A systematic approach to the synthesis of layered double hydroxides nanoparticles by response surface methodology

CECILIA VASTI; VALERIA PFAFFEN; ERNESTO AMBROGGIO; MAURICIO R. GALIANO; RICARDO ROJAS; 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 opti- mize their design innovative systemsfor biomedical applications. Response surfacemethodologies (RSMs), a col- lection ofmathematical and statistical techniques that allowsmultivariate optimization of processes, are a useful tool for LDH-NPs customization. In this work, RSMswere used to study the synthesis parameters governing the size and composition of MgAl LDH-NPs(Mg/Al=3) labeledwith fluorescein isothiocyanate (FITC2−) and pre-pare customized 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 dependencewith the synthesis variableswas described by polynomial model. The model cor- related high [Al3+]withlarge dH values due to aggregation processes,while tHT was themain variable governing the size of the disaggregated units. These results were explained based on the precipitation and recrystallization mechanismsof LDH-NPs. Themathematicalmodel derived fromthe BBDaccurately predicted the synthesis con- ditions to obtain LDH-NPs with controlled dH values between 50 and 200nm, minimumPI and tunable %FITC.The convenience of the synthesized LDH-NPs for biological assayswere tested in experiments with giant unilamellar vesicles and cell cultures monitored by confocal microscopy.