Toughening of Bio-Based PA 6.19 by Copolymerization with PA 6.6 - Synthesis and Production of Melt-Spun Monofilaments and Knitted Fabrics.

This work reports on the synthesis of statistical copolymers of bio-based PA 6.19 and PA 6.6 together with the production of melt-spun monofilaments for the production of sustainable textile fibers. The plant oil-based 1.19-nonadecanedioic acid is synthesized from bio-derived oleic acid via isomerizing methoxycarbonylation. The homopolymer PA 6.19 with a carbon-based bio-content of 72% shows a good elongation at break of 166%, but lower tensile strength than commercial PA 6 (43 MPa versus 82 MPa). Addition of adipic acid to form statistical PA 6.6/6.19 copolymers improves toughness while maintaining the high elongation at break. Two PA 6.6/6.19 copolymers with a carbon-based bio-content of 26% and 33% are successfully synthesized and exhibited comparable toughness (94  ±  6 MPa and 92  ±  2 MPa) to the commercial PA 6 (92  ±  15 MPa). The bio-based copolymers also exhibit a much lower water uptake than PA 6 and PA 6.6, resulting in a higher dimensional stability. Melt spinning of the oleic acid-based polyamides is successfully carried out to produce monofilaments with sufficient properties for further processing in a knitting process, demonstrating the capabilities of the bio-based PA 6.6/6.19 copolymers for use in the textile industry.

In Vitro Blood-Brain Barrier Permeability and Cytotoxicity of an Atorvastatin-Loaded Nanoformulation Against Glioblastoma in 2D and 3D Models.

Inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase of the family of statins have been suggested as therapeutic options in various tumors. Atorvastatin is a statin with the potential to cross the blood-brain barrier; however, the concentrations necessary for a cytotoxic effect against cancer cells exceed the concentrations achievable via oral administration, which made the development of a novel atorvastatin formulation necessary. We characterized the drug loading and basic physicochemical characteristics of micellar atorvastatin formulations and tested their cytotoxicity against a panel of different glioblastoma cell lines. In addition, activity against tumor spheroids formed from mouse glioma and mouse cancer stem cells, respectively, was evaluated. Our results show good activity of atorvastatin against all tested cell lines. Interestingly, in the three-dimensional (3D) models, growth inhibition was more pronounced for the micellar formulation compared to free atorvastatin. Finally, atorvastatin penetration across a blood-brain barrier model obtained from human induced-pluripotent stem cells was evaluated. Our results suggest that the presented micelles may enable much higher serum concentrations than possible by oral administration; however, if transport across the blood-brain barrier is sufficient to reach the therapeutic atorvastatin concentration for the treatment of glioblastoma via intravenous administration remains unclear.