Bisphosphonates incorporation into silica nanoparticles and their exposure to bone cell cultures

GS ALVAREZ; ML FOGLIA; DE CAMPOROTONDI; AM MEBERT; JA BERTINATTO RODRIGUEZ; MF DESIMONE; LE DIAZ

Mendoza

Congreso; 48º Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2012

SAIB

Implants based on the application of polymers colonized by cells such as osteoblasts to regenerate bone tissue are being widely studied. Some of them use nanocomposites that are the combination of polymers with filler nanoparticles (NPs). Bisphosphonates such as ibandronate are drugs used to treat certain diseases involving bone resorption and could be applied locally in bone implants increasing periprosthetic bone density leading to a stronger and successful implant fixation. The aim of this work is to synthesize different NPs containing ibandronate: solid silica NPs obtained by the Stöber method, chemically modified silica NPs with amino groups (APTES), and hollow silica nanoparticles (HSNPs) with or without CaCO . The drug content was studied by means of capillary electrophoresis and the effect over cell cultures was evaluated using bone cells. All tested NPs were approximately 350 nm. The content of drug incorporated to silica NPs was 44.7 mg/100 mg NPfor HSNP, 25.5 for HSNP with CaCO (0.05% p/p), 11.6 for APTES modified NP and 9.16 for Stöber NPs. HSNPs which incorporated higher amounts of Ibandronate were exposed to cell cultures to evaluate their intrinsic toxicity (without drug) using the MTT assay. It was observed that hollow silica NPs were toxic for cells when NPs concentrations were higher than 2.4 mg/ml but this effect was not seen for hollow silicaNPwithCaCO .