[EN] Several polyurethane-formulated films with curcumin and/or chitosan additives for food packaging have been previously obtained. The study examines the effect of the additives on the film¿s morphological, mechanical, barrier, and migration properties. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), water contact angle, thermogravimetric and differential thermal analysis (TGA and DTGA), differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), oxygen transmission rate (OTR), water vapor transmission rate (WVTR), and the overall and specific migration tests were conducted. The results show that the presence of chitosan significantly increased the overall migration and mechanical properties, such as the elongation at break, tensile strength, and Young¿s modulus of most polyurethane formulations, while curcumin had a minor influence on the mechanical performance. Based on the results, formulations with curcumin but without chitosan are suitable for food packaging., This research was funded by Universidad de La Sabana, grant number ING-289-2021.
The APC was funded by Universidad de La Sabana and the Centre for Biomaterials and Tissue
Engineering at Universitat Politècnica de València. CIBER-BBN, Biomedical Research Networking
Center in Bioengineering, Biomaterials, and Nano-medicine is an initiative funded by the VI National
R&D&I Plan 2008¿2011, Iniciativa Ingenio 2010, Consolider Program. CIBER Actions were financed
by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund.
J.A.G.-T thanks MCIN/AEI/10.13039/501100011033 grant number PID2020-114894RB-I00.

[EN] Green solvent strategies are increasingly important for advancing sustainable polymer processing and deepening the understanding of structure-property relationships. In this work, we report a coaxial electrospinning approach that employs dimethyl sulfoxide and ethyl acetate as environmentally benign solvents to fabricate nanofibers composed of polyvinyl alcohol (PVA) cores and poly(L-lactic acid) (PLLA) shells. Comprehensive morphological and physicochemical characterization confirmed the successful formation of uniform, defect-free core-shell architectures. Comparative transport studies revealed clear architecture-dependent behavior: uniaxial PVA fibers displayed rapid burst release, PLLA-only fibers acted as complete diffusion barriers, and coaxial PVA/PLLA fibers enabled finely tunable, diffusion-controlled transport over extended timescales. These findings establish direct links between solvent choice, processing architecture, and transport properties in biodegradable nanofiber systems. This study provides both a scalable eco-conscious electrospinning strategy and a fundamental framework for correlating processing, morphology, and mass transport in polymeric materials., Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research and APC were funded by MCIN/AEI/https://doi.org/10.13039/501100011033 grant number PID2020-114894RB-I00.

[EN] The increased demand for vascular grafts for the treatment of cardiovascular diseases has led to the search for novel biomaterials that can achieve the properties of the tissue. According to this, the investigation of polyurethanes has been a promising approach to overcome the present limitations. However, some biological properties remain to be overcome, such as thrombogenicity and hemocompatibility, among others. This paper aims to synthesize polyurethanes based on castor oil and castor oil transesterified with triethanolamine (TEA) and pentaerythritol (PE) and with the incorporation of 1% chitosan. Analysis of the wettability, enzymatic degradation, mechanical properties (tensile strength and elongation at break), and thermal stability was performed. Along with the evaluation of the cytotoxicity against mouse fibroblast (L929) and human dermal fibroblast (HDFa) cells, the hemolysis rate and platelet adhesion were determined. The castor-oil-based polyurethanes with and without 1% chitosan posed hydrophobic surfaces and water absorptions of less than 2% and enzymatic degradation below 0.5%. Also, they were thermally stable until 300 °C, with tensile strength like cardiovascular tissues. The synthesized castor oil/chitosan polyurethanes are non-cytotoxic (cell viabilities above 80%) to L929 and HDFa cells and non-thrombogenic and non-hemolytic (less than 2%); therefore, they are suitable for cardiovascular applications., This research was funded by Universidad de La Sabana, project number ING-282-2021.

[EN] In this study, electrospun membranes were developed for controlled drug release applications. Both uniaxial Polyvinyl alcohol (PVA) and coaxial fibers with a PVA core and a poly (L-lactic acid) (PLLA) and polycaprolactone (PCL) coating were produced with different coating structures. The best conditions for the manufacture of the fibers were also studied and their morphology was analyzed as a function of the electrospinning parameters. Special attention was paid to the fiber surface morphology of the coaxial fibers, obtaining both porous and non-porous coatings. Bovine serum albumin (BSA) was used as the model protein for the drug release studies and, as expected, the uncoated fibers were determined to have the fastest release kinetics. Different release rates were obtained for the coated fibers, which makes this drug release system suitable for different applications according to the release time required., This research and APC were funded by MCIN/AEI/10.13039/501100011033 grant number PID2020-114894RB-I00.