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Fusarium solani cutinase catalyzes the synthesis of glycerides through the monomolecular film technique. Surface pressure is a critical factor in this process, in which glycerol replaces the water subphase. Acylation of the oleic acid film spread on the surface of glycerol occurs within a few minutes after the reaction begins. This reaction is very quick and can be extended to the synthesis of diolein or triolein.

Abstract Background Serum and high ionic strength solutions constitute important barriers to cationic lipid-mediated intravenous gene transfer. Preparation or incubation of lipoplexes in these media results in alteration of their biophysical properties, generally leading to a decrease in transfection efficiency. Accurate quantification of these changes is of paramount importance for the success of lipoplex-mediated gene transfer in vivo. Results In this work, a novel time-resolved fluorescence resonance energy transfer (FRET) methodology was used to monitor lipoplex structural changes in the presence of phosphate-buffered saline solution (PBS) and fetal bovine serum. 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP)/pDNA lipoplexes, prepared in high and low ionic strength solutions, are compared in terms of complexation efficiency. Lipoplexes prepared in PBS show lower complexation efficiencies when compared to lipoplexes prepared in low ionic strength buffer followed by addition of PBS. Moreover, when serum is added to the referred formulation no significant effect on the complexation efficiency was observed. In physiological saline solutions and serum, a multilamellar arrangement of the lipoplexes is maintained, with reduced spacing distances between the FRET probes, relative to those in low ionic strength medium. Conclusion The time-resolved FRET methodology described in this work allowed us to monitor stability and characterize quantitatively the structural changes (variations in interchromophore spacing distances and complexation efficiencies) undergone by DOTAP/DNA complexes in high ionic strength solutions and in presence of serum, as well as to determine the minimum amount of potentially cytotoxic cationic lipid necessary for complete coverage of DNA. This constitutes essential information regarding thoughtful design of future in vivo applications.

Abstract: BACKGROUND: Monoclonal antibodies are becoming a leading class of biopharmaceuticals but to increase their accessibility by the general population, new production processes must be developed in particular for the downstream processing. RESULTS: In this work, an alternative and innovative affinity chromatographic method using quaternary amine matrices is proposed. Separation is driven by the dual affinity ligand LYTAG‐Z, composed of a choline binding polypeptide (LYTAG) and the synthetic antibody binding Z domain. A two‐elution method was developed for the purification of mAbs and the performance of different anion exchangers containing quaternary amines that act as choline analogues – CIMmultus Q, Q Sepharose and gPore Q – were tested and compared, with both CIMmultus Q and Q Sepharose allowing a recovery of more than 94% of mAbs from a CHO cell supernatant with a purity greater than 95%. An integrated platform combining an initial affinity extraction step for the clarification and capture of mAbs and a subsequent chromatographic separation using Q‐matrices for the polishing of mAbs is also proposed. LYTAG‐Z triggers the extraction of 94.7 ± 1.7% mAbs to the PEG‐rich phase, as opposed to 26.9 ± 0.6% in the absence of the ligand, using 7% PEG 3350 and 6% dextran 500 k. Further purification using Q Sepharose allowed a mAb recovery of 95.3 ± 1.4% with a purity level of 91.4 ± 13.0%. CONCLUSION: An integrated platform based on two purification steps – affinity extraction and affinity chromatography – results in an overall process yield of 90%, allowing the processing of mAbs directly from a non‐clarified CHO cell culture. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]