Unimolecular micelles have attracted
wide attention in the field
of drug delivery because of their thermodynamic stability and uniform
size distribution. However, their drug loading/release mechanisms
at the molecular level have been poorly understood. In this work,
the stability and drug loading/release behaviors of unimolecular micelles
formed using generation-5 polyamidoamine-graft-poly(carboxybetaine
methacrylate) (PAMAM(G5)-PCBMA) were studied by dissipative particle
dynamics simulations. In addition, the unimolecular micelles formed
using generation-5 polyamidoamine-graft-poly(ethyleneglycol methacrylate)
(PAMAM(G5)-PEGMA) were used as a comparison. The simulation results
showed that PAMAM(G5)-PCBMA can spontaneously form core–shell
unimolecular micelles. The PAMAM(G5) dendrimer constitutes a hydrophobic
core to load the doxorubicin (DOX), while the zwitterionic PCBMA serves
as a protective shell to improve the stability of the unimolecular
micelle. The DOX can be encapsulated into the cavity of PAMAM(G5)
at the physiological pH 7.4. The drug loading efficiency and drug
loading content showed some regularities with the increase in the
drug concentration. At the acidic pH 5.0, the loaded DOX can be released
gradually from the hydrophobic core. The comparison of DOX-loaded
morphologies between the PAMAM(G5)-PCBMA system and PAMAM(G5)-PEGMA
system showed that the former has better monodisperse stability. This
work could offer theoretical guidance for the design and development
of promising unimolecular micelles for drug delivery.
A new member in the barium fluorooxoborate family, Ba2B7O12F, was obtained by the high-temperature solution method in an open system under ambient pressure. The structure features a new fundamental building...
A new silicate fluoride, NaBa 3 Si 2 O 7 F, has been successfully synthesized by a high-temperature solution method. It crystallizes in the orthorhombic space group Cmcm (No. 63). NaBa 3 Si 2 O 7 F is the first barium-containing alkali metal silicate fluoride with the [NaO 6 ] polyhedra, the [BaO 8 F] polyhedra and isolated [Si 2 O 7 ] units. The optical characterizations indicate that NaBa 3 Si 2 O 7 F possesses wide transparent window and available luminescence properties. To confirm the coordination surroundings of anionic groups and its thermostability, infrared spectroscopy and thermal behaviors were also analyzed, which proved the existence of tetrahedronly coordinated silicium atoms and the good stability of NaBa 3 Si 2 O 7 F at high temperature. First-principles calculation was also implemented for better understanding the relationship between the structure of NaBa 3 Si 2 O 7 F and its property. Additionally, to further explore the structural novelty of NaBa 3 Si 2 O 7 F, the comparison of the anionic structures was carried out in mixed alkali and alkaline-earth metal silicate fluorides. Interestingly, the result indicates the isolated [Si 2 O 7 ] dimer is rare among the above systems, which enriches the structural chemistry of silicate fluorides.
In this work, dissipative particle dynamics simulation was carried out to investigate the intelligent switching effect of nanopores grafted by the zwitterionic polymer brushes poly(carboxybetaine) with excellent antifouling property. The...
CsB7O10(OH)2 with new FBB features a 2D anionic structure whose band gap is about 6.6 eV and CsBaB7O12 features a 3D anionic structure whose band gap is 5.6 eV. And their simulated birefringence are about 0.08 and 0.05 at 1064 nm, respectively.
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