Preparation and Crystal Structures of 2-Aminoethyl Phosphate Complexes of Magnesium, Calcium, and Zinc

Cation-Ligand Complexation Mediates the Temporal Evolution of Colloidal Fluoride Nanocrystals through Transient Aggregation

Colloidal inorganic nanofluorides have aroused great interest for various applications with their development greatly accelerated thanks to advanced synthetic approaches. Nevertheless, understanding their colloidal evolution and the factors that affect their dispersion could improve the ability to rationally design them. Here, using a multimodal in situ approach that combines DLS, NMR, and cryogenic-TEM, we elucidate the formation dynamics of nanofluorides in water through a transient aggregative phase. Specifically, we demonstrate that ligand-cation interactions mediate a transient aggregation of as-formed CaF₂ nanocrystals (NCs) which governs the kinetics of the colloids' evolution. These observations shed light on key stages through which CaF₂ NCs are dispersed in water, highlighting fundamental aspects of nanofluorides formation mechanisms. Our findings emphasize the roles of ligands in NCs' synthesis beyond their function as surfactants, including their ability to mediate colloidal evolution by complexing cationic precursors, and should be considered in the design of other types of NCs.

Modulation of the nuclearity of molecular Mg(ii)-phosphates: solid-state structural change involving coordinating solvents

Herein, we report the synthesis and molecular structures of various magnesium(ii)-phosphate monoesters. By using a bulky aryl substituted phosphate monoester, ArOPO₃H₂ (Ar = 2,6-(CHPh₂)₂-4-tBu-C₆H₂), we have reproducibly assembled mono-, di-, tetra- (cage and ring), hexa-, and polynuclear magnesium(ii)-phosphate monoesters. Interestingly, the hexanuclear magnesium(ii)-phosphate monoester encapsulates an open-cage dodecanuclear water cluster.

New advances in nanocrystalline apatite colloids intended for cellular drug delivery

Intracellular drug delivery using colloidal biomimetic calcium phosphate apatites as nanocarriers is a seducing concept. However, the colloid preparation to an industrial scale requires the use of easily handled raw materials as well as the possibility to tailor the nanoparticles size. In this work, the stabilization of the colloids was investigated with various biocompatible agents. Most interestingly, nanoscale colloids were obtained without the need for toxic and/or hazardous raw materials. Physico-chemical characteristics were investigated by chemical analyses, dynamic light scattering, FTIR/Raman spectroscopies, XRD, and electron microscopy. A particularly promising colloidal system associates biomimetic apatite stabilized with a natural phospholipid moiety (AEP(r), 2-aminoethylphosphoric acid). Complementary data described such colloids as apatite nanocrystals covered with surface Ca(2+)(AEP(r)(-))(2) complexes involving "supernumerary" Ca(2+) ions. The effects of the concentration in AEPr, synthesis temperature, duration of aging in solution, pH, and sonication were followed, showing that it is possible to modulate the mean size of the nanoparticles, typically in the range 30-100 nm. The perfect biocompatibility of such colloids allied to the possibility to prepare them from innocuous compounds shows great promise for intracellular drug delivery.

Colloidal and monocrystalline Ln3+ doped apatite calcium phosphate as biocompatible fluorescent probes

Ultrafine individualised mono crystalline Ca(10-x)(PO4)(6-x)(HPO4)x(OH)(2-x) deficient calcium hydroxyapatite nanocrystals displaying fluorescence under visible excitation are proposed for utilisation as biocompatible biological probes.