Photodynamic Therapy Research Articles

β-Ketoenamine covalent organic framework nanoplatform combined with immune checkpoint blockade via photodynamic immunotherapy inhibit glioblastoma progression

The synergistic approach of combining photodynamic immunotherapy with endogenous clearance of PD-L1 immune checkpoint blockade therapy holds promise for enhancing survival outcomes in glioblastoma (GBM) patients. The observed upregulation of O-GlcNAc glycolysis in tumors may contribute to the stabilization of endogenous PD-L1 protein, facilitating tumor immune evasion. This study presents a pH-adapted excited state intramolecular proton transfer (ESIPT)-isomerized β-ketoamide-based covalent organic framework (COF) nanoplatform (denoted as OT@COF-RVG). Temozolomide (TMZ) and OSMI-4 (O-GlcNAc transferase inhibitor) were integrated into COF cavities, then modified on the surface with polyethylene glycol and the rabies virus peptide RVG-29, showing potential for sensitizing TMZ chemotherapy and initiating photodynamic therapy (PDT). By inhibiting O-GlcNAc and promoting lysosomal degradation of PD-L1, OT@COF-RVG enhanced the effectiveness of immune checkpoint blockade (ICB) therapy. Additionally, treatment with OT@COF-RVG led to a notable elevation in reactive oxygen species (ROS) levels, thereby re-establishing an immunostimulatory state, inducing immunogenic cell death (ICD). In summary, our research unveiled a correlation between O-GlcNAc in GBM and the evasion of immune responses by tumors, while showcasing the potential of OT@COF-RVG in reshaping the immunosuppressive microenvironment of GBM and offering a more effective approach to immunotherapy in clinical settings.

Photodynamic therapy compared with loop electrosurgical excision procedure in patients with cervical high-grade squamous intraepithelial lesion

The study aimed to compare the effectiveness between Hiporfin-photodynamic therapy (PDT) and loop electrosurgical excision procedure (LEEP) in treating cervical high-grade squamous intraepithelial lesion (HSIL). We conducted a retrospective analysis of 104 women diagnosed with cervical HSIL at our hospital from April 2019 to July 2023. With 1:1 matched case-control, 52 cases received Hiporfin-PDT and 52 cases underwent LEEP. All PDT-treated cases received Hiporfin (2 mg/kg) I.V. and a diode laser at a wavelength of 630-nm. T-test, Chi-square test, Fisher’s exact test, and Yates’s correction for continuity were conducted for statistical. A P value < 0.05 was considered significant. The complete response (CR) post-PDT at 3rd-6th months,10th-12th months and 24th months was in 98.1% (51/52),100.0% (45/45) and 100.0% (22/22) patients respectively, compared to 98.1% (51/52), 100.0% (46/46) and 100.0% (24/24) patients respectively after LEEP. HPV clearance rates after PDT at 3rd-6th months,10th-12th months and 24th months was 76.9% (40/52), 88.9% (40/45) and 95.5% (21/22) respectively, compared to 69.2% (36/52), 93.5% (43/46) and 95.8% (23/24) respectively after LEEP, with no significant difference between the two groups (P = 0.508, P = 0.687 and P = 1.000, respectively). Postoperative complications in the PDT group were tolerable. The cure rates and HPV eradication of Hiporfin-PDT were comparable with that of LEEP in the management of cervical HSIL. Hiporfin-PDT may serve an alternative method for organ-saving in cervical HSIL.

Artificial daylight photodynamic therapy using methyl aminolevulinate in a real-world setting in Germany - Results from the non-interventional study ArtLight.

Artificial daylight photodynamic therapy (ADL-PDT) is an alternative, all-year applicable, nearly painless treatment approach for actinic keratoses (AK) with comparable effectiveness to daylight or conventional PDT. At the time this study was initiated, methyl aminolevulinate (MAL) was the only photosensitizer approved for ADL-PDT in Germany. To gain comprehensive insights into the practicability of MAL-ADL-PDT in patients with AK using different artificial daylight sources under real-world conditions. This prospective, non-interventional, multicenter study (ArtLight, NCT05725213) enrolled patients with Olsen grade 1 or 2 AK on the face and scalp in Germany. Patients were treated with MAL-ADL-PDT (160mg/g MAL cream). The primary outcome measure was the practicability of MAL-ADL-PDT assessed as rate of resolved AK lesions in the focus area (10x10 cm area within the treatment area). Secondary outcomes included treatment-associated pain (numeric rating scale, NRS-11), Actinic Keratosis Area and Severity Index (AKASI), total lesion count over time, skin preparation, safety, overall assessment of effectiveness, tolerability, adherence, and patient satisfaction. In total, 224 patients (median age: 75.0 years (range 50-91), 85.3% male, 62.5% AK Olsen grade 2, 55.4% treatment-naïve) were included and treated with MAL-ADL-PDT. Three months after treatment, lesion counts were reduced in the focus area by 71% (p<0.001) indicating practicability of the treatment. Nearly all patients (93.3%) experienced none or mild pain during PDT (NRS score 0-3). Median AKASI decreased from 6.2 at baseline to 3.4 at month 3 (95% CI 2.4-3.0; p<0.001). The majority of investigators (82.8%) and patients (80.0%) were satisfied with the treatment. No new safety signals were reported. The clinical practicability of MAL-ADL-PDT was demonstrated under real-world conditions by effective lesion reduction and predominantly none to mild procedural pain. Thus, MAL-ADL-PDT is a convenient way for healthcare professionals to deliver PDT treatment to patients with AK located on the face and scalp.

Enhancing Cancer Treatment Through Combined Approaches: Photodynamic Therapy in Concert with Other Modalities

This review explores the role of photodynamic therapy (PDT) as an adjunctive treatment for cancers, with a focus on its potential to enhance the effects of established therapies like chemotherapy, surgery, and radiotherapy. Given the limitations of conventional cancer treatments, PDT’s ability to improve therapeutic outcomes through combination strategies is examined. In cancers such as lung, breast, cholangiocarcinoma, and cervical, PDT shows promise in enhancing response rates, reducing recurrence, and minimizing adverse effects when used alongside standard modalities. This study highlights current findings on PDT’s mechanisms in complementing chemotherapy, augmenting surgical precision, and enhancing radiotherapeutic effects, thus offering a multi-faceted approach to cancer treatment. Additionally, insights into the clinical application of PDT in these cancers emphasize its potential for reducing tumor resistance and supporting more effective, personalized care. By providing an overview of PDT’s synergistic applications across diverse cancer types, this review underscores its emerging significance in oncology as a tool to address traditional treatment limitations. Ultimately, this review aims to inform and inspire researchers and clinicians seeking to refine and innovate cancer therapy strategies through PDT integration, contributing to the advancement of more effective, synergistic cancer treatments.

An Aged Tree with a New Bloom: A Simple Spatiotemporal Programming Strategy Enables Carbon Dot Photosensitizers to Regulate Cell Pyroptosis for Enhanced Tumor Photodynamic-Immunotherapy.

Pyroptosis induced by photodynamic therapy (PDT) is a promising field in both PDT and immunotherapy for tumors. However, effectively inducing tumor cell pyroptosis while triggering a strong immune response using current photosensitizers remains challenging. Herein, the developed positively charged carbon dots (PCDs) nanoPSs were utilized to modulate tumor cell pyroptosis for the first time through a simple spatiotemporal programming strategy. Briefly, PCDs enabled precisely time-dependent targeting of the cell membrane or lysosome. Upon light irradiation, in vitro studies revealed that lysosome-targeted PDT primarily induced apoptosis, while membrane-targeted PDT triggered pyroptosis, resulting in enhanced PDT efficacy and robust activation of the immune response. Conclusively, in vivo studies demonstrated that PCDs could serve as a novel pyroptosis nanotuner for enhanced photodynamic-immunotherapy, thereby simultaneously eliminating primary tumors and inhibiting distant tumor growth and metastases. This spatiotemporal programming strategy unprecedentedly offers a rejuvenation of aged PSs and expands the biomedical use of CDs in immunotherapy.

Anthracene-Based Endoperoxides as Self-Sensitized Singlet Oxygen Carriers for Hypoxic-Tumor Photodynamic Therapy.

Singlet oxygen is a crucial reactive oxygen species (ROS) in photodynamic therapy (PDT). However, the hypoxic tumor microenvironment limits the production of cytotoxic singlet oxygen through the light irradiation of PDT photosensitizers (PSs). This restriction poses a major challenge in improving the effectiveness of PDT. To overcome this challenge, researchers have explored the development of singlet oxygen carriers that can capture and release singlet oxygen in physiological conditions. Among these developments, anthracene-based endoperoxides, initially discovered almost 100 years ago, have shown the ability to generate singlet oxygen controllably under thermal or photo stimuli. Recent advancements have led to the development of a new class of self-sensitized anthracene-endoperoxides, with potential applications in enhancing PDT effects for hypoxic tumors. This review discusses the current research progress in utilizing self-sensitized anthracene-endoperoxides as singlet oxygen carriers for improved PDT. It covers anthracene-conjugated small organic molecules, metal-organic complexes, polymeric structures, and other self-sensitized nano-structures. The molecular structural designs, mechanisms, and characteristics of these systems will be discussed. This review aims to provide valuable insights for developing high-performance singlet oxygen carriers for hypoxic-tumor PDT.

Design and synthesis of glycofullerene derivatives as novel photosensitizer for potential application in PDT to treat cancer

Cancer is one of the most aggressive diseases known to humanity, characterized by low survival rates and poor prognoses. Currently, platinum-based anticancer drugs and traditional photosensitizers used in photodynamic therapy (PDT) are the most widely employed treatment modalities. However, the platinum-based medications, particularly cisplatin, the most commonly used agent, have several drawbacks. These drawbacks may include systemic toxicity, which can manifest as nephrotoxicity, neurotoxicity, ototoxicity, or emesis during treatment. Such side effects can severely impair patients and significantly diminish the overall effectiveness of therapeutic interventions. In contrast, photodynamic therapy does not present these disadvantages. PDT offers numerous benefits, including reduced long-term morbidity, minimal systemic toxicity, low invasiveness, negligible drug resistance, and temporal and geographic selectivity, all of which enhance patients' quality of life. Consequently, the search for novel, effective, and practical photosensitizers is essential. Fullerenes possess unique physicochemical properties that make them highly suitable as photosensitizers. In this study, we developed a comprehensive and straightforward synthesis for two water-soluble sugar fullerene derivatives, designated as 12 and 13. Multiple analytical techniques, including 1H NMR, 13C NMR, high-resolution mass spectrometry (HRMS), Fourier-transform infrared spectroscopy (FT-IR), and ultraviolet–visible (UV–Vis) spectroscopy, collectively confirmed the chemical structures of these derivatives and validated their successful synthesis. Upon exposure to white light irradiation at an intensity of 2.5J/cm2, compound 13 demonstrated significant biological activity against three distinct tumor cell lines: HepG2, MKN45, and RPMI 4788, with IC50 values of 5.65 μM, 2.43 μM, and 1.82 μM, respectively. This study establishes a foundation for the development of innovative clinical photosensitizers.

Smart molecular designs and applications of activatable organic photosensitizers.

Photodynamic therapy (PDT) - which combines light, oxygen and photosensitizers (PS) to generate reactive oxygen species - has emerged as an effective approach for targeted ablation of pathogenic cells with reduced risk of inducing resistance. Some organic PS are now being applied for PDT in the clinic or undergoing evaluation in clinical trials. A limitation of the first-generation organic PS was their potential off-target toxicity. This shortcoming prompted the design of constructs that can be activated by the presence of specific biomolecules - from small biomolecules to large enzymes - in the target cells. Here, we review advances in the design and synthesis of activatable organic PS and their contribution to PDT in the past decade. Important areas of research include novel synthetic methodologies to engineer smart PS with tuneable singlet oxygen generation, their integration into larger constructs such as bioconjugates, and finally, representative examples of their translational potential as antimicrobial and anticancer therapies.

An AIE fungal vacuole membrane probe toward species differentiation, vacuole formation visualization, and targeted photodynamic therapy

Vacuoles are unique organelles of fungi. The development of probes targeting the vacuoles membrane will enable visualization of physiological processes and precise diagnosis and therapy. Herein, a zwitterionic molecule, MXF-R, comprising of an aggregation-induced emission (AIE) photosensitizing unit and an antibiotic moxifloxacin, was found capable of specifically imaging vacuole membrane and using for targeted antifungal therapy. MXF-R demonstrated a higher signal-to-noise ratio, stronger targeting capability, and better biocompatibility than the commercial probe FM4-64. By using MXF-R, real-time visualization of vacuole formation during Candida albicans (C. albicans) proliferation was achieved. More importantly, owing to its varying staining ability towards different fungus, MXF-R could be used to quickly identify C. albicans in mixed strains by fluorescence imaging. Moreover, MXF-R exhibits a remarkable ability to generate reactive oxygen species under white light, effectively eradicating C. albicans by disrupting membrane structure. This antifungal therapy of membrane damage is more effective than clinical drug fluconazole. Therefore, this work not only presents the initial discovery of a probe targeting vacuolar membrane, but also provides a way to develop novel materials to realize integrated diagnosis and therapy.

Lignin-Derived Gold-Titanium Dioxide Nanophotocomposites as Potent Photoactivatable Probes for Microbial Inactivation.

The overuse of antibiotics has accelerated antibiotic resistance, and it is a significant global threat to public health. To combat the rising threat of drug-resistant microbes, antimicrobial photodynamic therapy (APDT) has emerged as a promising alternative therapeutic strategy. This study focuses on the synthesis of eco-friendly lignin-derived gold-titanium dioxide nanophotocomposites (L@Au-TiO2 NCs). Lignin was utilized as a sustainable precursor for the synthesis of L@Au-TiO2 NCs. The gold and TiO2 nanoparticles possess inherent photodynamic properties, and thus the developed L@Au-TiO2 NCs exhibit enhanced antimicrobial efficacy due to the synergistic combination of their attributes. The antimicrobial potential of the L@Au-TiO2 NCs was evaluated against various microbial strains (Escherichia coli, Bacillus megaterium, and Candida tropicalis) under dark and green light conditions. The outcome of this study highlights the promising potential of L@Au-TiO2 NCs for photodynamic antimicrobial applications. The L@Au-TiO2 nanophotocomposites could be explored in the fields of medicine and nanotechnology to introduce innovative ideas into the biomedical field.

A novel NIR-activatable and photodegradable mitochondria-targeted nano-photosensitizer for superior photodynamic therapy

Photodynamic therapy (PDT) has garnered significant interest as a promising approach for cancer treatment due to its effectiveness, versatility, and non-invasiveness. However, its clinical application is hindered by several factors, such as suboptimal efficacy, poor targeting capabilities, shallow penetration depth, and safety concerns. Herein, we introduce B-SQ, a novel nano-photosensitizer that addresses these challenges. B-SQ is a self-assembling, cancer mitochondria-targeting agent that is both activatable and photodegradable, designed by strategically modifying a near-infrared fluorescent squaraine dye. We extensively assessed the PDT potential of B-SQ in various cancer cell models and explored the molecular mechanisms of PDT-induced cell death. Importantly, B-SQ demonstrated high specificity for cancer cells, and its PDT efficiency was activatable, with near-infrared fluorescence to distinguish cancer cells from normal cells. This work provides the first evidence of B-SQ inducing the intrinsic mitochondrial apoptosis pathway and cell cycle arresting in cancer cells via PDT. Additionally, its photodegradable nature is likely to minimize side effects after treatment. This research introduces an innovative class of nano-photosensitizers that are activatable, targeting cancer mitochondria, and are photodegradable with near-infrared fluorescence. These qualities present new possibilities for safer and more effective clinical cancer treatments in the future.

Imaging treatment efficacy of repeated photodynamic therapy in glioblastoma using chemical exchange transfer saturation MRI.

To observe the tumor responses during photodynamic therapy in a murine glioblastoma model using chemical exchange saturation transfer (CEST) MRI and to compare the treatment effectiveness between single photodynamic therapy (sPDT) and repeated PDT (rePDT). After tumor cell implantation in NSG mouse brain(n = 27), mice were subjected to four PDT sessions (rePDT), sPDT after the administration of 5-aminolevulinic acid 6 h before each session, and a non-PDT session (control). A 630-nm LED light was used to effectuate PDT. After 24 h for each PDT session, T2-weighted and CEST MRI were performed over 7 days. We observed that rePDT resulted in a continuous suppression of tumors according to T2-weighted images; thus, the tumor volume was the smallest among three groups on Day 7. Both CEST contrasts at 3.5 ppm (amide proton transfer, APT) and 3.5 ppm (relayed nuclear Overhauser enhancement, rNOE) in the rePDT group were significantly lower (p < 0.05) than those in the control group starting from Day 5, which corresponds to lower protein and cellularity in tumors in the rePDT group, respectively. CEST contrast decreased by 17.9% at 3.5 ppm and 11.3% at 3.5 ppm for rePDT group. This was validated by histology, where we observed moderatecorrelations between APTwith cell proliferation (R = 0.730, p < 0.01) and cell apoptosis (R = 0.715, p < 0.05) and moderate correlation between rNOE with cellularity (R = 0.796, p < 0.01). rePDT has a better effect in tumor growth suppression when compared with sPDT, and CEST could be a robust and noninvasive mean to assess the molecular changes related to treatment efficacy.

Carborane-based BODIPY dyes: synthesis, structural analysis, photophysics and applications

Icosahedral boron clusters-based BODIPY dyes represent a cutting-edge class of compounds that merge the unique properties of boron clusters with the exceptional fluorescence characteristics of BODIPY dyes. These kinds of molecules have garnered substantial interest due to their potential applications across various fields, mainly including optoelectronics, bioimaging, and potential use as boron carriers for Boron Neutron Capture Therapy (BNCT). Carborane clusters are known for their exceptional stability, rigid geometry, and 3D-aromaticity, while BODIPY dyes are renowned for their strong absorption, high fluorescence quantum yields, and photostability. The integration of carborane into BODIPY structures leverages the stability and versatility of carboranes while enhancing the photophysical properties of BODIPY-based fluorophores. This review explores the synthesis and structural diversity of boron clusters-based BODIPY dyes, highlighting how carborane incorporation can lead to significant changes in the electronic and optical properties of the dyes. We discuss the enhanced photophysical characteristics, such as red-shifted absorption and emission poperties, charge and electronic transfer effects, and improved cellular uptake, resulting from carborane substitution. The review also delves into the diverse applications of these compounds. In bioimaging, carborane-BODIPY dyes offer superior fluorescence properties and cellular internalization, making them ideal for cell tracking. In photodynamic therapy, (PDT) these dyes can act as potent photosensitizers capable of generating reactive oxygen species (ROS) for targeted cancer treatment making them excellent candidates for PDT. Additionally, their unique electronic properties make them suitable candidates for optoelectronic applications, including organic light-emitting diodes (OLEDs) and sensors. Overall, carborane-BODIPY dyes represent a versatile and promising class of materials with significant potential for innovation in scientific and technological applications. This review aims to provide a comprehensive overview of the current state of research on carborane-BODIPY dyes, highlighting their synthesis, properties, and broad application spectrum.

A Flexible Antibacterial Gel Electrochemiluminescence Device for Monitoring and Therapy of Chronic Diabetic Wounds

ABSTRACTThe rapid development of internal light‐driven photodynamic therapy stems from its capability to eliminate bulky physical light sources, addressing the medical requirements for comfort and portability in long‐term diabetic wound management. To overcome limitations such as tissue penetration depth and controllability of internal light sources, this study introduces an antibacterial gel electrochemiluminescence device for the treatment of diabetic wounds and the monitoring of wound bacteria. We deploy a large‐area luminescent device combining flexible screen‐printed electrodes and a dual‐network hydrogel, in which photodynamic therapy is driven by Ru@COFs' nanoconfinement‐enhanced near‐infrared electrochemiluminescence to achieve a deeper and safer antibacterial effect. The custom‐sized screen‐printed electrodes inherit the inborn electrochemical sensing function and enable intimate contact between reactive oxygen species and the wound. The device avoids physical light sources and provides a new paradigm for developing miniaturized integrated diagnostic and therapeutic wearable devices.

Construction of Somatostatin-Based Multiphase "Core-Shell" Coacervates as Photodynamic Biomimetic Organelles.

Biomimetic coacervates have recently attracted great interest in biomedical fields, especially for drug delivery and as protocells. However, these membraneless structures are easily coalesced and poorly targetable, limiting their real biomedical applications. Here multiphase "core-shell" coacervate (CSC) constructed by dsDNA and somatostatin (SST), a 14-mer cyclopeptide is designed. The CSC shows enhanced tumor targetability through SST binding to SST receptors on the tumor cells' surface. G4 quadruplex-hemin complex can be embedded in the CSC by interaction with SST, as demonstrated by molecular simulation and isothermal titration calorimetry. The G4-hemin embedded CSC can further recruit photosensitizers such as tetracarboxyphenyl porphyrin to form the CSC-GHT composite for photodynamic therapy (PDT). As photodynamic biomimetic organelles, CSC-GHT can convert oxygen to singlet oxygen (catalyzed by the catalase-mimetic activity of G4-hemin), resulting in enhanced PDT effect, which allows the inhibition of cellular migration in vitro and tumor growth in vivo. Owing to high stability, targetability, and biosafety, the proposed CSC can recruit various cargos from small dyes to large biomacromolecules (up to 430kDa), providing promising theranostic applications.

Blazing Carbon Dots: Unfolding its Luminescence Mechanism to Photoinduced Biomedical Applications.

Carbon dots (CDs) are carbon-based nanomaterials that have garnered immense interest due to their exceptional photophysical and optoelectronic properties. They have been employed extensively for biomedical imaging and phototherapy due to their superb water dispersibility, low toxicity, outstanding biocompatibility, and exceptional tissue permeability. This review summarizes the luminescence mechanism of CDs. The modification in CDs via various doping routes is comprehensively reviewed, and the effect of such alterations on their photophysical properties, such as photoluminescence (PL), absorbance, and reactive oxygen species generation ability, is also highlighted. This review also aims to summarize the role of CDs in cellular imaging and fluorescence lifetime imaging for cellular metabolism. Subsequently, recent advancements and the future prospects of CDs as nanotheranostic agents have been discussed. Herein, we have discussed the role of CDs in photothermal, photodynamic, and synergistic therapy of anticancer, antiviral, and antibacterial applications. The overall summary of the review highlights the future prospects of CD-based research in bioimaging and biomedicine.

Clinical Benefits of Photodynamic Therapy Using Talaporfin Sodium in Patients With Isocitrate Dehydrogenase-Wildtype Diagnosed Glioblastoma: A Retrospective Study of 100 Cases.

Photodynamic therapy (PDT) with talaporfin sodium is an intraoperative local therapy administered after the surgical removal of malignant gliomas. However, its clinical efficacy in a large patient population has not been determined. To analyze the clinical outcomes and prognosis in isocitrate dehydrogenase (IDH)-wildtype glioblastoma patients treated with PDT. This retrospective study included patients with newly diagnosed IDH-wildtype glioblastoma treated at Kobe University Hospital between January 2013 and December 2022. PDT involves irradiation of the resection cavity with a 664-nm semiconductor laser after an intravenous infusion of talaporfin sodium. The main outcome measures were the recurrence patterns and survival times, which were compared between the PDT and non-PDT groups. Univariate and multivariate analyses were used to determine the prognostic factors. In addition, adverse events and prognostic factors in the PDT group were analyzed. A total of 44 and 56 patients were included in the PDT and non-PDT groups, respectively. The local recurrence rate was significantly lower in the PDT group than in the non-PDT group (51.3% vs 83.9%), whereas the distant recurrence and dissemination rates were significantly higher in the PDT group than in the non-PDT group (48.7% vs 16.1%). Two grade 3 adverse events were observed in the PDT group. The median progression-free survival and overall survival times were significantly longer in the PDT group than in the non-PDT group (progression-free survival: 10.8 vs 9.3 months, respectively, and overall survival: 24.6 vs 17.6 months, respectively). Multivariate analysis of the PDT groups revealed that younger age was an independent prognostic factor. PDT with talaporfin sodium provided effective local control with minimal adverse effects. The survival time of the patients treated with PDT was significantly longer than that of the patients who did not receive PDT. Therefore, a randomized controlled clinical trial on PDT is warranted.

Pediatric genital warts successfully treated with photodynamic therapy

Genital warts (GWs) are the most common sexually transmitted infections worldwide, caused by the human papillomavirus (HPV). In adults, the primary mode of transmission is through sexual contact, whereas in children it can occur through skin-to-skin or skin-to-mucosa contact and be sexual or non-sexual. The increasing prevalence of GWs in children has renewed the interest in therapeutic management which still presents a unique challenge, being influenced by many variables including size, quantity, and location of warts, as well as the presence of comorbidities. Photodynamic therapy (PDT) has already shown encouraging results in treating viral warts in adult patients, but its use is still not standardized in the pediatric population. On this topic, we report the case of an otherwise healthy 5-year-old child affected by GWs, successfully treated with three sessions of PDT with 10% 5-aminolaevulinic acid (ALA), at one-month intervals. Our case is paradigmatic of the potentiality of PDT to treat difficult lesions in a pediatric setting.

In vitro antibacterial activity of photoactivated flavonoid glycosides against Acinetobacter baumannii

Acinetobacter baumannii’s extensive antibiotic resistance makes its infections difficult to treat, so effective strategies to fight this bacterium are urgently needed. This study aims to evaluate the effectiveness of antimicrobial photodynamic therapy (aPDT) mediated by Rutin-Gal(III) complex and Quercetin against A. baumannii. Absorbance spectra, fluorescence spectra, and minimum inhibitory concentration (MIC) of Rutin-Gal(III) complex and Quercetin were determined. The intracellular reactive oxygen species (ROS), extracellular polymeric substances (EPS), cell membrane permeability, expression of ompA and blaOXA−23, anti-biofilm activity, and anti-metabolic activity of Rutin-Gal(III) complex- and Quercetin-mediated aPDT were measured. Rutin-Gal(III) complex and Quercetin revealed absorption peaks in the visible spectra. Quercetin and Rutin-Gal(III) complex displayed fluorescence peaks at 524 nm and 540 nm, respectively. MIC values for the Rutin-Gal(III) complex and Quercetin were 64 µg/mL and 256 µg/mL, respectively. Quercetin- and Rutin-Gal(III) complex-mediated aPDT significantly reduced the colony forming units/mL (58.4% and 67.5%), EPS synthesis (47.4% and 56.5%), metabolic activity (30.5% and 36.3%), ompA (5.5- and 10.5-fold), and blaOXA−23 (4.1-fold and 7.8-fold) genes expression (respectively; all P < 0.05). Quercetin- and Rutin-Gal(III) complex-mediated aPDT enhanced notable biofilm degradation (36.2% and 40.6%), ROS production (2.55- and 2.90-folds), and membrane permeability (10.8– and 9.6-folds) (respectively; all P < 0.05). The findings indicate that Rutin-Gal(III) complex- and Quercetin-mediated aPDT exhibits antibacterial properties and could serve as a valuable adjunctive strategy to conventional antibiotic treatments for A. baumannii infections. One limitation of this study is that it was conducted solely on the standard strain; testing on clinical isolates would allow for more reliable interpretation of the results.

Photodynamic therapy – modern views and innovations in dentistry

Photodynamic therapy (PDT) consists of three elements: a photosensitizer, light and oxygen. The photosensitizer has the property of selective accumulation in target tissues without harming healthy cells. This innovative therapeutic method has already been successfully adapted in many areas of medicine, such as dermatology, gynecology, urology and oncology. PDT is also beginning to be introduced in dentistry. The antibacterial and fungicidal properties of the photosensitizer are used to achieve better results in the medical and surgical treatment of patients. Objective. To analyze current scientifi data on the application of photodynamic therapy (PDT) in various fi of dentistry, evaluate its effectiveness, and assess prospects for development. Materials and methods. A review of recent scientifi literature was conducted, including original studies, systematic reviews, and meta-analyses focused on PDT application in dentistry. Data on mechanisms of action, clinical efficacy, and new developments in PDT were analyzed. Results. High effi of PDT was established in the treatment of periodontal diseases, peri-implantitis, endodontic infections, and oral oncological diseases. Advantages of combined application of PDT with other treatment methods were noted. Promising directions for PDT development were identifi including the creation of new photosensitizers and technological innovations in equipment. Conclusions. PDT is a promising treatment method in dentistry, demonstrating high efficacyand safety. Further research is aimed at optimizing treatment protocols, developing personalized approaches, and integrating PDT with other modern technologies.