We report a Monte Carlo simulation study of the phase behavior of colloids coated with long, flexible DNA chains. We find that an important change occurs in the phase diagram when the number of DNAs per colloid is decreased below a critical value. In this case, the triple point disappears and the condensed phase that coexists with the vapor is always liquid. Our simulations thus explain why, in the dilute solutions typically used in experiments, colloids coated with a small number of DNA strands cannot crystallize. We understand this behavior in terms of the discrete nature of DNA binding.
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http://dx.doi.org/10.1103/PhysRevLett.107.045902 | DOI Listing |
Nucleic Acids Res
January 2025
Department of Pharmaceutical Sciences, University of California, Irvine, CA 92697-3958, United States.
Growth in the development of engineered polymerases for synthetic biology has led to renewed interest in assays that can measure the fidelity of polymerases that are capable of synthesizing artificial genetic polymers (XNAs). Conventional approaches require purifying the XNA intermediate of a replication cycle (DNA → XNA → DNA) by denaturing polyacrylamide gel electrophoresis, which is a slow, costly, and inefficient process that requires a large-scale transcription reaction and careful extraction of the XNA strand from the gel slice. In an effort to streamline the assay, we developed a purification-free approach in which the XNA transcription and reverse transcription steps occur inside the matrix of a hydrogel-coated magnetic particle.
View Article and Find Full Text PDFUltrason Sonochem
January 2025
Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy; Polito(BIO)Med Lab, Politecnico di Torino, 10129 Turin, Italy. Electronic address:
In the context of molecular imaging, the present work explores an innovative platform made of lipid-coated nanocrystals as contrast-enhanced agent for both ultrasound imaging and sonoluminescence. At first, the dynamics of gas bubbles generation and cavitation under insonation with either pristine or lipid-coated nanocrystals (ZnO-Lip) are described, and the differences between the two colloidal systems are highlighted. These ZnO-Lip show an unprecedented ability to assist cavitation, which is reflected in enhanced sonoluminescent light emission with respect to the pristine nanocrystals or the pure water.
View Article and Find Full Text PDFDiscov Nano
January 2025
Nuclear and Energy Research Institute, IPEN, CNEN/SP, Av. Prof. Lineu Prestes, 2242, São Paulo, SP, CEP05508-000, Brazil.
Gold nanoparticles are widely used in biomedical applications due to their unique properties. However, traditional synthesis methods generate contaminants that cause cytotoxicity and compromise the biocompatibility of the nanomaterials. Therefore, green synthesis methods are essential to produce pure and biocompatible nanoparticles, ensuring their effectiveness in biomedical applications.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Department of Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden.
Functional gold nanoparticles have emerged as a cornerstone in targeted drug delivery, imaging, and biosensing. Their stability, distribution, and overall performance in biological systems are largely determined by their interactions with molecules in biological fluids as well as the biomolecular layers they acquire in complex environments. However, real-time tracking of how biomolecules attach to colloidal nanoparticles, a critical aspect for optimizing nanoparticle function, has proven to be experimentally challenging.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water and Waste Management, Laboratory of Soil and Groundwater Management, Pauluskirchstraße 7, Wuppertal 42285, Germany. Electronic address:
Two novel and unique adsorptive materials, one (Fluorolock®) from clay mineral sepiolite coated with the cationic polymer polydiallyldimethylammionium chloride (pDADMAC) and the other (Intraplex®) from colloidal activated carbon were specially developed for the in situ remediation of per- and polyfluoroalkyl substances (PFAS) in the saturated zone. We evaluated the potential of both materials to immobilize PFAS in soils under flow conditions via soil column experiments using groundwater, which was contaminated with PFAS in the field. Furthermore, the potential ecotoxicological effects of both materials on aquatic organisms were assessed by exposing the soil column effluent to Daphnia magna.
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