Thiol­(-click) chemistry has been extensively investigated to conjugate (bio)­molecules to polymers. Handling of cysteine-containing molecules may however be cumbersome, especially in the case of fast-oxidizing coiled-coil-forming peptides. In the present study, we investigated the practicality of a one-pot process to concomitantly reduce and conjugate an oxidized peptide to a polymer. Three thiol-based conjugation chemistries (vinyl sulfone (VS), maleimide, and pyridyldithiol) were assayed along with three reducing agents (tris­(2-carboxyethyl)­phosphine (TCEP), dithiothreitol, and β-mercaptoethanol). Seven out of the nine possible combinations significantly enhanced the conjugation yield, provided that an adequate concentration of reductant was used. Among them, the coincubation of an oxidized peptide with TCEP and a VS-modified polymer displayed the highest level of conjugation. Our results also provide insights into two topics that currently lack consensus: TCEP is stable in 10 mM phosphate buffered saline and it reacts with thiol-alkylating agents at submillimolar concentrations, and thus should be carefully used in order to avoid interference with thiol-based conjugation reactions.

Extubation failure can occur in 10 to 25% of patients who were successfully separated from their ventilator. In which case, patients need to be re-intubated. To reduce the extubation failure rate, we monitor patients during 48h after extubation using Electrical Impedance Tomography (EIT). In total, we recruited 34 patients from which 8 failed their extubation in the ICU ward. Prediction of extubation success or failure using only non-invasive EIT data show a sensitivity of 0.80 and a specificity of 0.73. The prediction for the 8 extubation failures was accurate for most right after the extubation and achieved 100% accuracy for the measurement set preceding the failure.