Chemistry

14 pages, 3604 KB

Open AccessArticle

Sustained Release of Antibacterial Therapeutic Elements from Functionalized Mesoporous Silica-Coated Silver Nanoparticles for Bone Tissue Engineering

by Lehao Han, Yuhan Zhang, Nian Liu, Jiajia Jing, Yanni Zhang and Qiang Chen

Chemistry 2025, 7(5), 146; https://doi.org/10.3390/chemistry7050146 - 10 Sep 2025

Abstract

Applying therapeutic elements to prevent injury from potential infections is a promising avenue in the development of novel bone substitutes; however, achieving controllable delivery of therapeutic ions is crucial to realizing their expected functions. In this study, a Ag nanoparticle core wrapped in [...] Read more.

Applying therapeutic elements to prevent injury from potential infections is a promising avenue in the development of novel bone substitutes; however, achieving controllable delivery of therapeutic ions is crucial to realizing their expected functions. In this study, a Ag nanoparticle core wrapped in an MSN shell was successfully synthesized using a one-pot sol–gel process. Subsequently, the produced Ag@MSN was functionalized with amino and carboxylic groups. The experimental results indicated that these core–shell-structured Ag@MSN spheres had a uniform size of ~60 nm and a specific area of 904.6 m²/g. Their release profiles, influenced by different surface charges, were investigated, with the aim of achieving sustainable release of Ag ions. The concentration-dependent biological effects of Ag@MSNs, including their anti-infection properties and biocompatibility, were comprehensively characterized in vitro, considering their potential for use as bioactive bone substitutes. Functionalized mesoporous silica nanoparticles significantly enhanced the sustained release profile of silver ions, achieving a cumulative release efficiency greater than 50% within 24 h. These nanoparticles also demonstrated exceptional antibacterial efficacy, with an inhibition rate surpassing 98% at a concentration of 30 μg/mL, while concurrently maintaining cell viability above 88%, indicating high biocompatibility. We achieved our goal of effectively decreasing the burst release of Ag to satisfy the intrinsic need for long-term resistance to bacteria in bone substitutes and stimulate osteoblast proliferation. Full article

(This article belongs to the Section Chemistry at the Nanoscale)

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19 pages, 2580 KB

Open AccessArticle

Manganese(I) and Rhenium(I) Chelate Complexes with 2-Azabutadienes (RS)₂C=C(H)-N=CPh₂: Topological AIM Bonding Analysis and Molecular Structure of fac-MnBr(CO)₃[(ⁱPrS)₂C=C(H)-N=CPh₂]

by Marek M. Kubicki, Abderrahim Khatyr and Michael Knorr

Chemistry 2025, 7(5), 145; https://doi.org/10.3390/chemistry7050145 - 9 Sep 2025

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Abstract

The thioether-functionalized 2-azabutadiene (ⁱPrS)₂C=C(H)-N=CPh₂ L1 ligates to Mn(CO)₅Br to form the five-membered chelate compound fac-MnBr(CO)₃[(ⁱPrS)₂C=C(H)-N=CPh₂] MnPropBr, whose crystal structure has been determined from X-ray diffraction [...] Read more.

The thioether-functionalized 2-azabutadiene (ⁱPrS)₂C=C(H)-N=CPh₂ L1 ligates to Mn(CO)₅Br to form the five-membered chelate compound fac-MnBr(CO)₃[(ⁱPrS)₂C=C(H)-N=CPh₂] MnPropBr, whose crystal structure has been determined from X-ray diffraction data. In the crystal, different secondary intermolecular interactions, such as Br^…HC and π^…π, give rise to a supramolecular network. The electronic properties of the metal–ligand bonds in MnPropBr are similar to those of complex MnPhBr (with R = SPh instead of ⁱPrS); this also applies to a series of structurally analogous fac-ReX(CO)₃[(RS)₂C=C(H)-N=CPh₂] (X = Cl, Br and I; R = SⁱPr, SPh and S^tBu) rhenium complexes and are discussed on the basis of QT-AIM (Quantum Theory of Atoms in Molecules) calculations. New bond length/electron density relationships are proposed for the metal–halide bonds, including, for the first time, complexes of one given metal and all three corresponding halides. In order to obtain a set of coherent data, three manganese complexes that belong to the family fac-MnX(CO)₃[N∩N] (X = Cl, Br and I; N∩N is a chelating ligand with two coordinating N atoms) were included in this study. Full article

(This article belongs to the Section Physical Chemistry and Chemical Physics)

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15 pages, 2394 KB

Open AccessArticle

Nitrogen-Doped Biocarbon Derived from Alginate-Extraction Residues of Sargassum spp.: Towards Low-Cost Electrocatalysts for Alkaline ORR

by Aurora Caldera, Beatriz Escobar, Juan Briceño, José M. Baas-López, Romeli Barbosa and Jorge Uribe

Chemistry 2025, 7(5), 144; https://doi.org/10.3390/chemistry7050144 - 3 Sep 2025

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Abstract

Extraction processes of alginates from Sargassum spp. generate a substantial number of solid residues that are commonly discarded. This study explores the sustainable transformation of these residues into nitrogen-doped biocarbon through chemical activation with KOH and nitrogen doping using urea. XRD, FTIR, SEM-EDX, [...] Read more.

Extraction processes of alginates from Sargassum spp. generate a substantial number of solid residues that are commonly discarded. This study explores the sustainable transformation of these residues into nitrogen-doped biocarbon through chemical activation with KOH and nitrogen doping using urea. XRD, FTIR, SEM-EDX, Raman spectroscopy, BET surface area analysis, XPS, and CHNS elemental analysis were used to characterize the materials. The doped and activated biocarbon (BDA) demonstrated excellent physicochemical properties, including a specific surface area of 1790 m² g⁻¹ and a mesoporous structure. Electrochemical evaluation in alkaline media revealed a current density of −4.37 mA cm⁻², an onset potential of 0.922 E vs. RHE, and a half-wave potential of 0.775 E vs. RHE. Koutecky–Levich analysis indicated a two-electron reduction pathway. The superior performance was attributed to the synergistic effects of high surface area, nitrogen functionalities (pyridinic-N and pyrrolic-N), and enhanced accessibility of active sites. These results highlight the potential of waste-derived, nitrogen-doped biocarbon as a sustainable and low-cost alternative for ORR electrocatalysis in alkaline fuel cells. Full article

(This article belongs to the Section Catalysis)

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11 pages, 639 KB

Open AccessArticle

Biocatalytic Reduction of α,β-Unsaturated Double Bonds of Curcuminoid Derivatives by Exserohilum rostratum

by Jânison Nazareno Pastana, Victória Lopes Ribeiro, Mayra Suelen da Silva Pinheiro, José Edson de Sousa Siqueira, Luana Cardoso Oliveira, Heriberto Rodrigues Bitencourt, Taícia Pacheco Fill, Andrey Moacir do Rosario Marinho and Patrícia Santana Barbosa Marinho

Chemistry 2025, 7(5), 143; https://doi.org/10.3390/chemistry7050143 - 3 Sep 2025

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Abstract

Turmeric is a spice that has gained significant popularity in global cuisine. Beyond its culinary applications, it possesses significant medicinal properties, including antioxidant, anti-inflammatory, and antibacterial properties, which are attributed to its majority compound, curcumin. In this study, we synthesized three curcuminoid derivatives [...] Read more.

Turmeric is a spice that has gained significant popularity in global cuisine. Beyond its culinary applications, it possesses significant medicinal properties, including antioxidant, anti-inflammatory, and antibacterial properties, which are attributed to its majority compound, curcumin. In this study, we synthesized three curcuminoid derivatives via the Claisen–Schmidt method (1E,4E)-1-(2-methoxy-phenyl)-5-(3-methoxy-phenyl)-pent-1,4-dien-3-one (2a), (1E,4E)-1-(2-methoxy-phenyl)-5-(3,4,5-trimethoxy-phenyl)-pent-1,4-dien-3-one (2b), and (1E,4E)-5-phenyl-1-(2-methoxy-phenyl)-pent-1,4-dien-3-one (2c). The synthetic compounds were hydrogenated in the olefinic double bond (CH=CH) by biotransformation catalyzed by the fungus Exserohilum rostratum given (CH₂-CH₂) 3a, 3b, and 3c. All compounds were identified by NMR and MS. The compounds were evaluated for their antibacterial properties against Gram-positive and Gram-negative bacteria, with the results indicating good activity, highlighting that the bioreduction from 2a to 3a led to an improvement of up to eight times in the observed activity against S. typhimurium of 250 to 31.25 µg/mL. Additionally, compounds 2a, 2b, 3a, and 3b are not previously documented in the literature. Full article

(This article belongs to the Section Biological and Natural Products)

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11 pages, 1951 KB

Open AccessReview

Recent Advances in Materials for Uranium Extraction from Salt Lake Brine: A Review

by Panting Wang, Miao Lei, Junhang Huang, Yuanhao Li, Ye Li and Junpeng Guo

Chemistry 2025, 7(5), 142; https://doi.org/10.3390/chemistry7050142 - 3 Sep 2025

Viewed by 318

Abstract

With the rising importance of nuclear energy in the global energy landscape, the sustainable development of uranium resources has garnered increasing attention. Salt lake brine, as an unconventional uranium source, holds significant potential due to its relatively high uranium concentration and the co-occurrence [...] Read more.

With the rising importance of nuclear energy in the global energy landscape, the sustainable development of uranium resources has garnered increasing attention. Salt lake brine, as an unconventional uranium source, holds significant potential due to its relatively high uranium concentration and the co-occurrence of valuable elements such as lithium, boron, and potassium. However, the high salinity and complex ionic composition of brine environments pose considerable challenges for the efficient and selective extraction of uranium. In recent years, the rapid advancement of novel adsorbent materials has provided promising technological pathways for uranium extraction from salt lake brine. This review systematically summarizes recent progress in the application of inorganic and carbon-based materials, organic polymers with functional group modifications, and biomass-derived and green adsorbents in this field. The construction strategies, performance characteristics, and adsorption mechanisms of these materials are discussed in detail, with particular emphasis on their selectivity and stability under complex saline conditions. Furthermore, the application status and future prospects of emerging materials and techniques—such as photocatalysis and electrochemistry—are also explored. This review aims to offer theoretical insights and technical references to support the sustainable exploitation of uranium resources from salt lake brines. Full article

(This article belongs to the Section Green and Environmental Chemistry)

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Graphical abstract

18 pages, 556 KB

Open AccessReview

Pea-Derived Antioxidant Peptides: Applications, Bioactivities, and Mechanisms in Oxidative Stress Management

by Yiming Gan, Ni Xie and Deju Zhang

Chemistry 2025, 7(5), 141; https://doi.org/10.3390/chemistry7050141 - 2 Sep 2025

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Abstract

Chronic injuries and diseases related to oxidative stress are major global concerns as they impose a great medical burden and lead to serious public health issues. Antioxidant peptides derived from pea protein can serve as potent antioxidants and food additives, contributing to address [...] Read more.

Chronic injuries and diseases related to oxidative stress are major global concerns as they impose a great medical burden and lead to serious public health issues. Antioxidant peptides derived from pea protein can serve as potent antioxidants and food additives, contributing to address the challenges posed by oxidative stress. This review will focus on the antioxidant effects of pea peptides demonstrated in various in vitro chemical, cellular, and in vivo antioxidant models. Additionally, this review also summarizes the regulatory role of pea peptides on the Nrf2 (NF-E2-related factor 2)/Kelch-like ECH-associated protein 1 (Keap1) pathway, aiming to elucidate their antioxidant mechanisms. Our review found that pea peptides with smaller molecular weights (<1 kDa) obtained through enzymatic hydrolysis or fermentation and/or those containing amino acids such as Glu, Asp, Gly, Pro, and Leu tend to exhibit higher antioxidant activity. These pea peptides exert their antioxidant effects by scavenging free radicals, chelating pro-oxidative transition metals, reducing hydrogen peroxide, inactivating reactive oxygen species, enhancing the expression of antioxidant enzymes, and reducing the accumulation of lipid peroxides. Our study provides a theoretical foundation for the development of pea resources and the processing of pea-related functional foods. Full article

(This article belongs to the Topic Natural Bioactive Compounds as a Promising Approach to Mitigating Oxidative Stress)

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19 pages, 2209 KB

Open AccessArticle

Fundamental Vibrational Frequencies and Spectroscopic Constants for Additional Tautomers and Conformers of NH₂CHCO

by Natalia Inostroza-Pino, Megan McKissick, Valerio Lattanzi, Paola Caselli and Ryan C. Fortenberry

Chemistry 2025, 7(5), 140; https://doi.org/10.3390/chemistry7050140 - 29 Aug 2025

Viewed by 405

Abstract

The creation of larger prebiotic molecules in astronomical regions may require aminoketene (NH₂CHCO) as an intermediate, and the two conformers of this molecule exhibit infrared vibrational frequencies with intensities larger even than the antisymmetric stretch in CO₂. While the [...] Read more.

The creation of larger prebiotic molecules in astronomical regions may require aminoketene (NH₂CHCO) as an intermediate, and the two conformers of this molecule exhibit infrared vibrational frequencies with intensities larger even than the antisymmetric stretch in CO₂. While the present quantum chemically computed frequencies of these fundamentals of ∼4.7 μm are in the same spectroscopic region as features from functionalized polycyclic aromatic hydrocarbons, they provide clear markers for what James Webb Space Telescope IR observations may be able to distinguish. Additionally, the IR and radioastronomical spectral characterization of two additional 2-iminoacetaldehyde, HN=CHC(=O)H, conformers are also computed as are the same data for a new carbene isomer (NH₂CC(=O)H). All conformers of aminoketene and 2-iminoacetaldehyde exhibit dipole moments of more than 2.0 D, if not greater than 4.0 D, implying that they would be notable targets for radioastronomical searches. Additionally, the 2-iminoacetaldehyde conformers have a notable mid-IR C=O stretch around 1735 cm⁻¹ slightly below the same fundamental in formaldehyde. This quantum chemical study is providing a more complete set of reference data for the potential observation of these tautomers and conformers of NH₂CHCO in the laboratory or even in space. Full article

(This article belongs to the Section Astrochemistry)

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24 pages, 3364 KB

Open AccessArticle

In Silico Analysis of Curcumin and Its Analogs MS13 and MS17 Against HSF1 and HSP Family Proteins

by Kha Wai Hon, Shafi Ullah Khan, Thet Thet Htar and Rakesh Naidu

Chemistry 2025, 7(5), 139; https://doi.org/10.3390/chemistry7050139 - 28 Aug 2025

Viewed by 367

Abstract

Heat shock proteins (HSPs), a family of proteins including HSP27, HSP40, HSP60, HSP70, and HSP90, play critical roles in cellular processes and are often dysregulated in cancer. Heat Shock Factor 1 (HSF1) protein, the master regulator of HSP expression, is also a promising [...] Read more.

Heat shock proteins (HSPs), a family of proteins including HSP27, HSP40, HSP60, HSP70, and HSP90, play critical roles in cellular processes and are often dysregulated in cancer. Heat Shock Factor 1 (HSF1) protein, the master regulator of HSP expression, is also a promising target for cancer therapy due to its involvement in tumorigenesis. This study is the first to investigate the potential of two novel curcumin analogs, MS13 (1,2-bis(4-hydroxy-3-methoxyphenyl)-1,4-pentadiene-3-one) and MS17 (1,5-bis(2-hydroxyphenyl)-1,4-pentadiene-3-one), as modulators of these key targets. Employing molecular docking and molecular dynamics (MD) simulations, we investigated the interactions of MS13 and MS17 with HSF1 and the panel of HSPs. Both compounds demonstrated strong binding affinity for all the proteins, particularly for HSP70, exhibiting greater affinity compared to curcumin. Molecular docking revealed specific binding sites for both compounds on each target protein, which were further investigated using MD simulations. MS17 generally formed more stable complexes with HSP27, HSP40, HSP60, and HSP70, suggesting it might be a more potent modulator of these specific proteins. In contrast, MS13 displayed greater stability when bound to HSF1 and HSP90. These different variations could be attributed to variations in the chemical structures of MS13 and MS17, leading to distinct interactions with each protein’s binding site. MS13 and MS17 exhibit more advantageous ADMET profiles compared to curcumin, particularly in their predicted Blood–Brain Barrier (BBB) permeability and MS17’s superior passive membrane permeability and absorption. These findings highlight the potential of both MS13 and MS17 as promising leads for developing HSP modulators for cancer treatment. Full article

(This article belongs to the Section Biological and Natural Products)

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28 pages, 6057 KB

Open AccessReview

Hydrogen Production from Methane Cracking by Molten Catalysts: A Review and New Perspectives

by Xiaoyang Yu, Qian Xu, Chuncheng Zhu, Hongwei Cheng, Xingli Zou, Xionggang Lu and Chenteng Sun

Chemistry 2025, 7(5), 138; https://doi.org/10.3390/chemistry7050138 - 26 Aug 2025

Viewed by 805

Abstract

A molten-metal catalyst exhibits strong resistance to carbon encapsulation and deactivation, due to its unique physical and chemical properties, demonstrating excellent catalytic activity and stability. This paper overviews recent developments in molten-metal catalysts for methane cracking and hydrogen production. It thoroughly examines the [...] Read more.

A molten-metal catalyst exhibits strong resistance to carbon encapsulation and deactivation, due to its unique physical and chemical properties, demonstrating excellent catalytic activity and stability. This paper overviews recent developments in molten-metal catalysts for methane cracking and hydrogen production. It thoroughly examines the stability of reactors, carbon products, and catalysts for each molten-metal system. The kinetics and mechanism of the catalysts in each system have also been analyzed. Finally, for future development, several recommendations for hydrogen production via methane cracking have been proposed, addressing the following research challenges: (1) gaining a deeper understanding of the active sites and methane conversion process, which can provide crucial guidance for designing high-performance catalysts; (2) fostering the advancement of new reaction interfaces; and (3) attempting to develop a low-eutectic-point molten salt system for chemical vapor deposition reactions. The molten-metal catalyst exhibits strong resistance to carbon encapsulation and deactivation due to its unique physical and chemical properties, demonstrating excellent catalytic activity and stability. Full article

(This article belongs to the Section Catalysis)

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31 pages, 3851 KB

Open AccessReview

The Role of Ion-Doped Hydroxyapatite in Drug Delivery, Tissue Engineering, Wound Healing, Implants, and Imaging

by Sorur Jadbabaee, Farnaz Mohebi Far, Javad Esmaeili and Majid Kolahdoozan

Chemistry 2025, 7(5), 137; https://doi.org/10.3390/chemistry7050137 - 26 Aug 2025

Viewed by 736

Abstract

The ion doping of hydroxyapatite (HA) has gained appeal as a chemical method of improving and adding new characteristics to materials used in biomedical engineering. Dimension, morphology, porosity, surface charge, topology, composition, and other material characteristics make doped HA more suitable for specific [...] Read more.

The ion doping of hydroxyapatite (HA) has gained appeal as a chemical method of improving and adding new characteristics to materials used in biomedical engineering. Dimension, morphology, porosity, surface charge, topology, composition, and other material characteristics make doped HA more suitable for specific biomedical applications. The main aim of this review study was to highlight the role of iHA (iHA) in developing drug delivery systems, tissue engineering, implant coating, wound healing, and multimodal imaging. To the best of our knowledge, depending on the dopant, iHA can have inherent distinct mechanical, physicochemical, and biological properties that make it eligible for biomedical application. More importantly, some ions make iHA a potent antibacterial agent and drug carrier for wound healing (e.g., silver, copper, zinc), have tissue engineering capabilities, improved proangiogenic and osteoconductive properties (e.g., strontium, cobalt, nickel), drug loading capacity (e.g., magnesium, ferric, strontium), metallic implant coating properties (e.g., manganese, silver, copper), and multimodal imaging potential (e.g., terbium, ytterbium, cerium). The concentration of ions and the number of dopants played a vital role in developing new approaches based on iHA. In conclusion, iHA, compared to HA, could show better improvements in biomedical applications. Full article

(This article belongs to the Topic Advanced Biomaterials: Processing and Applications)

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17 pages, 4213 KB

Open AccessArticle

Physical Mechanisms of Linear and Nonlinear Optical Responses in Ferrocene-Embedded Cycloparaphenylenes

by Gang Zhang, Qianqian Wang, Yi Zou, Ying Jin and Jingang Wang

Chemistry 2025, 7(5), 136; https://doi.org/10.3390/chemistry7050136 - 25 Aug 2025

Viewed by 415

Abstract

This study employs molecular orbital (MO) analysis, density of states (DOS) analysis, and advanced techniques such as charge density difference (CDD), transition density matrix (TDM), transition electric dipole moment density (TEDM), and transition magnetic dipole moment density (TMDM) to systematically investigate the electronic [...] Read more.

This study employs molecular orbital (MO) analysis, density of states (DOS) analysis, and advanced techniques such as charge density difference (CDD), transition density matrix (TDM), transition electric dipole moment density (TEDM), and transition magnetic dipole moment density (TMDM) to systematically investigate the electronic structure characteristics of Fc-[8]CPP and Fc-[11]CPP. Using density functional theory (DFT) and time-dependent DFT (TD-DFT), the π-electron delocalization properties and optical behaviors of these molecules were analyzed. Furthermore, their responses to external electromagnetic fields were explored through electronic circular dichroism (ECD) and Raman spectroscopy, comparing chiral optical responses and electron–vibration coupling effects to elucidate their photophysical properties. The results reveal that the HOMO-LUMO energy gaps of Fc-[8]CPP and Fc-[11]CPP are 5.81 eV and 5.95 eV, respectively, with a slight increase as ring size grows; Fc-[8]CPP exhibits a stronger chiral response, while Fc-[11]CPP shows reduced chirality due to enhanced symmetry. Finally, TD-DFT calculations demonstrate that their optical absorption is dominated by localized excitations with partial charge transfer contributions. These findings provide a theoretical foundation for designing conjugated macrocyclic materials with superior optoelectronic performance. Full article

(This article belongs to the Section Theoretical and Computational Chemistry)

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