Comparative Thermo-Mechanical Properties of Sustainable Epoxy Polymer Networks Derived from Linseed Oil

Considering its great industrial potential, epoxidized linseed oil (ELO) was crosslinked with different agents, both natural and synthetic: citric acid (CA, in the presence of water—W, or tetrahydrofuran—THF, as activator molecules) and Jeffamine D230, respectively, resulting bio-based polymeric matrices, studied further, comparatively, in terms of their properties, through different methods. Thermal curing parameters were established by means of Differential Scanning Calorimetry (DSC). Fourier transform Infrared Spectroscopy (FTIR) and DSC were used to identify the reactivity of each ELO-based formulation, discussing the influence of the employed curing systems under the conversion of the epoxy rings. Then, the obtained bio-based materials were characterized by different methods, establishing the structure–properties relation. Thermogravimetric analysis revealed higher thermal stability for the ELO_CA material when THF was used as an activator. Moreover, a higher glass transition temperature (Tg) with ~12 °C was registered for this material when compared with the one that resulted through the crosslinking of ELO with D230 conventional amine. Other important features, such as crosslink density, storage modulus, mechanical features, and water affinity, were discussed. Under the loop of a comprehensive approach, a set of remarkable properties were obtained for ELO_CA_THF material when compared with the one resulting from the crosslinking of ELO with the synthetic Jeffamine

Development of Biocomposite Alginate-Cuttlebone-Gelatin 3D Printing Inks Designed for Scaffolds with Bone Regeneration Potential

Fabrication of three-dimensional (3D) scaffolds using natural biomaterials introduces valuable opportunities in bone tissue reconstruction and regeneration. The current study aimed at the development of paste-like 3D printing inks with an extracellular matrix-inspired formulation based on marine materials: sodium alginate (SA), cuttlebone (CB), and fish gelatin (FG). Macroporous scaffolds with microporous biocomposite filaments were obtained by 3D printing combined with post-printing crosslinking. CB fragments were used for their potential to stimulate biomineralization. Alginate enhanced CB embedding within the polymer matrix as confirmed by scanning electron microscopy (ESEM) and micro-computer tomography (micro-CT) and improved the deformation under controlled compression as revealed by micro-CT. SA addition resulted in a modulation of the bulk and surface mechanical behavior, and lead to more elongated cell morphology as imaged by confocal microscopy and ESEM after the adhesion of MC3T3-E1 preosteoblasts at 48 h. Formation of a new mineral phase was detected on the scaffold’s surface after cell cultures. All the results were correlated with the scaffolds’ compositions. Overall, the study reveals the potential of the marine materials-containing inks to deliver 3D scaffolds with potential for bone regeneration applications