The magnetic characteristics of a system of triply charged gadolinium ions Gd chelated with carboxyls on the surface of detonation nanodiamond (DND) particles have been studied. Gd ions demonstrate almost perfect spin (S = 7/2) paramagnetism with negligible antiferromagnetic interaction between spins (Weiss temperature about -0.35 K) for a wide range of concentrations up to ~18 ions per 5 nm particle. The study of the concentration dependence of the electron paramagnetic resonance signal for DND intrinsic defects with spin ½ ( = 2.0027) shows that Gd ions are located on average at a distance of no more than 1.4 nm from shallow subsurface defects with spin /. At the same time, they are located (according to density functional theory calculations) at a distance of about or at least 0.28 nm from the particle surface. Magnetic studies also confirm the isolated nature of the gadolinium chelate complexes on the surface of DND particles. DND particles turn out to be an optimal carrier for high-spin ions (gadolinium) in a highly concentrated isolated state. This property makes DND-Gd particles a candidate for the role of a contrast agent for magnetic resonance imaging.
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http://dx.doi.org/10.3390/nano13131995 | DOI Listing |
Eur J Pharm Sci
January 2025
Department of Pharmaceutical Technology and Biopharmacy, Institute of Pharmaceutical Sciences, University of Graz, Universitätsplatz 1, 8010, Graz, Austria. Electronic address:
Cationic nanostructured lipid carriers (cNLCs) represent promising non-viral carriers for nucleic acids, such as miRNAs, forming stable self-assembled miRNA complexes due to electrostatic interactions. Prepared by high-pressure homogenization, cNLC formulations, both with and without Nile Red dye demonstrated stable particle sizes in the range of 100-120 nm and positive surface charges (>30 mV), which are necessary for effective cellular uptake. The miRNA complexes formed at mass ratios of 1:2.
View Article and Find Full Text PDFNanomaterials (Basel)
March 2024
Institute of Physics of the Czech Academy of Sciences, Cukrovarnická 10, 162 00 Prague, Czech Republic.
The modification of nanodiamond (ND) surfaces has significant applications in sensing devices, drug delivery, bioimaging, and tissue engineering. Precise control of the diamond phase composition and bond configurations during ND processing and surface finalization is crucial. In this study, we conducted a comparative analysis of the graphitization process in various types of hydrogenated NDs, considering differences in ND size and quality.
View Article and Find Full Text PDFMaterials (Basel)
September 2023
Institute of Mineralogy, Geochemistry and Crystalchemistry of Rare Elements, Moscow 121357, Russia.
Aqueous suspensions (colloids) containing detonation nano-diamond (DND) feature in most applications of DND and are an indispensable stage of its production; therefore, the interaction of DND with water is actively studied. However, insufficient attention has been paid to the unique physico-chemical and biological properties of transparent colloids with DND content (≤0.1%), which are the subject of this review.
View Article and Find Full Text PDFACS Omega
July 2023
Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma "Tor Vergata" and Consorzio INSTM RU "Roma Tor Vergata", Via della Ricerca Scientifica 1, Rome 00133, Italy.
We present an experimental study on the etching of detonation nanodiamond (DND) seeds during typical microwave chemical vapor deposition (MWCVD) conditions leading to ultra-thin diamond film formation, which is fundamental for many technological applications. The temporal evolution of the surface density of seeds on the Si(100) substrate has been assessed by scanning electron microscopy (SEM). The resulting kinetics have been explained in the framework of a model based on the effect of the particle size, according to the Young-Laplace equation, on both chemical potential of carbon atoms in DND and activation energy of the reaction with atomic hydrogen.
View Article and Find Full Text PDFNanomaterials (Basel)
July 2023
Department of Chemical Science and Technology, Hosei University, Tokyo 184-8584, Japan.
The magnetic characteristics of a system of triply charged gadolinium ions Gd chelated with carboxyls on the surface of detonation nanodiamond (DND) particles have been studied. Gd ions demonstrate almost perfect spin (S = 7/2) paramagnetism with negligible antiferromagnetic interaction between spins (Weiss temperature about -0.35 K) for a wide range of concentrations up to ~18 ions per 5 nm particle.
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