%0 Journal Article
%A Nairi, Valentina
%A Magnolia, Silvia
%A Piludu, Marco
%A Nieddu, Mariella
%A Caria, Cristian Antonio
%A Sogos, Valeria
%A Vallet Regí, María Dulce Nombre
%A Monduzzi, Maura
%A Salis, Andrea
%T Mesoporous Silica Nanoparticles Functionalized withHyaluronic Acid. Effect of the Biopolymer Chain Length onCell Internalization
%D 2018
%@ 0927-7765
%U https://hdl.handle.net/20.500.14352/11969
%X Mesoporous silica nanoparticles (MSNs) were functionalized with amino groups (MSN-NH2) and then with hyaluronic acid, a biocompatible biopolymer which can be recognized by CD44 receptors in tumor cells, to obtain a targeting drug delivery system. To this purpose, three hyaluronic acid samples differing for the molecular weight, namely HAS (8 -15 kDa), HAM (30-50 kDa) and HAL (90-130 kDa), were used. The MSN-HAS, MSN-HAM, and MSN-HAL materials were characterized through zeta potential and dynamic light scattering measurements at pH=7.4 and T=37°C to simulate physiological conditions. While zeta potential showed an increasing negative value with the increase of the HA chain length, an anomalous value of the hydrodynamic diameter was observed for MSN-HAL, which was smaller than that of MSN-HAS and MSN-HAM samples. The cellular uptake of MSN-HA samples on HeLa cells at 37°C was studied by optical and electron microscopy. HA chain length affected significantly the cellular uptake that occurred at a higher extent for MSN-NH2 and MSN-HAS than for MSN-HAM and MSN-HAL samples. Cellular uptake experiments carried out at 4°C showed that the internalization process was inhibited for MSN-HA samples but not for MSN-NH2. This suggests the occurrence of two different mechanisms of internalization. For MSN-NH2 the uptake is mainly driven by the attractive electrostatic interaction with membrane phospholipids, while MSN-HA internalization involves CD44 receptorsoverexpressed in HeLa cells.
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