Polymeric Microfiltration Membranes Modification by Supercritical Solvent Impregnation—Potential Application in Open Surgical Wound Ventilation

Abstract

This study investigated supercritical solvent impregnation of polyamide microfiltration membranes with carvacrol and the potential application of the modified membranes in ventilation of open surgical wounds. The impregnation process was conducted in batch mode at a temperature of 40 °C under pressures of 10, 15, and 20 MPa for contact times from 1 to 6 h. FTIR was applied to confirm the presence of carvacrol on the membrane surface. In the next step, the impact of the modification on the membrane structure was studied using scanning electron and ion beam microscopy and cross-filtration tests. Further, the release of carvacrol in carbon dioxide was determined, and finally, an open thoracic cavity model was applied to evaluate the efficiency of carvacrol-loaded membranes in contamination prevention. Carvacrol loadings of up to 43 wt.% were obtained under the selected operating conditions. The swelling effect was detectable. However, its impact on membrane functionality was minor. An average of 18.3 µg of carvacrol was released from membranes per liter of carbon dioxide for the flow of interest. Membranes with 30–34 wt.% carvacrol were efficient in the open thoracic cavity model applied, reducing the contamination levels by 27% compared to insufflation with standard membranes.

Supercritical Foaming and Impregnation of Polycaprolactone and Polycaprolactone-Hydroxyapatite Composites with Carvacrol

“…Overall, satisfactory impregnation yields (7.22-10.57 wt.%) were achieved for all the samples at the studied conditions. Nevertheless, these impregnation yields were lower than the reported for carvacrol in other polymers such as cellulose acetate films (31 wt.%) [52] and polyamide membranes (40 wt.%) [53] using similar processing conditions, which evidence the low chemical affinity between carvacrol and PCL. Interestingly, the reported impregnation yield of thymol (14.8 wt.%) in pure PCL [20] was considerably higher than the obtained in this study for carvacrol in the pure PCL scaffolds using very similar processing conditions (7.22-7.71 wt.%), even considering the great chemical similarity between both phenolic compounds.…”

Cellulose Acetate Membranes Modification by Aminosilane Grafting in Supercritical Carbon Dioxide towards Antibiofilm Properties

“…Our previous studies demonstrated that it was possible to modify commercial polyamide and cellulose acetate microfiltration membranes by impregnation in scCO 2 with thymol and carvacrol as antibacterial agents [4,27,28] . The active substance loadings over 30% were possible without membranes microstructure disturbance.…”