Photosensitizing Agent Research Articles

A EFICÁCIA DA TERAPIA FOTODINÂMICA NO TRATAMENTO ENDODÔNTICO EM DENTES IMATUROS COM DIAGNÓSTICO DE NECROSE PULPAR: RELATO DE CASO CLÍNICO

Photodynamic Therapy (PDT) has been very effective in endodontics due to its benefits in eliminating resistant microorganisms in root canals. Being combined with a photosensitizing agent such as Methylene Blue, enhancing the effect of PDT, complementing conventional disinfection treatments, improving the effectiveness of endodontic treatment. The objective of this study was to report a clinical case on the use of photodynamic therapy in immature teeth with pulp necrosis, emphasizing the procedures performed, clinical and radiographic results obtained, as well as the effectiveness of different methods for disinfecting root canals. Research was carried out in electronic databases: Pubmed and Virtual Health Library from 2018 to 2024. The present work concluded that having knowledge about diagnosis and management in cases of immature teeth with pulp necrosis is extremely important to the dentist so that a good prognosis can be obtained in the treatment and so that the patient has the functionality of their oral environment reestablished.

Novel phthalocyanines bearing fluoro-methylquinolin substituents: Synthesis, characterization, photophysical and photochemical properties

The novel 4-((6-fluoro-2-methylquinolin-4-yl)oxy)phthalonitrile (3a), 3-((6-fluoro-2-methylquinolin-4-yl)oxy)phthalonitrile (3b), tetra 6-fluoro-2-methylquinolin-4-yl)oxy substituted zinc(II) phthalocyanines (4a and 4b) and their water soluble derivatives (5a and 5b) were prepared. The proposed structures of novel compounds were comfirmed via FT-IR, 1HNMR , UV–Vis and MALDI-TOF mass data. The aggregation tendency, fluorescence quantum yield, singlet oxygen quantum yield and photodegradation measurements were performed to examine the photodynamic therapy potential of both peripherally tetra substituted zinc(II) phthalocyanines (4a and 4b) and the water soluble quaternized tetra substituted zinc(II) phthalocyanines (5a and 5b). The result showed that both the novel tetra 6-fluoro-2-methylquinolin-4-yl)oxy substituted zinc(II) phthalocyanines (4a and 4b) and their water soluble derivatives (5a and 5b) could be used as photosensitizer agents in PDT thanks to their lack of aggregation tendency, having sufficient fluorescence emission for monitoring and produce high amount of singlet oxygen to destroy cancerous tissues and having moderate photostability.

Comparison of the antimicrobial reduction effect of photodynamic inactivation with the addition of chlorophyll and curcumin photosensitizer in Aggregatibacter actinomycetemcomitans and Enterococcus faecalis

Background Aggregatibacter actinomycetemcomitans and Enterococcus faecalis are pathogenic bacteria of the oral cavity that cause various diseases such as periodontitis and endodontics. These bacteria are easily resistant to antibiotics. Photodynamic inactivation (PDI) is a method of inactivating microorganisms that utilizes light to activate a photosensitizer agent (PS) that produces reactive oxygen species causing cell lysis. Methods This study used the PDI method with a 405 nm diode laser at various energy density with the addition PS curcumin or chlorophyll Alfalfa, as much as 1.6 mg/ml on A. actinomycetemcomitans and E. faecalis bacteria. Results The study on E. faecalis bacteria showed that the energy density diode laser irradiation of 1.59 J/cm² gave the percentage of E. faecalis bacteria death 36.7% without PS, 69.30% with the addition of chlorophyll Medicago sativa L and 89.42% with the addition of curcumin. Meanwhile, the bacteria A. actinomycetemcomitans showed that the energy density diode laser irradiation of 1.59 J/cm² gave the percentage of bacterial death 35.81% without PS, 64.39% with the addition of chlorophyll Medicago sativa L and 89.82% with the addition of curcumin. PS was critical to the success of the PDI. Conclusions The addition of PS curcumin increased the effectiveness of reducing bacteria E. faecalis and A. actinomycetemcomitans compared to chlorophyll Medicago sativa L.

Photodynamic Therapy Review: Past, Present, Future, Opportunities and Challenges

Photodynamic therapy (PDT) is a medical treatment that utilizes photosensitizing agents, along with light, to produce reactive oxygen species that can kill nearby cells. When the photosensitizer is exposed to a specific wavelength of light, it becomes activated and generates reactive oxygen that can destroy cancer cells, bacteria, and other pathogenic micro-organisms. PDT is commonly used in dermatology for treating actinic keratosis, basal cell carcinoma, and other skin conditions. It is also being explored for applications in oncology, such as treating esophageal and lung cancers, as well as in ophthalmology for age-related macular degeneration. In this study, we provide a comprehensive review of PDT, covering its fundamental principles and mechanisms, as well as the critical components for its function. We examine key aspects of PDT, including its current clinical applications and potential future developments. Additionally, we discuss the advantages and disadvantages of PDT, addressing the various challenges associated with its implementation and optimization. This review aims to offer a thorough understanding of PDT, highlighting its transformative potential in medical treatments while acknowledging the areas requiring further research and development.

Role of photosensitizer in control of mealybug and scale insects (Homoptera: Margarodidae and Diaspididae), in comparison with conventional insecticide

BackgroundTwo photosensitizer agents were used: rose bengal and eosin alone and mixed with soap. Two other chemical compounds were used: active cable oil and soap. All these materials were compared with malathion as a conventional insecticide. The Egyptian mealybug Icerya aegyptiaca attacking ornamental–medicinal plants (acalypha and rose shrubs) and the black Parlatoria scale Parlatoria ziziphus attacking sour orange were evaluated against the tested materials.ResultsThe results obtained suggest that soap, rose bengal mixed, eosin mixed, malathion and active cable oil revealed potency in reducing the population of I. aegyptiaca by 57.24, 87.25, 75.62, 98.71 and 59.91%, respectively, on rose; and by 54.91, 82.64, 62.48, 96.67 and 48.13%, respectively, on acalypha shrubs; their potency on insects showed a significant difference on infested rose than on infested acalypha. The tested compounds revealed lower potency in reducing the population of P. ziziphus than malathion. Reduction percentages were 35.43, 40.39, 34.25, 91.81 and 28.21%, respectively. The accumulation potency of the tested compounds on two insects collectively, without regard to insect species, stages or infested plant species, was assessed at 51.49, 66.18, 55.86, 94.37 and 44.69, respectively. The obtained results confirmed that malathion was the most effective agent against both tested insects, followed by rose bengal mixed with soap, eosin mixed with soap, soap alone and active cable oil.ConclusionsThe obtained results showed that rose bengal (as a photosensitizers) mixed with soap can be used as a promising agent against all tested insects.

Porphyrinoid macrocycles as potential photosensitizers for photodynamic inhibition of biofilm formation in household water storage systems

AbstractThe issue of biofilm formation by microorganisms in household water storage systems is a problem that lowers the efficiency of disinfectants. Antimicrobial photodynamic inactivation (aPDI) is a potential alternative to the current water disinfection methods. It employs a photosensitizer agent that inactivates microbes by absorbing light of a specific wavelength in the presence of molecular oxygen. Although aPDI has been proven in literature to have a wide spectrum of action, effective against resistant microbes and biofilms, it has not been approved for real-life applications yet. Therefore, there is an ongoing search for ideal photosensitizers that can produce sufficient reactive oxygen species for efficient inactivation of microbes and disruption of biofilms in household water storage systems. This review summarises the developments that have been made so far with porphyrin-, expanded porphyrin-, corrole-, and boron dipyrromethene-based photosensitizers. First, the issues with the current water disinfection methods are described, and then aPDI is also described as a possible alternative to the current methods. Emphasis is put on the antimicrobial activities and the solid support materials that the porphyrinoid family members have been incorporated into for potential application in the disinfection of household water and limitation of biofilm formation in water storage systems.

Tuning Electronic and Proton Transfer Properties on Amino-Functionalized Co-Based MOF for Efficient Photocatalytic Hydrogen Evolution.

Efficient hydrogen (H2) production through photocatalytic water splitting was achieved by using an amino-functionalized azolate/cobalt-based metal-organic framework (MOF). While previous reports highlighted the amino group's role only as a substituent group for enabling light absorption of MOFs in the visible region, our present study revealed its dual role. The amino substituent not only acts as an electron donor to increase the electron availability at the active Co sites but also provides hydrogen-hopping sites within the pore channel, facilitating proton (H+) diffusion along the framework. This dual functionality significantly boosts the performance of this Co-MOF as a hydrogen evolution cocatalyst. When combined with fluorescein and triethylamine as the photosensitizer and sacrificial agent, respectively, the Co-MOF achieved a remarkable H2 production rate of 27 mmol g-1 over 4 h. Notably, this performance surpasses those of benchmark platinum (Pt) and titanium dioxide (TiO2) cocatalysts.

In-situ construction of Bi-MOF-derived S-scheme BiOBr/CdIn2S4 heterojunction with rich oxygen vacancy for selective photocatalytic CO2 reduction using water

In this study, a highly selective MOF-BiOBr/CdIn2S4 (MOF-BiOBr/CIS) heterostructure with CdIn2S4 nanosheets grown in situ on the tubular structure derived from Bi-MOF-based BiOBr was successfully constructed using a hydrothermal method. Under simulated solar light without sacrificial or photosensitizing agents, the 20-MOF-BiOBr/CIS composite exhibited excellent photocatalytic CO2 performance, achieving production rates of 30.18 μmol‧g−1‧h−1 for CO and 1.50 μmol‧g−1‧h−1 for CH4. Compared to pure MOF-BiOBr and CdIn2S4, the CO production rates were increased by approximately 9 and 116 times, respectively. It was revealed that the 20-MOF-BiOBr/CIS composite with rich oxygen vacancy exhibited close interfacial contact and efficient charge transfer. The formation of MOF-BiOBr/CdIn2S4 heterojunction thereby provided efficient CO2 photocatalytic reduction. The CO selectivity of 20-MOF-BiOBr/CIS reached 83.4 %, and the MOF-BiOBr/CIS heterojunction exhibited good stability over multiple cycles. Furthermore, a mechanism for enhanced photocatalytic CO2 reduction by the MOF-BiOBr/CIS heterojunction was also proposed.

One-pot synthesis and covalent conjugation of methylene blue in mesoporous silica nanoparticles – a platform for enhanced photodynamic therapy

Photodynamic therapy (PDT) is an emerging clinical modality for diverse disease conditions, including cancer. This technique involves, the generation of cytotoxic reactive oxygen species by a photosensitizer in the presence of light and oxygen. Methylene blue (MB) is a cationic dye with an ability to act as photosensitizing and bioimaging agent. The direct utilization of MB as photosensitizer for biological applications has often been impeded by its poor photostability and unwanted tissue interactions. Nanocarriers such as mesoporous silica nanoparticles (MSNs) providing an effective means of overcoming these limitations. However, the mere physical adsorption of the dye within the MSN can result in leakage, compromising the effectiveness of PDT. Therefore, in this work, we report the conjugation of MB into MSNs using novel MB-silane derivatives, namely MBS1 and MBS2, to create dye-doped and amine-functionalized MSNs (MBS1-AMSN and MBS2-AMSN). The PDT efficacy and bioimaging capability of these nanoparticles were compared with those of MSNs in which MB was non-covalently encapsulated (MB@AMSN). The synthesized nanoparticles, ultra-small in size (≤ 35 ± 4nm) with monodispersity, exhibited enhanced fluorescence quantum yields. MBS1-AMSN demonstrated 70-fold increase, while MBS2-AMSN showed 33-fold improvement in fluorescence quantum yields compared to MB@AMSN at the same concentration. Covalent conjugation resulted in a 2-fold enhancement in the singlet oxygen quantum yield of the dye in MBS1-AMSN and 1.2-fold improvement in MBS2-AMSN, compared to non-covalent encapsulation. Assessment on RAW 264.7 macrophages revealed superior fluorescence in cell imaging for MBS1-AMSN, establishing it as a more efficient PDT agent compared to MBS2-AMSN and MB@AMSN. These findings suggest that MBS1-AMSN holds significant potential as a theranostic nanoplatform for image-guided PDT.

Mucosal Injection of the Silicon Phthalocyanine Pc 4 in a Rabbit Model-A Pilot Study.

The silicon phthalocyanine Pc 4 is a photosensitizing agent previously shown to be a promising treatment for cutaneous neoplasms using photodynamic therapy (PDT). Based on prior preclinical studies, we believe Pc 4-PDT has potential as a targeted treatment of human recurrent respiratory papillomatosis or laryngeal leukoplakia by direct injection into mucosal surfaces. This was a proof-of-concept pilot study assessing direct mucosal injection of Pc 4 into buccal and vocal fold mucosae in a rabbit model. Five New Zealand white rabbits underwent tattooing of bilateral buccal mucosae to delineate injection sites, followed by submucosal injections of control and Pc 4 solutions. Rabbits were monitored for post-injection tolerance. Punch biopsies were obtained from injected mucosa and assessed histopathologically. Once the buccal mucosa was found to be tolerant, vocal folds of three rabbits were injected. The rabbits were then sacrificed, and laryngeal tissue was assessed histopathologically. All rabbits tolerated injection of Pc 4 and control solutions into buccal mucosa with no evidence of gross visual inflammatory changes and no changes in behavior or masticatory function. Histopathologic analysis of Pc 4 injected buccal and control mucosal tissue revealed mild focal histological changes and no stigmata of diffuse inflammatory reactions. The histopathologic analysis of Pc 4 injected into laryngeal tissue revealed similar findings with addition of mild eosinophilia in one sample. Direct mucosal injection of Pc 4 in rabbit buccal and vocal fold mucosae appears to be well tolerated with no gross inflammatory changes, and only mild histopathologic inflammatory changes observed. NA Laryngoscope, 2024.

Adipocyte-Targeted Nanocomplex with Synergistic Photothermal and Pharmacological Effects for Combating Obesity and Related Metabolic Syndromes.

Obesity is a global epidemic which induces a multitude of metabolic disorders. Browning of white adipose tissue (WAT) has emerged as a promising therapeutic strategy for promoting weight loss and improving associated metabolic syndromes in people with obesity. However, current methods of inducing white adipose tissue browning have limited applicability. We developed a nanocomplex pTSL@(P+I), which is a temperature-sensitive liposome (TSL) surface-conjugated with an adipocyte-targeting peptide (p) and loaded with both browning-promoting agents (P) and photosensitizing agents (I). This nanocomplex exhibits adipocyte targeting, as well as synergistic pharmacological and photothermal properties to promote browning. pTSL@(P+I) effectively upregulates UCP1 and COX5B expression by activating the transcription axis of PPARγ/PGC1α and HSF1/PGC1α, thereby promoting white adipose tissue browning and reducing obesity. This novel nanocomplex exhibited a uniform spherical shape, with an average diameter of approximately 200 nm. Additionally, the nanocomplexes exhibited remarkable photothermal properties and biocompatibility. Further, when adipocytes were treated with pTSL@(P+I), their triglyceride content decreased remarkably and intracellular mitochondrial activity increased significantly. When applied to diet-induced obesity (DIO) mice, the nanocomplex exhibited significant efficacy, demonstrating a notable 14.4% reduction in body weight from the initial measurement, a decreased fat/lean mass ratio of 20.8%, and no statistically significant disparities (p > 0.05) in associated side effects when compared to the control group. In summary, implementation of the targeted nanocomplex pTSL@(P+I) to enhance energy expenditure by stimulating white adipose tissue browning offers a promising therapeutic approach for the treatment of obesity and related metabolic syndromes.

Catalytic and Selective Red Light-Triggered Photodegradation of a G-Quadruplex DNA by a Zinc (II) Phthalocyanine.

Water-soluble phthalocyanine (Pc) derivatives have been regarded as potential G-quadruplex (G4) nucleic acid-targeting ligands for anticancer therapy and have been extensively studied as effective photosensitizers for photodynamic therapy (PDT). Understanding how photosensitizers interact with nucleic acids and the subsequent photolytic reactions is essential for deciphering the initial steps of PDT, thereby aiding in the development of new photosensitizing agents. In this study, we found that red-light irradiation of a mixture of a Zn(II) Pc derivative and an all-parallel G4 DNA leads to catalytic and selective photodegradation of the DNA by reactive oxygen species (ROS) generated from the Zn(II) Pc derivative bound to DNA through a reaction mechanism similar to that of an enzyme reaction. This finding provides a novel insight into the molecular design of a photosensitizer to enhance its PDT efficacy.

MXene-Polydopamine-antiCEACAM1 Antibody Complex as a Strategy for Targeted Ablation of Melanoma.

Photothermal therapy (PTT) is a method for eradicating tumor tissues through the use of photothermal materials and photosensitizing agents that absorb light energy from laser sources and convert it into heat, which selectively targets and destroys cancer cells while sparing healthy tissue. MXenes have been intensively investigated as photosensitizing agents for PTT. However, achieving the selectivity of MXenes to the tumor cells remains a challenge. Specific antibodies (Ab) against tumor antigens can achieve homing of the photosensitizing agents toward tumor cells, but their immobilization on MXene received little attention. Here, we offer a strategy for the selective ablation of melanoma cells using MXene-polydopamine-antiCEACAM1 Ab complexes. We coated Ti3C2Tx MXene with polydopamine (PDA), a natural compound that attaches Ab to the MXene surface, followed by conjugation with an anti-CEACAM1 Ab. Our experiments confirm the biocompatibility of the Ti3C2Tx-PDA and Ti3C2Tx-PDA-antiCEACAM1 Ab complexes across various cell types. We also established a protocol for the selective ablation of CEACAM1-positive melanoma cells using near-infrared irradiation. The obtained complexes exhibit high selectivity and efficiency in targeting and eliminating CEACAM1-positive melanoma cells while sparing CEACAM1-negative cells. These results demonstrate the potential of MXene-PDA-Ab complexes for cancer therapy. They underline the critical role of targeted therapies in oncology, offering a promising avenue for the precise and safe treatment of melanoma and possibly other cancers characterized by specific biomarkers. Future research will aim to refine these complexes for clinical use, paving the way for new strategies for cancer treatment.

Green Synthesis of Silver Nanoparticles using Moringa oleifera: Implementation to Photoantimicrobial of Candida albicans with LED Light

Green synthesis of silver nanoparticles using Moringa oleifera (AgNPs/MO) was carried out to produce nanoscale antifungal agents which are used as photosensitizing agents in photoantimicrobial therapy. This study focused on investigating the potential of AgNPs/MO producing some toxic radical compounds that inhibit the growth of Candida albicans biofilms. The inhibition mechanism uses the principle of photoinactivation treatment which combines a photosensitizer with an LED light source at a power of 100 mW for 60 - 300 s of exposure. Quantitative data analyzed were the number of viable cells and radical compounds, formed by malondialdehyde (MDA) level. It is investigated through staining the XTT (2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide) and TBARS (Thiobarbituric Acid Reactive Substances). The results show that the maximum wavelength of AgNPs is 440 nm while the Moringa oleifera has 2 peaks at 425 and 635 nm. The maximum effect occurred in the group of photosensitizer AgNPs/MO combined LED with percentage inactivation about 76.80 % for blue LEDs and 76.20 % for red LEDs. The group of LED irradiation without photosensitizer obtained about 51.85 % for blue LEDs and 50.04 % for red LEDs. The MDA level group of AgNPs/MO combined LED also produced MDA levels of 1.772 nmol/mL for blue LED and 1.617 nmol/mL for red LED. Meanwhile, the application of photoantimicrobial using only LEDs produced MDA levels of only 1.353 nmol/mL for blue LEDs and 1.347 nmol/mL for red LEDs. This research has shown that the green synthesis of AgNPs/MO has a good potential to inhibit the growth of Candida albicans biofilms as a photosensitizer agent. HIGHLIGHTS Silver nanoparticles (AgNPs) combined with Moringa oleifera (MO) extract have been shown to have potential as a photosensitizer to inhibit the growth of Candida albicans Green synthesis AgNPs/MO have a characteristic spectrum at 440 nm which is close to the blue light spectrum. Green synthesis AgNPs/MO combined with LED light irradiation energy can reduce the cell viability of Candida albicans up to 76.80 % through the XTT assay staining test method and produce 1.772 nmol/mL of Malondialdehyde that reacts with ROS compounds to cause cell damage. GRAPHICAL ABSTRACT

Microfluidic-blow-spinning of carvacrol-loaded porphyrin metal − organic framework nanofiber films with synergistic antibacterial capabilities for food packaging

The adherence of foodborne microorganisms threatens human health, necessitating the development of antibacterial food packaging films. In this study, the antibacterial agent carvacrol (CV), hindered by its high volatility and intense aromatic odor, was encapsulated within the photosensitive metal-organic frameworks (MOFs) material PCN-224 (loading rate 50%). Subsequently, the microfluidic-blow-spinning (MBS) technique was employed for the rapid fabrication of CV@PCN-224/polycaprolactone (PCL)/chitosan (CS) nanofiber films. The incorporation of CV@PCN-224 NPs enhances the nanofiber films' thermal stability and mechanical properties and improves the water vapor permeability while maintaining the sustained release of CV over an extended period and good biocompatibility. Due to the simultaneous loading of antibacterial agent (CV) and photosensitive agent (PCN-224), the CV@PCN-224/PCL/CS films exhibited good synergistic antibacterial functionality, as demonstrated by effective inhibition against both E. coli and S. aureus. All results show the vast potential of the prepared nanofiber films in antibacterial food packaging.

Evaluation of the cumulative effect of photodynamic therapy and local fluoride on the microhardness and topography of demineralized enamel and cementum surfaces

BackgroundThe present study aimed to determine the cumulative effect of two photodynamic therapy methods with methylene blue and indocyanine green and two topical fluoride therapy methods with fluoride varnish and silver diamine fluoride alone and in combination on the microhardness and topography of demineralized enamel and cementum surfaces. Materials and methodsSeventy-two sound human teeth were selected, and their buccal and lingual surfaces were assigned to two main groups of enamel and cementum using simple randomization. The initial surface hardness (SH) of the enamel and cementum in each sample was determined using a micro-Vickers hardness tester using a 200-g force in 10 s. Then artificial caries was induced by immersion in a demineralizing/remineralizing solution (i.e., each tooth provided two samples, one on the buccal aspect and the other on the lingual aspect). Each enamel/cementum main group was divided into two subgroups using simple randomization based on the local fluoride type (fluoride varnish and silver diamine fluoride) and the type of the photosensitizer agent (methylene blue and indocyanine green). Finally, 16 groups were achieved (n = 9). The final surface hardness of the enamel and cementum samples was determined as described above. Finally, the sample surfaces were prepared for the surface topography evaluation under a scanning electron microscope. The baseline microhardness was compared between the 16 study groups in the first step using one-way ANOVA. Then, three-way ANOVA was used to evaluate the effect of fluoride, laser, and surface (enamel and cementum) on microhardness. ResultsAll the groups exhibited decreased microhardness due to the induction of artificial caries. In both main groups of enamel and cementum, the lowest decrease in microhardness was recorded with combined photodynamic therapy and methylene blue photosensitizer material and fluoride varnish (15.1 % for cementum and 16.7 % for enamel), and the highest decrease in microhardness was recorded in the methylene blue group (35.7 % for cementum and 34.9 % for enamel). ConclusionThe combination of photodynamic therapy with the photosensitizer substance methylene blue or indocyanine green together with fluoride varnish or silver diamine fluoride is effective on the remineralization of demineralized enamel and cementum. Although there is no difference between the combination of photodynamic therapy with fluoride varnish compared to fluoride varnish alone, both of these treatments are more effective than using photodynamic therapy alone.

Systemic Effects of Photoactivated 5,10,15,20-tetrakis(N-methylpyridinium-3-yl) Porphyrin on Healthy Drosophila melanogaster.

Porphyrins are frequently employed in photodynamic therapy (PDT), a non-invasive technique primarily utilized to treat subcutaneous cancers, as photosensitizing agents (PAs). The development of a new PA with improved tissue selectivity and efficacy is crucial for expanding the application of PDT for the management of diverse cancers. We investigated the systemic effects of 5,10,15,20-tetrakis(N-methylpyridinium-3-yl)-porphyrin (TMPyP3) using Drosophila melanogaster adult males. We established the oral administration schedule and demonstrated that TMPyP3 was absorbed and stored higher in neuronal than in non-neuronal extracts. Twenty-four hours after oral TMPyP3 photoactivation, the quantity of hydrogen peroxide (H2O2) increased, but exclusively in the head extracts. Regardless of photoactivation, TMPyP3 resulted in a reduced concentration of H2O2 after 7 days, and this was linked with a decreased capacity to climb, as indicated by negative geotaxis. The findings imply that systemic TMPyP3 therapy may disrupt redox regulation, impairing cellular signaling and behavioral outcomes in the process. To determine the disruptive effect of porphyrins on redox homeostasis, its duration, and the mechanistic variations in retention across various tissues, more research is required.

CPP10-targeted photoactivatable MOF nanosystem for combined photodynamic Therapy−Chemotherapy of cancer

The annual prevalence of gastric cancer has increased in recent years. Curcumin (CUR) has shown great potential in the treatment of gastric cancer; however, its low bioavailability and poor efficacy hinder its widespread clinical application. Additionally, CUR has been found to be excellent photosensitizer in photodynamic therapy. In this study, the Fe-based metal-organic framework (MOF) Fe Tetrakis (4-carboxyphenyl) porphyrin (Fe-TCPP，FT) was used as a photosensitizer and mononuclear agent. The natural anti-tumor active ingredient CUR was loaded as both a chemotherapeutic agent and photosensitizer to form the nanoparticles CUR@FT (CF). Finally, a cell-penetrating peptide (CPP10) was modified on the surface of the nanoparticles to construct a drug delivery system (named CPP10-PEG@CUR@FT, CCF) that could actively target tumor cells while exerting a synergistic therapeutic effect of chemotherapy and photodynamic therapy. This can improve the efficacy of CUR as a chemotherapeutic drug or photosensitizer, and the high drug load and pH sensitivity of FT nanoparticles provide an excellent carrier for the efficient delivery of CUR. The polyethene glycol (PEG)-conjugated CPP10 (PEG-CPP10) coating allows nanoparticles to specifically target gastric cancer cells, significantly improving the absorption of nanoparticles in vivo and in vitro and improving biosafety. We evaluated the thermal stability, drug loading capacity, and safety of FT as a drug delivery vehicle. We also assessed the in vitro photodynamic performance and toxicity of various nanoparticles and the targeting and biocompatibility of CPP10-PEG@CUR@FT. CPP10-PEG@CUR@FT could specifically target tumor cells, and its effect on killing gastric cancer cells (MKN45) under light was much stronger than that of free CUR. Its toxicity and side effects to other organs and tissues are low, offering good biosafety. The experimental results showed that FT and CUR exerted synergistic effects on photodynamic therapy and chemotherapy. In summary, our novel CUR-loaded targeted nano drug delivery system offers significant advantages by combining photodynamic therapy and chemotherapy for tumor treatment. This approach introduces a new concept for integrating chemotherapy, photodynamic therapy and targeted drug delivery, potentially providing a new strategy for the clinical treatment of gastric cancer.

The Effect of Photodynamic Therapy on Enterococcus spp. and Its Application in Dentistry: A Scoping Review.

Enterococci spp. are Gram-positive bacteria that cause mild to severe infections, many associated with the oral cavity, such as periapical infections and healthcare-associated infections (HAIs). Many of these infections become serious diseases that are difficult to resolve, specifically when multidrug-resistant (MDR) strains cause them. In recent years, the number of MDR strains of Enterococcus spp. has increased significantly. This increased prevalence of MDR strains produces significant pressure to generate more antimicrobial therapies, but there is a decline in the production of new antibiotics, driving the development of complementary therapies, such as photodynamic therapy (PDT). PDT combines a photosensitizer agent (PS), light, and oxygen to cause photooxidative stress in bacterial cells. PDT can eradicate Enterococcus spp. contaminations, improve the classic cleaning processes, and eradicate the bacteria in dental pieces. PDT's effectiveness can be improved with nanoparticles that function as carriers. Our work aims to describe the advances in PDT against Enterococcus spp. as a complement to antibiotic therapy, focusing on infections by Enterococcus faecium and Enterococcus faecalis, dental hygiene, and using nanoparticles to improve the antimicrobial effect. A systematic bibliographic search without a meta-analysis was conducted on various databases, using inclusion and exclusion criteria to identify the most relevant research. Of the 193 non-redundant articles found, 65 were selected for a systematic review, from which a summary table was created and a manual description was made. Photodynamic therapy for treating E. faecium and E. faecalis is a widely studied area, with promising results concerning bactericidal effectiveness and reductions in biofilm formation, particularly in regard to dental hygiene. Because most of the studies were conducted in vitro or ex vivo, the results indicated that there were not sufficient data to initiate clinical trials for safety and efficacy studies on humans.

Keeping patients in the dark: perioperative anesthetic considerations for patients receiving 5-aminolevulinic acid for glioma resection.

5-Aminolevulinic acid hydrochloride (5-ALA), available under the trade name Gleolan, is an orally administered fluorophore drug used to enhance visual differentiation of cancerous tissue from healthy tissue, primarily during surgical resection of high-grade gliomas. Although given preoperatively, 5-ALA has important implications for anesthetic care throughout the perioperative period. This article reviews pharmacology, safety concerns, and perioperative considerations for patients who receive oral 5-ALA. Although approved for clinical use by the United States Food and Drug Administration in 2017, studies and case reports published since then have further delineated side effects of this medication and its mechanisms and pharmacokinetics. Mitigating the possible side effects of 5-ALA requires an understanding of its basic mechanism as well as focused perioperative planning and communication. Administration of this medication may result in nausea, vomiting, photosensitivity, increase in serum concentration of liver enzymes, and hypotension. Patients who receive 5-ALA must be protected from prolonged light exposure during the first 48 h after consumption and administration of other photosensitizing agents should be avoided (Supplemental Video File/Video abstract).