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Item type:Publication, Access status: with files , New insights in the morphological characterization and modelling of poly(ε-caprolactone) bone scaffolds obtained by supercritical CO₂ foaming(Elsevier, 2020-08-07); ; ; ; Hierarchically porous synthetic bone grafts (scaffolds) are gaining attention in the clinical arena. Scaffolds should combine morphological (macro- and microporosity, pore interconnectivity), mechanical and biological (biocompatibility, degradation rate) properties to fit this specific use. Supercritical (sc-) foaming is a versatile scaffold processing technology. However, the selection of the optimum operating conditions to obtain a defined scaffold structure is hampered by the lack of a single characterization technique able to fully elucidate the porous features of the resulting scaffolds. In this work, the effect of soaking time (1, 3 and 5 h) on the preparation of poly(ε-caprolactone) (PCL, 50 kDa) scaffolds by sc-foaming was evaluated by a combined X-ray microtomography (μ-CT) and mercury intrusion porosimetry (MIP) 3D-morphological analysis. Mechanical tests and in silico modelling for cell penetration and water permeability of the scaffolds were also conducted. Results evidenced the relevance of μ-CT and MIP as a synergistic analytical duo to fully elucidate the morphology of the sc-foamed scaffolds and the soaking time effect.Publicationtype: Journal ArticleScopus© Citations 18 170 339 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Preparation and stability of dexamethasone-loaded polymeric scaffolds for bone regeneration processed by compressed CO₂ foamingCompressed CO₂ foaming allows for obtaining porous solid drug-loaded scaffolds for regenerative medicine under mild conditions and in the absence of organic solvents. However, a precise process design and optimization as well as certain modifications of the technology are still needed to tackle certain limitations like the control of the porosity of scaffolds from certain low molecular weight biopolymers. Besides, stability under storage is a critical quality attribute to define the usefulness of scaffolds. In the particular case of bone scaffolds, the information on this regard is still very limited and strongly dependent on each particular composition and architecture. In order to gain an insight into this issue, scaffolds composed of poly(lactic-co-glycolic acid) (PLGA) and poly(ε-caprolactone) (PCL) as polymeric matrix, with and without pre-gelified starch (St) as release-controlling agent and dexamethasone (DXMT) as bioactive compound were designed and prepared by a modified compressed CO₂ foaming technique (26 °C, 60 bar) and assessed regarding stability under storage. The scaffolds were stored at 25 °C and 65% relative humidity (zone II ICH-climatic conditions for Europe, USA and Japan) for up to three months to determine the effect of storage on the structural, physicochemical and mechanical properties, and DXMT release. Changes in the scaffolds point out the importance of stability assays and storage conditions. Namely, a decrease in the viscoelastic moduli of the scaffolds and a faster degradation rate were observed after prolonged storage periods. DXMT release from the scaffolds was erosion-controlled and thus modified for scaffolds stored for longer time periods.Publicationtype: Journal Article134