Search Results (211)

Newborns are unable to reliably express changes in their physical condition due to their physiological immaturity and limited capacity for communication; therefore, continuous and systematic monitoring during phototherapy is essential to ensure timely detection of adverse responses and maintenance of therapeutic safety. This study extends our prior work, which introduced an indirect method for measuring light intensity to improve precision in monitoring newborn skin illumination. Light-emitting diode (LED) phototherapy has attracted considerable attention as an effective treatment for neonatal jaundice (NNJ). This study introduces an three-dimensional configuration of blue LEDs. An Arduino Mega 2560 microcontroller with pulse-width modulation (PWM) technology was employed to independently regulate the intensity of LED strips, enabling precise control of light output. The strips were mounted on an arc-shaped structure that can be adjusted mechanically and electronically through pre-programmed instructions embedded in the microcontroller. The results demonstrate that blue light at a wavelength of 460 ± 10 nm aligns with the peak absorption spectrum of bilirubin, thereby optimizing the efficacy of phototherapy for NNJ. Both observed absorption peaks were within the therapeutically effective range. Computer simulations confirmed that stable output contours can be achieved using rapid electronic scanning with a PID control algorithm to dynamically adjust the duty cycle. Experimental data showed that LED radiation output was largely linear. This supports the use of linear control algorithms and confirms the platform’s feasibility for future research. 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

While there have been reports indicating the potential anticancer benefits of blue light irradiation and its enhanced effectiveness when combined with anticancer drugs, no studies have explored its combined use with radiation therapy. In this study, the anticancer effects of blue light irradiation alone and in combination with radiation therapy were investigated in vitro. Blue light was applied using a transilluminator (470 nm). For combination experiments, cells were exposed to X-rays 24 h after blue light irradiation. Cell viability was assessed using the trypan blue exclusion method, and protein expression was analyzed by Western blotting. Blue light irradiation suppressed the proliferation of human head and neck squamous cell carcinoma (HNSCC) cells. Furthermore, combined blue light and X-ray irradiation more effectively inhibited the proliferation of human HNSCC cells compared to either irradiation alone. Mechanistically, the irradiation of HNSCC cell line SAS with blue light suppressed the activity of extracellular signal-regulated kinase (ERK1/2), which is an important kinase that is involved in cell proliferation. Collectively, these findings suggest that blue light suppresses the proliferation of HNSCC cells, at least in part through ERK1/2 inactivation observed in SAS cells, and that its combination with radiation may represent a promising therapeutic approach. Full article

Background: Antimicrobial photodynamic therapy (aPDT) is a useful adjunct for managing oral biofilm diseases. Natural photosensitizers may be safer and more biocompatible than synthetic ones, but their dental effectiveness is still unclear. Methods: A PRISMA compliant review (PROSPERO ID: CRD420251233910) searched PubMed, Embase, Scopus, and the Cochrane Library for randomized controlled trials published from 2015 to 2025 that used natural photosensitizers for aPDT in dental settings. Three reviewers screened studies, extracted data, and assessed bias with a nine-domain tool adapted for photodynamic therapy. Results: Eleven of 249 records met the established criteria. Natural photosensitizers included curcumin, riboflavin, phycocyanin, chlorophyll derivatives, and plant extracts, tested in periodontitis, peri-implant mucositis, denture stomatitis, caries-related biofilms, and general oral decontamination. Most trials showed short-term microbial reductions and modest clinical gains, with performance comparable to chlorhexidine, methylene blue, or standard care. Adverse effects were minimal. Study quality was generally good, but wide variation in photosensitizer type, light settings, and outcomes, and short follow-up periods hindered meta-analysis and limited conclusions about long-term effectiveness. Conclusions: Natural photosensitizer-based aPDT appears effective and safe as an adjunct, offering consistent short-term microbiological improvements. Current evidence does not support replacing established antimicrobial approaches. Larger, well-controlled trials with standardized methods and longer follow-up periods are needed to define best practice and clarify the role of aPDT in routine dentistry. Full article

Amphotericin: B (AmpB)-resistant Candida (C.) species, such as C. parapsilosis, are among the most common causes of invasive fungal infections, posing significant challenges in hospital settings. Although AmpB is considered the first-line treatment owing to its broad-spectrum fungicidal activity, its use is hampered by severe side effects and the emergence of acquired resistance, particularly in C. parapsilosis, which exhibits reduced susceptibility to polyene, azole, and echinocandin-based antifungal drugs. Here, we present findings on photodynamic therapy (PDT) that targets the opportunistic fungal pathogens C. parapsilosis and C. albicans via the use of photosensitizers from the iodocyanine and newly developed iodinated Methylene blue families. These compounds contain heavy iodine atoms that increase the production of reactive oxygen species (ROS), the agents responsible for oxidative cellular damage, via the heavy-atom effect, which promotes intersystem crossing (ISC) and triplet-state formation. A strong antifungal effect was observed against AmpB-resistant C. parapsilosis, indicating a correlation between the quantum yield of ROS generation and the photosensitizing efficacy under near-infrared (NIR) light irradiation. The combination of efficient cellular uptake and enhanced ROS generation positions iodinated photosensitizers as promising candidates for the treatment of drug-resistant Candida strains. Full article

Photodynamic therapy (PDT), which combines light and dyes, has emerged as a cost-effective, selective, and less toxic alternative to conventional chemotherapy for cutaneous leishmaniasis (CL), offering potential benefits for millions, especially those who are socioeconomically vulnerable. Therefore, this study investigated the in vitro effects of methylene blue (MB), a widely used photosensitizer with proven clinical efficacy, along with its derivatives—new methylene blue—NMB, NMB-B, and NMB-P—in PDT against L. amazonensis promastigotes, using a red LED device. Inhibitory concentrations (ICs) and 168 h proliferation curves were obtained. The production of reactive oxygen species (ROS) and the mechanism of cell death induction were analyzed by flow cytometry. PDT enhanced leishmanicidal effects compared to non-PDT conditions, reducing ICs by up to 85% and outperforming miltefosine, reaching the submicromolar range (IC_25NMB-P = 0.73 ± 0.16 µM, p < 0.05). The proliferation curve showed a consistent inhibitory effect, with MB exhibiting a greater decline than miltefosine, a pattern also observed with MB derivatives. PDT also increased ROS production by up to 5-fold and induced apoptosis-like cell death, characterized by AV⁺ parasites (up to 51.49 ± 2.90%, p < 0.0001). The results demonstrated that the tested dyes effectively eliminated L. amazonensis promastigotes, highlighting the potential of the NMB derivatives as photosensitizers and supporting further investigations. Full article

Oral infections caused by Candida spp. represent a major health concern due to the increasing resistance of these fungi to conventional antifungal agents. Photodynamic therapy (PDT) is a treatment based on the use of light at a specific wavelength that activates a photosensitizer (PS) in the presence of oxygen. The activated PS selectively binds to infected cells and induces apoptosis through the generation of reactive oxygen species (ROS). Previous biomolecular studies on Candida albicans have demonstrated that its infection triggers characteristic molecular signals, such as miRNA-146a and miRNA-155, which serve as inflammatory markers. This in vitro study aimed to evaluate the impact of PDT on the expression of their primary transcripts (pri-miRNAs) in a cell culture model of C. albicans infection. Human embryonic kidney (HEK-293) cells were infected with a multidrug-resistant strain of C. albicans (CA97) and subsequently exposed to curcumin-based PDT activated by blue light (470 nm). The expression of pri-miRNAs 146a and 155 was assessed before and after PDT treatment for each experimental group. The expression levels of pri-miRNAs increased approximately 2- to 3.5-fold following C. albicans infection but returned to baseline values after PDT treatment. The evaluation of pri-miRNAs 146a/155 may serve as a valuable research tool for monitoring early inflammatory responses induced by Candida infection, as well as a sensitive biomarker for assessing the effectiveness of photodynamic therapy in an in vitro cell culture model. Full article

Background: Candida albicans is increasingly recognized in peri-implantitis due to its capacity to form resilient biofilms on implant surfaces, limiting treatment success. Antimicrobial photodynamic therapy (aPDT) may offer a non-invasive adjunct by leveraging photosensitizer activation to produce reactive oxygen species that disrupt microbial cells. This in vitro study assessed the antifungal efficacy of QroxB2, a dual-photosensitizer containing riboflavin and curcumin, activated by 450 nm blue light against C. albicans biofilms on titanium implants. Methods: C. albicans biofilms were formed on 63 titanium implants and randomly assigned to nine groups (n = 7): untreated control (GC), chlorhexidine (CHX), riboflavin (RIB), curcumin (CUR), QroxB2 (QBX), laser only (L), and three photodynamic therapy groups combining laser irradiation with each photosensitizer (L + RIB, L + CUR, L + QBX). Treatments were followed by colony-forming unit (CFU) enumeration. Results: The L + QBX group showed the strongest antifungal effect, achieving a 94% reduction in fungal load, with median CFU counts decreasing from 49,000 in the untreated control to 2800 CFU/mL. CHX eradicated all viable cells (0 CFU/mL). Among photosensitizer-only groups, QBX produced a moderate reduction (median 21,800 CFU/mL), whereas laser irradiation alone (L) exhibited no meaningful antifungal activity, with median counts comparable to the untreated control (49,000 CFU/mL). Conclusions: QroxB2-mediated aPDT achieved a significant reduction in Candida albicans colony-forming units on implant surfaces. While not as potent as chlorhexidine, this light-activated, biocompatible approach may serve as a complementary tool in managing peri-implant fungal infections. Clinical validation is warranted. Full article

Background and Objectives: The treatment of Chronic Myeloid Leukemia (CML) faces challenges such as resistance to Tyrosine Kinase Inhibitors (TKIs), necessitating new adjuvant therapies. This study aimed to evaluate the cytotoxic effect of direct, photosensitizer-free irradiation with LASER and LED light on the CML cell line K-562, hypothesizing that LASER light at a specific wavelength would be selectively effective. This work serves as a foundational in vitro study to establish the basis for a potential ex vivo therapeutic strategy. Methods: The human CML cell line K-562 was irradiated with LASER (405, 532, 629 nm) and LED (457, 517, 630 nm) sources at energy doses from 1 to 10 J/cm². Cell viability was assessed 24 h post-irradiation using Trypan Blue exclusion, the MTT assay, and biophysical changes in the cell absorbance spectrum. Results: Irradiation with a 532 nm LASER was the only condition that induced massive, statistically significant, and dose-dependent cytotoxicity, reaching up to 67.8% cell death at 10 J/cm² (p < 0.05). In contrast, other LASER wavelengths and all tested LED wavelengths failed to produce a significant cytotoxic effect. The superiority of the LASER over the LED of a similar wavelength highlights the critical role of the physical properties of light. Conclusions: Direct, photosensitizer-free irradiation with 532 nm LASER light is a potent and selective method for inducing cytotoxicity in K-562 cells in vitro. This effect is critically dependent on both the specific wavelength and the optical properties of the light source. These findings establish a solid foundation for the development of new ex vivo adjuvant therapies, such as extracorporeal photopheresis, for CML, pending further validation of its mechanism and selectivity. Full article

Background/Aim: Photodynamic therapy uses a photosensitizer and light to generate reactive oxygen species that kill tumor cells and can shift inflammatory signaling. Hypericin is a potent photosensitizer, but its immunomodulatory impact in breast cancer needs clarification. We evaluated the phototoxic and cytokine-modulating effects of hypericin-mediated photodynamic therapy in MCF-7 human breast adenocarcinoma cells. This study examines how HYP-PDT affects MCF-7 breast cancer cells by assessing viability and cytokine secretion to guide the development of targeted, immune-enhancing PDT protocols. Methods: MCF-7 cells were incubated with hypericin at 0, 0.125, 0.25, 0.5, or 1 μM, then exposed to light doses of 0, 1, 2, or 5 J/cm². Viability was measured 24 h later by MTT; selected conditions were also assessed by Trypan Blue. Cell supernatants collected after sublethal treatment were analyzed for IL-6, IL-8, IL-10, and TNF-α using a multiplex immunoassay. Experiments were repeated four times. Statistical analyses followed the study’s plan for group comparisons. Results: At 1 J/cm², MTT values did not differ from matched dark controls across hypericin concentrations. At 2 and 5 J/cm², some conditions showed increased MTT signal relative to controls, indicating higher metabolic activity; Trypan Blue performed at 0 J/cm² showed a concentration-dependent reduction in viability with hypericin. Hypericin-PDT decreased IL-6 and IL-8 concentrations and increased TNF-α in MCF-7 supernatants. No statistically significant changes were detected for IL-10. Conclusions: Hypericin-PDT altered inflammatory readouts in MCF-7 cells, with reductions in IL-6 and IL-8 and an increase in TNF-α, consistent with a pro-inflammatory shift. Viability results suggest condition-dependent changes in metabolic activity or survival effects that warrant confirmation with matched cell counts across all light doses. These findings support further standardized dosimetry and multi-line validation of hypericin-PDT in breast cancer models. Full article

Photodynamic therapy (PDT) is a promising antimicrobial strategy whose efficacy depends largely on the photosensitizers (PSs) used. While conventional PDT relies on a single PS, recent studies suggest that combining different PSs may improve outcomes by introducing complementary mechanisms. However, such combinations also add complexity, as timing, composition, and PS interactions must be considered alongside bacterial structures, uptake pathways, and light dosimetry. This study investigated the effects of PSs, methylene blue (MB), Photodithazine (PDZ), and their combinations on the PDT of Gram-negative bacterium Klebsiella pneumoniae. MB-mediated PDT demonstrated greater antibacterial effectiveness than PDZ-PDT. The combination of MB and PDZ produced varying results. When applied simultaneously, PDZ dose-dependently decreased MB’s antibacterial activity. Sequential treatment with PDZ followed by MB showed only slight antagonism compared to MB alone, while the reverse order (MB → PDZ) nearly abolished MB’s activity. Since both PSs are activated at the same wavelength (660 nm), their combined use was not additive. Photobleaching was performed on individuals and combined PSs to compare inactivation results with changes in chemical properties under red light (660 nm). This study highlights the limitations of using two photosensitizers together in antimicrobial photodynamic therapy and emphasizes the need for further optimization of combination protocols. Full article

Background/Objectives: Glioblastoma (GBM) is a fatal tumor in the central nervous system (CNS) with a poor prognosis. Preventing tumors from post-surgical recurrence is a significant clinical challenge, since current methods deliver chemotherapeutic agents in a rapid manner and are not effective against the residual tumor cells. To address these limitations, we develop a blue light-crosslinking hydrogel which can be rapidly gelled in situ and tightly adhere on the tissues for controlled chemotherapy, radiotherapy, and enhanced laser interstitial thermal therapy (LITT) to inhibit residual tumor cells from post-surgical recurrence. Methods: We utilize gelatin-MA based hydrogel with crosslinker VA-086 as hydrogel scaffold to encapsulate small-molecule drugs (Epirubicin and Cisplatin) and LITT agent polypyrrole-coated graphine oxide (PPy@GO). The mixture can form into hydrogel in situ by blue light irradiation and performed chemo-LITT and radio therapy simultaneously. Then we determine the prevailing factors that affect efficient encapsulation of therapeutic agents within hydrogels, efficiency of gelation, LITT enhancement, and drug release. Then evaluate efficiency in human cancer cells and an in vivo tumor model. Results: Our results demonstrate that 18 wt% Gelatin MA formulation achieved >95% gelation within 2 min, with drug-loaded gels forming within 5 min. The gelation can perform both in vitro and in vivo without affect the drug efficiency. This multi-treatment system can effectively prevent tumor recurrence and significantly prolong the medium survival of glioma-bearing (MBR-614 or U87-MGFL) mice to above 65 days compared with the control group (36 days). Conclusions: The results demonstrated promising effect of this system as a multi-therapeutic platform which combined chemo-LITT and RT. This synergistic strategy presents a new approach to the development of a local drug delivery system for the prevention of brain tumor recurrence. Full article

Due to their excellent physicochemical properties, the nanoparticles (NPs) have been utilized in various potential applications, including environmental remediation, energy storage, and nanomedicine. In this work, the ultrasonic and manual stirring approaches were used to integrate yttrium oxide (Y₂O₃) nanoparticles (NPs) into reduced graphene oxide (RGO) and carbon nanotubes (CNTs) to enhance their photocatalytic and anticancer properties. Pure Y₂O₃NPs, Y₂O₃/RGO NCs, and Y₂O₃/CNTs NCs were characterized using different analytical techniques, such as XRD, SEM, EDX with Elemental Mapping, FTIR, UV-Vis, PL, and DLS to investigate their improved structural, surface morphological, chemical bonding, optical, and surface charge properties. XRD data confirmed the successful integration of Y₂O₃into RGO and CNTs, with minor changes in crystallite sizes. SEM images with EDX analysis revealed that Y₂O₃NPs were uniformly distributed on RGO and CNTs, reducing aggregation. Chemical bonding and interactions between Y₂O₃and carbon materials were investigated using Fourier Transform Infrared (FTIR) analysis. UV and PL results suggest that the optical studies showed a shift in absorption peaks upon integration with RGO and CNTs. This indicates enhanced light absorption and modifications to the band gap between (3.79–4.40 eV) for the obtained samples. In the photocatalytic experiment, the degradation efficiency of bromophenol blue (BPB) dye for Y₂O₃RGO NCs was up to 87.3%, outperforming pure Y₂O₃NPs (45.83%) and Y₂O₃/CNTs NCs (66.78%) after 120 min of UV irradiation. Additionally, the MTT assay demonstrated that Y₂O₃/RGO NCs exhibited the highest anticancer activity against MG-63 bone cancer cells with an IC50 value of 45.7 µg/mL compared to Y₂O₃CNTs NCs and pure Y₂O₃NPs. This work highlights that Y₂O₃/RGO NCs could be used in significant applications, including environmental remediation and in vivo cancer therapy studies. Full article

Yeasts of the genus Candida (C.) and the bacterium Staphylococcus aureus (S. aureus) are among the most common pathogens responsible for infections that are difficult to treat, including those resistant to standard therapy. In recent decades, this has become an increasing clinical problem. In response to the limitations of traditional procedures, antimicrobial photodynamic therapy (aPDT), which combines light, a photosensitizer, and oxygen, is gaining growing interest. The aim of this study was to evaluate the in vitro effectiveness of aPDT using a 635 nm diode laser in combination with toluidine blue O (TBO) against Candida spp. and S. aureus. Reference strains of C. albicans, C. glabrata, C. krusei, and S. aureus were subjected to aPDT. In phase I of this study, the optimal TBO incubation time was assessed with constant laser parameters. In phase II, the impact of the physical parameters of the laser, irradiation time, and output power, was analyzed, with the TBO incubation time set based on the phase I results, to evaluate the degree of microbial reduction (CFU/mL). Statistical analyses were then conducted to assess significance. TBO-mediated aPDT significantly reduced microbial viability, depending on incubation time and laser settings. The minimal effective incubation times were 10 min for Candida spp. and 5 min for S. aureus. The highest pathogen inactivation efficacy was observed at an output power of 400 mW and an irradiation time of 120 s. The use of the photosensitizer or laser alone did not result in significant antimicrobial effects. TBO-mediated aPDT may serve as an effective complement to conventional antimicrobial therapy and, in selected cases (e.g., drug resistance), has the potential to partially or fully replace it. The observed minimal effective incubation times provide a practical baseline, but further statistical comparisons are required to determine whether these durations are truly optimal. Full article

Background/Objectives: Abnormal differentiation of human skin fibroblasts into myofibroblasts contributes to fibrotic skin disorders such as hypertrophic scars, keloids, and Dupuytren’s disease. This process is characterized by increased fibroblast proliferation, enhanced differentiation into myofibroblasts, and reduced programmed cell death (apoptosis). We previously demonstrated that blue light irradiation (λ = 453 nm) significantly and dose-dependently inhibits both spontaneous and TGF-β-induced fibroblast differentiation. Methods: Because fibroblast differentiation depends on cellular energy metabolism, we investigated whether the inhibitory effect of blue light is linked to changes in the cells’ energy balance. Results: We found that blue light reduced TGF-β-induced differentiation, as shown by decreased levels of α-SMA and EDA-fibronectin, key markers of myofibroblast formation. This effect was strongly associated with almost complete inhibition of mitochondrial respiration, reduced glycolysis, a lower NAD⁺/NADH ratio, and decreased ATP production. ATP-dependent processes, including endocytosis and lysosomal activity, both essential parameters of fibroblast differentiation, were also strongly suppressed. Importantly, all these changes were fully reversible within 24 h after the last irradiation. Conclusions: Mechanistically, we propose that blue light triggers photochemical reduction in flavins in proteins of the respiratory chain and possibly the Krebs cycle, which temporarily alters cellular energy metabolism. These findings suggest that non-toxic blue light therapy (80 J/cm²) can effectively prevent factor-induced fibroblast differentiation and may serve as a standalone or supportive treatment to reduce fibrotic events such as scarring and keloid formation. Furthermore, our results indicate that targeting cellular energy metabolism, whether physically or pharmacologically, could be a promising strategy to prevent sclerotic skin disorders. Full article