Search

Antimicrobial photodynamic therapy uses photosensitizers to produce reactive oxygen species under light exposure to inhibit pathogenic bacteria. Although its application in the management of oral infectious diseases has increased over recent years, it is limited by inadequate tissue and biofilm penetration and suboptimal bioavailability exhibited by individual photosensitizers. These challenges can potentially be surmounted through the integration of nanomaterials, such as polymers, metals and metal oxides, metal-organic frameworks, and carbon and silicon nanomaterials. Polymers allow the controlled release of photosensitizers through structural adjustments but have low stability, while metals and metal oxides possess strong antibacterial properties but can be potentially toxic. Meanwhile, metal-organic frameworks have flexible structures and multifunctionality but have low stability and potential toxicity. Moreover, carbon and silicon nanomaterials, despite exhibiting excellent antibacterial properties and biocompatibility, have limited application due to high production costs. Materials with inherent antibacterial properties, such as chitosan and graphene oxide, have broader application prospects, as they can form multimodal antibacterial platforms with photosensitizers, enhancing the antibacterial effects and eliminating infections. Future research could incorporate other functional materials, such as anti-inflammatory agents and immunomodulatory materials, to construct comprehensive therapeutic nanoplatforms for the treatment of oral infectious diseases.

Sheeja S Rajan, Rahul Chandran, Heidi Abrahamse Laser Research Centre, Faculty of Health Sciences, University of Johannesburg, Johannesburg, South AfricaCorrespondence: Sheeja S Rajan; Heidi Abrahamse, Laser Research Centre, Faculty of Health Sciences, University of Johannesburg, Johannesburg, South Africa, Email srajan@uj.ac.za; habrahamse@uj.ac.zaAbstract: Hypocrellin-based photodynamic therapy (PDT) is developing as a viable cancer therapeutic option, especially when enhanced by nanoconjugation. This review investigates the methods by which nano-conjugated hypocrellin enhances therapeutic efficacy and precision when targeting cancer cells. These nanoconjugates encapsulate or covalently bind hypocrellin photosensitizers (PSs), allowing them to accumulate preferentially in malignancies. When activated by light, the nanoconjugates produce singlet oxygen and other reactive oxygen species (ROS), resulting in oxidative stress that selectively destroys cancer cells while protecting healthy tissues. We look at how they can be used to treat a variety of cancers. Clinical and preclinical studies show that they have advantages such as increased water solubility, improved tumor penetration, longer circulation times, and tailored delivery, all of which contribute to fewer off-target effects and overall toxicity. Ongoing research focuses on improving these nanoconjugates for better tumor targeting, drug release kinetics, and overcoming biological obstacles. Furthermore, the incorporation of developing technologies such as stimuli-responsive nanocarriers and combination therapies opens exciting opportunities for enhancing hypocrellin-based PDT. In conclusion, the combination of hypocrellin and nanotechnology constitutes a significant approach to cancer treatment, increasing the efficacy and safety of PDT. Future research will seek to create conjugates including hypocrellin, herceptin, and gold nanoparticles to induce apoptosis in human breast cancer cells in vitro, opening possibilities for therapeutic applications.Keywords: hypocrellin, cancer, photodynamic therapy, photosensitizer, nanoparticles

Abstract New Schiff base ligand: 4-methoxy salicaldhyde-2-2-phenyl-hydrazono acetaldehíyde prepared by facile method. The molecular structures characterized by elemental analysis and proton magnetic resonance spectra (1H-NMR spectra). This spectra at the chemical shifts (3.5–10.39 ppm) confirmed the types and the numbers of protons. The sharp melting point at the range 110–112 °C confirmed purity. New optically active metal (samarium, terbium and gadolinium) complexes of the Schiff base synthesized in a one pot reaction. Vibrational IR spectra confirmed functional groups. Scanning electron microscopy micrographs confirmed that the modified microstructure of the metal complexes differed in morphology than the ligand. Powder X-ray diffraction patterns confirmed good crystalline structure. The optically activity of the solid metal complexes confirmed from electronic absorption spectra. The UV absorbance band at the wavelength range 280–390 nm and the intense phosphorescence bands up to 830 nm enabled application in photo dynamic therapy for apoptosis cancer cells by conversion triplet oxygen in the tissues into reactive singlet oxygen. Low charge transfer energy: 2.59–2.61 eV, high molar extinction coefficients (ε) at the order of magnitude $$\:{10}^{6}$$ M− 1 cm− 1 and the intense phosphorescence bands reflected good photodynamic activity. The metal complexes are thermally stable.

Objectives. To synthesize Pt-containing derivatives of natural chlorins as potential agents for the combination therapy in oncology. Platinum compounds are known to occupy an important place as chemotherapeutic agents in the treatment of oncological diseases. However, Pt(II) complexes are highly toxic to the body and are not selectively accumulated in tumor cells. If photodynamic and chemotherapy methods are combined in a single drug, the pigments are responsible for the selectivity of conjugate accumulation in the tumor, while a chemotherapeutic agent based on Pt(II) complexes is responsible for the cytotoxic effect on tumor cells. This will not affect healthy cells and thereby minimize the systemic toxicity of the drug to the body.Methods. Methods for the synthesis of pyridine-containing derivatives of natural chlorins and their metal complexes for use as potential binary agents in oncology were applied. As part of the study, the structures of the compounds obtained were confirmed by mass spectrometry, nuclear magnetic resonance spectroscopy, ultraviolet spectroscopy, and high-resolution chromatography-mass spectrometry. Preparative methods, including thin-layer and column chromatography, centrifugation and recrystallization, were used to isolate and purify the compounds obtained.Results. Platinum(II) complexes of pyridine-containing derivatives of natural chlorins were obtained for application in combination therapy in oncology. The schemes for synthesizing the target photosensitizers were optimized, in order to increase the yields and for subsequent transfer to industrial sites.Conclusions. It was found that pyridine-containing derivatives of natural chlorins could be obtained in high yields, that they possess chelating properties for platinum, and can be considered as binary agents in cancer therapy after successful preclinical trials.

The aim of the study was to present various types of radiation that can increase the effectiveness of combined photodynamic therapy (PDT) for malignant and premalignant lesions. Material and Methods. The Web of Science, Scopus, MedLine, Library, and RSCI databases were used for finding publications on this topic, mainly over the last 10 years. Of 230 sources, 64 were included in the review. Results. Photodynamic therapy is a new cancer treatment technology that has become increasingly popular in recent years. It is often an alternative method of treating cancer when there is a high risk of side effects and complications during traditional treatments such as surgery, radiation therapy and chemotherapy. PDT requires a photosensitizer, light energy, and oxygen to create reactive oxygen species that destroy cancer cells. This review examines the basic principles and mechanisms of PDT used alone and in combination with other traditional therapies. Despite the fact that PDT is an effective and non-invasive cancer treatment, it has some limitations, such as low light penetration depth, ineffective photosensitizers and tumor hypoxia. Our study examines new strategies that use other energy sources, such as infrared- and x-rays, ultrasound, as well as electric and magnetic fields, to enhance the PDT effect and overcome its limitations. Great hopes are also associated with the use of a combination of PDT and neutron capture therapy (NСT). Currently, chlorin derivatives associated with boron carriers have been developed. They can be used for both fluorescence diagnostics and PDT, as well as for NСT. The synthesized compounds have a high selectivity of accumulation in the tumor. To date, encouraging preclinical results of high efficiency of combined use of NСT and PDT have already been obtained. Conclusion. Combination with various energy sources is a key factor for further development of PDT. Future research aimed at overcoming the limitations of PDT will contribute to unlocking the full potential of this technology in clinical practice.

Abstract Singlet oxygen is considered an important cell damaging agent due to its propensity to react with organic compounds. This drives the interest in developing methods for determination of 1O2. Simplicity of application and high sensitivity makes fluorescent probes a popular choice for in vivo 1O2 detection. Despite its proclaimed cell-impermeability, the commercially available Singlet Oxygen Sensor Green (SOSG) is widely applied to support assertions of 1O2 involvement in cell and tissue damage. Our investigation, however, demonstrate that different microbial species and cancer cells become fluorescent when exposed to SOSG under conditions which exclude generation of 1O2. Cells, permeabilized with chlorhexidine or by heat exposure under anaerobic conditions, exhibited SOSG fluorescence. Permeabilized cells could be stained with SOSG even 24 h post-permeabilization. Since SOSG is cell impermeable, the main factor that led to fluorescent staining was plasma membrane damage. Spectral analyses of different batches of SOSG revealed that SOSG endoperoxide (SOSG-EP) did not increase even after prolonged storage under the recommended conditions. The commercial preparations of SOSG, however, were not SOSG-EP free, which can produce erroneous results when SOSG staining is used as a proof of singlet oxygen production in vivo.

AbstractNeurological disorders such as neurodegenerative diseases and nervous system tumours affect more than one billion people throughout the globe. The physiological sensitivity of the nervous tissue limits the application of invasive therapies and leads to poor treatment and prognosis. One promising solution that has generated attention is Photodynamic therapy (PDT), which can potentially revolutionise the treatment landscape for neurological disorders. PDT attracted substantial recognition for anticancer efficacy and drug conjugation for targeted drug delivery. This review thoroughly explained the basic principles of PDT, scientific interventions and advances in PDT, and their complicated mechanism in treating brain-related pathologies. Furthermore, the merits and demerits of PDT in the context of neurological disorders offer a well-rounded perspective on its feasibility and challenges. In conclusion, this review encapsulates the significant potential of PDT in transforming the treatment landscape for neurological disorders, emphasising its role as a non-invasive, targeted therapeutic approach with multifaceted applications.

Relevance. The development of antimicrobial drugs and alternative methods, technologies and means of prevention, diagnosis and treatment of human infectious diseases caused by antibiotic-resistant microorganisms is one of the priorities of ensuring the biological safety of the country. Aims. To evaluate the bactericidal activity of tetrapyrrole macroheterocycles (porphyrins) at different light irradiation durations in relation to staphylococci, in vitro. Materials and methods. Studied strains of microorganisms: museum strains of microorganisms – S. aureus ATCC 29213, S. epidermidis ATCC 14990 and antibiotic-resistant strains of bacteria of the genus Staphylococcus (n=18) isolated from clinical biomaterial and from environmental objects in a medical organization. The studied chemical compounds are three different compounds of water-soluble asymmetrically substituted porphyrins containing heterocyclic fragments on the periphery of the porphyrin cycle (residues of benzoxazole, N-methylbenzimidazole and benzothiazole). Results. The activity of all three porphyrin compounds in relation to museum strains of staphylococcus and 77.8% of clinical antibiotic-resistant strains (n=14; 95% CI 20.1-97.5) turned out to be maximal (complete lysis) after 10 minutes of irradiation. Conclusions. The tested tetrapyrrole macroheterocycles (porphyrins) exhibit bactericidal activity against museum and clinical strains of staphylococcus, with different levels of antibiotic resistance, which determines Keywords: antibiotic resistance, water-soluble porphyrin, photodynamic inactivation, photosensitizer, photochemistry, staphylococci No conflict of interest to declare.

Abstract Background Medicinal plant-mediated combinational therapies have gained importance globally due to minimal side effects and enhanced treatment outcomes compared to single-drug modalities. We aimed to analyze the cytotoxic potential of each conventional treatment i.e., photodynamic therapy (PDT), chemotherapy (doxorubicin hydrochloride; Dox-HCl) with or without various concentrations of medicinal plant extracts (PE) on soft tissue cancer Rhabdomyosarcoma (RD) cell line. Methods The Rhabdomyosarcoma (RD) cell line was cultured and treated with Photosensitizer (Photosense (AlPc4)), Chemo (Dox-HCl), and their combinations with different concentrations of each plant extract i.e., Thuja occidentalis, Moringa oleifera, Solanum surattense. For the source of illumination, a Diode laser (λ = 630 nm ± 1 nm, Pmax = 1.5 mW) was used. Photosensitizer uptake time (∼ 45 min) was optimized through spectrophotometric measurements (absorption spectroscopy). Drug response of each treatment arm was assessed post 24 h of administration using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5- 5-diphenyl-2 H- tetrazolium bromide (MTT) assay. Results PE-mediated Chemo-Photodynamic therapy (PDT) exhibited synergistic effects (CI

This comprehensive research has explored the potential of enhancing dye-sensitized solar cells (DSSC) by harnessing environmentally friendly natural dyes, such as chlorophyll pigments from pandanus (664.1 nm) and papaya leaves (664.0 nm), as well as betacyanin pigments from sappan-mangosteen (536.2 nm). Electrochemical analyses elucidated the energy band gaps, revealing a hierarchy with the smallest band gap observed for papaya leaves (1.387 eV), followed closely by sappan-mangosteen (1.389 eV) and pandan leaves (1.396 eV). This research effectively addressed the persistent issue of electrolyte leakage in DSSC development by introducing a polymer electrolyte derived from polyvinylidene fluoride (PVDF) through electrospinning and phase inversion techniques. SEM characterization results and thermogravimetric analysis underscored the superior characteristics and high thermal stability of the PVDF nanofiber polymer for DSSC applications. The study's pivotal findings underscore the remarkable DSSC performance achieved with chlorophyll pigment from papaya leaves, reaching 1.31% efficiency without a polymer electrolyte. Moreover, the sappan-mangosteen dye emerged as a promising contender with the highest efficiency values when applied with polymer electrolyte, recording rates of 1.17% for PVDF NF and 0.95% for PVDF, which are notably comparable to the efficiency of liquid electrolyte at 1.26%.

Abstract While surgical resection is a mainstay of cancer treatment, many tumors are unresectable due to stage, location, or comorbidities. Ablative therapies, which cause local destruction of tumors, are effective alternatives to surgical excision in several settings. Ethanol ablation is one such ablative treatment modality in which ethanol is directly injected into tumor nodules. Ethanol, however, tends to leak out of the tumor and into adjacent tissue structures, and its biodistribution is difficult to monitor in vivo. To address these challenges, this study presents a cutting‐edge technology known as Light‐Activatable Sustained‐Exposure Ethanol Injection Technology (LASEIT). LASEIT comprises a three‐part formulation: (1) ethanol, (2) benzoporphyrin derivative, which enables fluorescence‐based tracking of drug distribution and the potential application of photodynamic therapy, and (3) ethyl cellulose, which forms a gel upon injection into tissue to facilitate drug retention. In vitro drug release studies showed that ethyl cellulose slowed the rate of release in LASEIT by 7×. Injections in liver tissues demonstrated a 6× improvement in volume distribution when using LASEIT compared to controls. In vivo experiments in a mouse pancreatic cancer xenograft model showed LASEIT exhibited significantly stronger average radiant efficiency than controls and persisted in tumors for up to 7 days compared to controls, which only persisted for less than 24 h. In summary, this study introduced LASEIT as a novel technology that enabled real‐time fluorescence monitoring of drug distribution both ex vivo and in vivo. Further research exploring the efficacy of LASEIT is strongly warranted.

BackgroundNear-infrared photoimmunotherapy (NIR-PIT) is an emerging cancer treatment technology that combines the advantages of optical technology and immunotherapy to provide a highly effective, precise, and low side-effect treatment approach. The aim of this study is to visualize the scientific results and research trends of NIR-PIT based on bibliometric analysis methods.MethodsThe Web of Science Core Collection (WoSCC) database was searched in August 2024 for relevant publications in the field of NIR-PIT. Data were analyzed using mainly CiteSpace and R software for bibliometric and visual analysis of the country/region, authors, journals, references and keywords of the publications in the field.ResultsA total of 245 publications were retrieved, including articles (n = 173, 70.61%) and reviews (n = 72, 29.39%). The annual and cumulative number of publications increased every year. The highest number of publications was from the United States (149, 60.82%), followed by Japan (70, 28.57%) and China (33, 13.47%). The research institution with the highest number of publications was National Institutes of Health (NIH)-USA (114, 46.53%). Kobayashi H (109) was involved in the highest number of publications, Mitsunaga M (211) was the most frequently cited in total. CANCERS (17) was the most frequently published journal, and NAT MED (220) was the most frequently co-cited journal. The top 10 keywords include near-infrared photoimmunotherapy (166), photodynamic therapy (61), monoclonal antibody (58), in vivo (50), cancer (46), expression (31), breast cancer (27), enhanced permeability (24), antibody (23), growth factor receptor (16). Cluster analysis based on the co-occurrence of keywords resulted in 13 clusters, which identified the current research hotspots and future trends of NIR-PIT in cancer treatment.ConclusionThis study systematically investigated the research hotspots and development trends of NIR-PIT in cancer treatment through bibliometric and visual analysis. As an emerging strategy, the research on the application of NIR-PIT in cancer treatment has significantly increased in recent years, mainly focusing on the targeting, immune activation mechanism, and treatment efficacy in solid tumors has received extensive attention. Future studies may focus on improving the efficacy and safety of NIR-PIT in cancer treatment, as well as developing novel photosensitizers and combination therapeutic regimens, and exploring the efficacy of its application in a wide range of solid tumors, which will provide an important reference and guidance for the application of NIR-PIT in clinical translation.

DSSC is solar based electrical energy with dye organic matter as sensitizer. The organic sensitizer used to be a freshly extracted pigment. This study used organic dye that had previously been prepared in dry form. This dry dye is more practical to be used in DSSC without taking a long time for extraction. The organic dye derived from Eichhornia crassipes (water hyacinth) leaves. The leave’s extract was dried by using a foam mat drying method with the fillers of dextrin (10% w/v) and gum Arabic (10% w/v), and egg white (2% w/v) as a foaming agent. The application of dried dye was arranged in 2, 4, 6, 8 and 10% (w/v, ethanol solvent), and a freshly prepared extract was also performed as a control. The results showed that the highest amount (0.63 mg/L) of chlorophyll content was in DSSC with the application of 10% (w/v) dried dye. The best DSSC electrical performance was found in the treatment of 4% dried dye with the electrical characteristics including: Voc: 589 mV, Isc: 0.0408 mA, Vmax: 230 mV, Imax: 0.0347, fill factor: 0.332, Output: 7.98 mW and efficiency: 4.95%.

Abstract Quantitative assessment of cell migration in vitro is often required in fundamental and applied research from different biomedical areas including wound repair, tumor metastasis or developmental biology. A collection of assays has been established throughout the years like the most widely used scratch assay or the so-called barrier assay. It is the principle of these assays to introduce a lesion into an otherwise confluent monolayer in order to study the migration of cells from the periphery into this artificial wound and determine the migration rate from the time necessary for wound closure. A novel assay makes use of photosensitizers doped into a polystyrene matrix. A thin layer of this composite material is coated on the bottom of regular cell culture ware showing perfect biocompatibility. When adherent cells are grown on this coating, resonant excitation of the photosensitizer induces a very local generation of 1O2, which kills the cells residing at the site of illumination. Cells outside the site of illumination are not harmed. When excitation of the photosensitizer is conducted by microscopic illumination, high-precision wounding in any size and geometry is available even in microfluidic channels. Besides proof-of-concept experiments, this study gives further insight into the mechanism of photosensitizer-mediated cell wounding.

The formation of dental plaque is well-known for its role in causing various oral infections, such as tooth decay, inflammation of the dental pulp, gum disease, and infections of the oral mucosa like peri-implantitis and denture stomatitis. These infections primarily affect the local area of the mouth, but if not treated, they can potentially lead to life-threatening conditions. Traditional methods of mechanical and chemical antimicrobial treatment have limitations in fully eliminating microorganisms and preventing the formation of biofilms. Additionally, these methods can contribute to the development of drug-resistant microorganisms and disrupt the natural balance of oral bacteria. Antimicrobial photodynamic therapy (aPDT) is a technique that utilizes low-power lasers with specific wavelengths in combination with a photosensitizing agent called photosensitizer to kill microorganisms. By inducing damage through reactive oxygen species (ROS), aPDT offers a new approach to addressing dental plaque and associated microbial biofilms, aiming to improve oral health outcomes. Recently, photosensitizers have been incorporated into dental materials to create photosensitive dental materials. This article aimed to review the use of photosensitive dental materials for aPDT as an innovative antimicrobial option in dentistry, with the goal of enhancing oral health.

The photogalvanic cells presented in this research work are energy devices having dual role of simultaneous solar power generation and storage. The study of photogalvanics of the Lactic acid reductant-Carmoisine A photosensitizer- Cocamidopropyl betaine (CAPB) surfactant-NaOH alkali has been done under artificial illumination for exploring a most suitable combination of photosensitizer, reductant and surfactant for further enhancing the solar harvesting efficiency. This combination of chemicals (Lactic acid-Carmoisine A-CAPB-NaOH) has shown remarkable improvement in the cell performance. The optimum conditions for cell have also been investigated for optimal cell performance. The electrical output of the cell has been found to depend on the cumulative effect of all cell fabrication variables. The observed power is of the order 1012.70 μW with efficiency 28.84 %. The electrical out-put of the photo-galvanic cells is found almost independent of the size of the illumination window. The initial power generated from the cell was ∼309.0 µW (taken as 100 %), and power at the end of 6th day was ∼0.0009 %. This long term study of the cell in post-illuminated dark conditions shows capacity of the cell to store and release the power over long period of time. Therefore, the Lactic acid reductant-Carmoisine A photosensitizer -CAPB surfactant combination is a good alternative for use in the fabrication of highly efficient photogalvanic cells.

Application of liposomes is a critical strategy in drug delivery and increase cellular uptake of drugs having low water solubility. Berberine (BBR) is a bioactive compound found in several plants, including Goldenseal, Barberry, and Oregon grape. It has garnered attention for its various health benefits, particularly in metabolic health and antimicrobial activity. However, one of the challenges associated with BBR is its water solubility. Moreover, BBR has photosensitizing potential via absorbance of light and generation of free radicals. Hence, to improve water solubility and bioavailability, one of the important strategies employed is using lipid-based carriers to enhance solubility. In this study we employed liposomes to deliver BBR in A549 lung cancer spheroid cells to enhance photodynamic therapy efficacies. Results from the EDS and UV–Vis spectroscopy revealed that the BBR had been loaded onto liposomes, with three peaks appearing between 250 and 450 nm. Morphology of Lipo@BBR nanocomplex was in wavy crest shape and the size was 56.99 ± 3.74 nm in SEM and TEM analysis, respectively. FTIR data illustrated that Lipo@BBR has four significant peaks at 1250, 1459, 1736, and 2907 cm−1. DLS data showed that Lipo@BBR has a negative surface charge with a −10.7 Zeta Potential (mV). Additionally, based on Zetasizer measurements, the size of Lipo@BBR complex was 82.7 ± 6.5. Cytotoxicity assay investigation with MTT assay presented that IC50 of Lipo@BBR in PDT was 10 ± 0.5 μg/mL that led to a volume reduction of the A549 spheroids after five sessions of PDT fractionation (total light dose was set at 25 J/cm2). qPCR and immunofluorescence results demonstrated that Lipo@BBR increases the BAX/BCL2 ratio in A549 spheroid cells, hence improving PDT efficiency. In conclusion, our results illustrated that safe dose of Lipo@BBR (10 ± 0.5 μg/mL) in PDT fractionation protocol can be one of the strategies to suppress the tumor volume and cell death proliferation. Authors recommend using Lipo@BBR nanocomplex in PDT fractionation as well as more in vivo investigation is warranted.

AbstractPhotodynamic cancer therapy circumvents the major side effects associated with the conventional cancer treatment methods, such as chemotherapy, surgery and exposure to radiation. Experimental measurement of photosensitizer quantum yield (PQY) singlet production of oxygen through either sensitive laser spectroscopy or luminescence detection at the wavelength of 1270 nm is costly; time consuming and intensive while unreliability of chemical traps experimental approach is of serious concern. Quantitative structure–activity relationship (QSAR) computational method proposed in the literature for computing PQY of singlet oxygen production has characteristics deviation from the measured values. PQY singlet oxygen production of twenty-nine pteridines photosensitizer compounds is modeled and predicted in this present contribution using extreme learning machine (ELM) and support vector regression (SVR) with hybridized particle swarm optimization (PSO) method for ensuring combinatory parameter selection. The performances of the developed SVR-PSO computational method are assessed using mean absolute error (MAE), correlation coefficient (CC), root mean square error (RMSE) and mean absolute percentage deviation (MAPD). The developed SVR-PSO model outperforms QSAR (2016) model with performance superiority of 34.78%, 3.65%, 17.64% and 42.16% on the basis of RMSE, CC, MAE and MAPD performance measuring parameters, respectively. The developed ELM-SINE (with sine activation function) and ELM-SIG (with sigmoid activation function) respectively outperform the existing QSAR (2016) model with improvement of 6.54% and 4.70% using R-squared metric. The demonstrated outstanding performance of the present predictive models is immensely meritorious in strengthening the potentials of alternative cancer therapy and circumventing the experimental challenges of PQY singlet oxygen production determination.

Abstract Aggregate‐level photodynamic therapy (PDT) has attracted significant interest and driven substantial advances in multifunction phototheranostic platforms. As exemplified by two typical instances of aggregation‐caused quenching of reactive oxygen species (ROS) and aggregation‐induced generation of ROS, the aggregation effect plays a significant role on the ROS generation of photosensitizers (PSs), which is worthy of in‐depth exploration and full utilization. However, in contrast to the well‐developed researches on the aggregation effect on luminescence, the studies concerning the aggregation effect on ROS generation are currently in a relatively nascent and disjointed stage, lacking guidance from a firmly established research paradigm. To advance this regard, this review aims at providing a consolidated overview of the fundamental principles and research status of aggregation effects on the ROS generation. Here, the research status can be organized into two main facets. One involves the comparison between isolated state and aggregated state, which is mainly conducted by two methods of changing solvent environments and adding adjuvants into a given solvent. The other underscores the distinctions between different aggregate states, consisting of three parts, namely comparison within the same or between different categories based on the classification of single‐component and multicomponent aggregates. In this endeavor, we will present our views on current research methodologies that explore how aggregation affects ROS generation and highlight the design strategies to leverage the aggregation effect to optimize PS regiments. We aspire this review to propel the advancement of phototheranostic platforms and accelerate the clinical implementation of precision medicine, and inspire more contributions to aggregate‐level photophysics and photochemistry, pushing the aggregate science and materials forward.

Background: This study aimed to evaluate the impact of photodynamic therapy (PDT) using two photosensitizers, methylene blue and indocyanine green, on the microtensile bond strength of a universal adhesive to caries-affected dentin. Methods: The occlusal enamel of 60 third molars was cut to expose the inner one-third of the dentin. Artificial caries were induced through a pH cycling process. The samples were divided into three groups: M (Methylene blue+ diode laser), I (Indocyanine green agents+ diode laser irradiation), and control. Each group was further divided into two subgroups according to the adhesive protocol (self-etch, total-etch). After restoring with Gradia composite resin, teeth were sectioned and exposed to 5000 thermal cycles. Microtensile bond strength was measured using a universal testing machine. The data were subjected to two- and one-way ANOVA and paired comparisons were performed by the Tamhane and Tukey tests. Results: The study found significant effects of the photosensitizer, etching pattern, and their interactions on the microtensile bond strength of composite resin to caries-affected dentin (P < 0.001). In the self-etching mode, PDT with indocyanine green exhibited significantly higher bond strength values compared to PDT with methylene blue (P = 0.001) and the control groups (P < 0.001). However, no significant differences were observed in the total-etch mode. (P = 0.54). Conclusions: The etching mode played a more significant role in the bond strength when using the universal adhesive alongside PDT with methylene blue and indocyanine green. Employing two photosensitizers in PDT during the self-etch mode significantly increased the bond strength values.

Antimicrobial resistance is an increasing challenge in semen preservation of breeding animals, especially in the porcine species. Bacteria are a natural component of semen, and their growth should be inhibited to protect sperm fertilizing capacity and the female’s health. In pig breeding, where semen is routinely stored at 17°C in the liquid state, alternatives to conventional antibiotics are urgently needed. Photodynamic inactivation (PDI) of bacteria is a well-established tool in medicine and the food industry but this technology has not been widely adopted in semen preservation. The specific challenge in this setting is to selectively inactivate bacteria while maintaining sperm integrity and functionality. The aim of this study was to test the principle of PDI in liquid stored boar semen using the photosensitizer 5,10,15,20-tetrakis(N-methyl-4-pyridyl)-21H,23H-porphine (TMPyP) and a white light LED-setup. In the first step, photophysical experiments comprising singlet oxygen phosphorescence kinetics of TMPyP and determination of the photosensitizer triplet time revealed a sufficiently high production of reactive singlet oxygen in the Androstar Premium semen extender, whereas seminal plasma acted as strong quencher. In vitro experiments with extended boar semen showed that the established PDI protocol preserves sperm motility, membrane integrity, DNA integrity, and mitochondrial activity while efficiently reducing the bacteria below the detection limit. A proof-of-concept insemination study confirmed the in vivo fertility of semen after photodynamic treatment. In conclusion, using the PDI approach, an innovative tool was established that efficiently controls bacteria growth in extended boar and maintains sperm fertility. This could be a promising contribution to the One Health concept with the potential to reduce antimicrobial resistance in animal husbandry.

Abstract Maintaining precise temperature control is vital for cold chain food transport, as temperature fluctuations can cause significant food safety and quality issues. During transport, ice that melts can promote the growth of microbes and their spread, resulting in microbial cross‐contamination. This study developed sustainable, non‐melting, self‐sanitizing “ice cubes” using food grade compositions including microporous cellulose sponges (MCS) and photosensitizers, aimed at enhancing temperature regulation and minimizing microbial contamination in the cold chain. Upon absorbing water, the MCS matched traditional ice in cooling efficiency and heat absorption and exhibit remarkable mechanical and thermal durability, withstanding multiple freeze‐thaw cycles and compressive stresses. The cationic MCS combined with erythrosine B demonstrated strong self‐sanitizing capabilities, effectively reducing microbial cross‐contamination in food models. Additionally, the release rates of photosensitizers from the MCS can be modulated by altering environmental ionic strength. This research offers viable solutions to address microbial cross‐contamination challenges in current cold chain systems.

The article provides an example of successful treatment of a patient with basal cell skin cancer of the lower eyelid of the right eye, stage IB cT2aN0M0, with the presence of concomitant pathology – a decrease in the activity of plasma factor XII of blood coagulation (Hageman disease). The patient’s medical history is associated with long-term ineffective treatment of the tumor with Curaderm ointment. After diagnosis and further examination at the Moscow Research Institute named after. P.A. Herzen, at the Center for Laser and Photodynamic Diagnostics and Therapy of Tumors, the patient underwent organ-preserving treatment using photodynamic therapy. 1 course of photodynamic therapy with the photosensitizer chlorin e6 was carried out. Complete tumor regression was obtained; relapse-free follow-up period was 1 year

Upconversion photodynamic therapy (UC-PDT), which integrates upconversion nanoparticles (UCNPs) with photosensitizers (PSs), presents a promising advancement in the field of phototherapy. However, despite the extensive studies focused on the design and synthesis of UCNPs, there is a paucity of systematic research on the mechanisms underlying the synergistic upconversion photodynamic effects. Here we have synthesized upconversion core@dotted-shell nanoparticles (CDSNPs) and covalently tethered them with two distinct PSs, thereby constructing a dual-PS UC-PDT system with high synergistic photodynamic performance. To unravel the mechanism underlying the synergism, we employed a combination of quantum mechanical calculations and ultrafast time-resolved spectroscopy techniques. The results indicate that rare earth oxides play a pivotal role in enhancing the intersystem crossing processes of PSs through modulating their excited electronic states. Additionally, Förster resonance energy transfer between two distinct PSs contributes to the amplification of triplet state populations, thus further enhancing the photodynamic effect. In vitro experiments demonstrate that the prepared CDSNPs based dual-PS system exhibits excellent biocompatibility with normal cells and exceptional synergistic photodynamic efficacy against tumor cells upon near-infrared excitation. This research contributes theoretical insights into the design and application of multi-photosensitizer UC-PDT systems, laying the groundwork for more efficient preclinical implementations in the future.

The photoreactions of selected styrylpyridine derivatives to the corresponding benzo[c]quinolizinium ions are described. It is shown that these reactions are more efficient in aqueous solution (97–44%) than in organic solvents (78–20% in MeCN). The quinolizinium derivatives bind to DNA by intercalation with binding constants of 6–11 × 104 M−1, as shown by photometric and fluorimetric titrations as well as by CD- and LD-spectroscopic analyses. These ligand–DNA complexes can also be established in situ upon irradiation of the styrylpyridines and formation of the intercalator directly in the presence of DNA. In addition to the DNA-binding properties, the tested benzo[c]quinolizinium derivatives also operate as photosensitizers, which induce DNA damage at relative low concentrations and short irradiation times, even under anaerobic conditions. Investigations of the mechanism of the DNA damage revealed the involvement of intermediate hydroxyl radicals and C-centered radicals. Under aerobic conditions, singlet oxygen only contributes to marginal extent to the DNA damage.

Recently, nano theranostics, by integrating diagnostic and therapeutic functions into a nano system, have provided increasing opportunities for the design of personalized medicine in cancer. Among the construction method of various theranostic nano systems, the design of single component nanoparticles which are composed of organic photosensitive dyes has become a promising approach to constructing multifunctional nano-theranostic systems, thanks to its unique advantages such as defined structure, 100% loading, and high repeatability. Specifically, depending on the inherent photonic imaging and therapeutic properties of the photosensitive dyes, the multifunctional purpose which integrates theranostic effects and targeting abilities can be realized via reasonable molecular modification and supramolecular assembly. In this review, recent advances in the development of nanostructured self-assemblies of porphyrins, phthalocyanines, and boron-dipyrromethanes for theranostics are summarized. Emphasis on their design consideration and theranostic applications are presented. Additionally, prospects for clinical practice and potential challenges of this rapidly growing field are also provided.

The development of aggregation-induced emission luminogens (AIEgens) with high brightness and efficient photodynamic therapy (PDT) is of great value for the precise diagnosis and treatment of cancers. In this contribution, two novel AIEgens, TBBCyP and TBTCyP with D-A-π-A structure, were designed and prepared based on molecular rational design of electron-donating receptors. Experimental and theoretical results indicated that both TBBCyP and TBTCyP own bright AIE feature, satisfy photos ability, and generate efficient singlet oxygen (1O2). Notably, TBBCyP exhibited brighter emission and higher 1O2 yield in compared with TBTCyP, which could be ascribed to its weaker twisted intramolecular charge transfer (TICT) effect and narrower singlet-triplet energy gap (ΔEST). Moreover, it was proved that TBBCyP and TBTCyP showed a great mitochondrial specificity and desired intracellular ROS productivity for realizing the effective mitochondria-targeted PDT of cancer cells.

In the past few years, there has been an increasing interest in mycosporines—UV-absorbing molecules—bringing important insights into their intrinsic properties as natural sunscreens. Herein, mycosporine-serinol and gadusol (enolate form)/gadusolate were exposed to UV radiation via a solar simulator and the photostability was assessed in pure water and different natural matrices like river, estuary and ocean water. In general, this study revealed that the photodegradation of gadusolate and mycosporine-serinol was higher in natural matrices than in pure water due to the generation of singlet oxygen on UV irradiation. In pure water, in terms of photostability, both gadusolate and mycosporine-serinol were found to offer good protection and high performance in terms of photodegradation quantum yield ((0.8 ± 0.2) × 10−4 and (1.1 ± 0.6) × 10−4, respectively). Nonetheless, the photostability of mycosporine-serinol was found to be superior to that of gadusolate in natural water, namely, ocean, estuary and river. The present work highlights how mycosporine-serinol and gadusolate resist photodegradation, and supports their role as effective and stable UV-B sunscreens.

Cancer treatment continues to be a substantial problem due to tumor complexities and persistence, demanding novel therapeutic techniques. This review investigates the synergistic potential of combining photodynamic therapy (PDT) and tailored medication delivery technologies to increase mitochondrial toxicity and improve cancer outcomes. PDT induces selective cellular damage and death by activating photosensitizers (PS) with certain wavelengths of light. However, PDT’s efficacy can be hampered by issues such as poor light penetration and a lack of selectivity. To overcome these challenges, targeted drug delivery systems have emerged as a promising technique for precisely delivering therapeutic medicines to tumor cells while avoiding off-target effects. We investigate how these technologies can improve mitochondrial targeting and damage, which is critical for causing cancer cell death. The combination method seeks to capitalize on the advantages of both modalities: selective PDT activation and specific targeted drug delivery. We review current preclinical and clinical evidence supporting the efficacy of this combination therapy, focusing on case studies and experimental models. This review also addresses issues such as safety, distribution efficiency, resistance mechanisms, and costs. The prospects of further research include advances in photodynamic agents and medication delivery technology, with a focus on personalized treatment. In conclusion, combining PDT with targeted drug delivery systems provides a promising frontier in cancer therapy, with the ability to overcome current treatment limits and open the way for more effective, personalized cancer treatments.

Photodynamic therapy (PDT) is a therapeutic modality that depends on the interaction of light, photosensitizers, and oxygen. The photon absorption and energy transfer process can lead to the Type II photochemical reaction of the photosensitizer and the production of singlet oxygen (1O2), which strongly oxidizes and reacts with biomolecules, ultimately causing oxidative damage to the target cells. Therefore, 1O2 is regarded as the key photocytotoxic species accountable for the initial photodynamic reactions for Type II photosensitizers. This article will provide a comprehensive review of 1O2 properties, 1O2 production, and 1O2 detection in the PDT process. The available 1O2 data of regulatory-approved photosensitizing drugs will also be discussed.

Ruthenium(II) polypyridyl complexes are being tested as potential anticancer agents in different therapies, which include conventional chemotherapy and light-activated approaches. A mechanistic study on a recently synthesized dual-action Ru(II) complex [Ru(bpy)2(sora)Cl]+ is described here. It is characterized by two mono-dentate leaving ligands, namely, chloride and sorafenib ligands, which make it possible to form a di-aquo complex able to bind DNA. At the same time, while the released sorafenib can induce ferroptosis, the complex is also able to act as a photosensitizer according to type II photodynamic therapy processes, thus generating one of the most harmful cytotoxic species, 1O2. In order to clarify the mechanism of action of the drug, computational strategies based on density functional theory are exploited. The photophysical properties of the complex, which include the absorption spectrum, the kinetics of ISC, and the character of all the excited states potentially involved in 1O2 generation, as well as the pathway providing the di-aquo complex, are fully explored. Interestingly, the outcomes show that light is needed to form the mono–aquo complex, after releasing both chloride and sorafenib ligands, while the second solvent molecule enters the coordination sphere of the metal once the system has come back to the ground-state potential energy surface. In order to simulate the interaction with canonical DNA, the di-aquo complex interaction with a guanine nucleobase as a model has also been studied. The whole study aims to elucidate the intricate details of the photodissociation process, which could help with designing tailored metal complexes as potential anticancer agents.

The combination of photodynamic therapy (PDT) and pneumatotherapy is emerging as one of the most effective strategies for increasing cancer treatment efficacy while minimizing side effects. Photodynamic forces affect nitric oxide (NO) levels as activated photosensitizers produce NO, and NO levels in the tumor and microenvironment directly impact tumor cell responsiveness to PDT. In this paper, 3-benzenesulfonyl-4-(1-hydroxy ether)-1,2,5-oxadiazole-2-oxide NO donor–silicon phthalocyanine coupling (SiPc–NO) was designed and prepared into self-assembled nanoparticles (SiPc–NO@NPs) by precipitation method. By further introducing arginyl-glycyl-aspartic acid (RGD) on the surface of nanoparticles, NO-photosensitizer delivery systems (SiPc–NO@RGD NPs) with photo-responsive and tumor-targeting properties were finally prepared and preliminarily evaluated in terms of their formulation properties, NO release, and photosensitizing effects. Furthermore, high reactive oxygen species (ROS) generation efficiency and high PDT efficiency in two breast cancer cell lines (human MCF-7 and mouse 4T1) under irradiation were also demonstrated. The novel SiPc–NO@RGD NPs show great potential for application in NO delivery and two-photon bioimaging-guided photodynamic tumor therapy.

Polyamines play a pivotal role in cancer cell proliferation. The excessive polyamine requirement of these malignancies is satisfied through heightened biosynthesis and augmented extracellular uptake via the polyamine transport system (PTS) present on the cell membrane. Meanwhile, photodynamic therapy (PDT) emerges as an effective anti-cancer treatment devoid of drug resistance. Recognizing these intricacies, our study devised a novel polyamine-derived photosensitizer (PS) for targeted photodynamic treatment, focusing predominantly on pancreatic cancer cells. We synthesized and evaluated novel spermine-derived fluorescent probes (N2) and PS (N3), exhibiting selectivity towards pancreatic cancer cells via PTS. N3 showed minimal dark toxicity but significant phototoxicity upon irradiation, effectively causing cell death in vitro. A significant reduction in tumor volume was observed post-treatment with no pronounced dark toxicity using the pancreatic cancer CDX mouse model, affirming the therapeutic potential of N3. Overall, our findings introduce a promising new strategy for cancer treatment, highlighting the potential of polyamine-derived PSs in PDT.

This study investigates hydrogels based on 2-Acrylamido-2-methyl-1-propanesulfonic acid sodium salt (AMPS) copolymers, incorporating N-hydroxyethyl acrylamide (HEA) and 3-sulfopropyl acrylate potassium salt (SPA). The addition of HEA and SPA is designed to fine-tune the hydrogels’ water absorption and mechanical properties, ultimately enhancing their characteristics and expanding their potential for biomedical applications. A copolymer of AMPS, 2-carboxyethyl acrylate (CEA) combined with methacrylic acid (MAA) as poly(AMPS-stat-CEA-stat-MAA, PACM), was preliminarily synthesized. CEA and MAA were modified with allyl glycidyl ether (AGE) through ring-opening, yielding macromers with pendant allyl groups (PACM-AGE). Copolymers poly(AMPS-stat-HEA-stat-CEA-stat-MAA) (PAHCM) and poly(AMPS-stat-SPA-stat-CEA-stat-MAA) (PASCM) were also synthesized and modified with AGE to produce PAHCM-AGE and PASCM-AGE macromers. These copolymers and macromers were characterized by 1H NMR, FT-IR, and GPC, confirming successful synthesis and functionalization. The macromers were then photocrosslinked into hydrogels and evaluated for swelling, water content, and mechanical properties. The results revealed that the PASCM-AGE hydrogels exhibited superior swelling ratios and water retention, achieving equilibrium water content (~92%) within 30 min. While the mechanical properties of HEA and SPA containing hydrogels show significant differences compared to PACM-AGE hydrogel (tensile strength 2.5 MPa, elongation 47%), HEA containing PAHCM-AGE has a higher tensile strength (5.8 MPa) but lower elongation (19%). In contrast, SPA in the PASCM-AGE hydrogels led to both higher tensile strength (3.7 MPa) and greater elongation (92%), allowing for a broader range of hydrogel properties. An initial study on drug delivery behavior was conducted using PACM-AGE hydrogels loaded with photosensitizers, showing effective absorption, release, and antibacterial activity under light exposure. These AMPS-based macromers with HEA and SPA modifications demonstrate enhanced properties, making them promising for wound management and drug delivery applications.

ABSTRACTMycobacterium abscessus is increasingly recognized as an emerging opportunistic pathogen causing severe lung diseases and cutaneous infections. However, treatment of M. abscessus infections remains particularly challenging, largely due to intrinsic resistance to a wide panel of antimicrobial agents. New therapeutic alternatives are urgently needed. Herein, we show that, upon limited irradiation with a blue-light source, newly developed porphyrin-peptide cage-type photosensitizers exert a strong bactericidal activity against smooth and rough variants of M. abscessus in planktonic cultures and in biofilms, at low concentrations. Atomic force microscopy unraveled important morphological alterations that include a wrinkled and irregular bacterial surface. The potential of these compounds for a photo-therapeutic use to treat M. abscessus skin infections requires further evaluations.IMPORTANCEMycobacterium abscessus causes persistent infections and is extremely difficult to eradicate. Despite intensive chemotherapy, treatment success rates remain very low. Thus, given the unsatisfactory performances of the current regimens, more effective therapeutic alternatives are needed. In this study, we evaluated the activity of newly described porphyrin-peptide cage-type conjugates in the context of photodynamic therapy. We show that upon light irradiation, these compounds were highly bactericidal against M. abscessus in vitro, thus qualifying these compounds for future studies dedicated to photo-therapeutic applications against M. abscessus skin infections.

Pathological scars (PS), including hypertrophic scars (HTS) and keloids, are a common complication of poor wound healing that significantly affects patients’ quality of life. Currently, there are several treatment options for PS, including surgery, drug therapy, radiation therapy, and biological therapy. However, these treatments still face major challenges such as low efficacy, high side effects, and a high risk of recurrence. Therefore, the search for safer and more effective treatments is particularly urgent. New materials often have less immune rejection, good histocompatibility, and can reduce secondary damage during treatment. New technology can also reduce the side effects of traditional treatments and the recurrence rate after treatment. Furthermore, derivative products of new materials and biomaterials can improve the therapeutic effect of new technologies on PS. Therefore, new technologies and innovative materials are considered better options for enhancing PS. This review concentrates on the use of two emerging technologies, microneedle (MN) and photodynamic therapy (PDT), and two novel materials, photosensitizers and exosomes (Exos), in the treatment of PS.

Near-infrared photoimmunotherapy (NIR-PIT) is a recently described method for cancer treatment that utilizes an antibody-conjugated phthalocyanine photosensitizer and NIR light. In NIR-PIT, light of 690 nm wavelength is used to activate a photosensitizer, IR700, while longer-wavelength light penetrates deeper into tissues. Thus, more effective NIR-PIT would be achieved by using photosensitizers that are activated by longer-wavelength light. The absorption wavelength would be red-shifted by destabilizing the highest occupied molecular orbital (HOMO) energy level by introducing electron donating groups at the α positions of a phthalocyanine ring. In this study, we developed a red-shifted photosensitizer for NIR-PIT, KA800, whose absorption wavelength was red-shifted by the introduction of ethoxy groups to IR700. As intended, the absorption maximum of KA800 was red-shifted compared to IR700 by 84 nm. Although phototoxicity of the antibody-KA800 (Ab-KA800) conjugate was observed in cultured cancer cells, no therapeutic effect was observed in mice. This is because the cytotoxicity of Ab-KA800 was mainly due to singlet oxygen, which can be quenched by abundant antioxidants in vivo. KA800 had low reactivity with respect to axial ligand cleavage required for inducing cell death via aggregate formation, a unique cytotoxic mechanism in NIR-PIT. The axial ligand cleavage proceeds via the anion radical formation of the photosensitizer, and KA800 was found to be less likely to receive an electron than IR700. This may be due to the destabilization of the HOMO energy level of KA800. Therefore, our findings suggest that stabilizing the lowest unoccupied molecular orbital (LUMO) energy level would be better than destabilizing the HOMO energy level for developing a red-shifted photosensitizer for NIR-PIT.

Background Managing recalcitrant oral lichen planus (OLP) can be challenging. Laser therapy has been suggested as an alternative to corticosteroids for treatment. Photodynamic therapy (PDT) is a non-invasive technique that enables the removal of lesions without surgery. Photobiomodulation therapy (PBMT) can promote healing and recovery of the lesions. Case presentation The objective was to treat unresponsive bilateral OLP of the whole buccal mucosae with a combination of PDT and PBMT. Results A 43-year-old Thai male presented with the severe painful reticular type of OLP of bilateral buccal mucosae involving upper and lower vestibular areas. The lesions were not remitted with either prednisolone systemic steroids or fluocinolone topical corticosteroids. After undergoing ten sessions of PDT with 10% 5-Aminolevulinic acid (5-ALA) in the form of thermoplastic gel and a 635 nm diode laser at 100 to 400 mW with an energy density of 20 to 30 J/cm2 in continuous wave mode, combined with five interim-sessions of PBMT using a 635 nm diode laser at 200 to 300 mW with an energy density of 6 to 10 J/cm2 in continuous wave, the patient reported relief of burning sensation beside remission of lesions without any complications. Conclusion The wide-spreading recalcitrant OLP with burning sensation can be managed by combining PDT and PBMT.

Introduction: Microbial photoinactivation using UV light can be enhanced by the addition of food-grade photosensitizers (PSs), such as curcumin. Micellization of curcumin can improve its stability and antimicrobial activity. The objective of this study was to investigate the potential mechanisms that contribute to the photoinactivation of Escherichia coli O157: H7 and Listeria innocua by curcumin-loaded surfactant solutions produced with Surfynol 465 (S465) or Tween 80 (T80) below, near, and above their critical micelle concentration (CMC).Methods: Stock curcumin-surfactant solutions were produced with S465 or T80 (5 mM sodium citrate buffer, pH 3.5). Mixtures of each bacterial suspension (initial inoculum = 6 LogCFU/mL), 1 µM curcumin, and surfactants were irradiated with UV-A light (λ = 365 nm) for 5 min. Microbial recovery after treatments was assessed by monitoring the growth of the treated E. coli O157: H7 or L. innocua using an oCelloscope™. The growth curves were characterized using a modified logistic model.Results and Discussion: Both gram-positive and gram-negative bacteria showed less and slower recovery when treated with curcumin-S465 (near or at CMC) than curcumin-T80 solutions after irradiation. FLIM micrographs suggested that curcumin was preferentially localized at the cell membrane when S465 was present, as evidenced by its longer lifetimes in samples treated with curcumin-S465 solutions. Washing after treatment resulted in the removal of loosely bound or unbound S465-curcumin micelles; hence, both E. coli O157: H7 and L. innocua recovery was faster. This suggested that curcumin partitioning has a significant role in microbial photoinactivation, possibly due to the production of reactive oxygen species (ROS) closer to/within the membrane. The permeability of the membrane of E. coli O157: H7, as inferred from the Live/Dead cell assay, increased when S465 was present, suggesting that S465 can also facilitate inactivation by disrupting the membrane and by favoring the localization of curcumin adjacent to the cell membrane. Therefore, a synergistic antimicrobial effect is observed when curcumin is present alongside S465 at concentrations below or near its CMC due to the disruption of the cell membrane by S465.

Dyes are significant components in Dye Sensitized Solar Cell (DSSC) performance because they act as photosensitizers. Natural dye-based DSSC system fabrication innovations continue to be produced in an effort to improve DSSC performance efficiency. In this study, a DSSC system was developed using double components of natural dyes as natural photosensitizers to enhance DSSC efficiency. This method of making natural dye-based DSSC uses a combination of dye extracts from two different dye sources that have the potential as natural photosensitizers in DSSC. The research aims to investigate the impact of the combined use of two natural dyes and pH variations on DSSC performance. DSSC performance measurements encompass the short-circuit current (Isc), open-circuit voltage (Voc), and DSSC efficiency parameters. The obtained results indicate efficiency values for dyes (a) sappan wood/ethanol and turmeric/methanol; (b) turmeric/methanol and beetroot/ethanol; and (c) beetroot/ethanol and turmeric/distilled water. At neutral pH, the efficiency values are 2.09%, 2.10%, and 2.19%, respectively. Meanwhile, at acidic pH of 2.59%; 2.39%; and 2.71%. Notably, the dye efficiency values at acidic pH surpass those found at neutral pH conditions. The highest efficiency is observed in the combination of dye (c) beetroot/ethanol and turmeric/distilled water with efficiency reaching 2.71% at acidic pH.

Literature review reflects the current status and development status of intraoperative photodynamic therapy in neurooncology and discusses the results of the most important studies on photodynamic therapy (PDT). We searched the Pubmed, EMBASE, Cochrane Library and eLibrary data-bases for publications published between January 2000 and December 2022. Found 204 publications in foreign sources and 59 publications in domestic editions, dealing with the issues of photodynamic therapy in neurooncology. An analysis of the literature has shown that intraoperative PDT in neurooncology is an important tool that contributes to increasing the radicality of the operation and local control. The basic rationale for the effectiveness of PDT lies in the study of the pathways leading to the complete devitalization of a malignant tumor, the study of the mechanisms of the local and systemic immune response. In addition, subcellular targets in PDT are determined by the properties of photosensitizers (PS). Second generation PSs have already been introduced into clinical practice. The effectiveness of PDT using photoditazine, 5-aminolevulinic acid has been demonstrated. The mechanisms of action and targets of these PS have been established. In Russia, a number of studies have repeatedly shown and proved the clinical effectiveness of PDT in groups of neurooncological patients with glial tumors and secondary metastatic tumors, but so far, the method has not been included in the clinical guidelines for the provision of high-tech neurosurgical care. There is certainly a need for further development of PTD techniques in neurooncology, especially in patients at high risk of recurrence and aggressive CNS tumors.

Abstract Bi12O17Cl2 is a potential photocatalyst in practical applications due to its excellent photostability, visible light activity, and competitive bandgap energy. However, the fast recombination of photogenerated charge carriers makes it impractical for pollution mitigation. Recently, aggregated porphyrins have emerged as photosensitizers in light-dependent applications such as photocatalysis. Although Bi12O17Cl2 and porphyrin can function as separate photocatalysts, their photocatalytic properties in terms of visible light adsorption, charge separation and transport, can be improved when they are combined to form heterostructure. In this study, rod-shaped aggregated 5,10,15, 20-Tetrakis (4-carboxyphenyl) porphyrin was synthesized by CTAB-assisted, self-assembly strategy and Bi12O17Cl2 by a facile microwave method. The porphyrin and Bi12O17Cl2 were combined to generate a series of x %Porphyrin@Bi12O17Cl2 having 0.02% wt., 0.1% wt., 0.4% wt., 1% wt. and 10% wt. as compositions of porphyrin. The materials’ photocatalytic degradation efficiency was tested on Rhodamine B dye as a representative pollutant. The best and worst performances were reported for 1%Porphyrin@Bi12O17Cl2 and 10%Porphyrin@Bi12O17Cl2, respectively, which are 3.1 and 0.5 times increases in efficiency compared to pure Bi12O17Cl2. From the radical trapping experiment, electrons and superoxide were the dominant reactive species in the degradation process. The enhanced photocatalytic capability of the materials was attributed to the photosensitizing property of porphyrin and the heterojunction formation, which promotes the separation of photogenerated charge carriers. A plausible step-scheme (S-scheme) was proposed for the photocatalytic degradation mechanism. The S-scheme provided the high redox potential of the photogenerated charge carriers. The findings herein offer a new option for improving the photocatalytic performance of Bi12O17Cl2 for environmental applications through the photosensitization strategy. Graphical abstract

Oral infection is a common clinical symptom. While antibiotics are widely employed as the primary treatment for oral diseases, the emergence of drug-resistant bacteria has necessitated the exploration of alternative therapeutic approaches. One such modality is antimicrobial photodynamic therapy (aPDT), which utilizes light and photosensitizers. Indeed, aPDT has been used alone or in combination with other treatment options dealing with periodontal disease for the elimination of biofilms from bacterial community to achieve bone formation and/or tissue regeneration. In this review article, in addition to factors affecting the efficacy of aPDT, various photosensitizers, the latest technology and perspectives on aPDT are discussed in detail. More importantly, the article emphasizes the novel design and clinical applications of photosensitizers, as well as the synergistic effects of chemical and biomolecules with aPDT to achieve the complete eradication of biofilms and even enhance the biological performance of tissues surrounding the treated oral area.

Resistant biofilms formed by Staphylococcus aureus on medical devices pose a constant medical threat. A promising alternative to tackle this problem is photodynamic inactivation (PDI). This study focuses on a polyurethane (PU) material with an antimicrobial surface consisting of a composite based on silicate, polycation, and erythrosine B (EryB). The composite was characterized using X-ray diffraction and spectroscopy methods. Anti-biofilm effectiveness was determined after PDI by calculation of CFU mL−1. The liquid PU precursors penetrated a thin silicate film resulting in effective binding of the PU/silicate composite and the PU bulk phases. The incorporation of EryB into the composite matrix did not significantly alter the spectral properties or photoactivity of the dye. A green LED lamp and laser were used for PDI, while irradiation was performed for different periods. Preliminary experiments with EryB solutions on planktonic cells and biofilms optimized the conditions for PDI on the nanocomposite materials. Significant eradication of S. aureus biofilm on the composite surface was achieved by irradiation with an LED lamp and laser for 1.5 h and 10 min, respectively, resulting in a 10,000-fold reduction in biofilm growth. These results demonstrate potential for the development of antimicrobial polymer surfaces for modification of medical materials and devices.

Cancer remains a significant global health challenge, with traditional therapies like surgery, chemotherapy, and radiation often accompanied by systemic toxicity and damage to healthy tissues. Despite progress in treatment, these approaches have limitations such as non-specific targeting, systemic toxicity, and resistance development in cancer cells. In recent years, nanotechnology has emerged as a revolutionary frontier in cancer therapy, offering potential solutions to these challenges. Nanoparticles, due to their unique physical and chemical properties, can carry therapeutic payloads, navigate biological barriers, and selectively target cancer cells. Metal-based nanoparticles, in particular, offer unique properties suitable for various therapeutic applications. Recent advancements have focused on the integration of metal-based nanoparticles to enhance the efficacy and precision of photodynamic therapy. Integrating nanotechnology into cancer therapy represents a paradigm shift, enabling the development of strategies with enhanced specificity and reduced off-target effects. This review aims to provide a comprehensive understanding of the pivotal role of metal-based nanoparticles in photodynamic therapy. We explore the mechanisms, biocompatibility, and applications of metal-based nanoparticles in photodynamic therapy, highlighting the challenges and the limitations in their use, as well as the combining of metal-based nanoparticles/photodynamic therapy with other strategies as a synergistic therapeutic approach for cancer treatment.

The functional investigation of proteins holds immense significance in unraveling physiological and pathological mechanisms of organisms as well as advancing the development of novel pharmaceuticals in biomedicine. However, the study of cellular protein function using conventional genetic manipulation methods may yield unpredictable outcomes and erroneous conclusions. Therefore, precise modulation of protein activity within cells holds immense significance in the realm of biomedical research. Chromophore-assisted light inactivation (CALI) is a technique that labels photosensitizers onto target proteins and induces the production of reactive oxygen species through light control to achieve precise inactivation of target proteins. Based on the type and characteristics of photosensitizers, different excitation light sources and labeling methods are selected. For instance, KillerRed forms a fusion protein with the target protein through genetic engineering for labeling and inactivates the target protein via light activation. CALI is presently predominantly employed in diverse biomedical domains encompassing investigations into protein functionality and interaction, intercellular signal transduction research, as well as cancer exploration and therapy. With the continuous advancement of CALI technology, it is anticipated to emerge as a formidable instrument in the realm of life sciences, yielding more captivating outcomes for fundamental life sciences and precise disease diagnosis and treatment.

Although our skin is not the primary visual organ in humans, it acts as a light sensor, playing a significant role in maintaining our health and overall well-being. Thanks to the presence of a complex and sophisticated optotransduction system, the skin interacts with the visible part of the electromagnetic spectrum and with ultraviolet (UV) radiation. Following a brief overview describing the main photosensitive molecules that detect specific electromagnetic radiation and their associated cell pathways, we analyze their impact on physiological functions such as melanogenesis, immune response, circadian rhythms, and mood regulation. In this paper, we focus on 6-formylindolo[3,2-b]carbazole (FICZ), a photo oxidation derivative of the essential amino acid tryptophan (Trp). This molecule is the best endogenous agonist of the Aryl hydrocarbon Receptor (AhR), an evolutionarily conserved transcription factor, traditionally recognized as a signal transducer of both exogenous and endogenous chemical signals. Increasing evidence indicates that AhR is also involved in light sensing within the skin, primarily due to its ligand FICZ, which acts as both a chromophore and a photosensitizer. The biochemical reactions triggered by their interaction impact diverse functions and convey crucial data to our body, thus adding a piece to the complex puzzle of pathways that allow us to decode and elaborate environmental stimuli.

Chlorin e6 is a well-known photosensitizer used in photodynamic diagnosis and therapy. A method for identifying and purifying a novel process-related impurity during the synthesis of chlorin e6 has been developed. Its structure was elucidated using NMR and HRMS. This new impurity is formed from chlorophyll b rather than chlorophyll a, which is the source of chlorin e6. The intermediates formed during chlorin e6 synthesis were monitored using HPLC-mass spectrometry. This new impurity was identified as rhodin g7 71-ethyl ester, the structure of which remains unknown to date. The cytotoxic effects of this novel compound in both dark and light conditions were studied against five cancer cell lines (HT29, MIA-PaCa-2, PANC-1, AsPC-1, and B16F10) and a normal cell line (RAW264.7) and compared to those of chlorin e6. Upon irradiation using a laser at 0.5 J/cm2, rhodin g7 71-ethyl ester demonstrated higher cytotoxicity (2-fold) compared to chlorin e6 in the majority of the cancer cell lines. Furthermore, this new compound exhibited higher dark cytotoxicity compared to chlorin e6. Studies on singlet oxygen generation, the accumulation in highly vascular liver tissue, and the production of reactive oxygen species in MIA-PaCa-2 cancer cells via rhodin g7 71-ethyl ester correspond to its higher cytotoxicity as a newly developed photosensitizer. Therefore, rhodin g7 71-ethyl ester could be employed as an alternative or complementary agent to chlorin e6 in the photodynamic therapy for treating cancer cells.

Chemotherapy is among the main classical approaches to the treatment of oncologic diseases. Its efficiency has been comprehensively proven by clinical examinations; however, the low selectivity of chemotherapeutic agents limits the possibilities of this method, making it necessary to search for new approaches to the therapy of oncologic diseases. Photodynamic therapy is the least invasive method and a very efficient alternative for the treatment of malignant tumors; however, its efficiency depends on the depth of light penetration into the tissue and on the degree of oxygenation of the treatment zone. In this work, a hitherto unknown conjugate of a natural bacteriochlorin derivative and doxorubicin was obtained. In vitro and in vivo studies showed a more pronounced activity of the conjugate against MCF-7 and 4T1 cells and its higher tumorotropicity in animal tumor-bearing animals compared to free anthracycline antibiotic. The suggested conjugate implements the advantages of photodynamic therapy and chemotherapy and has great potential in cancer treatment.

Photodynamic Therapy (PDT) is recognized for its exceptional effectiveness as a promising cancer treatment method. However, it is noted that overexposure to the dosage and sunlight in traditional PDT can result in damage to healthy tissues, due to the low tumor selectivity of currently available photosensitizers (PSs). To address this challenge, we introduce herein a new strategy where the small molecule-targeted agent, erlotinib, is integrated into a boron dipyrromethene (BODIPY)-based PS to form conjugate 6 to enhance the precision of PDT. This conjugate demonstrates optical absorption, fluorescence emission, and singlet oxygen generation efficiency comparable to the reference compound 7, which lacks erlotinib. In vitro studies reveal that, after internalization, conjugate 6 predominantly accumulates in the lysosomes of HepG2 cells, exhibiting significant photocytotoxicity with an IC50 value of 3.01 µM. A distinct preference for HepG2 cells over HELF cells is observed with conjugate 6 but not with compound 7. In vivo experiments further confirm that conjugate 6 has a specific affinity for tumor tissues, and the combination treatment of conjugate 6 with laser illumination can effectively eradicate H22 tumors in mice with outstanding biosafety. This study presents a novel and potential PS for achieving precise PDT against cancer.