Screening of the supercritical impregnation of Olea europaea leaves extract into filaments of thermoplastic polyurethane (TPU) and polylactic acid (PLA) intended for biomedical applications

MACHADO, NOELIA D.; CEJUDO-BASTANTE, CRISTINA; GOÑI, MARÍA L.; GAÑAN, NICOLÁS A.; CASAS-CARDOSO, LOURDES; MANTELL-SERRANO, CASIMIRO

ANTIOXIDANTS

MPDI

Lugar: Basilea; Año: 2022 vol. 11 p. 1 - 20

2076-3921

The leaves of Olea europaea as agricultural waste represent a convenient source of antioxidants. In combination with supercritical CO2 (scCO2), assisted impregnation is an interesting strategyfor the preparation of biomedical devices with specific bioactivity. For this purpose, 3D-printablefilaments of thermoplastic polyurethane (TPU) and polylactic acid (PLA) were employed for thesupercritical impregnation of ethanolic olive leaves extract (OLE) for biomedical application. Theextraction of OLE was performed using pressurized liquids. The effect of pressure (100–400 bar),temperature (35–55 ◦C), and the polymer type on the OLE impregnation and the swelling degreewere studied including a morphological analysis and the measurement of the final antioxidant activity. All the studied variables as well as their interactions showed significant effects on the OLEloading. Higher temperatures favored the OLE loading while the pressure presented opposite effectsat values higher than 250 bar. Thus, the highest OLE loadings were achieved at 250 bar and 55 ◦C for both polymers. However, TPU showed c.a. 4 times higher OLE loading and antioxidant activity incomparison with PLA at the optimal conditions. To the best of our knowledge, this is the first reportusing TPU for the supercritical impregnation of a natural extract with bioactivity.