In the last decades bioresorbable and biodegradable polymers have gained a very good reputation both in research and in industry thanks to their unique characteristics. They are able to ensure high performance and biocompatibility, at the same time avoiding post-healing surgical interventions for device removal. In the medical device industry, it is widely known that product formulation and manufacturing need to follow specific procedures in order to ensure both the proper mechanical properties and desired degradation profile. Moreover, the sterilization method is crucial and its impact on physical properties is generally underestimated. In this work we focused our attention on the effect of different terminal sterilization methods on two commercially available poly(l-lactide-co-ε-caprolactone) with equivalent chemical composition (70% PLA and 30% PCL) and relatively similar initial molecular weights, but different chain arrangements and crystallinity. Results obtained show that crystallinity plays a key role in helping preserve the narrow distribution of chains and, as a consequence, defined physical properties. These statements can be used as guidelines for a better choice of the most adequate biodegradable polymers in the production of resorbable medical devices.

Lithium-ion batteries are the key for modern electricity-based transportation systems and more generally for sustainable large-scale energy applications. However, typical commercial batteries seldom meet safety regulations because of the presence of organic, flammable, and volatile liquid electrolytes, and viable alternatives need to be found. Ionic liquids (IL) are considered to be one of the most promising candidates, when combined with a polymer matrix to form the so-called gel polymer electrolyte, working as separator. Along this line, a new, purely water-based methodology has been developed in this work to produce thin separators. This involves the formation of fractal polymer clusters (PCs) through intense shear-driven gelation of poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP) nanoparticles in water, impregnation of the IL (Pyr13TFSI-LiTFSI) solution into the dried PCs, and hot-pressing to form continuous, porous, and transparent membranes. Because of the large amount of pores generated in the fractal structures with well-defined pore dimensions, the impregnated IL solution forms a continuous phase in the PC-IL matrix without any dead volume, thus forming a bicontinuous structure and presenting good ionic conductivity. The formed membrane has been used as the separator to assemble a half-coin cell having LiFePO 4 and Li as the cathode and the counter electrode, respectively, which is tested at 60 °C. The electrochemical performances of the cell are excellent not only at low but also at high current densities. The parameters affecting the performance of the membrane have been investigated, and the proper optimal preparation conditions have been proposed.

Cells form stress granules (SGs) upon stress stimuli to protect sensitive proteins and RNA from degradation. In the yeast , specific stresses such as nutrient starvation and heat-shock trigger recruitment of the yeast pyruvate kinase Cdc19 into SGs. This RNA-binding protein was shown to form amyloid-like aggregates that are physiologically reversible and essential for cell cycle restart after stress. Cellular Cdc19 exists in an equilibrium between a homotetramer and monomer state. Here, we show that Cdc19 aggregation is governed by protein quaternary structure, and we investigate the physical-chemical basis of Cdc19's assembly properties. Equilibrium shift toward the monomer state exposes a hydrophobic low-complexity region (LCR), which is prone to induce intermolecular interactions with surrounding proteins. We further demonstrate that hydrophobic/hydrophilic interfaces can trigger Cdc19 aggregation Moreover, we performed biophysical analyses to compare Cdc19 aggregates with fibrils produced by two known dysfunctional amyloidogenic peptides. We show that the Cdc19 aggregates share several structural features with pathological amyloids formed by human insulin and the Alzheimer's disease-associated Aβ42 peptide, particularly secondary β-sheet structure, thermodynamic stability, and staining by the thioflavin T dye. However, Cdc19 aggregates could not seed aggregation. These results indicate that Cdc19 adopts an amyloid-like structure that is regulated by the exposure of a hydrophobic LCR in its monomeric form. Together, our results highlight striking structural similarities between functional and dysfunctional amyloids and reveal the crucial role of hydrophobic/hydrophilic interfaces in regulating Cdc19 aggregation.