Authors: Elena Mavropoulos Moema Hausen Andrea M Costa Gutemberg Alves Alexandre Mello C A Ospina M Mir José M Granjeiro Alexandre M Rossi
Publish Date: 2013/03/14
Volume: 24, Issue: 5, Pages: 1271-1283
Abstract
The incorporation of zinc into the hydroxyapatite structure ZnHA has been proposed to stimulate osteoblast proliferation and differentiation Another approach to improve cell adhesion and hydroxyapatite HA performance is coating HA with adhesive proteins or peptides such as RGD arginine–glycine–aspartic acid The present study investigated the adhesion of murine osteoblastic cells to nonsintered zincsubstituted HA disks before and after the adsorption of RGD The incorporation of zinc into the HA structure simultaneously changed the topography of disk’s surface on the nanoscale and the disk’s surface chemistry Fluorescence microscopy analyses using RGD conjugated to a fluorescein derivative demonstrated that ZnHA adsorbed higher amounts of RGD than nonsubstituted HA Zinc incorporation into HA promoted cell adhesion and spreading but no differences in the cell density adhesion and spreading were detected when RGD was adsorbed onto ZnHA The pretreatment of disks with fetal bovine serum FBS greatly increased the cell density and cell surface area for all RGDfree groups overcoming the positive contribution of zinc to cell adhesion The presence of RGD on the ZnHA surface impaired the effects of FBS pretreatment possibly due to competition between FBS proteins and RGD for surface binding sitesThe authors would like to thank CNPq CAPES and FAPERJ for financial support IME and LABNANO/CBPF for support with the SEM analysis Jessica Dornelas Suzana Anjos and Luciana Consentino for support with the in vitro tests and Priscila Lotsch for the mycoplasma verification assay We also acknowledge the Brazilian Nanotechnology National Laboratory at Brazilian Center for Research in Energy and Materials for the electron microscopy facilities
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