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Angel S, Braun M, Alkan B, Landers J, Salamon S, Wende H, Andronescu C, Schulz C, Wiggers H. Spray-Flame Synthesis of LaFe xCo 1-xO 3 ( x = 0.2, 0.3) Perovskite Nanoparticles for Oxygen Evolution Reaction in Water Splitting: Effect of Precursor Chemistry (Acetates and Nitrates). J Phys Chem A 2023; 127:2564-2576. [PMID: 36896577 DOI: 10.1021/acs.jpca.2c06601] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
The product properties of mixed oxide nanoparticles generated via spray-flame synthesis depend on an intricate interplay of solvent and precursor chemistries in the processed solution. The effect of two different sets of metal precursors, acetates and nitrates, dissolved in a mixture of ethanol (35 Vol.%) and 2-ethylhexanoic acid (2-EHA, 65 Vol.%) was investigated for the synthesis of LaFexCo1-xO3 (x = 0.2, 0.3) perovskites. Regardless of the set of precursors, similar particle-size distributions (dp = 8-11 nm) were obtained and a few particles with sizes above 20 nm were identified with transmission electron microscopy (TEM) measurements. Using acetates as precursors, inhomogeneous La, Fe, and Co elemental distributions were obtained for all particle sizes according to energy dispersive X-ray (EDX) mappings, connected to the formation of multiple secondary phases such as oxygen-deficient La3(FexCo1-x)3O8 brownmillerite or La4(FexCo1-x)3O10 Ruddlesden-Popper (RP) structures besides the main trigonal perovskite phase. For samples synthesized from nitrates, inhomogeneous elemental distributions were observed for large particles only where La and Fe enrichment occurred in combination with the formation of a secondary La2(FexCo1-x)O4 RP phase. Such variations can be attributed to reactions in the solution prior to injection in the flame as well as precursor-dependent variations in in-flame reactions. Therefore, the precursor solutions were analyzed by temperature-dependent attenuated total reflection Fourier-transform infrared (ATR-FTIR) measurements. The acetate-based precursor solutions indicated the partial conversion of, mainly La and Fe, acetates to metal 2-ethylhexanoates. In the nitrate-based solutions, esterification of ethanol and 2-EHA played the most important role. The synthesized nanoparticle samples were characterized by BET (Brunauer, Emmett, Teller), FTIR, Mössbauer, and X-ray photoelectron spectroscopy (XPS). All samples were tested as oxygen evolution reaction (OER) catalysts, and similar electrocatalytic activities were recorded when evaluating the potential required to reach 10 mA/cm2 current density (∼1.61 V vs reversible hydrogen electrode (RHE)).
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Affiliation(s)
- Steven Angel
- EMPI, Institute for Energy and Materials Processes - Reactive Fluids, University of Duisburg-Essen, 47048 Duisburg, Germany
| | - Michael Braun
- Chemical Technology III, University of Duisburg-Essen, 47048 Duisburg, Germany
| | - Baris Alkan
- Fritz-Haber-Institut der Max-Planck Gesellschaft, Departments of Physical Chemistry and Inorganic Chemistry, Faradayweg 4-6, 14195 Berlin, Germany
| | - Joachim Landers
- Experimental Physics, Faculty of Physics, University of Duisburg-Essen, 47048 Duisburg, Germany
| | - Soma Salamon
- Experimental Physics, Faculty of Physics, University of Duisburg-Essen, 47048 Duisburg, Germany
| | - Heiko Wende
- Experimental Physics, Faculty of Physics, University of Duisburg-Essen, 47048 Duisburg, Germany
- CENIDE, Center for Nanointegration, University of Duisburg-Essen, 47048 Duisburg, Germany
| | - Corina Andronescu
- Chemical Technology III, University of Duisburg-Essen, 47048 Duisburg, Germany
- CENIDE, Center for Nanointegration, University of Duisburg-Essen, 47048 Duisburg, Germany
| | - Christof Schulz
- EMPI, Institute for Energy and Materials Processes - Reactive Fluids, University of Duisburg-Essen, 47048 Duisburg, Germany
- CENIDE, Center for Nanointegration, University of Duisburg-Essen, 47048 Duisburg, Germany
| | - Hartmut Wiggers
- EMPI, Institute for Energy and Materials Processes - Reactive Fluids, University of Duisburg-Essen, 47048 Duisburg, Germany
- CENIDE, Center for Nanointegration, University of Duisburg-Essen, 47048 Duisburg, Germany
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Synthesis, Drug Release, and Antibacterial Properties of Novel Dendritic CHX-SrCl 2 and CHX-ZnCl 2 Particles. Pharmaceutics 2021; 13:pharmaceutics13111799. [PMID: 34834214 PMCID: PMC8625704 DOI: 10.3390/pharmaceutics13111799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/15/2021] [Accepted: 10/23/2021] [Indexed: 12/29/2022] Open
Abstract
This work demonstrated for the first time the synthesis of novel chlorhexidine particles containing strontium and zinc, to provide an effective, affordable, and safe intervention in the treatment of recurrent infections found in Medicine and Dentistry. The CHX-SrCl2 and CHX-ZnCl2 particles were synthesized by co-precipitation of chlorhexidine diacetate (CHXD) and zinc chloride or strontium chloride, where particle size was manipulated by controlling processing time and temperature. The CHX-ZnCl2 and CHX-SrCl2 particles were characterized using SEM, FTIR, and XRD. UV-Vis using artificial saliva (pH 4 and pH 7) was used to measure the drug release and ICP-OES ion release. The antibacterial properties were examined against P. gingivalis, A. actinomycetemcomitans, and F. nucleatum subsp. Polymorphum, and cytotoxicity was evaluated using mouse fibroblast L929 cells. The novel particles were as safe as commercial CHXD, with antibacterial activity against a range of oral pathogens. UV-Vis results run in artificial saliva (pH 4 and pH 7) indicated a higher release rate in acidic rather than neutral conditions. The CHX-ZnCl2 particles provided the functionality of a smart Zinc and CHX release, with respect to environmental pH, allowing responsive antibacterial applications in the field of medicine and dentistry.
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Kathuria D, Raul AD, Wanjari P, Bharatam PV. Biguanides: Species with versatile therapeutic applications. Eur J Med Chem 2021; 219:113378. [PMID: 33857729 DOI: 10.1016/j.ejmech.2021.113378] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 03/04/2021] [Accepted: 03/08/2021] [Indexed: 12/18/2022]
Abstract
Biguanides are compounds in which two guanidine moieties are fused to form a highly conjugated system. Biguanides are highly basic and hence they are available as salts mostly hydrochloride salts, these cationic species have been found to exhibit many therapeutic properties. This review covers the research and development carried out on biguanides and accounts the various therapeutic applications of drugs containing biguanide group-such as antimalarial, antidiabetic, antiviral, anticancer, antibacterial, antifungal, anti-tubercular, antifilarial, anti-HIV, as well as other biological activities. The aim of this review is to compile all the medicinal chemistry applications of this class of compounds so as to pave way for the accelerated efforts in finding the drug action mechanisms associated with this class of compounds. Importance has been given to the organic chemistry of these biguanide derivatives also.
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Affiliation(s)
- Deepika Kathuria
- University Center for Research and Development, Chandigarh University, Gharuan, Punjab, 140413, India
| | - Akshay D Raul
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S. Nagar, 160 062, Punjab, India
| | - Pravin Wanjari
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S. Nagar, 160 062, Punjab, India
| | - Prasad V Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S. Nagar, 160 062, Punjab, India.
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Kowalczuk D, Gładysz A, Pitucha M, Kamiński DM, Barańska A, Drop B. Spectroscopic Study of the Molecular Structure of the New Hybrid with a Potential Two-Way Antibacterial Effect. Molecules 2021; 26:molecules26051442. [PMID: 33799954 PMCID: PMC7961860 DOI: 10.3390/molecules26051442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/27/2021] [Accepted: 03/01/2021] [Indexed: 11/16/2022] Open
Abstract
Bacterial strains become resistant to almost all classes of antibiotics, which makes it necessary to look for new substitutes. The non-absorbable ciprofloxacin–biguanide bismuth complex, used locally, may be a good alternative to a conventional therapy. The purpose of this study was to study the structure of the proposed ciprofloxacin (CIP) -bismuth(III)—chlorhexidine (CHX) composite (CIP-Bi-CHX). The spectroscopic techniques such as UV-VIS (ultraviolet-visible) spectroscopy, FTIR (Fourier-transform infrared) spectroscopy and NMR (Nuclear Magnetic Resonance) spectroscopy were used for structure characterization of the hybrid compound. The performed analysis confirmed the presence of the two active components—CIP and CHX and revealed the possible coordination sites of the ligands with bismuth ion in the metallo-organic structure. Spectroscopic study showed that the complexation between Bi(III) and CIP occurs through the carboxylate and ketone groups of the quinolone ring, while CHX combines with the central ion via the biguanide moieties.
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Affiliation(s)
- Dorota Kowalczuk
- Department of Medicinal Chemistry, Faculty of Pharmacy, Medical University, Jaczewskiego 4, 20-090 Lublin, Poland;
- Correspondence: ; Tel.: +48-81-448-7388
| | - Agata Gładysz
- Department of Medicinal Chemistry, Faculty of Pharmacy, Medical University, Jaczewskiego 4, 20-090 Lublin, Poland;
| | - Monika Pitucha
- Independent Radiopharmacy Unit, Faculty of Pharmacy, Medical University, Chodzki 4A, 20-093 Lublin, Poland;
| | - Daniel M. Kamiński
- Department of Chemistry, University of Life Sciences in Lublin, Akademicka 15, 20-950 Lublin, Poland;
| | - Agnieszka Barańska
- Department of Informatics and Medical Statistics, Medical University, Jaczewskiego 4, 20-090 Lublin, Poland; (A.B.); (B.D.)
| | - Bartłomiej Drop
- Department of Informatics and Medical Statistics, Medical University, Jaczewskiego 4, 20-090 Lublin, Poland; (A.B.); (B.D.)
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Dubovoy V, Desai P, Hao Z, Cheng CY, Verma G, Wojtas L, Brinzari TV, Boyd JM, Ma S, Asefa T, Pan L. Synthesis, Characterization, and Antimicrobial Investigation of a Novel Chlorhexidine Cyclamate Complex. CRYSTAL GROWTH & DESIGN 2020; 20:4991-4999. [PMID: 34054352 PMCID: PMC8159181 DOI: 10.1021/acs.cgd.0c00107] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The synthesis, crystal structure, and antimicrobial efficacy are reported for a novel material comprising a 1:2 ratio of chlorhexidine (CHX) to N-cyclohexylsulfamate (i.e., artificial sweetener known as cyclamate). The chemical structure is unambiguously identified by incorporating a combination of single-crystal X-ray diffraction (SC-XRD), electrospray ionization mass spectrometry (ESI-MS), 1H nuclear magnetic resonance (NMR) spectroscopy, correlation spectroscopy (COSY), and attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR). The new material: 1) is amongst only several reported structures identified to date incorporating the vital chlorhexidine antimicrobial drug; 2) exhibits broad spectrum antimicrobial activity at concentrations less than 15 μg/mL; and 3) provides a unique delivery method for the essential active pharmaceutical ingredient (API). Furthermore, substitution of inactive gluconate with bioactive cyclamate counterion potentially provides the additional benefit of improving the taste profile of chlorhexidine.
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Affiliation(s)
- Viktor Dubovoy
- Colgate-Palmolive Company, 909 River Road, Piscataway, New Jersey 08854, United States
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 610 Taylor Road, Piscataway, New Jersey 08854, United States
| | - Primit Desai
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, 76 Lipman Drive, New Brunswick, New Jersey 08901, United States
| | - Zhigang Hao
- Colgate-Palmolive Company, 909 River Road, Piscataway, New Jersey 08854, United States
| | - Chi-yuan Cheng
- Colgate-Palmolive Company, 909 River Road, Piscataway, New Jersey 08854, United States
| | - Gaurav Verma
- Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida 33620, United States
| | - Lukasz Wojtas
- Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida 33620, United States
| | - Tatiana V. Brinzari
- Colgate-Palmolive Company, 909 River Road, Piscataway, New Jersey 08854, United States
| | - Jeffrey M. Boyd
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, 76 Lipman Drive, New Brunswick, New Jersey 08901, United States
| | - Shengqian Ma
- Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida 33620, United States
| | - Tewodros Asefa
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 610 Taylor Road, Piscataway, New Jersey 08854, United States
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, New Jersey 08854, United States
| | - Long Pan
- Colgate-Palmolive Company, 909 River Road, Piscataway, New Jersey 08854, United States
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Luo D, Hasan MS, Shahid S, Khlebtsov BN, Cattell MJ, Sukhorukov GB. Gold Nanorod Mediated Chlorhexidine Microparticle Formation and Near-Infrared Light Induced Release. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:7982-7993. [PMID: 28707889 DOI: 10.1021/acs.langmuir.7b01656] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Gold nanorods (GNR) are good light harvesting species for elaboration of near-infrared (NIR) responsive drug delivery systems. Herein, chlorhexidine microparticles are grown directly on the surface of gold nanorods and then stabilized with polyelectrolyte multilayer encapsulation, producing novel composite drug-GNR particles with high drug loading and NIR light sensitivity. Crystallization of chlorhexidine is caused by the ionic strength of the chloride solution that has been demonstrated via formation of a homogeneous porous spherical structure at 0.33 M CaCl2. By introducing GNRs into the CaCl2 solution, the nucleation of chlorhexidine molecules and size of produced spheres are affected, since GNRs act as sites for chlorhexidine nucleation. Similarly, when GNRs are replaced by chlorhexidine seeds (5.2 ± 1.7 μm), a core-shell crystal structure is observed. The encapsulated GNR/chlorhexidine composites are responsive to NIR light (840 nm) that increases the temperature at the chlorhexidine crystals, followed by microparticle dissolution and rupture of capsules which is illustrated with confocal microscopy and SEM. Furthermore, a stepwise burst release of chlorhexidine can be induced by multiple cycles of NIR light exposure. The GNR/chlorhexidine composites show good biocompatibility and antimicrobial activity. The proposed method of antibacterial drug release may therefore indicate that this NIR responsive chlorhexidine composite may be useful for future clinical applications.
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Affiliation(s)
- Dong Luo
- School of Engineering and Materials Science, Queen Mary University of London , London E1 4NS, United Kingdom
| | - Md Samiul Hasan
- Barts and The London School of Medicine and Dentistry, Queen Mary University of London , London E1 2AD, United Kingdom
| | - Saroash Shahid
- Barts and The London School of Medicine and Dentistry, Queen Mary University of London , London E1 2AD, United Kingdom
| | - Boris N Khlebtsov
- Saratov State University, Astrakhanskaya Street 83, Saratov 410012, Russia
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences , 13 Prospekt Entuziastov, Saratov 410049, Russia
| | - Michael J Cattell
- Barts and The London School of Medicine and Dentistry, Queen Mary University of London , London E1 2AD, United Kingdom
| | - Gleb B Sukhorukov
- School of Engineering and Materials Science, Queen Mary University of London , London E1 4NS, United Kingdom
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Luo D, Shahid S, Wilson RM, Cattell MJ, Sukhorukov GB. Novel Formulation of Chlorhexidine Spheres and Sustained Release with Multilayered Encapsulation. ACS APPLIED MATERIALS & INTERFACES 2016; 8:12652-12660. [PMID: 27176115 DOI: 10.1021/acsami.6b02997] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This work demonstrates the synthesis of new chlorhexidine polymorphs with controlled morphology and symmetry, which were used as a template for layer-by-layer (LbL) encapsulation. LbL self-assembly of oppositely charged polyelectrolytes onto the drug surface was used in the current work, as an efficient method to produce a carrier with high drug content, improved drug solubility and sustained release. Coprecipitation of the chlorhexidine polymorphs was performed using chlorhexidine diacetate and calcium chloride solutions. Porous interconnected chlorhexidine spheres were produced by tuning the concentration of calcium chloride. The size of these drug colloids could be further controlled from 5.6 μm to over 20 μm (diameter) by adjusting the coprecipitation temperature. The chlorhexidine content in the spheres was determined to be as high as 90%. These particles were further stabilized by depositing 3.5 bilayers of poly(allylamine hydrochloride) (PAH) and polystyrenesulfonate (PSS) on the surface. In vitro release kinetics of chlorhexidine capsules showed that the multilayer shells could prolong the release, which was further demonstrated by characterizing the remaining chlorhexidine capsules with SEM and confocal microscopy. The new chlorhexidine polymorph and LbL coating has created novel chlorhexidine formulations. Further modification to the chlorhexidine polymorph structure is possible to achieve both sustained and stimuli responsive release, which will enhance its clinical performance in medicine and dentistry.
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Affiliation(s)
- Dong Luo
- School of Engineering and Materials Science, Queen Mary University of London , London E1 4NS, United Kingdom
| | - Saroash Shahid
- Barts and The London School of Medicine and Dentistry, Queen Mary University of London , London E1 2AD, United Kingdom
| | - Rory M Wilson
- School of Engineering and Materials Science, Queen Mary University of London , London E1 4NS, United Kingdom
| | - Michael J Cattell
- Barts and The London School of Medicine and Dentistry, Queen Mary University of London , London E1 2AD, United Kingdom
| | - Gleb B Sukhorukov
- School of Engineering and Materials Science, Queen Mary University of London , London E1 4NS, United Kingdom
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