Human metabolite-derived alkylsuccinate/dilinoleate copolymers: from synthesis to application.

The advances in polymer chemistry have allowed the preparation of biomedical polymers using human metabolites as monomers that can hold unique properties beyond the required biodegradability and biocompatibility. Herein, we demonstrate the use of endogenous human metabolites (succinic and dilinoleic acids) as monomeric building blocks to develop a new series of renewable resource-based biodegradable and biocompatible copolyesters. The novel copolyesters were characterized in detail employing several standard techniques, namely 1H NMR, 13C NMR, and FTIR spectroscopy and SEC, followed by an in-depth thermomechanical and surface characterization of their resulting thin films (DSC, TGA, DMTA, tensile tests, AFM, and contact angle measurements). Also, their anti-fungal biofilm properties were assessed via an anti-fungal biofilm assay and the biological properties were evaluated in vitro using relevant human-derived cells (human mesenchymal stem cells and normal human dermal fibroblasts). These novel highly biocompatible polymers are simple and cheap to prepare, and their synthesis can be easily scaled-up. They presented good mechanical, thermal and anti-fungal biofilm properties while also promoting cell attachment and proliferation, outperforming well-known polymers used for biomedical applications (e.g. PVC, PLGA, and PCL). Moreover, they induced morphological changes in the cells, which were dependent on the structural characteristics of the polymers. In addition, the obtained physicochemical and biological properties can be design-tuned by the synthesis of homo- and -copolymers through the selection of the diol moiety (ES, PS, or BS) and by the addition of a co-monomer, DLA. Consequently, the copolyesters presented herein have high application potential as renewable and cost-effective biopolymers for various biomedical applications.

Ionic Liquid-Silica Precursors via Solvent-Free Sol-Gel Process and Their Application in Epoxy-Amine Network: A Theoretical/Experimental Study.

This work describes the solvent-free sol-gel synthesis of epoxy-functionalized silica-based precursors in the presence of 1-butyl-3-methylimidazolium-based ionic liquids (ILs) containing different anions: chloride (Cl-) and methanesulfonate (MeSO3-). The IL-driven sol-gel mechanisms were investigated in detail using experimental characterizations (29Si NMR and ATR FTIR spectroscopy) and a theoretical computational method based on density functional theory (DFT). We observed complex IL influence on both hydrolysis and condensation steps, involving especially H-bonding and Coulomb coupling stabilization of the process intermediates. The obtained IL-silica precursors and their further xerogels were widely characterized (rheology measurements, MALDI TOF, 29Si NMR, ATR FTIR, and DFT simulation), which allowed observation of their precise silica structures and established their most energetically favorable conformations. The detected silica structures were dependent on the IL type and varied from highly condensed 3D cage-like to branched ladder-like and cyclic ones. The application of prepared IL-silica precursors as reinforcing additives into the epoxy-amine network led to an improvement in the organic/inorganic interphase interactions through chemical and physical bonding. Uniform and well-dispersed silica aggregates, in the size of ∼30 nm, were formed when ≤6.8 wt % of each IL-silica precursor was applied into the epoxy-amine network. The use of imidazolium-based ILs contributed to a significant improvement in thermomechanical properties of hybrids and reduced their UV absorption ability compared to that of the reference matrix. All hybrids exhibited an increase in energy to break (up to ∼53%), elongation at break (up to ∼43%), shear storage modulus in the rubbery region (up to 4 times), and thermo-oxidative stability.