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Metal–tetrapyrrole cofactors are involved in multiple cellular functions, and chelatases are key enzymes for the biosynthesis of these cofactors. CfbA is an ancestral, homodimeric‐type class II chelatase which is able to use not only Ni2+ as a physiological metal substrate, but also Co2+ as a nonphysiological substrate with higher activity than for Ni2+. The Ni/Co‐chelatase function found in CfbA is also observed in SirB, a descendant, monomeric‐type class II chelatase. This is despite the distinct active site structure of CfbA and SirB; specifically, CfbA shows a unique four His residue arrangement, unlike other monomeric class II chelatases such as SirB. Herein, we studied the Ni‐chelatase activity of SirB variants R134H, L200H, and R134H/L200H, the latter of which mimics the His alignment of CfbA. Our results showed that the SirB R134H variant exhibited the highest Ni‐chelatase activity among the SirB enzymes, which in turn suggests that the position of His134 could be more important for the Ni‐chelatase activity than that of His200. The SirB R134H/L200H variant showed lower activity than R134H, despite the four His residues found in SirB R134H/L200H. CD spectroscopy showed secondary structure denaturation and a slight difficulty in Ni‐binding of SirB R134H/L200H, which may be related to its lower activity. Finally, a docking simulation suggested that the His134 of the SirB R134H variant could function as a base catalyst for the Ni‐chelatase reaction in a class II chelatase architecture. [ABSTRACT FROM AUTHOR]

Background Since effective antiviral drugs for COVID-19 are still limited in number, the exploration of compounds that have antiviral activity against SARS-CoV-2 is in high demand. Porphyrin is potentially developed as a COVID-19 antiviral drug. However, its low solubility in water restricts its clinical application. Reconstruction of porphyrin into carbon dots is expected to possess better solubility and bioavailability as well as lower biotoxicity. Methods and results In this study, we investigated the antiviral activity of porphyrin and porphyrin-derived carbon dots against SARS-CoV-2. Through the in silico analysis and assessment using a novel drug screening platform, namely dimer-based screening system, we demonstrated the capability of the antivirus candidates in inhibiting the dimerization of the C-terminal domain of SARS-CoV-2 Nucleocapsid. It was shown that porphyrin-derived carbon dots possessed lower cytotoxicity on Vero E6 cells than porphyrin. Furthermore, we also assessed their antiviral activity on the SARS-CoV-2-infected Vero E6 cells. The transformation of porphyrin into carbon dots substantially augmented its performance in disrupting SARS-CoV-2 propagation in vitro. Conclusions Therefore, this study comprehensively demonstrated the potential of porphyrin-derived carbon dots to be developed further as a promisingly safe and effective COVID-19 antiviral drug. [ABSTRACT FROM AUTHOR]

Bright pink-orange-red photoluminescent (fluorescent and/or phosphorescent) fur is being found in an increasing number and diversity of mammal species. With the molecules causing these colours of photoluminescent emission suspected to be mostly photosensitive porphyrins, degradation from light exposure is an unquantified contributor to false negatives in museum-based surveys. I tested the resistance of pink photoluminescent bandicoot, Peramelidae, fur to exposure to natural sunlight and artificial laboratory lighting. Photoluminescence underwent visibly noticeable photobleaching in two minutes of direct sun exposure, or a few hours when exposed to indoor lighting. The fleeting nature of porphyrins means that an accurate representation of pink-orange-red photoluminescence should not be expected in specimens that have been exposed to light, whether in life, post-mortem, during taxidermy or on display. [ABSTRACT FROM AUTHOR]

[Display omitted] • The relationship between the structure and NLO property of [21]smaragdyrin-BF 2 -NiII porphyrin fused hybrids was investigated. • The P S P fused hybrids show larger NLO response as compared to S P fused hybrids. • HRS hyperpolarizability of the complex at λ = 1907 nm is higher than the static value. Nonlinear optical response of four [22]smaragdyrin-BF 2 (S)-NiII porphyrin (P) fused hybrids were explored by using DFT at CAM-B3LYP/6–31 + G(d)/SDD level of theory. We choose two types of hybrids, S P and P S P fused hybrids, for our study. Calculations indicate that these fused hybrids might be promising candidates for NLO materials based on considerable static and dynamic hyper-Rayleigh scattering (HRS) hyperpolarizability. The P S P fused hybrids possess larger first hyperpolarizabilities values compared to S P hybrids. Further analysis of hyperpolarizability density reveals the nature of the large first hyperpolarizability of the P S P fused hybrids. For all compounds, HRS hyperpolarizability at λ = 1907 nm is higher than the static value. After the interpretation of dipolar and octupolar character of β HRS , these hybrids show the high dipolar character. [ABSTRACT FROM AUTHOR]

• How to improve the tissue penetration ability of PDT and improve the therapeutic effect on deep tumors is the first attempt to give our clinical ideas: 1. Improve porous NMOF sulfur quantum dots within one or two Windows of two photon or three photon absorption cross section. The filling rate of CHN QDS in porous NMOFs and the nature of CHN QDS themselves greatly affect the multiphoton absorption of excitation light by nanoparticle composites and thus the singlet oxygen generation efficiency. 2. To improve the filling rate of chedulide QDS by optimizing the filling conditions of chedulide precursors and the size and uniformity of NMOF pores; by changing the structure and composition of quantum dots, the absorption peak position and absorption coefficient are precisely adjusted to improve the multi-photon absorption ability of quantum dots. The energy transfer efficiency of the excited sulfur QDS is also an important factor affecting the efficiency of singlet oxygen generation. amongst them, the energy level matching between the sulfur quantum dot and the porphyrin ring is the key. Vasp, Win 2 K and Gaussian series software were used to simulate the energy level structure of the material, and the optimal energy level matching structure was explored combined with experiments. • Put forward the technical points that need to be overcome: (1) master the modulation law of two-photon absorption or three-photon absorption cross section to obtain higher energy transfer efficiency. (2) synthesize one or more nano photosensitizers capable of achieving efficient two - or three-photon absorption photodynamic therapy in infrared single window (860 nm) and dual window (1320 nm). Gliomas of the brain are characterised by high aggressiveness, high postoperative recurrence rate, high morbidity and mortality, posing a great challenge to clinical treatment. Traditional treatments include surgery, radiotherapy and chemotherapy; they also have significant associated side effects, leading to difficulties in tumour resection and recurrence. Photodynamic therapy has been shown to be a promising new strategy to help treat malignant tumours of the brain. It irradiates the tumour site at a specific wavelength to activate a photosensitiser, which selectively accumulates at the tumour site, triggering a photochemical reaction that destroys the tumour cells. It has the advantages of being minimally invasive, highly targeted and with few adverse reactions, and is expected to be well used in anti-tumour therapy. However, the therapeutic effect of traditional PDT is limited by the weak tissue penetration ability of photosensitiser, hypoxia and immunosuppression in the tumour microenvironment. This paper reviews the current research status on the therapeutic principle of photodynamic therapy in glioma and the mechanism of tumour cell injury, and also analyses the advantages and disadvantages of the current application in glioma treatment, and clarifies the analysis of ideas to improve the tissue penetration ability of photosensitizers. It aims to provide a feasible direction for the improvement of photodynamic therapy for glioma and a reference for the clinical treatment of deep brain tumours. [ABSTRACT FROM AUTHOR]

Organic cathode materials find increasing use in alkali ion batteries for their ease of synthesis, multiple redox functionalities, and high gravimetric capacity. However, the precise control of alkali ion kinetics to concurrently meet the practical demands of high energy density and cycling stability remains a major unresolved challenge. Here, we propose a simple modification method to achieve efficient control over the lithium/sodium ion adsorption and diffusion kinetics by harnessing metal coordination chemistry of highly π-conjugated porphyrins. We introduce various metal ions (Zn2+, Cu2+, Co2+, and Ni2+) to coordinate with tetra(4-pyridyl) porphyrin (H 2 TPyP) and therefore to electrochemically modify the active sites. Our findings reveal that nitrogen atoms in pyridyl units serve as primary charge storage sites, and the charge storage ability is influenced by the identity of the central metal ion. Zn-TPyP outperforms the other three ones, exhibiting the highest specific capacity of 163 mAh g−1 in lithium-ion batteries and 135 mAh g−1 in sodium-ion batteries at 0.5 C, mainly attributed to the higher formation energy with the ligand which in turn imparts a higher electron density on the pyridyl moieties, affording stronger binding with the lithium/sodium ions. The high mean diffusion coefficients of lithium/sodium ions also validate the high current densities of Zn-TPyP at 10 C. [Display omitted] • The coordination of different metal ions onto porphyrin cathode enables fine modulation of its electrochemical performance. • Zn2+ coordination complex achieves the highest energy capacity and energy retention rate in lithium and sodium ion batteries. • This superior performance is attributed to the higher formation energy of Zn-porphyrin and its faster adsorption kinetics. [ABSTRACT FROM AUTHOR]

The greenhouse gas (GHG) emissions from fossil fuel combustion and carbon dioxide (CO 2) cause global warming and climate change. In this study, we synthesized three porphyrin-based azo-porous organic polymers (PBPOP1, PBPOP2, and PBPOP3) that enable the capture and one-step conversion of CO 2. These catalysts effectively capture the CO 2 molecules over N 2 in a post-combustion environment. PBPOP3 exhibited an enhanced CO 2 /N 2 selectivity at 313 K, with a value of 534. We characterized the porphyrin-based azo-POPs catalysts using FT-IR, 13C solid-state NMR, XRD, TGA, and HR-FESEM. We evaluated the gas adsorption properties using Brunauer–Emmett–Teller analysis, which included adsorption–desorption isotherms, NLDFT pore-size distribution, and adsorption at 298, 313, and 353 K. The fixation of CO 2 with styrene oxide and phenyl glycidyl ether was performed using catalysts for conversion to styrene carbonate (tetra-n-butylammonium bromide was used as a co-catalyst). Thus, our findings can be used for reducing the amount of CO 2 gas in the atmosphere by synthesizing porphyrin-based azo-POP catalysts. [Display omitted] • Synthesized porphyrin-based azo-porous organic polymers (PBPOP1, PBPOP2, and PBPOP3). • PBPOP3 exhibited an enhanced CO 2 /N 2 selectivity at 313 K, with a value of 534. • Capture and one-step conversion of CO 2 [ABSTRACT FROM AUTHOR]

Donor-p-acceptor type porphyrin-fullerene dyads with an acetylene bridge were designed and synthesized. The dyad was found to produce a charge-separated state with a lifetime of 0.42's and a quantum yield of 0.78 in benzonitrile. The p-type dye-sensitized solar cells with the dyad exhibited higher photovoltaic performance than that with the porphyrin reference without the fullerene moiety. [ABSTRACT FROM AUTHOR]

The crystal structure of a bisporphyrin cleft molecule revealed that the head-to-head dimeric structure is directed by the intermolecular self-complementary hydrogen-bonding interactions of amide groups and π-π stacking interactions. The UV/ Vis absorption spectrum of the homodimeric structure in the solid-state resulted in a broad Soret band. Time-dependent density functional theory (TD-DFT) calculation of the dimer indicated that an intra- and intermolecular charge transfer transition as well as a π-π* transition were responsible for the observed broad Soret band. [ABSTRACT FROM AUTHOR]

Owing to their reversibly dynamic features, and the regularity of their architectures, supramolecular organic frameworks (SOFs) have attracted attention as new porous materials. Herein, we propose a smart SOF platform for enhanced photodynamic therapy, where the SOF with a superior mitochondria-targeting capability could be cleaved by reactive oxygen species (ROS) produced by itself for highly enhancing PDT. Moreover, it can further work as a platform for carrying chemo-therapeutic drug doxorubicin for synergistic chemo-photodynamic therapy. The SOF is constructed by combining a tetra-β-cyclodextrin-conjugated porphyrin photosensitizer and a ROS-sensitive thioketal linked adamantane dimer utilizing a host-guest supramolecular strategy. The unique supramolecular framework not only completely resolves the aggregation caused quenching of porphyrin photosensitizers but also endows them with significantly enhanced water-solubility. The in vitro and in vivo results demonstrate that the SOF could be targeted onto mitochondria by confocal imaging, and dissociated by ROS generated by itself, leading to autonomous release of porphyrin photosensitizers and DOX for high anti-cancer activity. It is believed that the strategy using a SOF has the potential of being used to construct versatile agents for combined therapies. Photosensitizers are the essential element in photodynamic therapy. However, typical photosensitizers commonly encounter poor water-solubility, non-specific tumor-targeting, aggregation-caused quenching (ACQ), which seriously reduce PDT efficacy. A mitochondria-targeting and ROS-sensitive supramolecular organic framework (SOF) is designed for photodynamic therapy in cancer treatment, which could completely overcome the bottleneck in the applications of photosensitizers (PSs). The SOF is constructed by combining a tetra-β-cyclodextrin-conjugated porphyrin photosensitizer and a ROS-sensitive thioketal linked adamantane dimer unit utilizing a host-guest supramolecular strategy. The unique supramolecular framework not only completely resolves the aggregation caused quenching of porphyrin photosensitizers but also endows them with significantly enhanced water-solubility. Moreover, the SOF can be readily functionalized to incorporate the anti-cancer agent Doxorubicin and mitochondria targeting molecules through respective physical encapsulation and host-guest interactions. [Display omitted] [ABSTRACT FROM AUTHOR]

• Non-precious metal catalyst CoS/TClPP was successfully fabricated via a one-pot method. • CoS/TClPP has better catalytic activity toward methanol oxidation reaction. • The mass activity of CoS/TClPP was 1188 mA mg−1 under visible light. High active and low expensive electrocatalysts for methanol oxidation reaction (MOR) still remain a signification challenge for large-scale commercial application of direct methanol fuel cells (DMFCs). Herein, the photoelectrocatalytic activity of cobalt sulfide (CoS) nanosheets are dramatically developed towards MOR by introduction of a photosensitive organic molecule (5, 10, 15, 20-tetrakis(4-achlorophenyl)porphyrin (TClPP). CoS/TClPP exhibits a high mass activity of 1188 mA mg−1 for MOR under visible light irradiation, which is 1.6 times higher than that of pure CoS under dark as well as 1.37 times higher than that of pure CoS under visible light. The photoelectrocatalytic mechanism of CoS/TClPP is ascribed to the effective inhibiting of recombination of photoelectrons and holes as well as acceleration of electron transfer, which are verified by photoluminescence (PL) emission spectra, photocurrent response curves and UV–vis diffuse reflectance spectra (DRS), respectively. The low cost, highly stable and active CoS/TClPP as a noble-metal-free anode photoelectrocatalyst has a potential application in DMFCs. [ABSTRACT FROM AUTHOR]

Meso -tetraarylporphyrins bearing nitro groups are considered as excellent templates to introduce new functionalities in the porphyrin core, namely through reactions with nucleophiles. Here the reaction of 2-nitro-5,10,15,20-tetraphenylporphyrin with p -chlorophenoxyacetonitrile was revisited and it was found that the reaction profile was strongly dependent on the presence or absence of a metal ion in the porphyrinic inner core and on the solvent used. Under the studied synthetic conditions several porphyrins modified at neighbouring β - positions with nitro, amino, ether, ester, nitrile, methylcyano and formyl functionalities were isolated. Most of them are suitable for further modifications and/or conjugation to other substrates or materials. The gas-phase fragmentation studies corroborated the proposed structures. In general, the formation of the main fragment ions involves intramolecular cyclization processes with the formation of five or six-membered rings between the β-pyrrolic and the ortho position of the adjacent meso -phenyl group. [ABSTRACT FROM AUTHOR]

Experiments were performed for the synthesis of meso-substituted tetraphenyl porphyrins in order to obtain growth active points for PAMAM branches and a functionalized periphery with thiazole groups for increasing the metal complexation activity. Characterization by 1H and 13C NMR, mass spectrometry and infrared spectrometry confirmed the produced dendrimeric nanostructures; the chemical reduction of metallic Ag and Cu inside the dendrimer was proved by XPS. Finally, the toxicity of the metal-dendrimer complex was analyzed by means of the bacterial respiration test. [ABSTRACT FROM AUTHOR]

The aggregation-caused quenching (ACQ) effect of photosensitizers and multidrug resistance are the major obstacles in photodynamic therapy (PDT) and chemotherapy, respectively. Synergistic photo-chemotherapy is a promising cancer treatment to overcome the short boards of each single therapy. However, the fabrication of nanocarriers acting as both photosensitizers in PDT and the vehicle of drug release is a key challenge. Herein, we constructed a well-defined porphyrin-containing Janus macromolecular brush and used it as both a photosensitizer and a pH-responsive vehicle for DOX release. The Janus macromolecular brush with pH-responsive side chains and porphyrin units linked covalently in each repeat unit was synthesized by the combination of reversible addition-fragmentation chain transfer (RAFT) polymerization and click chemistry. The high grafting content of porphyrin units in the macromolecular brush improved the DOX loading capability by π–π stacking and therefore reduced the total treatment dose of DOX-loaded macromolecular brush nanoparticles (NPs). The pH-responsive side chains played triple roles in synergistic cascade-amplified PDT and enhanced chemotherapy including an executor of controlled drug release, a ligand with a mitochondria-targeting feature, and a barrier to reduce the ACQ effect of porphyrin units. In vitro and in vivo studies confirmed that the DOX-loaded macromolecular brush NPs exhibited high phototoxicity and significant tumor inhibition efficacy. Synergistic photodynamic therapy (PDT) and chemotherapy has emerged as a promising cancer treatment to overcome the challenges of a single modality. Herein, we constructed new pH-responsive vesicles using porphyrin-containing Janus macromolecular brushes as theranostic nanocarriers to encapsulate high-loading doxorubicin (DOX) for synergistic cascade-amplified PDT and enhanced chemotherapy. The high grafting content of porphyrin units in Janus macromolecular brushes improved DOX loading capability by π–π stacking for enhanced chemotherapy. Moreover, pH-responsive side chains subsequently enhanced the suppression of the aggregation-caused quenching (ACQ) effect of porphyrins for cascade-amplified PDT. In vitro and in vivo studies confirmed that DOX-loaded macromolecular brush nanoparticles exhibited high phototoxicity and significant tumor inhibition efficacy. Image, graphical abstract [ABSTRACT FROM AUTHOR]

• Porphyrin derivative had anti-inflammatory PDT activity. • This activity was exerted at subtoxic concentrations on the macrophages. • Novel drug candidates with immunomodulatory PDT potential can be generated from porphyrin derivatives. Our group focused on a meso‑aryl substituted porphyrin molecule for its photodynamic anti-inflammatory activities on the mammalian macrophages. The porphyrine derivative previously synthesized in this study was synthesized and characterized by 1H NMR. We then examined their immunomodulatory activities based on the changes in the pro-inflammatory cytokine production levels after LPS stimulation in dark and light activated conditions. Our results suggest that porphyrin derivative had anti-inflammatory photodynamic activity in vitro at subtoxic concentrations. Our study aims to pave a way for anti-inflammatory photodynamic therapy application in the inflammatory and autoimmune disorders. Most of the studies either focus on photodynamic cytotoxicity of the porphyrin derivatives to suppress the inflammation or porphyrin derivatives' anti-inflammatory activity without the photodynamic activation. Our future studies will focus on the generation and in vitro as well as in vivo characterization of the porphyrin derivatives with anti-inflammatory photodynamic therapy applications. In this way, novel drug candidates that would have lower side effects can be generated for the patients. Porphyrin derivative POR-D had anti-inflammatory PDT activity. It did not alter the proinflammatory cytokine production levels by the activated macrophages in the dark conditions whereas it substantially and significantly decreased the pro-inflammatory cytokine production after its light induced activation. [Display omitted] [ABSTRACT FROM AUTHOR]

Development of inorganic semiconductor photocatalysts for efficient photocatalytic production of clean and renewable hydrogen has long been attracting tremendous attentions. Herein, we report an ultrathin porphyrin-based metal-organic framework (PMOF) with Ti-oxo clusters, exhibiting a photocatalytic hydrogen evolution rate of as high as 8.52 mmol⋅g−1⋅h−1 in the presence of Pt as cocatalyst under a wide range of visible light irradiation up to 700 nm. The photocatalytic reaction over PMOF is a typical ligand-to-metal charge transfer (LMCT) process, i.e., the photoinduced electrons transfer from porphyrin-based ligands (light harvester) to Ti-oxo clusters (catalytic center), and thereby the charge carriers' separation is significantly enhanced. Moreover, the long-term course reaction confirms the excellent water-resistance and photo-stability of PMOF in photocatalytic hydrogen evolution. An ultrathin porphyrin-based metal-organic framework (PMOF) with Ti-oxo clusters exhibits efficient photocatalytic hydrogen evolution under a wide range of visible-light irradiation. Image 1 • Ultrathin porphyrin-based MOF (PMOF) shows high water-resistance and photostability. • Efficient photocatalytic H 2 evolution over PMOF under wide range visible light. • Porphyrin-based ligands harvest light; Ti-oxo clusters act as catalytic center. • The ligand-to-metal charge transfer plays a role in photocatalytic H 2 evolution. [ABSTRACT FROM AUTHOR]

Fusion is a relatively new concept to produce unique members of the porphyrin family. A representative compound formed by fusion is N-fused porphyrin, which is synthesized from N-confused porphyrin. N-Fused porphyrin has an unusually narrow HOMO-LUMO energy gap and exhibits absorption in the near infrared region up to 1100 nm. Moreover, N-fused porphyrin serves as a versatile mono-negative tridentate ligand, which can bind a variety of metal centers tightly. While inner-core fusion is rare in tetrapyrrolic porphyrinoids, it becomes more common in expanded porphyrins, where a variety of novel structures are produced unanticipatedly. [ABSTRACT FROM AUTHOR]

Infection is a disease caused by the invasion of pathogenic bacteria or microorganisms that breed on the wound. Infectious bacteria such as Staphylococcus aureus can cause wound infections. Systemic therapy using antibiotics leads to bacterial resistance. Meanwhile, bacteria naturally produce light-sensitive porphyrins, as endogenous photosensitizer. Light irradiance with suitable wavelength spectrum to the spectral absorption of porphyrin with the proper irradiation energy density can cause inactivation of bacterial cells. This study aims to determine effectiveness photodynamic inactivation with wide spectrum range of diode laser 405 nm to inactivate the Staphylococcus aureus bacteria with endogenous photosensitizer. In order to determine the role of energy density of diode laser to activate the endogenous photosensitizer porphyrin in bacteria, the study was divided into two parts: 1) characterization of diode laser light source and absorption spectrum of endogenous photosensitizer Staphylococcus aureus, 2) determine the antimicrobial effect of diode laser with endogenous photosensitizer. Combination treatment were divided into the following experimental groups: C group for the control group without laser irradiation treatment and T group for groups with laser irradiation at various exposure time (120; 150; 180, 210; 240; 270) s. The results were analyzed by Anova and the Tukey test with P value ≤0.05. The statistical analysis showed that there was no significantly difference between the control group and the laser treatments at 120 s exposure time, as well as on treatments with 180 s and 210 s. Treatment of laser exposure resulting in significant differences in bacteria survival of 0.00 (P <0.05) at 150 s, 270 s and 240 s laser exposure time. 240 s laser exposure time with energy density of 55.02 J/cm2 resulted in the lowest bacteria survival of 5.89 log CFU/ml with a 55.22% reduction in bacterial reduction, which was significantly different from the other treatment groups. The suitability between wavelength of the diode laser with photosensitizer’s absorption spectrum affect the effectiveness of bacterial inactivation. The more precisely the absorption of photon light energy, the more photosensitizer will be activated to produce various reactive oxygen species that have an effect on the number of bacterial deaths. [ABSTRACT FROM AUTHOR]

Graphical abstract Synthesis and properties of porphyrins bearing basic amine and pentafluorophenyl groups as photosensitizer to inactivate Staphylococcus aureus , Escherichia coli and Candida albicans. Highlights • New porphyrins containing pentafluorophenyl and basic amine groups were synthetized. • The basic aliphatic amino groups can be protonated at physiological pH. • High affinity was found between F 5 APP and the microbial cells. • F 5 APP was highly effective as a broad-spectrum antimicrobial photosensitizer. • These porphyrins appear to act as photosensitizers mainly via the intermediacy of O 2 (1Δ g). Abstract New porphyrin derivatives bearing basic aliphatic amino groups were synthesized from the condensation of meso -4-[(3- N , N -dimethylaminopropoxy)phenyl]dipyrromethane, pentafluorobenzaldehyde and 4-(3- N , N -dimethylaminopropoxy)benzaldehyde. The reaction was catalyzed by trifluoroacetic acid in acetonitrile. This approach was used to obtain porphyrins with different patterns of substitution, of which three of them were isolated: 5,15-di(4-pentafluorophenyl)-10,20-di[4-(3- N , N -dimethylaminopropoxy)phenyl]porphyrin (F 10 APP), 5-(4-pentafluorophenyl)-10,15,20-tris[4-(3- N , N -dimethylaminopropoxy)phenyl]porphyrin (F 5 APP) and 5,10,15,20-tetrakis[4-(3- N , N -dimethylaminopropoxy)phenyl]porphyrin (TAPP). The UV–vis spectroscopic characterizations and the photodynamic effect of these compounds were compared in N,N -dimethylformamide. These porphyrins showed red fluorescence emission with quantum yields of 0.09-0.15. Moreover, they sensitized the production of singlet molecular oxygen, reaching quantum yields values of 0.33-0.53. Photodynamic inactivation was studied in two bacteria, Staphylococcus aureus and Escherichia coli , and a yeast Candida albicans. High amount of cell-bound porphyrin was obtained at short times (<2 min) of incubation. After 15 min irradiation, a 7 log reduction of S. aureus was found for cells treated with 1 μM F 5 APP. Similar photokilling was obtained in E. coli , but using 7.5 μM F 5 APP and 30 min irradiation. Under these conditions, a decrease of 5 log was observed in C. albicans cells. An increase in cell survival was observed by addition of sodium azide, whereas a slight protective effect was found in the presence of D-mannitol. Moreover, the photoinactivation mediated by these porphyrins was higher in D 2 O than in water. Thus, these porphyrins induced the photodynamic activity mainly through the intermediacy of O 2 (1Δ g). In particular, F 5 APP was a highly effective photosensitizer with application as a broad-spectrum antimicrobial. This porphyrin contains three basic aliphatic amino groups that may be protonated at physiological pH. In addition, it is substituted by a lipophilic pentafluorophenyl group, which confers an amphiphilic character to the tetrapyrrolic macrocycle. This effect can increase the interaction with the cell envelopment, improving the photocytotoxic activity against the microorganisms. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Facile synthesis of nanoporous azo polymers (NAPs) using metal-catalyst free polycondensations in basic medium. • NAPs have been designed to include triptycene, phorphyrin and azo units in the polymer backbone. • NAPs exhibits high surface area up to 1095 m2 g−1. • High CO 2 uptake up to 3.93 mmol g−1 at 273 K and 1 bar uptake by these NAPs. • Good CO 2 /N 2 selectivity (up to 64 at 273 K) shown by these NAPs. Abstract Two nanoporous azo polymers (NAPs) have been designed incorporating triptycene and porphyrin motifs in the polymer framework that are linked covalently by azo functional groups. NAPs are synthesized using metal-catalyst free polycondensations in basic medium. These are thermally stable, microporous (Type-I isotherms in N 2 adsorption–desorption measurements at 77 K) and have moderately high surface areas (SA BET = 1095 and 923 m2 g−1). NAPs show enhanced surface areas relative to either triptycene networks with azo-linkages or porphyrinic polymers having azo bridges. NAPs register high CO 2 uptake (upto 3.93 mmol g−1 at 1 bar and 273 K) with good CO 2 /N 2 selectivity (upto 64:1 at 273 K) for CO 2 capture from flue gas. Incorporation of CO 2 -philic porphyrin rings and N 2 -phobic azo groups results in improved CO 2 /N 2 selectivity in these triptycene based microporous polymers. Performance of NAPs as nanoporous polymer (in terms of gas sorption properties such as surface areas, low pressure gas uptake and gas selectivity) is also better than several non-triptycene/porphyrin but azo based porous organic polymers (POPs). NAPs have potential use in post-combustion CO 2 capture and sequestration technology. [ABSTRACT FROM AUTHOR]

Sensitive and selective detection of copper ions (Cu2+) using fluorometric methods is of growing significance due to their widespread industrial use, which poses severe environmental and health risks. Here, we reported a porphyrin-based luminescent metal-organic framework (labelling LMOF), Al-TCPP, which exhibits dual emission peaks at 467 and 646 nm upon excitation by a single wavelength. When exposed to Cu2+ ions, the fluorescence peak at 646 nm reduces while the intensity of the 467 nm remains steady. This intriguing property enables the construction of a ratio-metric fluorescence sensor that utilizes an internal standard, significantly enhancing Cu2+ sensing accuracy. Our study establishes a linear relationship (y = 0.0454x + 0.3081) between the fluorescence intensity ratio I 467 /I 646 and the Cu2+ concentration, with a high correlation coefficient R2 = 0.9943. Impressively, the present Al-TCPP achieves a low limit of detection (LOD) of 5.28 nM, one of the lowest reported values for Cu2+ detection. The mechanism underlying this phenomenon involves charge transfer from TCPP ligands in Al-TCPP to Cu2+ ions, as revealed by solid-state NMR and X-ray photoelectron spectroscopy analysis. Utilizing Al-TCPP, we successfully developed test strips for the practical Cu2+ detection. Furthermore, the present Al-TCPP has also effectively applied to determine low Cu2+ content in various samples, including water, tea and serum. This study demonstrates the versatility and practical applicability of present Al-TCPP LMOF for selective detection of Cu2+ ions in diverse environments. [Display omitted] • Al-TCPP exhibits dual emission properties. • Al-TCPP functions as a ratiometric fluoresce sensor for the detection of Cu2+. • Al-TCPP achieves an extremely low limit of detection. [ABSTRACT FROM AUTHOR]

Water pollution, associated with both the modern productions and pathogen contamination, has become a worldwide safety concern, seriously threatening the health of living beings. Herein, a multifunctional porous polymer, denoted as Fc-PP-POP, composed by porphyrin (PP) and Ferrocene (Fc) unites, capable of self-enhanced synergetic antibacterial effect, as well as reversible capture of iodine pollutants, was facilely prepared through the simple but efficient Alder-Longo method via direct polymerization of pyrrole with Ferrocene dialdehyde. Fc-PP-POP integrated the features of Porphyrin (photoactivity) and Ferrocene (enzymatic activity), simultaneously, can serve as a broad-spectrum antibacterial agent, which could not only realize the rapidly and efficiently converting of light energy into local thermal energy for photothermal therapy (PTT), but also the transformation of low concentration of H 2 O 2 into toxic hydroxyl radical (•OH) for the enzyme therapy. The as-generated local heat could further improve the enzymatic activity, displaying a remarkably enhanced synergistic therapeutic effect, realizing the efficient sterilization at low concentrations (300 μg/mL). In vivo assay revealed Fc-PP-POP can significantly promote the healing of infected wounds. Meanwhile, Fc-PP-POP can function as an efficient adsorbent, capturing the iodine contaminants from the environment. This work opens up a new mean for the application of low-cost POPs in the field of environmental remediation and public health. [Display omitted] • A multifunctional environmental remediation material (Fc-PP-POP) is prepared. • Fc-PP-POP features the performance of porphyrin and Ferrocene, concurrently. • Fc-PP-POP utilizes acidic and H 2 O 2 to initiate the peroxidase-like activity. • Fc-PP-POP offers a prominent PTT to boost the enzymatic therapeutic effect. • Fc-PP-POP function as an adsorbent removing radioactive iodine from water. [ABSTRACT FROM AUTHOR]

Noncovalent functionalization of graphene with porhyrins that possess a large conjugated π-system of bonds can extend the range of practical applications of this nanomaterial. In this work the structures of hybrids formed by porphin and meso -5,10,15,20-tetraphenyl porphyrin (TPP) with graphene and the corresponding intermolecular interaction energies are studied with the DFT and molecular dynamics (MD) calculations. The influence of the peripheral rings arranged around the porphyrin core in the TPP structure on its interaction energy with graphene upon the TPP adsorption on graphene is analyzed. The flattening of the TPP structure occurring due to the adsorption is observed. The interaction of TPP with graphene also leads to distortion of the flat structure of the porphyrin core and to some twisting of its side rings, so the dihedral angle between the planes of the porphyrin core and the side residues decreases from 64° to 50°. In spite of the flattening and the larger size of the TPP structure compared to the porphin structure their interaction energies with graphene are similar (about 20 kcal/mol). It is also shown that TPP alters the uniform distribution of the electrostatic potential on graphene by reducing the zone of small negative potential of graphene located under the porphyrin molecule. The MD simulation performed in this work describes the process of the adsorption of porphin and TPP on graphene in water environment and reveals significant mobility of this molecule on the graphene surface. [ABSTRACT FROM AUTHOR]

The nature of the solvent and composition of the solution in which optical absorption spectra are acquired can substantially affect the structures of analytes as well as spectra and relative intensities of spectral features. We have computed the effects of the solvent for dilute solutions on the electronic absorption spectra and structures of a prototypical porphyrin—free-base porphyrin (herein referred to as FBP and H 2 FBP)—and its protonated form (H 4 FBP) in the ground and the lowest triplet states, both important in device and medical applications. Density functional theory (DFT) and time-dependent-DFT (TD-DFT) have been employed to investigate solvent effects on structure and singlet-singlet (S 0  → S n ) and triplet-triplet (T 1  → T n ) absorption spectra. We also calculated the solvent dependence of energy gaps between optically allowed singlet and nearest triplet states for the species. Soret band positions are found to be strongly solvent dependent, but less so are Q bands. The finding of dependence of the spectroscopic features of the porphyrin on the dielectric constant of the solvent, from 1.00 (gas-phase) to about 20.493 (acetone)—with the features becoming stable for polar solvents with the dielectric constants ε > 20—can be used to monitor micro environmental changes of porphyrin (and its derivatives) embedded in biological systems and nanoparticles; such composites may also be suitable to study and monitor modifications of the chemical environment in different solutions and interactions with biological systems and nanoparticles. This is first systematical study on the solvent-dependence of the porphyrin compounds. [ABSTRACT FROM AUTHOR]

The successful isolation of fully conjugated polypyrrolic macrocycles with peripheries containing more than 18 π-electrons led to a new class of azaannulenes. These systems, referred to as expanded porphyrins, have been found to possess unexpected electronic features, display multiple redox states, and display dynamic aromaticity and antiaromaticity characteristics, as well as interesting reactivity. The large cavities found in many expanded porphyrins have made them excellent systems for both metal cation coordination and anion binding. Often, they display recognition chemistry that differs dramatic from their smaller porphyrin congeners. This has made expanded porphyrins of both academic interest and potential utility in the development of more efficient extractants, sensors, and smart electronic devices. Here, the cation complexation chemistry of representative expanded porphyrins containing more than four pyrrole (or pyrrole-like) subunits is presented. Also reviewed are the anion binding properties of several well-studied protonated oligopyrrolic macrocycles. [ABSTRACT FROM AUTHOR]

• The porphyrin-associated spectroscopic is a simple and fast procedure that improves the biofilm detection. • This method avoids negative outcomes in the diagnosis of biofilm in orthodontic appliances. • It is a non-invasive method that does not stain teeth. : This study assessed the presence of dental biofilm with fluorescence spectroscopy associated with porphyrin (Photogen®) in users of orthodontic appliances. : This cross-sectional observational clinical trial included 21 patients with metallic orthodontic fixed appliances. The presence of biofilm was evaluated by fluorescence spectroscopy (Evince—MMÓptics. São Carlos-SP, Brazil) with a porphyrin photo-evidence device (Photogen®). Digital images of the buccal surface of the upper anterior teeth (central and lateral incisors and canines) without and with porphyrin were analyzed using the histogram R (red) function in ImageJ software. The results were analyzed using the maximum and mode values of the red pixels from the histograms. The statistical analysis considered the significance level of 5%. : The maximum values and modes of the red pixels were significantly higher in biofilms analyzed by porphyrin-associated optical spectroscopy compared to optical spectroscopy alone. : Porphyrin-associated fluorescence spectroscopy was able to detect dental biofilm in the oral environment of patients with orthodontic treatment. This method better evidenced the presence of biofilm on the buccal surfaces of the upper teeth compared to that observed with fluorescence spectroscopy without porphyrin. [ABSTRACT FROM AUTHOR]

Porphyrins are an important class of ligands with a tremendous ability to capture metal ions closely related to the rich coordination chemistry of porphyrins. Herein we use this characteristic to develop silica gel grafted derivatives for water remediation applications. Therefore, two porphyrin derivatives, one with three and the other with four mercaptopyridyl units were grafted on silica gel functionalized with 3-aminopropyltriethoxysilane. The new adsorbents Si3PyS and Si4PyS were characterized using a suitable set of techniques confirming the covalent attachment of the porphyrins to the silica surface. Additionally, microscopy and N 2 adsorption analysis confirmed the structural integrity and preservation of the mesoporous structure of Si during surface modification. The results show that both hybrid materials exhibit good chemical and thermal stability and an outstanding Cu2+ removal capability, with a chemical adsorption capacity of 176.32 mg g–1 and 184.16 mg g–1, respectively. These materials have also been used in real water and industrial wastewater samples with minimal interference in their adsorption capabilities. Density Functional Theory calculations were performed to confirm the good performance of the hybrid materials Si3PyS and Si4PyS towards metal ions. The functionalization of silica surface with porphyrin-based ligands bearing additional binding motifs drastically improves the adsorption capability of the new hybrids towards metal ions. The presence of pyridyl units brings a meaningful advantage, since both porphyrin core and appended pyridyl groups are able of binding Cu2+ ions with high affinity, contributing to the enhancement of the chelating features of the adsorbents prepared when compared with other ligands supported in silica-based materials. [Display omitted] • Mercaptopyridyl-porphyrins were successfully prepared and grafted onto silica gel. • New hybrids shows an excellent and fast adsorption capacity towards Cu2+, with spontaneous coordination achieved in 15 min. • They are robust and show high efficiency after several reusability cycles without loss of effectivity and selectivity. • The final materials show a remarkable cation removal capability in real water samples. • Compared with other sorbents a reported they possess higher efficiencies and are excellent alternatives for Cu2+ water removal. [ABSTRACT FROM AUTHOR]

The use of Diatomaceous Earth (DE) as a promising support of a synthetic metalloporphyrin is reported, trying to heterogenize metalloporphyrin catalysts to mimicking enzyme site isolation and improving reaction selectivity. New multifunctional hybrid materials consisting of DE amino–functionalized with aminopropyltriethoxysilane (DE–APTES), followed by grafting with [meso–tetrakis(pentafluorophenyl)porphinato]iron(III) (DE–APTES–FeTFPP), were prepared and fully characterized. FeTFPP was grafted into DE–APTES via the amine groups (band at 1570 cm–1). The brown color of the materials indicated that FeTFPP was immobilized in the matrix; a Soret band characteristic of ironporphyrin located in a confined space, was found at 416 nm. Leaching studies confirmed that the ironporphyrin was entrapped and not just adsorbed on the silica surface. DE was composed of typical quartz and cristobalite crystalline phases and amorphous silica. The intensity of its characteristic reflection at 22° (2θ) decreased in the presence of FeTFPP, evidencing that the ironporphyrin influenced the organization of the material. Catalytic tests using DE–APTES–FeTFPP in cyclooctene epoxidation to cyclooctene oxide (56 % yield, with complete selectivity for the epoxide) and cyclohexane oxidation (4 % yield of oxidized products, with ketone/alcohol selectivity ∼ 3:1), evidenced the versatility of the catalyst and the multifunctionality of the resulting hybrid materials and the ability of DE as a promising natural support for ironporphyrin catalysts. Finally, the capacity of the materials as CO 2 adsorbents was evaluated in the temperature range 100–200 °C. DE–APTES showed a maximum adsorption capacity of 1.26 mmol/g at 100 °C, 18 times higher than the value found under the same conditions for the non–functionalized support. [Display omitted] • Functionalized diatomaceous earth/iron(III)porphyrin hybrids were prepared. • The material catalyzed cyclooctene and cyclohexane oxidation. • Oxidation was effective under mild, environmentally friendly conditions. • The material also showed potential use as an adsorbent for CO 2. [ABSTRACT FROM AUTHOR]

Background Antimicrobial photodynamic therapy (aPDT) has been used as an adjuvant treatment for periodontitis. It combines a photosensitizer with a light source to induce reactive oxygen species and kill microbial cells. PpNetNI is a protoporphyrin derivative, and it has a chemical binding site at biofilm and great affinity to microbial cells. The aim of this study was to investigate the effects of aPDT as an adjuvant treatment for periodontitis. Methods Thirty healthy male rats Wistar ( Rattus norvegicus ) were used in this study (Approved by UNINOVE Ethical committee AN0029/2015). Periodontitis was induced by placing a cotton ligature around the first mandibular molar in a subgengival position. The contralateral mandibular first molar received neither a ligature nor any treatment, and was used as a control. After 7 days, the ligature was removed and all animals received scaling and root planing (SRP) and were divided according to the following treatments: SRP group (received SRP and irrigation with PpNetNI, 10 μM) and aPDT group (PpNetNI 10 μM followed by LED irradiation). aPDT was performed with a LED (630 nm) with an output power of 400 mW (fluence-rate 200 mW/cm 2 ; fluence 18 J/cm 2 ). Rats were euthanized at 24 h, 48 h and 7 days postoperatively. The area of bone loss in vestibular region of the first molar was evaluated by Optical Coherence Tomography (OCT, THORLABS LTD., Ely, UK). Data were analyzed statistically (ANOVA and Tukey tests, p < 0.05). Results The animals treated by aPDT showed bone gain of approximately 30% compared to the SRP group following 7 days from the treatment. Conclusion aPDT promoted bone recovery 7 days after periodontal intervention. [ABSTRACT FROM AUTHOR]

Background Photodynamic therapy (PDT) is a promising anti-tumor treatment strategy. Photosensitizer is one of the most important components of PDT. In this work, the anticancer activities of PDT mediated by six new ruthenium porphyrin complexes were screened. The mechanisms of the most efficacious candidate were investigated. Methods Photocytotoxicity of the six porphyrins was tested. The most promising complex, Rup-03, was further investigated using Geimsa staining, which indirectly detects reactive oxygen species (ROS) and subcellular localization. Mitochondrial membrane potential (MMP), cell apoptosis, DNA fragmentation, c-Myc gene expression, and telomerase activities were also assayed. Results Rup-03 and Rup-04 had the lowest IC 50 values. Rup-03 had an IC 50 value of 29.5 ± 2.3 μM in HepG2 cells and 59.0 ± 6.1 μM in RAW264.7 cells, while Rup-04 had an IC 50 value of 40.0 ± 3.8 μM in SGC-7901 cells. The complexes also induced cellular morphological changes and impaired cellular ability to scavenge ROS, and accumulated preferentially in mitochondria and endoplasmic reticulum. Rup-03 reduced MMP levels, induced apoptosis, and repressed both c-Myc mRNA expression and telomerase activity in HepG2 cells. Conclusions Among six candidates, Rup-03-mediated PDT is most effective against HepG2 and RAW264.7, with a similar efficacy as that of Rup-04-mediated PDT against SGC-7901 cells. Repression of ROS scavenging activities and c-Myc expression, which mediated DNA damage-induced cell apoptosis and repression of telomerase activity, respectively, were found to be involved in the anticancer mechanisms of Rup-03. [ABSTRACT FROM AUTHOR]

Recently, we described porphyrin-based periodic mesoporous organosilica (PMO) nanoparticles synthesized from a large functional octatriethoxysilylated porphyrin precursor. The framework of the nanoparticles was formed by J-aggregates of porphyrins allowing two-photon excitation photodynamic therapy (TPE-PDT) and NIR imaging. In this study, we functionalized these PMO with polyethylene glycol (PEG) moieties and an analogue of mannose 6-phosphate functionalized on anomeric position (AMFA). These AMFA are known to efficiently target mannose 6-phosphate receptors (M6PR) which are over-expressed in various cancer cell lines (breast, prostate). Here we show that M6PR is also over-expressed in rhabdomyosarcoma (RMS) cell lines. We targeted this receptor with PMO-AMFA and efficiently performed TPE imaging and TPE-PDT of RMS cells. Furthermore the same treatment did not affect healthy myoblasts, which have a low expression of M6PR. [ABSTRACT FROM AUTHOR]

X-ray-induced Photodynamic Therapy (X-PDT) is an alternative strategy to improve Photo Dynamic Therapy (PDT) for cancer treatment [1]. The X-PDT principle is based on the conversion of X-ray photons into visible photons, from nanoscintillator embedded in nanoparticles (NPs) and linked to the photosensitizer, which, in turn, produces singlet oxygen and reactive species. Recently, several lines of evidence demonstrated that radionuclides can be used instead of X-rays irradiation to produce similar photodynamic effect, using NPs containing both nanoscintillator and photosensitizer. [1]. The obtained results are related to the Cerenkov luminescence and it is based on the positrons emission along lifetime of the radionuclides [2]. The ultra-small Gadolinium (Gd) based nanoparticle, namely AGuIX®, were initially designed for a non-toxic resonance magnetic agent and for its imaging properties [3]. Recently, we replaced Gd from the AGuIX@ platform by Terbium and added 5-(4-carboxyphenyl succinimide ester)-10,15,20-triphenylporphyrin (P1) [4]. The new NP, referred as AGuIX@Tb-P1, was characterized for its photo-physical and biological properties. We demonstrated that the NP design is compatible for X-PDT. Using U-251 MG human glioblastoma cells, we showed that AGuIX@Tb-P1 pre-treated cells exposed to X-rays underwent cell growth arrest with an enhanced factor of 35%, when the results were compared to those obtained with untreated cells exposed to X-rays [4]. Based on our results, we assessed whether free Gallium-68 (68Ga) could be used in order to substitute X-ray irradiation, using the same experimental procedure as previously described [4]. We showed i) that 68Ga-mediated Cerenkov luminescence is sufficient to transfer photon to AGuIX@Tb-P1 whose produced P1-mediated singlet oxygen under Cerenkov radiation; ii) U-251 MG cell exposure to 68Ga reduced cell clone formation. Both irradiation procedures were associated to change in the redox statue providing evidence of reactive derived oxygen species production. In conclusion, free 68Ga could be substituted to X-ray to produce a photodynamic effect, in our experimental conditions, using AGuIX@Tb-P1, in order to limit X- ray dose and radiation-mediated damage on tumor environment. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) successful clinical use has led to an emerging interest in the development of improved delivery systems for photosensitizers. Amongst different formulations, gels have the advantage of being easier to apply, providing greater adhesion to the affected region and allowing light penetration. Importantly, we have previously reported that by incorporating porphyrin into a bisimidazolium gelator matrix there is an increased reactive oxygen species (ROS) generation compared to the photosensitizer in solution [1]. Motivated by this, we report further assessment on the photosensitizing capabilities of porphyrins in a gel structure. In this work, we evaluated effect of varying the chemical structures of porphyrins on their photosensitizing capabilities whilst embedded within a supramolecular hydrogel based on gemini imidazolium amphiphiles. The investigated porphyrins presented enhanced singlet oxygen (1O2) within the hydrogel matrix compared to solution and showed negligent release in relevant biological media. Rheological measurements revealed that porphyrin hydrogels presented desirable viscoelastic properties as a functional delivery system for PDT. ACKNOWLEDGEMENT: This work was supported with funds from the Spanish Government Grant PID2020-115663GB-C32 funded by MCIN/AEI/10.13039/501100011033. We also thank the Universitat de Barcelona, the Spanish Ministry of Universities, the NextGenerationEU plan, the European Union and the Spanish national Recovery, Transformation and Resilience plan. [ABSTRACT FROM AUTHOR]

We have developed liposomes that are doped with a small amount of a photosensitizing lipid; porphyrin-phospholipid (PoP).[1] Long-circulating doxorubicin (Dox) in porphyrin–phospholipid (PoP) liposomes (LC-Dox-PoP) is similar to the FDA-approved liposomal doxorubicin form of Doxil, but incorporates a phospholipid-like photosensitizer (2 mole %) in the bilayer of Dox-loaded stealth liposomes.[2] A liposomal irinotecan formulation has been made in a similar manner based on the FDA-approved liposomal Onivyde.[3] Drugs loaded in PoP liposomes, as well as the PoP itself are stable and exhibit long circulation times in blood. However, red laser irradiation rapidly releases the entrapped drug from the carrier. When mouse or rat tumors are treated with these chemophototherapy agents, a single treatment is frequently sufficient to ablate established tumors at a relatively low chemotherapy dose of drug. Pharmacokinetic analysis shows that a major mechanism for the efficacy pertains to enhanced drug delivery following permeabilization of tumor blood vessels damaged by PDT. We will discuss our experience and outlook for this approach to chemophotherapy as a strong ablation modality with systemic drug delivery. [ABSTRACT FROM AUTHOR]

Photodynamic therapy has several benefits over chemotherapy and radiotherapy in the treatment of localized tumors such as a high selectivity, low side effects and immune stimulatory properties [1]. Due to the fast spread of multi-resistant microorganisms that represent a threat to public health, antimicrobial photodynamic therapy (a-PDT) is also experiencing renewed interest [2]. A major strength of a-PDT is the absence of bacterial resistance to the treatment and its effectiveness on resistant strains [3]. Nevertheless, treatments based on PDT have severallimitations related to the photosensitizer properties, selectivity, light delivery and tissue oxygenation. Regarding these issues, our group has developed photosensitizers for PDT, a-PDT and theranostic applications that can be excited in the optical therapeutic window for deeper treatment with less photodamage. They are based on porphyrins with an extended π-conjugated system for one or two-photon excitation in the near infrared (Figure 1) [4]. For a-PDT, a porphyrin connected to an antimicrobial peptide was recently synthesized to target and kill bacteria upon near-infrared excitation and its photodynamic disinfection capacity will be discussed [5]. [ABSTRACT FROM AUTHOR]

The technique of colorimetric sensor array (CSA) is proved to be a novel and helpful method to detect and determine the quality of food and beverages with simple, inexpensive, rapid and sensitive advantages. The limit of this technique is considered to be the sensor design. In this study, density functional theory (DFT) at B3LYP/LANL2DZ level was employed to investigate the ability of CSA sensor to bind volatile organic compounds (VOCs). The results showed that silver porphyrin (AgP) is sensitive to trimethylamine (L1), followed by propanol (L2) and N 2 , whereas O 2 and propane (L3), ethyl acetate (L4), butanone (L5), and propionaldehyde (L6) cannot be easily detected by AgP. The analysis of charge distribution indicated that the nature of AgP reacted with VOCs is the electron transfer from Ag atom to porphyrin plane. This theoretical study may be a useful guide for the design of CSA sensor to detect and determine a special analyte. [ABSTRACT FROM AUTHOR]

In this study, antiviral effect of porphyrin was investigated. Cooper strain of Bovine Herpes Virus type 1(BoHV-1) and Kos strain of Herpes Simplex Virus type-1 (HSV-1) were used to determine the potential of porphyrins to inhibit infection in vitro (with morphological and cytopathological criteria). Apoptotic and necrotic changes were determined by using DAPI and propidium staining. The non-cytotoxic dose of porphyrin (NCD-p) was initially calculated as 312.50µg/mL on MDBK and Vero cells. The apoptotic cell (APC) count was found 10% with BoHV-1 while it was 5.3% with BoHV-1 treated with porphyrin on MDBK cells between 6th to 24th hours post infection (hpi). Necrotic cell (NEC) count was 51% with BoHV-1 and 37.8% BoHV-1 treated with porphyrin on MDBK cells at 24th hpi. On the other hand, the APC count was found 23% with HSV-1, while 22% with the HSV-1 treated with porphyrin on Vero cells between 6th to 24th hpi. NEC count was 49% with HSV-1 and 34% HSV-1 treated with porphyrin on MDBK cells at 24th hpi. The results show that BoHV-1 was inhibited by porphyrin resulting in decreased apoptotic and necrotic changes in MDBK cells. On the contrary, porphyrine was not effective in the inhibition of HSV-1 in terms of apoptosis but it caused necrotic changes in Vero cells. [ABSTRACT FROM AUTHOR]

Background Photodynamic Therapy (PDT) using Aminolevulinic acid (ALA) and derivative molecules as topical medication and as a precursor of protoporphyrin (PPIX), is limited due to low permeation through skin or efficiency in porphyrin production. This behavior affects the production and homogeneity of PPIX distribution on superficial skin and in the deeper skin layers. Many authors propose alternatives to solve this such as, modification in the ALA and derivativemolecules, modifying the chemical properties of emulsion external phase or incorporating a delivery system to the emulsion. The goal of this study is to discuss what proportion of ALA and Methyl aminolevulinate (MAL) on mixtures increase the amount and uniformity of PPIX formation at superficial skin by fluorescence evaluations. Methods The study was conducted in vivo using a pig skin model. PPIX production was monitored using fluorescence spectroscopy and widefield fluorescence imaging on skin surface. 20% of ALA and MAL cream were done mixing the following proportions: ALA, M2 (80% ALA–20% MAL), M3 (60% ALA–40% MAL), M4 (50% ALA–MAL), M5 (40% ALA–60% MAL), M6 (20% ALA–80% MAL) and MAL. Results Mixtures M3, M4, and M5 showed the most PPIX production on skin by widefield fluorescence imaging and fluorescence spectroscopy in 3 h of incubation. These results suggest that 50% of ALA and MAL in the same mixture increase the PPIX production in amount, homogeneity and time production when compared to ALA and MAL. This has a positive impact on photodynamic damage optimizing the PDT treatment. [ABSTRACT FROM AUTHOR]

The photodynamic inactivation mediated by 5,10,15,20-tetrakis[4-(3- N,N -dimethylaminopropoxy)phenyl]porphyrin (TAPP) and 5,10,15,20-tetrakis[4-(3- N,N,N -trimethylaminepropoxy)phenyl]porphyrin (TAPP 4+ ) were compared in Candida albicans cells. A strong binding affinity was found between these porphyrins and the yeast cells. Photosensitized inactivation of C. albicans increased with both photosensitizer concentration and irradiation time. After 30 min irradiation, a high photoinactivation (∼5 log) was found for C. albicans treated with 5 μM porphyrin. Also, the photoinactivation of yeast cells was still elevated after two washing steps. However, the photocytotoxicity decreases with an increase in the cell density from 10 6 to 10 8 cells/mL. The high photodynamic activity of these porphyrins was also established by growth delay experiments. This C. albicans strain was susceptible to fluconazole with a MIC of 1.0 μg/mL. The effect of photosensitization and the action of fluconazole were combined to eradicate C. albicans . After a PDI treatment with 1 μM porphyrin and 30 min irradiation, the value of MIC decreased to 0.25 μg/mL. In addition, a complete arrest in cell growth was found by combining both effects. TAPP was similarly effective to photoinactivate C. albicans than TAPP 4+ . This porphyrin without intrinsic positive charges contains basic amino groups, which can be protonated at physiological pH. Moreover, an enhancement in the antifungal action was found using both therapies because lower doses of the agents were required to achieve cell death. [ABSTRACT FROM AUTHOR]

Colloidal lipid particles such as solid lipid nanoparticles and liquid crystalline nanoparticles have great opportunities as drug carriers especially for lipophilic drugs intended for intravenous administration. In order to evaluate drug release from these nanoparticles and determine their behavior after administration, emulsion droplets were used as a lipophilic compartment to which the transfer of a model drug was measured. The detection of the model drug transferred from monoolein cubic particles and trimyristin solid lipid nanoparticles into emulsion droplets was performed using a flow cytometric technique. A higher rate and amount of porphyrin transfer from the solid lipid nanoparticles compared to the monoolein cubic particles was observed. This difference might be attributed to the formation of a highly ordered particle which leads to the expulsion of drug to the surface of the crystalline particle. Furthermore, the sponge-like structure of the monoolein cubic particles decreases the rate and amount of drug transferred. In conclusion, the flow cytometric technique is a suitable technique to study drug transfer from these carriers to large lipophilic acceptors. Monoolein cubic particles with their unique structure can be used successfully as a drug carrier with slow drug release compared with trimyristin nanoparticles. [ABSTRACT FROM AUTHOR]

The design of trackable anticancer agents is of major interest for the future development of therapeutics based on nonplatinum metal complexes such as Ru(II), Os(II), or Au(I) derivatives, and more particularly for the understanding of the mechanism of action of these metal-based drugs. This review reports the synthesis and the first biological studies of original trackable complexes, in which the metal complex was coupled to an imaging probe, such as a fluorophore (coumarin, borodipyrromethene derivative (BODIPY), porphyrin), or a chelating agent (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)) for radioisotopic imaging PET (positron emission tomography) or SPECT (single photon emission computed tomography). In the case of fluorescent theranostics, the photophysical properties of the different compounds were studied and the cell uptake could be evaluated on different cell lines, by microscopy imaging. A fluorescent smart probe based on coumarin-phosphine, whose fluorescence strongly depends on the coordination of the metal was also studied, revealing a nonusual cellular target with respect to the classical gold therapeutic systems. In the last section, the synthesis of new potential fluorescent trackable-radiotherapeutics is also presented. [ABSTRACT FROM AUTHOR]

In this account, the synthesis and biological evaluation of metalloporphyrins and related structures for use in biomedical imaging applications are outlined. The structural design of these tetrapyrrolic metal chelators is discussed, with evaluation of strategies designed to facilitate more rapid chelation under milder conditions, improve water solubility, and allow for conjugation to targeting groups and macromolecular structures. Particular emphasis is given to the application of these metalloporphyrin structures to clinically relevant imaging techniques including magnetic resonance imaging, fluorescence imaging, radio-imaging, and Raman and photo-acoustic imaging, with a broad overview of the progress made in these areas. The future of research in this area is also examined, with the emerging research interest in more modern multimodal imaging set to dominate the future of biomedical imaging. [ABSTRACT FROM AUTHOR]

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• Cu@NC-ZrO 2 , a high-selective and low-cost catalyst, is prepared by simple pyrolysis of PCN-222(Cu) MOF. • The Cu@NC-ZrO 2 –600 catalyst contains the original mesoporous structure from PCN-222(Cu) and abundant Cu-N x active sites. • The conversion and selectivity of the hydrogenation of benzonitrile to benzylamine can be up to 95% and 100% selectivity, respectively. • Cu@NC-ZrO 2 –600 catalyst exhibits excellent stability and recyclability. Designing high-selective and low-cost catalysts for the selective hydrogenation of nitriles to high value-added amines is important and challenging. Herein, a non-noble metal Cu@NC-ZrO 2 catalyst was prepared by simple pyrolysis using PCN-222(Cu) MOF as the precursor. Under lower temperature pyrolysis, the small Cu nanoparticles (NPs) and abundant Cu-N x active sites were uniformly embedded in the N-doped support and the produced catalyst retains the mesoporous structure of PCN-222(Cu), which are beneficial for catalytic performance. The Cu@NC-ZrO 2 –600 catalyst was found to be economic and efficient for the selective hydrogenation of benzonitrile to benzylamine, and the selectivity and conversion can be up to 100% and 95%, respectively. Moreover, due to the encapsulation of Cu nanoparticles in the support N-doped carbon matrix, this catalyst showed outstanding stability of resistance to leaching. [Display omitted] [ABSTRACT FROM AUTHOR]

Immunogenic phototherapy has the potential to enhance tumor immunotherapy. Nevertheless, its efficacy is severely restricted by optimal photosensitizer deficiency and efficient delivery of the photosensitizers. We thus constructed TAPP-GCP@TCPP@BSA nanoparticles by self-assembling of a porphyrin derivative (TAPP-GCP), meso-tetra(4-carboxyphenyl) porphyrin (TCPP), and bovine serum albumin (BSA) to achieve effective phototherapy and further enhance tumor immunotherapy. Nanoparticles (NPs) subjected to laser irradiation can induce tumor cytotoxicity and immunogenic cell death (ICD). They can accumulate in tumors after intravenous injection and induce significant ICD after laser illumination, thereby promoting the maturation of antigen-presenting cells and activating the specific antitumor killing effect of cytotoxic T cells in a breast tumor model. NPs combined with anti-PD-L1 blockade significantly inhibited distant tumor growth by initiating an excellent antitumor immune response. The phototherapy of NPs through multicomponent synergistic self-assembly is a promising approach for boosting immune checkpoint blockade therapy. [Display omitted] • Nanophosensitizers was constructed by weak interaction, and phototherapy for tumor was achieved. • The nanodrug exhibited multi-mode imaging, and induced immunogenetic cell death (ICD) for tumor cells. • ICD strategy decreased the immune suppression and reversed the suppressive tumor microenvironment. • The photo-immunotherapy strategy accomplished an efficient inhibition of distant tumor. [ABSTRACT FROM AUTHOR]