Light-activated conjugated polymer nanoparticles to defeat pathogens associated with bovine mastitis.

Bovine mastitis (BM) represents a significant challenge in the dairy industry. Limitations of conventional treatments have prompted the exploration of alternative approaches, such as photodynamic inactivation (PDI). In this study, we developed a PDI protocol to eliminate BM-associated pathogens using porphyrin-doped conjugated polymer nanoparticles (CPN). The PDI-CPN protocol was evaluated in four mastitis isolates of Staphylococcus and in a hyper-biofilm-forming reference strain. The results in planktonic cultures demonstrated that PDI-CPN exhibited a bactericidal profile upon relatively low light doses (∼9.6 J/cm2). Furthermore, following a seven-hour incubation period, no evidence of cellular reactivation was observed, indicating a highly efficient post-photodynamic inactivation effect. The successful elimination of bacterial suspensions encouraged us to test the PDI-CPN protocol on mature biofilms. Treatment using moderate light dose (∼64.8 J/cm2) reduced biofilm biomass and metabolic activity by up to 74% and 88%, respectively. The impact of PDI-CPN therapy on biofilms was investigated using scanning electron microscopy (SEM), which revealed nearly complete removal of the extracellular matrix and cocci. Moreover, ex vivo studies conducted on bovine udder skin demonstrated the efficacy of the therapy in eliminating bacteria from these scaffolds and its potential as a prophylactic method. Notably, the histological analysis of skin revealed no signs of cellular degeneration, suggesting that the protocol is safe and effective for BM treatment. Overall, this study demonstrates the potential of PDI-CPN in treating and preventing BM pathogens. It also provides insights into the effects of PDI-CPN on bacterial growth, metabolism, and survival over extended periods, aiding the development of effective control strategies and the optimization of future treatments.

Synthesis, Characterization, X-ray Molecular Structure, Antioxidant, Antifungal, and Allelopathic Activity of a New Isonicotinate-Derived meso-Tetraarylporphyrin.

The present article describes the synthesis of an isonicotinate-derived meso-arylporphyrin, that has been fully characterized by spectroscopic methods (including fluorescence spectroscopy), as well as elemental analysis and HR-MS. The structure of an n-hexane monosolvate has been determined by single-crystal X-ray diffraction analysis. The radical scavenging activity of this new porphyrin against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical has been measured. Its antifungal activity against three yeast strains (C. albicans ATCC 90028, C. glabrata ATCC 64677, and C. tropicalis ATCC 64677) has been tested using the disk diffusion and microdilution methods. Whereas the measured antioxidant activity was low, the porphyrin showed moderate but encouraging antifungal activity. Finally, a study of its effect on the germination of lentil seeds revealed interesting allelopathic properties.

Encapsulation of Gemcitabine on Porphyrin Aluminum Metal-Organic Framework by Mechano-Chemistry, Delayed Drug Release and Cytotoxicity to Pancreatic Cancer PANC-1 Cells.

Gemcitabine is a widely used antimetabolite drug of pyrimidine structure, which can exist as a free-base molecular form (Gem). The encapsulated forms of medicinal drugs are of interest for delayed and local drug release. We utilized, for the first time, a novel approach of mechano-chemistry by liquid-assisted grinding (LAG) to encapsulate Gem on a "matrix" of porphyrin aluminum metal-organic framework Al-MOF-TCPPH2 (compound 2). The chemical bonding of Gem to compound 2 was studied by ATR-FTIR spectroscopy and powder XRD. The interaction involves the C=O group of Gem molecules, which indicates the formation of the encapsulation complex in the obtained composite. Further, the delayed release of Gem from the composite was studied to phosphate buffered saline (PBS) at 37 °C using an automated drug dissolution apparatus equipped with an autosampler. The concentration of the released drug was determined by HPLC-UV analysis. The composite shows delayed release of Gem due to the bonded form and constant concentration thereafter, while pure Gem shows quick dissolution in less than 45 min. Delayed release of Gem drug from the composite follows the kinetic pseudo-first-order rate law. Further, for the first time, the mechanism of delayed release of Gem was assessed by the variable stirring speed of drug release media, and kinetic rate constant k was found to decrease when stirring speed is decreased (diffusion control). Finally, the prolonged time scale of toxicity of Gem to pancreatic cancer PANC-1 cells was studied by continuous measurements of proliferation (growth) for 6 days, using the xCELLigence real-time cell analyzer (RTCA), for the composite vs. pure drug, and their differences indicate delayed drug release. Aluminum metal-organic frameworks are new and promising materials for the encapsulation of gemcitabine and related small-molecule antimetabolites for controlled delayed drug release and potential use in drug-eluting implants.

Isolation, Identification, and Biological Activities of a New Chlorin e6 Derivative.

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.

Conjugate of Natural Bacteriochlorin with Doxorubicin for Combined Photodynamic and Chemotherapy.

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.

Layer-by-Layer Nanoparticles for Calcium Overload in situ Enhanced Reactive Oxygen Oncotherapy.

Background: Challenges such as poor drug selectivity, non-target reactivity, and the development of drug resistance continue to pose significant obstacles in the clinical application of cancer therapeutic drugs. To overcome the limitations of drug resistance in chemotherapy, a viable treatment strategy involves designing multifunctional nano-platforms that exploit the unique physicochemical properties of tumor microenvironment (TME). Methods: Herein, layer-by-layer nanoparticles with polyporous CuS as delivery vehicles, loaded with a sonosensitizer (tetra-(4-aminophenyl) porphyrin, TAPP) and sequentially functionalized with pH-responsive CaCO3, targeting group hyaluronic acid (HA) were designed and synthesized for synergistic treatment involving chemodynamic therapy (CDT), sonodynamic therapy (SDT), photothermal therapy (PTT), and calcium overload. Upon cleavage in an acidic environment, CaCO3 nanoparticles released TAPP and Ca2+, with TAPP generating 1O2 under ultrasound trigger. Exposed CuS produced highly cytotoxic ·OH in response to H2O2 and also exhibited a strong PTT effect. Results: CuS@TAPP-CaCO3/HA (CTCH) delivered an enhanced ability to release more Ca2+ under acidic conditions with a pH value of 6.5, which in situ causes damage to HeLa mitochondria. In vitro and in vivo experiments both demonstrated that mitochondrial dysfunction greatly amplified the damage caused by reactive oxygen species (ROS) to tumor, which strongly confirms the synergistic effect between calcium overload and reactive oxygen therapy. Conclusion: Collectively, the development of CTCH presents a novel therapeutic strategy for tumor treatment by effectively responding to the acidic TME, thus holding significant clinical implications.

H2O2 promotes photodynamic efficacy of TMPyP4 against ovarian cancer in vitro by downregulating HIF-1α expression.

Photodynamic therapy (PDT), employing photosensitizers to induce formation of reactive oxygen species (ROS) for tumor elimination, is emerging as a promising treatment modality in oncology due to its unique benefits. However, the PDT application in ovarian cancer, the most prevalent and lethal type of gynecological malignancy with a severe hypoxic microenvironment, remains unknown. This study revealed that photosensitizer TMPyP4 exhibited enhanced efficacy under H2O2 stimulation, with minimal change in cytotoxicity compared to TMPyP4 alone. The results showed that H2O2 increased ROS production induced by TMPyP4, leading to exacerbated mitochondrial dysfunction and DNA damage, ultimately inhibiting proliferation and inducing apoptosis in ovarian cancer cells. Mechanistically, H2O2 primarily enhanced the therapeutic efficacy of PDT with TMPyP4 against ovarian cancer cells by degrading HIF-1α, which subsequently modulated the HIF-1 signaling pathway, thereby alleviating the hypoxic environment in ovarian cancer cells. Our findings underscore the therapeutic potential of targeting HIF-1α within the hypoxic microenvironment for PDT in ovarian cancer and propose a novel integrated strategy for PDT treatment of this malignancy in vitro.

Photodynamic black phosphorus nanosheets functionalized with polymyxin B for targeted ablation of drug-resistant mixed-species biofilms.

Biofilms, particularly those formed by multiple bacterial species, pose significant economic and environmental challenges, especially in the context of medical implants. Addressing the urgent need for effective treatment strategies that do not exacerbate drug resistance, we developed a novel nanoformulation, Ce6&PMb@BPN, based on black phosphorus nanosheets (BPN) for targeted treatment of mixed-species biofilms formed by Acinetobacter baumannii (A. baumannii) and methicillin-resistant Staphylococcus aureus (MRSA).The formulation leverages polymyxin B (PMb) for bacterial targeting and chlorin e6 (Ce6) for photodynamic action. Upon near-infrared (NIR) irradiation, Ce6&PMb@BPN efficiently eliminates biofilms by combining chemotherapy, photodynamic therapy (PDT) and photothermal therapy (PTT), reducing biofilm biomass significantly within 30 min. In vivo studies on mice infected with mixed-species biofilm-coated catheters demonstrated the formulation's potent antibacterial and biofilm ablation effects. Moreover, comprehensive biosafety evaluations confirmed the excellent biocompatibility of Ce6&PMb@BPN. Taken together, this intelligently designed nanoformulation holds potential for effectively treating biofilm-associated infections, addressing the urgent need for strategies to combat antibiotic-resistant biofilms, particularly mixed-species biofilm, in medical settings.

Reactive oxygen species responsive chitooligosaccharides based nanoplatform for sonodynamic therapy in mammary cancer.

Sonodynamic therapy (SDT) has been extensively studied as a new type of non-invasive treatment for mammary cancer. However, the poor water solubility and defective biocompatibility of sonosensitizers during SDT hinder the sonodynamic efficacy. Herein, a nanoplatform has been developed to achieve high efficient SDT against mammary cancer through the host-guest interaction of ß-cyclodextrin/5-(4-hydroxyphenyl)-10,15,20-triphenylporphyrin (ß-CD-TPP) and ferrocenecarboxylic acid/chitooligosaccharides (FC-COS). Moreover, the glucose oxidase (GOx) was loaded through electrostatic adsorption, which efficiently restricts the energy supply in tumor tissues, thus enhancing the therapeutic efficacy of SDT for tumors. Under optimal conditions, the entire system exhibited favorable water solubility, suitable particle size and viable biocompatibility. This facilitated the integration of the characteristics of starvation therapy and sonodynamic therapy, resulting in efficient inhibition of tumor growth with minimal side effects in vivo. This work may provide new insights into the application of natural oligosaccharides for construct multifunctional nanocarrier systems, which could optimize the design and development of sonodynamic therapy strategies and even combination therapy strategies.

Endogenous and exogeneous stimuli-triggered reactive oxygen species evoke long-lived carbon monoxide to fight against lung cancer.

Reactive oxygen species (ROS)-associated anticancer approaches usually suffer from two limitations, i.e., insufficient ROS level and short ROS half-life. Nevertheless, no report has synchronously addressed both concerns yet. Herein, a multichannel actions-enabled nanotherapeutic platform using hollow manganese dioxide (H-MnO2) carriers to load chlorin e6 (Ce6) sonosensitizer and CO donor (e.g., Mn2(CO)10) has been constructed to maximumly elevate ROS level and trigger cascade catalysis to produce CO. Therein, intratumoral H2O2 and ultrasound as endogenous and exogeneous triggers stimulate H-MnO2 and Ce6 to produce •OH and 1O2, respectively. The further cascade reaction between ROS and Mn2(CO)10 proceeds to release CO, converting short-lived ROS into long-lived CO. Contributed by them, such a maximumly-elevated ROS accumulation and long-lived CO release successfully suppresses the progression, recurrence and metastasis of lung cancer with a prolonged survival rate. More significantly, proteomic and genomic investigations uncover that the CO-induced activation of AKT signaling pathway, NRF-2 phosphorylation and HMOX-1 overexpression induce mitochondrial dysfunction to boost anti-tumor consequences. Thus, this cascade catalysis strategy can behave as a general means to enrich ROS and trigger CO release against refractory cancers.

Lutetium Texaphyrin-Celecoxib Conjugate as a Potential Immuno-Photodynamic Therapy Agent.

Immuno-photodynamic therapy (IPDT) has emerged as a new modality for cancer treatment. Novel photosensitizers can help achieve the promise inherent in IPDT, namely, the complete eradication of a tumor without recurrence. We report here a small molecule photosensitizer conjugate, LuCXB. This IPDT agent integrates a celecoxib (cyclooxygenase-2 inhibitor) moiety with a near-infrared absorbing lutetium texaphyrin photocatalytic core. In aqueous environments, the two components of LuCXB are self-associated through inferred donor-acceptor interactions. A consequence of this intramolecular association is that upon photoirradiation with 730 nm light, LuCXB produces superoxide radicals (O2-•) via a type I photodynamic pathway; this provides a first line of defense against the tumor while promoting IPDT. For in vivo therapeutic applications, we prepared a CD133-targeting, aptamer-functionalized exosome-based nanophotosensitizer (Ex-apt@LuCXB) designed to target cancer stem cells. Ex-apt@LuCXB was found to display good photosensitivity, acceptable biocompatibility, and robust tumor targetability. Under conditions of photoirradiation, Ex-apt@LuCXB acts to amplify IPDT while exerting a significant antitumor effect in both liver and breast cancer mouse models. The observed therapeutic effects are attributed to a synergistic mechanism that combines antiangiogenesis and photoinduced cancer immunotherapy.

A functionalized cell membrane biomimetic nanoformulation based on layered double hydroxide for combined tumor chemotherapy and sonodynamic therapy.

The development of nanoformulations with simple compositions that can exert targeted combination therapy still remains a great challenge in the area of precision cancer nanomedicine. Herein, we report the design of a multifunctional nanoplatform based on methotrexate (MTX)-loaded layered double hydroxide (LDH) coated with chlorin e6 (Ce6)-modified MCF-7 cell membranes (CMM) for combined chemo/sonodynamic therapy of breast cancer. LDH nanoparticles were in situ loaded with MTX via coprecipitation, and coated with CMM that were finally functionalized with phospholipid-modified Ce6. The created nanoformulation of LDH-MTX@CMM-Ce6 displays good colloidal stability under physiological conditions and can release MTX in a pH-dependent manner. We show that the formulation can homologously target breast cancer cells, and induce their significant apoptosis through arresting the cell cycle via cooperative MTX-based chemotherapy and ultrasound (US)-activated sonodynamic therapy. The assistance of US can not only trigger sonosensitizer Ce6 to produce reactive oxygen species, but also enhance the cellular uptake of LDH-MTX@CMM-Ce6 via an acoustic cavitation effect. Upon intravenous injection and US irradiation, LDH-MTX@CMM-Ce6 displays an admirable antitumor performance towards a xenografted breast tumor mouse model. Furthermore, the modification of Ce6 on the CMM endows the LDH-based nanoplatform with fluorescence imaging capability. The developed LDH-based nanoformulation here provides a general intelligent cancer nanomedicine platform with simple composition and homologous targeting specificity for combined chemo/sonodynamic therapy and fluorescence imaging of tumors.

Porphyrin-Based Organic Nanoparticles with NIR-IIa Fluorescence for Orthotopic Glioblastoma Theranostics.

The development of efficient theranostic nanoagents for the precise diagnosis and targeted therapy of glioblastoma (GBM) remains a big challenge. Herein, we designed and developed porphyrin-based organic nanoparticles (PNP NPs) with strong emission in the near-infrared IIa window (NIR-IIa) for orthotopic GBM theranostics. PNP NPs possess favorable photoacoustic and photothermal properties, high photostability, and low toxicity. After modification with the RGD peptide, the obtained PNPD NPs exhibited enhanced blood-brain barrier (BBB) penetration capability and GBM targeting ability. NIR-IIa imaging was employed to monitor the in vivo biodistribution and accumulation of the nanoparticles, revealing a significant enhancement in penetration depth and signal-to-noise ratio. Both in vitro and in vivo results demonstrated that PNPD NPs effectively inhibited the proliferation of tumor cells and induced negligible side effects in normal brain tissues. In general, the work presented a kind of brain-targeted porphyrin-based NPs with NIR-IIa fluorescence for orthotopic glioblastoma theranostics, showing promising prospects for clinical translation.

Gold(III) Porphyrin-Metal-Polyphenolic Nanocomplexes: Breaking Intracellular Redox Environment for Enhancing Mild-Temperature Photothermal Therapy.

Photothermal therapy (PTT) is a promising clinical antitumor strategy. However, local hyperthermia inevitably induces heat damage to adjacent normal tissues, while alternative mild-temperature therapy (MPTT, T < 45 °C) is also inefficient due to the overexpressed hyperthermia-induced heat shock proteins (HSPs) by cancer cells. Therefore, developing PTT strategies with minimizing damage to healthy tissues with improved cellular temperature sensitivity is extremely valuable for clinical application. Herein, we proposed the strategy of disrupting the intracellular redox environment via destroying the ROS-defending systems to promote MPTT. The gold(III) porphyrin-Fe3+-tannic acid nanocomplexes (AuTPP@TA-Fe NPs) were achieved via interfacial cohesion and supramolecular assembly of bioadhesive species, which could trigger the Fenton reaction to produce ·OH radicals and downregulation of reductive TrxR enzyme and mitochondrial chaperone protein Hsp60. The aggravation of oxides and the inactivation of Hsp60 provide favorable pathways for impeding the heat shock-induced self-repair mechanism of cancer cells, which strengthens AuTPP@TA-Fe NPs mediated MPTT.

Synthesis and characterization of new acid-functionalized porphyrins displaying antimicrobial activity against gram positive bacteria, yeasts and filamentous fungi with or without ultra-high irradiance.

The antimicrobial activity of new acid-functionalized porphyrins, with or without ultra-high irradiance, was investigated. Antibacterial efficacy was evaluated against Staphylococcus aureus (methicillin-resistant or methicillin-sensitive strains) and antifungal efficacy was evaluated against the yeast Candida albicans and the filamentous fungi Aspergillus fumigatus. Overall, the porphyrins tested are more effective against S. aureus. The best results were obtained with zinc diacid porphyrins 4 and 5 after only 3 min of ultra-high irradiation (500 mW/cm2, 405 nm), demonstrating that acid-functionalized porphyrins are promising as novel antimicrobial drugs for surface disinfection.

Self-assembled copper-based nanoparticles for enzyme catalysis-enhanced chemodynamic/photodynamic/antiangiogenic tritherapy against hepatocellular carcinoma.

As an emerging cancer treatment strategy, reactive oxygen species-based tumor catalytic therapies face enormous challenges due to hypoxia and the overexpression of glutathione (GSH) in the tumor microenvironment. Herein, a self-assembled copper-based nanoplatform, TCCHA, was designed for enzyme-like catalysis-enhanced chemodynamic/photodynamic/antiangiogenic tritherapy against hepatocellular carcinoma. TCCHA was fabricated from Cu2+, 3,3'-dithiobis (propionohydrazide), and photosensitizer chlorine e6 via a facile one-pot self-assembly strategy, after which an aldehyde hyaluronic acid was coated, followed by loading of the antivascular drug AL3818. The obtained TCCHA nanoparticles exhibited pH/GSH dual-responsive drug release behaviors and multienzymatic activities, including Fenton, glutathione peroxidase-, and catalase-like activities. TCCHA, a redox homeostasis disruptor, promotes ⋅OH generation and GSH depletion, thus increasing the efficacy of chemodynamic therapy. TCCHA, which has catalase-like activity, can also reinforce the efficacy of photodynamic therapy by amplifying O2 production. In vivo, TCCHA efficiently inhibited tumor angiogenesis and suppressed tumor growth without apparent systemic toxicity. Overall, this study presents a facile strategy for the preparation of multienzyme-like nanoparticles, and TCCHA nanoparticles display great potential for enzyme catalysis-enhanced chemodynamic/photodynamic/antiangiogenic triple therapy against cancer.

Design of a new porphyrin-based compound and investigation of its photosensitive properties for antibacterial photodynamic therapy.

Considering the increasing number of pathogens resistant to commonly used antibiotics as well as antiseptics, there is an urgent need for antimicrobial approaches that can effectively inactivate pathogens without the risk of establishing resistance. An alternative approach in this context is antibacterial photodynamic therapy (APDT). APDT is a process that involves bacterial cell death using appropriate wavelength light energy and photosensitizer and causes the production of reactive oxygen species inside or outside the microbial cell depending on the penetration of light energy. In our study, a new porphyrin compound 4,4'-methylenebis(2-((E)-((4-(10,15,20-triphenylporphyrin-5-yl)phenyl)imino)methyl)phenol) (SP) was designed and synthesized as photosensitizer and its structure was clarified by NMR (13C and 1H) and mass determination method. Photophysical and photochemical properties were examined in detail using different methods. Singlet oxygen quantum yields were obtained as 0.48 and 0.59 by direct and indirect methods, respectively. Antibacterial activity studies have been conducted within the scope of biological activity and promising results have been obtained under LED light (500-700 nm, 265 V, 1500 LM), contributing to the antibacterial photodynamic therapy literature.

In vitro antimicrobial, antibiofilm photodynamic activity, and molecular dynamic simulations of tetra-cationic porphyrinmembrane interactions against foodborne microorganisms.

This manuscript presents a new report on the in vitro antimicrobial photo-inactivation of foodborne microorganisms (Salmonella spp. and Listeria monocytogenes) using tetra-cationic porphyrins. Isomeric tetra-cationic porphyrins (3MeTPyP, 4MeTPyP, 3PtTPyP, and 4PtTPyP) were tested, and antimicrobial activity assays were performed at specific photosensitizer concentrations under dark and white-light LED irradiation conditions. Among the tested bacterial strains, 4MeTPyP exhibited the highest efficiency, inhibiting bacterial growth within just 60 min at low concentrations (17.5 µM). The minimal inhibitory concentration of 4MeTPyP increased when reactive oxygen species scavengers were present, indicating the significant involvement of singlet oxygen species in the photooxidation mechanism. Furthermore, the checkerboard assay testing the association of 4MeTPyP showed an indifferent effect. Atomic force microscopy analyses and dynamic simulations were conducted to enhance our understanding of the interaction between this porphyrin and the strain's membrane.

Effectiveness of laser pulsed irradiation for antimicrobial photodynamic therapy.

The aim of this study was to compare two types of light irradiation devices for antimicrobial photodynamic therapy (aPDT). A 660-nm light-emitting diode (LED) and a 665-nm laser diode (LD) were used for light irradiation, and 0.1 mg/L TONS 504, a cationic chlorin derivative, was used as the photosensitizer. We evaluated the light attenuation along the vertical and horizontal directions, temperature rise following light irradiation, and aPDT efficacy against Staphylococcus aureus under different conditions: TONS 504 only, light irradiation only, and TONS 504 with either LED (30 J/cm2) or LD light irradiation (continuous: 30 J/cm2; pulsed: 20 J/cm2 at 2/3 duty cycle, 10 J/cm2 at 1/3 duty cycle). Both LED and LD light intensities were inversely proportional to the square of the vertical distance from the irradiated area. Along the horizontal distance from the nadir of the light source, the LED light intensity attenuated according to the cosine quadrature law, while the LD light intensity did not attenuate within the measurable range. Following light irradiation, the temperature rise increased as the TONS 504 concentration increased in the order of pulsed LD < continuous LD < LED irradiation. aPDT with light irradiation only or TONS 504 only had no antimicrobial effect, while aPDT with TONS 504 under continuous or pulsed LD light irradiation provided approximately 3 log reduction at 30 J/cm2 and 20 J/cm2 and approximately 2 log reduction at 10 J/cm2. TONS 504-aPDT under pulsed LD light irradiation provided anti-microbial effect without significant temperature rise.

Porphyrin derivatives inhibit tumor necrosis factor α-induced gene expression and reduce the expression and increase the cross-linked forms of cellular components of the nuclear factor κB signaling pathway.

The transcription factor nuclear factor κB (NF-κB) is activated by proinflammatory cytokines, such as tumor necrosis factor α (TNF-α) and Toll-like receptor (TLR) ligands. Screening of NPDepo chemical libraries identified porphyrin derivatives as anti-inflammatory compounds that strongly inhibited the up-regulation of intercellular adhesion molecule-1 (ICAM-1) expression induced by TNF-α, interleukin-1α, the TLR3 ligand, and TLR4 ligand in human umbilical vein endothelial cells. In the present study, the mechanisms of action of porphyrin derivatives were further elucidated using human lung adenocarcinoma A549 cells. Porphyrin derivatives, i.e., dimethyl-2,7,12,18-tetramethyl-3,8-di(1-methoxyethyl)-21H,23H-porphine-13,17-dipropionate (1) and pheophorbide a (2), inhibited TNF-α-induced ICAM-1 expression and decreased the TNF-α-induced transcription of ICAM-1, vascular cell adhesion molecule-1, and E-selectin genes. 1 and 2 reduced the expression of the NF-κB subunit RelA protein for 1 h, which was not rescued by the inhibition of proteasome- and lysosome-dependent protein degradation. In addition, 1 and 2 decreased the expression of multiple components of the TNF receptor 1 complex, and this was accompanied by the appearance of their cross-linked forms. As common components of the NF-κB signaling pathway, 1 and 2 also cross-linked the α, ß, and γ subunits of the inhibitor of NF-κB kinase complex and the NF-κB subunits RelA and p50. Cellular protein synthesis was prevented by 2, but not by 1. Therefore, the present results indicate that porphyrin derivative 1 reduced the expression and increased the cross-linked forms of cellular components required for the NF-κB signaling pathway without affecting global protein synthesis.