RESUMEN
A decrease in CO2 emissions is urgently required in the present situation due to the fast growth of carbon dioxide (CO2) in the atmosphere, which has caused a series of global climate issues. This study used an impregnation-evaporation method to immobilize an amino functionalized ionic liquid [C2OHmim][Lys] on a chromatographic column filler GDX-103 and create a novel supported ionic liquid. The results showed that the supported ionic liquid with 60 wt % ionic liquid content had the best adsorption performance at 40 °C, and the CO2 adsorption isotherm showed that the adsorption capacity at 0.1 MPa was 1.29 mmol CO2/g sorbent, which was 6 times greater than the adsorption capacity of the pure carrier. The sample with 60% ionic liquid content has an adsorption capacity of 1.02 mmol CO2/g sorbent under the condition of CO2/N2 mixed gas with 10% CO2 content. This is 43 times greater than the adsorption capacity of the pure carrier, and its adsorption performance is stable after three adsorption and desorption cycles. Through the rich porous structure of GDX-103, the ionic liquid is effectively supported and dispersed, which expands the contact area between CO2 and ionic liquid and enhances the mass transfer of CO2. At the same time, CO2 can be chemically bound to the groups on the anion of ionic liquid and be immobilized, so it has a high selective adsorption capacity of CO2, which makes it a great alternative to traditional CO2 adsorbents.
RESUMEN
Glycation has been observed in antibody therapeutics manufactured by the fed-batch fermentation process. It not only increases the heterogeneity of antibodies, but also potentially affects product safety and efficacy. In this study, non-glycated and glycated fractions enriched from a monoclonal antibody (mAb1) as well as glucose-stressed mAb1 were characterized using a variety of biochemical, biophysical and biological assays to determine the effects of glycation on the structure and function of mAb1. Glycation was detected at multiple lysine residues and reduced the antigen binding activity of mAb1. Heavy chain Lys100, which is located in the complementary-determining region of mAb1, had the highest levels of glycation in both stressed and unstressed samples, and glycation of this residue was likely responsible for the loss of antigen binding based on hydrogen/deuterium exchange mass spectrometry analysis. Peptide mapping and intact liquid chromatography-mass spectrometry (LC-MS) can both be used to monitor the glycation levels. Peptide mapping provides site specific glycation results, while intact LC-MS is a quicker and simpler method to quantitate the total glycation levels and is more useful for routine testing. Capillary isoelectric focusing (cIEF) can also be used to monitor glycation because glycation induces an acidic shift in the cIEF profile. As expected, total glycation measured by intact LC-MS correlated very well with the percentage of total acidic peaks or main peak measured by cIEF. In summary, we demonstrated that glycation can affect the function of a representative IgG1 mAb. The analytical characterization, as described here, should be generally applicable for other therapeutic mAbs.
