Hydroxyapatite functionalization to trigger adsorption and release of risedronate.
Bisphosphonates are widely employed drugs for the treatment of pathologies characterized by excessive bone resorption, and display a great affinity for apatitic supports. In this work we investigate how hydroxyapatite functionalization can influence the processes of adsorption and release of a bisphosphonate, namely risedronate. To this aim, pure hydroxyapatite (HA), hydroxyapatite with a partial substitution of Zn to Ca (ZnHA) and poly-ethylenimine-functionalized hydroxyapatite (HAPEI) were submitted to interaction with risedronate solution. The results indicate that the mechanisms of adsorption and release are greatly influenced by the type of the apatitic support. All the apatitic supports display Langmuir isotherms for risedronate adsorption. However in the case of HAPEI the plateau is not reached even at high equilibrium concentrations in solution. The data suggest that risedronate adsorption on HAPEI mineral-organic support occurs not only through chemisorption on apatitic phase, as on HA and ZnHA, but also through physisorption involved by PEI coating, which modulates also bisphosphonate release. These properties of tailor-made hydroxyapatite supports could be exploited to develop delivery systems for antiresorptive agents directly on osteoporotic sites.
['Forte|Lucia|L|', 'Sarda|Stéphanie|S|', 'Combes|Christèle|C|', 'Brouillet|Fabien|F|', 'Gazzano|Massimo|M|', 'Marsan|Olivier|O|', 'Boanini|Elisa|E|', 'Bigi|Adriana|A|']
D000327:Adsorption D000818:Animals D050071:Bone Density Conservation Agents D001862:Bone Resorption D001842:Bone and Bones D003692:Delayed-Action Preparations D065546:Drug Liberation D017886:Durapatite D007700:Kinetics D046529:Microscopy, Electron, Transmission D011094:Polyethyleneimine D000068296:Risedronic Acid D013816:Thermodynamics D014961:X-Ray Diffraction
Hydroxyapatite Adsorption Release Risedronate Bisphosphonate Poly-ethylenimine Zinc