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Poly(ε-caprolactone) (PCL) is a bioresorbable synthetic polyester with numerous biomedical applications. PCL membranes show great potential in guided tissue regeneration because they are biocompatible, occlusive and space maintaining, but lack osteoconductivity. Therefore, two different types of mesoporous bioactive glasses (SiO2-CaO-P2O5 and SiO2-SrO-P2O5) were synthesized and incorporated in PCL thin membranes by spin coating. To enhance the osteogenic effect of resulting membranes, the bioglasses were loaded with the bisphosphonate drug ibandronate prior to their incorporation in the polymeric matrix. The effect of the composition of the bioglasses as well as the presence of absorbed ibandronate on the physicochemical, cell attachment and differentiation properties of the PCL membranes was evaluated. Both fillers led to a decrease of the crystallinity of PCL, along with an increase in its hydrophilicity and a noticeable increase in its bioactivity. Bioactivity was further increased in the presence of a Sr substituted bioglass loaded with ibandronate. The membranes exhibited excellent biocompatibility upon estimation of their cytotoxicity on Wharton’s Jelly Mesenchymal Stromal Cells (WJ-SCs), while they presented higher osteogenic potential in comparison with neat PCL after WJ-SCs induced differentiation towards bone cells, which was enhanced by a possible synergistic effect of Sr and ibandronate.

Poly(ε-caprolactone) (PCL) is a bioresorbable synthetic polyester widely studied as a biomaterial for tissue engineering and controlled release applications, but its low bioactivity and weak mechanical performance limits its applications. In this work, nanosized bioglasses with two different compositions (SiO2–CaO and SiO2–CaO–P2O5) were synthesized with a hydrothermal method, and each one was used as filler in the preparation of PCL nanocomposites via the in situ ring opening polymerization of ε-caprolactone. The effect of the addition of 0.5, 1 and 2.5 wt % of the nanofillers on the molecular weight, structural, mechanical and thermal properties of the polymer nanocomposites, as well as on their enzymatic hydrolysis rate, bioactivity and biocompatibility was systematically investigated. All nanocomposites exhibited higher molecular weight values in comparison with neat PCL, and mechanical properties were enhanced for the 0.5 and 1 wt % filler content, which was attributed to extensive interactions between the filler and the matrix, proving the superiority of in situ polymerization over solution mixing and melt compounding. Both bioglasses accelerated the enzymatic degradation of PCL and induced bioactivity, since apatite was formed on the surface of the nanocomposites after soaking in simulated body fluid. Finally, all samples were biocompatible as Wharton jelly-derived mesenchymal stem cells (WJ-MSCs) attached and proliferated on their surfaces.

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In this work, the effect of two different types of bioactive coatings on the properties of 3D printed poly(lactic acid)/montmorillonite (PLA/MMT) nanocomposite scaffolds was examined. To improve their suitability for bone tissue engineering applications, the PLA nanocomposite scaffolds were coated with (i) ordered mesoporous Strontium bioglass (SrBG) and (ii) SrBG and nanohydroxyapatite (nHA) using a simple dip coating procedure. The effect of the coatings on the morphology, chemical structure, wettability and nanomechanical properties of the scaffolds was examined. The hydrophilicity of PLA nanocomposite scaffolds increased after the SrBG coating and increased even more with the SrBG/nHA coating. Moreover, in the case of PLA/MMT/SrBG/nHA 3D printed scaffolds, the elastic modulus increased by ~ 80% and the hardness increased from 156.9 ± 6.4 to 293.6 ± 11.3 MPa in comparison with PLA. Finally, the in vitro biocompatibility and osteogenic potential were evaluated using bone marrow-derived stem cells. The coating process was found to be a fast, economical and effective way to improve the biomineralization and promote the differentiation of the stem cells toward osteoblasts, in comparison with the neat PLA and the PLA/MMT nanocomposite scaffold. Graphical abstract