estrogenic effects. H. sosnowskyi also contains essential oils, which are particularly active during flowering and can irritate the mucous membranes of the eyes and respiratory tract, as well as cause allergic reactions in the form of bronchospasm in people with asthma and hypersensitivity. When released in high concentrations, these biologically active compounds have an allelopathic effect on native plant species, displacing them and reducing biodiversity. As H. sosnowskyi is not native; the biologically active compounds it secretes have a xenobiotic effect, causing serious damage to the ecosystems it occupies. However, in parallel with these negative properties, furanocoumarins have been found to be effective in the treatment of cancer and skin diseases. Furanocoumarins possess antimicrobial antioxidant osteo- and neuroprotective properties. Essential oils containing octyl acetate, carboxylic acid esters, and terpenes can be used in the pharmaceutical industry as antiseptic and anti-inflammatory agents. Additionally, essential oils can be used as biofumigants and natural herbicides. A comprehensive approach allows H. sosnowskyi to be viewed in two ways. On the one hand, it is an aggressive alien species that causes significant damage to ecosystems and poses a threat to human health. On the other hand, it is a potentially valuable natural resource whose biomass can be used within the principles of the circular economy. It is hoped that the use of H. sosnowskyi for economic interests can be a partial compensation for the problem of its aggressive invasion, which is of anthropogenic origin. Full article

Biomolecule–photosensitizer conjugates have rapidly evolved into one of the most powerful strategies for improving the selectivity, efficacy, and translational potential of photodynamic therapy (PDT). By integrating photosensitizers (PSs) with carbohydrates, amino acids, peptides, aptamers, proteins, cofactors, vitamins or antibodies, these constructs overcome long-standing limitations of classical PDT, including poor solubility, insufficient tumour accumulation, and strong dependence on oxygen availability. Beyond enhancing receptor-mediated uptake and enabling precise interactions with the tumour microenvironment (TME), bioconjugation also modulates aggregation, photochemical properties, intracellular accumulation, and immune system activation. A particularly transformative trend is the emergence of supramolecular architectures in which photosensitizers form defined nanostructured aggregates with peptides or proteins. Once considered an undesirable phenomenon, aggregation is now recognized as a tenable feature that governs photochemical behaviour. Engineered aggregates can undergo environment-triggered disassembly to monomeric, photoactive states, or operate as semiconductor-like nanodomains capable of Type I reaction through symmetry-breaking charge separation. This shift toward oxygen-independent radical pathways offers a promising solution to the challenge of hypoxia, a hallmark of the TME that severely compromises conventional Type II PDT. Parallel advances in 3D experimental platforms such as tumour organoids and organ-on-chip systems provide physiologically relevant validation of these conjugates, enabling the assessment of penetration, subcellular localization, immunogenic cell death, and therapeutic synergy within realistic TME conditions. Collectively, the integration of biomolecular targeting with controlled supramolecular design is redefining the landscape of PDT. Future progress will depend on designing conjugates that retain high activity under hypoxia, engineering dynamic aggregate states, and systematically validating these systems in advanced TME-mimetic models. Together, these developments position biomolecule–photosensitizer conjugates as a versatile and increasingly less oxygen-dependent class of next-generation phototherapeutic agents. Full article