title: Dexamethasone-loaded poly(ε-caprolactone)/silica nanoparticles composites prepared by supercritical CO2 foaming/mixing and deposition.
abstract: A supercritical carbon dioxide (scCO2)-assisted foaming/mixing method (SFM) was implemented for preparing dexamethasone (DXMT)-loaded poly(ε-caprolactone)/silica nanoparticles (PCL/SNPs) composite materials suitable for bone regeneration. The composites were prepared from PCL and mesoporous SNPs (MCM-41/SBA-15) by means of scCO2-assisted SFM at several operational pressures, processing times and depressurization conditions. DXMT was loaded into SNPs (applying a scCO2 solvent impregnation/deposition method - SSID) and into PCL/SNPs composites (using the SFM method). The effects of the employed operational and compositional variables on the physicochemical and morphological features as well as in the in vitro release profiles of DXMT were analyzed in detail. This work demonstrates that the above-referred scCO2-based methods can be very useful for the preparation of DXMT-loaded PCL/SNPs composites with tunable physicochemical, thermomechanical, morphological and drug release properties and suitable for hard-tissue regeneration applications.
authors.affiliation: CIEPQPF, Chemical Engineering Department, FCTUC, University of Coimbra, Rua Sílvio Lima, Pólo II - Pinhal de Marrocos, 3030-790 Coimbra, Portugal.
authors.forename: M B C
authors.initials: MB
authors.lastname: de Matos
authors.forename: A P
authors.initials: AP
authors.lastname: Piedade
authors.forename: C
authors.initials: C
authors.lastname: Alvarez-Lorenzo
authors.forename: A
authors.initials: A
authors.lastname: Concheiro
authors.forename: M E M
authors.initials: ME
authors.lastname: Braga
authors.forename: H C
authors.initials: HC
authors.lastname: de Sousa
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D003907:Dexamethasone / Q000138:chemical synthesis*; D053758:Nanoparticles / Q000737:chemistry*; D011091:Polyesters / Q000138:chemical synthesis*; D012822:Silicon Dioxide / Q000138:chemical synthesis*; D014961:X-Ray Diffraction
chemical_list: D011091:Polyesters; D002245:Carbon Dioxide; C016240:polycaprolactone; D012822:Silicon Dioxide; D003907:Dexamethasone
keywords: Composites; Mezoporous silica nanoparticles; Poly(ɛ-caprolactone); Supercritical CO(2) foaming/mixing; Supercritical CO(2) impregnation/deposition