A systematic approach to the synthesis of LDH nanoparticles by response surface methodology

VALERIA PFAFFEN; RICARDO ROJAS; CECILIA VASTI; VALERIA PFAFFEN; MAURICIO GALIANO; RICARDO ROJAS; CECILIA VASTI; MAURICIO GALIANO; ERNESTO AMBROGGIO; CARLA E. GIACOMELLI; ERNESTO AMBROGGIO; CARLA E. GIACOMELLI

APPLIED CLAY SCIENCE

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2017 vol. 137 p. 151 - 159

0169-1317

The customization of the properties of layered double hydroxides nanoparticles (LDH-NPs) is essential to optimizetheir design innovative systems for biomedical applications. Response surface methodologies (RSMs), a collectionof mathematical and statistical techniques that allows multivariate optimization of processes, are a usefultool for LDH-NPs customization. In this work, RSMs were used to study the synthesis parameters governing thesize and composition of MgAl LDH-NPs (Mg/Al = 3) labeled with fluorescein isothiocyanate (FITC2−) and preparecustomized samples for biological assays. The influence of [Al3+], [OH−]/[Mg2++Al3+], 2[FITC2−]/[Al3+]and time of the hydrothermal treatment (tHT) was determined by a Box-Behnken experimental design (BBD).The experimental responses were hydrodynamic diameter (dH), polidispersity index (PI) and FITC2− content(%FITC), and their dependence with the synthesis variables was described by polynomial model. The model correlatedhigh [Al3+] with large dH values due to aggregation processes, while tHT was the main variable governingthe size of the disaggregated units. These results were explained based on the precipitation and recrystallizationmechanisms of LDH-NPs. The mathematical model derived from the BBD accurately predicted the synthesis conditionsto obtain LDH-NPs with controlled dH values between 50 and 200 nm, minimum PI and tunable %FITC. Theconvenience of the synthesized LDH-NPs for biological assays were tested in experiments with giant unilamellarvesicles and cell cultures monitored by confocal microscopy.