We have synthesized calcium carbonate nanoparticles (Ca-NPs) in the cavity of a cage-shaped protein, apoferritin, by regulating the electrostatic potential of the molecule. The electrostatic potential in the cavity was controlled by pH changes resulting from changes in the dissolved carbon dioxide (CO(2)) concentration in the reaction solution. Recombinant L-apoferritin was mixed with a suspension of calcium carbonate (CaCO(3)), and the mixture was pressurized with gaseous CO(2) at 2 MPa. The pH of the solution decreased from 9.3 to 4.4; the CaCO(3) dissolved during pressurization, and then precipitated after the pressure was reduced to ambient. After repeating the pressurization/depressurization process three times, about 70% of the apoferritin molecules were found to contain nanoparticles with an average diameter of 5.8 ± 1.2 nm in their cavity. Energy-dispersive X-ray spectroscopy and electron diffraction analysis showed that the nanoparticles were calcite, one of the most stable crystal forms of CaCO(3). Electrostatic potential calculations revealed a transition in the potential in the apoferritin cavity, from negative to positive, below pH 4.4. The electrostatic potential change because of the change in pH was crucial for ion accumulation. Since the Ca-NPs synthesized by this method were coated with a protein shell, the particles were stably dispersed in solution and did not form aggregates. These Ca-NPs may be useful for medical applications such as synthetic bone scaffolds.
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http://dx.doi.org/10.1021/ic200117x | DOI Listing |
Int J Biol Macromol
January 2025
State Key Laboratory of Tea Plant Biology and Utilization, Joint Research Center for Food Nutrition and Health of IHM and Anhui Provincial Key Laboratory of Food Safety Monitoring and Quality Control, Anhui Agricultural University, Hefei 230036, PR China; College of Food and Nutrition, Anhui Agricultural University, Hefei 230036, PR China. Electronic address:
To mitigate the risk associated with water-soluble fluoride in tea and to have less influence on the contents of tea infusion, a highly selective lanthanum modified silk fibroin (SF) and polyvinyl alcohol (PVA) composite film (SF/PVA-La) was prepared to remove fluoride from brick tea infusion. Notably, SF/PVA-La could remove about 48 % of the fluoride from in brick tea infusion within 30 min. Importantly, the reduction in total tea polyphenols in brick tea did not exceed 10 %, and the reduction in caffeine was only 0.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Guangdong Key Laboratory of Intelligent Food Manufacturing, Foshan University, Foshan, Guangdong 528225, China; Department of Food Science, Foshan University, Foshan, Guangdong 528000, China. Electronic address:
The toughening coix seed oil (CSO) high internal phase Pickering emulsion (CSO-HIPES) and gel (CSO-HIPESG) comprised of carrageenan (CR)/super-deamidated-gluten (SDG) micro-particles (CR/SDG) were investigated via acid-heat induction. Results showed polysaccharide natural deep eutectic solvent (P-NADES) by citric acid-glucose-carrageenan ((CGCR), molar ratio at 1:1:0.035) was the crucial for the preparation of SDG (deamidation degree, 99.
View Article and Find Full Text PDFNeuroscience
January 2025
Chemistry Department (emeritus), Willamette University, Salem, OR, USA.
In two recent papers (Curr Trends Neurol 17: 83-98, 2023; J Neurophysiol 124: 1029-1044, 2020), James Lee has argued that his Transmembrane Electrostatically-Localized Cations (TELC) hypothesis offers a model of neuron transmembrane potentials that is superior to Hodgkin-Huxley classic cable theory and the Goldman-Hodgkin-Katz (GHK) equation. Here we examine critically the arguments in these papers, finding key weaknesses and fallacies. We also examine closely the literature cited by Lee, and find (i) strong support for the GHK equation; (ii) published measurements that contradict TELC predictions; and (iii) no convincing support for the TELC hypothesis.
View Article and Find Full Text PDFChemosphere
January 2025
Center for Green Chemistry and Environmental Biotechnology, Ghent University Global Campus, 119-5 Songdomunhwa-Ro, Yeonsu-Gu, Incheon, 406-840 South Korea; Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, 653 Coupure Links, Ghent, B-9000, Belgium. Electronic address:
The photocatalytic degradation of rhodamine B (RhB), a cationic dye, and bromocresol green (BCG), an anionic dye, was investigated using oxygen vacancy-enriched ZnO as the catalyst. These dyes were selected due to their differing charges and molecular structures, allowing for a deeper exploration of how these characteristics impact the degradation process. The catalyst was prepared by reducing ZnO with 10% H/Ar gas at 500°C, and the introduction of oxygen vacancies was confirmed using various characterization techniques.
View Article and Find Full Text PDFBiomaterials
December 2024
Institute of Molecular Virology, Ulm University Medical Center, Ulm, 89081, Germany. Electronic address:
Retroviral gene transfer is the preferred method for stable, long-term integration of genetic material into cellular genomes, commonly used to generate chimeric antigen receptor (CAR)-T cells designed to target tumor antigens. However, the efficiency of retroviral gene transfer is often limited by low transduction rates due to low vector titers and electrostatic repulsion between viral particles and cellular membranes. To overcome these limitations, peptide nanofibrils (PNFs) can be applied as transduction enhancers.
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