Novel bioactive polyester scaffolds prepared from unsaturated resins based on isosorbide and succinic acid

Biodegradable Scaffolds for Vascular Regeneration Based on Electrospun Poly(L-Lactide-co-Glycolide)/Poly(Isosorbide Sebacate) Fibers

Vascular regeneration is a complex process, additionally limited by the low regeneration potential of blood vessels. Hence, current research is focused on the design of artificial materials that combine biocompatibility with a certain rate of biodegradability and mechanical robustness. In this paper, we have introduced a scaffold material made of poly(L-lactide-co-glycolide)/poly(isosorbide sebacate) (PLGA/PISEB) fibers fabricated in the course of an electrospinning process, and confirmed its biocompatibility towards human umbilical vein endothelial cells (HUVEC). The resulting material was characterized by a bimodal distribution of fiber diameters, with the median of 1.25 µm and 4.75 µm. Genotyping of HUVEC cells collected after 48 h of incubations on the surface of PLGA/PISEB scaffolds showed a potentially pro-angiogenic expression profile, as well as anti-inflammatory effects of this material. Over the course of a 12-week-long hydrolytic degradation process, PLGA/PISEB fibers were found to swell and disintegrate, resulting in the formation of highly developed structures resembling seaweeds. It is expected that the change in the scaffold structure should have a positive effect on blood vessel regeneration, by allowing cells to penetrate the scaffold and grow within a 3D structure of PLGA/PISEB, as well as stabilizing newly-formed endothelium during hydrolytic expansion.

Effects of Isosorbide Incorporation into Flexible Polyurethane Foams: Reversible Urethane Linkages and Antioxidant Activity

Isosorbide (ISB), a nontoxic bio-based bicyclic diol composed from two fuzed furans, was incorporated into the preparation of flexible polyurethane foams (FPUFs) for use as a cell opener and to impart antioxidant properties to the resulting foam. A novel method for cell opening was designed based on the anticipated reversibility of the urethane linkages formed by ISB with isocyanate. FPUFs containing various amounts of ISB (up to 5 wt%) were successfully prepared without any noticeable deterioration in the appearance and physical properties of the resulting foams. The air permeability of these resulting FPUFs was increased and this could be further improved by thermal treatment at 160 °C. The urethane units based on ISB enabled cell window opening, as anticipated, through the reversible urethane linkage. The ISB-containing FPUFs also demonstrated better antioxidant activity by impeding discoloration. Thus, ISB, a nontoxic, bio-based diol, can be a valuable raw material (or additive) for eco-friendly FPUFs without seriously compromising the physical properties of these FPUFs.

Novel copolyimides containing 1,4:3,6-dianhydro-d-mannitol unit Preparation, characterization, thermal, mechanical, soluble, and optical properties

In order to obtain colorless and soluble polyimide films, a dianhydride containing 1,4:3,6-dianhydro-d-mannitol unit, 2,5-bis(3,4-dicarboxyphenoxy)-1,4:3,6-dianhydromannitol dianhydride (IMDA) was synthesized. And a series of copolyimides were prepared from IMDA, 1,2,4,5-benzenetetracarboxylic anhydride (PMDA), and 4,4′-oxydianiline by adjusting the mole fraction (between IMDA and PMDA) of IMDA from 0% to 100%. It was found that the solubility as well as the transmittance of the copolyimide films enhanced with the increased content of IMDA. Especially, when the content of IMDA was 60% or more, the copolyimides were readily soluble in common polar solvents and could afford flexible, tough, and colorless films with transparency up to 84% at 450 nm, which may be ascribed to the incorporation of the relatively twisted and flexible 1,4:3,6-dianhydro-d-mannitol units into the backbone of copolyimides. Additionally, the influence of IMDA on the thermal, mechanical, and morphological properties of copolyimides was investigated.

Facile preparation of stereochemistry-controllable biobased poly(butylene maleate-co-butylene fumarate) unsaturated copolyesters: a chemoselective polymer platform for versatile functionalization via aza-Michael addition

Biobased stereochemistry-controllable poly(butylene maleate-co-butylene fumarate) unsaturated copolyesters were facilely prepared as a chemoselective polymer platform for versatile functionalization via aza-Michael addition.