A novel porphyrin derivative and its metal complexes: Electrochemical, photoluminescence, thermal, DNA-binding and superoxide dismutase activity studies

Photodynamic anti-inflammatory activity of meso‑aryl substituted porphyrin derivative on mammalian macrophages

BACKGROUND

Our group focused on a meso‑aryl substituted porphyrin molecule for its photodynamic anti-inflammatory activities on the mammalian macrophages.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

Design, synthesis, biomedical investigation, DFT calculation and molecular docking of novel Ru(II)-mixed ligand complexes

A novel series of bioactive water-soluble mononuclear Ru(II)-mixed ligand complexes of 2,2'-bipyridyl and V-shaped Schiff base ligands were synthesized and structurally characterized. Biomedical activities of Ru(II) complexes have been tested in view of antioxidant activities, interaction with calf thymus DNA (CT-DNA), and anticancer performance. The optimized structure of these complexes has been further supported by density functional theory (DFT) calculations. Further, validation of the interaction studies of some complexes was accomplished by carrying out molecular docking studies with DNA using molecular operating environment (MOE) software are reported.Communicated by Ramaswamy H. Sarma.

Overall Surfacial Antenna Immobilization Boosts Carrier Migration for Visible Light Superoxide Generation

The artificial photosynthesis efficiency is restricted for the covering of introduced light-absorbing antennas, where they could generally be immobilized at specific surface sites of semiconductors. Here, we highlight the emerging π-π interaction strategies in realizing overall surfacial antenna immobilization onto semiconductor supports, during which large-scale built-in electric fields are established, strongly driving photocarrier migration to catalytic centers accompanied with enhanced light absorption. By taking porphyrin and ZIF-8 as a prototype, both theoretical calculation and experimental results show that the photocatalytic systems with overall surfacial antennas could absorb broader visible light and form abundant photocarrier transport pathways from porphyrin to ZIF-8, boosting the generation of superoxide and organic synthesis efficiency. This work develops a universal strategy for design of efficient artificial photosynthetic systems.

One-Pot Synthesis of MnOx-SiO2 Porous Composites as Nanozymes with ROS-Scavenging Properties

The development of nanomaterials that mimic the activity of enzymes is a topic of interest, for the decomposition of reactive oxygen species (ROS). We report the preparation of a novel nanocomposite of MnO_x needles covered with SiO₂ porous material. The material was prepared in one pot with a two-step procedure. The material was characterized by EDX, SEM, TEM, XRD, nitrogen adsorption-desorption isotherms, and XPS. The synthesis protocol took advantage of the atrane method, favoring the nucleation and initial growth of manganese oxide needles that remained embedded and homogeneously dispersed in a mesoporous silica matrix. The final composite had a high concentration of Mn (Si/Mn molar ratio of ca. 1). The nanozyme presented bimodal porosity: intraparticle and interparticle association with the surfactant micelles and the gaps between silica particles and MnO_x needles, respectively. The porosity favored the migration of the reagent to the surface of the catalytic MnO_x. The nanozyme showed very efficient SOD and catalase activities, thus improving other materials previously described. The kinetics were studied in detail, and the reaction mechanisms were proposed. It was shown that silica does not play an innocent role in the case of catalase activity, increasing the reaction rate.

Interactions of porphyrins with DNA: A review focusing recent advances in chemical modifications on porphyrins as artificial nucleases

The advance of porphyrins as artificial nucleases along the years have developed a class of compounds having potential therapeutic applications. Being an extrovert of chemistry, a variety of chemical modifications have been done on porphyrin macrocycle in order to improve the spectroscopic properties and to adapt as artificial receptors that can recognize molecules. The last twenty years has witnessed broad research in the arena of porphyrin- DNA interactions and their evolution from simple to more complex entities. In this review, we summarize the recent advances in the porphyrin-based structural modifications, with a specific emphasis on various effects of porphyrin on DNA cleavage potency. We particularly detailed the nuclease activity of cationic and anionic porphyrins, porphyrin dimers and conjugates as well as heme proteins till the third generation porphyrins as artificial nucleases.

Zinc Complexes with Nitrogen Donor Ligands as Anticancer Agents

The search for anticancer metal-based drugs alternative to platinum derivatives could not exclude zinc derivatives due to the importance of this metal for the correct functioning of the human body. Zinc, the second most abundant trace element in the human body, is one of the most important micro-elements essential for human physiology. Its ubiquity in thousands of proteins and enzymes is related to its chemical features, in particular its lack of redox activity and its ability to support different coordination geometries and to promote fast ligands exchange. Analogously to other trace elements, the impairment of its homeostasis can lead to various diseases and in some cases can be also related to cancer development. However, in addition to its physiological role, zinc can have beneficial therapeutic and preventive effects on infectious diseases and, compared to other metal-based drugs, Zn(II) complexes generally exert lower toxicity and offer few side effects. Zinc derivatives have been proposed as antitumor agents and, among the great number of zinc coordination complexes which have been described so far, this review focuses on the design, synthesis and biological studies of zinc complexes comprising N-donor ligands and that have been reported within the last five years.

Preparation of Keratin-Glycine Metal Complexes and Their Scavenging Activity for Superoxide Anion Radicals

To address the problem of limited application of natural SOD, the development of SOD mimic enzymes is of great importance for bioantioxidation. Herein, we report on a new type of biopolymer antioxidant with excellent scavenging activity for O2•-, keratin-glycine metal complexes (FK-GlyM, M = Zn, Cu, Mn, Ni). They are prepared by feather keratin firstly combined with glycine and then metal ions. Using FT-IR, TG, CD, and SEM, the performance of the obtained complexes (FK-GlyM) for scavenging O2•- is analysed and investigated. Importantly, the scavenging activity of FK-GlyCu is excellent in all FK-GlyM, and FK-GlyCu60 has the most excellent anti-O2•- activity in all FK-GlyCux, of which EC50 and degree of simulation were, respectively, up to 4.5×10-3±0.0012 μmol/L and 911.1% compared with nature Cu, Zn-SOD. Finally, its mechanism was also discussed. In summary, this method about the simulation strategies will provide a novel idea for exploiting new-type biocompatible and highly reactive antioxidants.

Preparation of spherical metal-organic frameworks encapsulating ag nanoparticles and study on its antibacterial activity

A metal-organic frameworks (CuTCPP MOFs) were synthesized with Cu(NO₃)₂·3H₂O and 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) by the solvothermal method. The structure and morphology of the CuTCPP MOFs were characterized by UV-vis absorption spectra, X-ray diffraction (PXRD), energy dispersive spectra, scanning electron microscopy (EDS-SEM) and transmission electron microscopy (TEM). The structure of the as-synthesized MOF includes copper ions and copper metalloporphyrin (Cu-TCPP) by UV-vis absorption spectra and PXRD. The SEM and TEM images of the as-synthesized MOF showed the morphology of the CuTCPP MOFs were spherical. The as-synthesized spherical MOFs as the carriers were used to encapsulate the Ag nanoparticles and prepared Ag-CuTCPP MOFs. The Ag-CuTCPP MOFs was also characterized by UV-vis, PXRD, SEM and TEM. The Ag nanoparticles were completely encapsulated into the CuTCPP MOFs and no surface absorption, which have been confirmed by comparing TEM and SEM-EDS of Ag-CuTCPP MOFs before crushing with that of Ag-CuTCPP MOFs after crushing. In addition, the release of Ag ions from Ag-CuTCPP MOFs was also investigated by Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). Furthermore, the antimicrobial activities and cytotoxicity of Ag-CuTCPP MOFs were performed by in vitro and in vivo experiment. In vitro, the antibacterial effect of Ag-CuTCPP MOFs was even better than that of the penicillin as the positive control and the cytotoxicity of Ag-CuTCPP MOFs was significantly lower than that of naked Ag nanoparticles and Ag ions; in vivo, Ag-CuTCPP MOFs not only exhibited the excellently antibacterial effect and extremely low cytotoxicity but also effectively promoted the wound healing.