The synthesis and purification of a poly(N-isopropylacrylamide)-lipid conjugate and its use in the preparation of a thermoresponsive lipid mesophase is described. Specifically, poly(N-isopropylacrylamide) with a single carboxyl group at one end was activated with dicyclohexylcarbodiimide/N-hydroxysuccinimide to form an active ester. This N-hydroxysuccinimide ester was then used to form a dimyristoyl-sn-glycero-3-phosphoethanolamine conjugate with poly(N-isopropylacrylamide) via an amide bond, rendering the conjugate amphiphilic. Quaternary phases comprising the conjugate, a phosopholipid, dimyristoylphosphatidylcholine, and a cosurfactant, N,N-dimethyldodecylamine-N-oxide, dispersed in water were found to self-assemble at room temperature to form liquid crystalline gels, adopting an expanded lamellar structure. A modest increase in temperature triggered the reversible conversion of the aggregate to a collapsed lamellar structure, while a modest reduction in temperature resulted in its conversion to a nonlamellar phase. The phases were characterized by polarized optical microscopy and small-angle X-ray scattering (SAXS).
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http://dx.doi.org/10.1021/ja039023e | DOI Listing |
Inorg Chem
January 2025
Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States.
The photophysical properties of six new luminescent tetrahedral Zn(II) complexes are presented that survey two electronic donor moieties (phenolate and carbazolate) and three electronic acceptors (pyridine, pyrimidine, and pyrazine). A unique ligand based on an -terphenyl motif forms an eight-membered chelate, which enhances through-space charge-transfer (CT) interactions by limiting through-bond conjugation between the donor and acceptor. A single isomeric product was obtained in yields up to 90%.
View Article and Find Full Text PDFJ Mater Chem B
January 2025
Department of Gastrointestinal Surgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China.
Hypoxia, a condition that enhances tumor invasiveness and metastasis, poses a significant challenge for diverse cancer therapies. There is a pressing demand for hypoxia-responsive nanoparticles with integrated photodynamic functions in order to address the aforementioned issues and overcome the reduced efficacy caused by tumor hypoxia. Here, we report a hypoxia-responsive supramolecular nanoparticle SN@IR806-CB consisting of a dendritic drug-drug conjugate (IR806-Azo-CB) and anionic water-soluble [2]biphenyl-extended-pillar[6]arene modified with eight ammonium salt ions (AWBpP6) the synergy of π-π stacking interaction, host-guest complexation, and hydrophobic interactions for synergistic photothermal therapy (PTT), photodynamic therapy (PDT), and chemotherapy (CT; , PTT-PDT-CT).
View Article and Find Full Text PDFJ Chem Theory Comput
January 2025
Department of Chemistry and Biochemistry, The University of Texas at El Paso, El Paso, Texas 79968, United States.
In this work, we describe a computational tool designed to determine the local dielectric constants (ε) of charge-neutral heterogeneous systems by analyzing dipole moment fluctuations from molecular dynamics (MD) trajectories. Unlike conventional methods, our tool can calculate dielectric constants for dynamically evolving selections of molecules within a defined region of space, rather than for fixed sets of molecules. We validated our approach by computing the dielectric constants of TIP3P water nanospheres, achieving results consistent with literature values for bulk water.
View Article and Find Full Text PDFJ Med Chem
January 2025
Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
In this study, a novel antibody-drug conjugate (ADC) consisting of Rituximab and Chlorambucil (Rituximab-CMB) was synthesized. The average number of drug molecules attached per Rituximab molecule was determined using MALDI-TOF mass spectrometry, revealing a range of 4-6 drug molecules per antibody. To further improve the therapeutic potential of the ADC, it was radiolabeled with the therapeutic radionuclide Lu via a DOTA chelator, achieving a final radiochemical purity of over 95%.
View Article and Find Full Text PDFJ Chem Theory Comput
January 2025
Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02453, United States.
The photocatalytic efficiency of materials such as graphene and noble metal nanoclusters depends on their plasmon lifetimes. Plasmon dephasing and decay in these materials is thought to occur on ultrafast time scales, ranging from a few femtoseconds to hundreds of femtoseconds and longer. Here we focus on understanding the dephasing and decay pathways of excited states in small lithium and silver clusters and in plasmonic states of the π-conjugated molecule anthracene, providing insights that are crucial for interpreting optical properties and photophysics.
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