Coordination and Bioorganometallic Chemistry: Exploring the Potential Applications of Metal Coordination and Organometallic Complexes in Medical and Microbiological Advancements.

In the field of coordination and bioorganometallic chemistry, a notable shift is occurring. This mini-review explores a new generation of carefully 3D-crafted coordination and organometallic complexes that differ from conventional structures. Emphasizing disease intervention and microbial control, these compounds, incorporate noble and transition metals, and aim to enhance therapeutic efficacy while minimizing potential health risks. The mini-review covers diverse applications, showcasing their effectiveness against bacteria, viruses, fungi, and as potential tools in cancer treatment. Additionally, it sheds light on the inventive aspects of these complexes within biological systems. By highlighting advancements in bioorganometallic chemistry, the review offers insights and guidance for future developments in safer and more effective therapeutics.

Synthesis and design of Ag-Fe bimetallic nanoparticles as antimicrobial synergistic combination therapies against clinically relevant pathogens.

The inappropriate use of antibiotics and the inadequate control of infections have led to the emergence of drug-resistant strains. In recent years, metallo-pharmaceutics and metallic nanoparticles have been proposed as potential alternative antimicrobials due to their broad-spectrum antimicrobial properties. Moreover, recent findings have shown that combinations of transition metal compounds can exhibit synergistic antimicrobial properties. Therefore, the synthesis and design of bimetallic nanoparticles is a field worth exploring to harness the interactions between groups of metals and organic complex structures found in different microbial targets, towards the development of more efficient combinatorial antimicrobials composed of synergistic metals. In this study, we present a green synthesis of Ag-Fe bimetallic nanoparticles using an aqueous extract from the leaves of Gardenia jasminoides. The characterization of the nanoparticles demonstrated that the synthesis methodology produces homogenously distributed core-shell Ag-Fe structures with spherical shapes and average diameter sizes of 13 nm (± 6.3 nm). The Ag-Fe bimetallic nanoparticles showed magnetic and antimicrobial properties; the latter were evaluated against six different, clinically relevant multi-drug-resistant microbial strains. The Ag-Fe bimetallic nanoparticles exhibited an antimicrobial (bactericidal) synergistic effect between the two metals composing the bimetallic nanoparticles compared to the effects of the mono-metallic nanoparticles against yeast and both Gram-positive and Gram-negative multidrug-resistant bacteria. Our results provide insight towards the design of bimetallic nanoparticles, synthesized through green chemistry methodologies, to develop synergistic combinatorial antimicrobials with possible applications in both industrial processes and the treatment of infections caused by clinically relevant drug-resistant strains.

Antibacterial and Antibiofilm Activity of Biosynthesized Silver Nanoparticles Coated With Exopolysaccharides Obtained From Rhodotorula mucilaginosa.

Antibacterial resistance is one of the biggest threats to health and economy worldwide. In the present work, we evaluated the antibacterial and antibiofilm properties of silver nanoparticles produced by green synthesis with exopolysaccharides produced by Rhodotorula mucilaginosa UANL-001L, against pathogens of clinical importance. The extraction of exopolysaccharides produced by Rhodotorula mucilaginosa was performed according to a previously described method. Synthesis of the nanobiocomposite was performed by mixing silver nitrate, Acacia rigidula, and Rhodotorula mucilaginosa-produced exopolysaccharides. The newly synthesized nanobiocomposite was lyophilized and kept frozen for further analysis. The characterization of the nanobiocomposite was carried out by UV-visible spectroscopic, Fourier transform infrared analysis and the surface morphology was analyzed by Transmission Electron Microscopy. The antibacterial and antibiofilm activity was tested in 96-well plates for different concentrations of the nanobiocomposite against Escherichia. coli ATCC 11229, Staphylococcus aureus ATCC 6538, and Pseudomonas aeruginosa ATCC 27853. The Rhodotorula mucilaginosa- produced exopolysaccharides were useful in the silver nanoparticle synthesis and the resulting nanobiocomposite had antibacterial and antibiofilm activity against Gram-positive and Gram-negative bacteria at lower concentrations than previously reported. Due to these properties, the nanobiocomposite seems to be a promising biocide against pathogens of clinical relevance. In addition, the nanobiocomposite proved to be advantageous in the formulation of hybrid metal-polymer coatings for medical devices or industrial settings.

Antibacterial Activity of combinatorial treatments composed of transition-metal/antibiotics against Mycobacterium tuberculosis.

Notwithstanding evidence that tuberculosis (TB) is declining, one of the greatest concerns to public health is the emergence and spread of multi-drug resistant strains of Mycobacterium tuberculosis (MDR-TB). MDR-TB are defined as strains which are resistant to at least isoniazid (INH) and rifampicin, the two most potent TB drugs, and their increasing incidence is a serious concern. Recently, notable efforts have been spent on research to pursue novel treatments against MDR-TB, especially on synergistic drug combinations as they have the potential to improve TB treatment. Our research group has previously reported promising synergistic antimicrobial effects between transition-metal compounds and antibiotics in Gram-negative and Gram-positive bacteria. In this work, we evaluated antimycobacterial activity of transition-metals/antibiotics combinatorial treatments against first-line drug resistant strains of Mycobacterium tuberculosis. Our data showed that INH/AgNO3 combinatorial treatment had an additive effect (bactericidal activity) in an isoniazid-resistant clinical strain of Mycobacterium tuberculosis. Moreover, in vitro evaluation of cytotoxicity induced by both, the individual tratments of AgNO3 and INH and the combinatorial treatment of INH/AgNO3 in murine RAW 264.7 macrophages and human A549 lung cells; showed no toxic effects. Together, this data suggests that the INH/AgNO3 combinatorial treatment could be used in the development of new strategies to treat resistant strains of Mycobacterium tuberculosis.