02044nas a2200265   4500008004100000022001400041245013100055210006900186260000800255300001000263490000800273520112000281653003401401653001401435653001401449653001401463653003801477653003501515653001601550100002501566700002001591700001801611700001801629856013101647       2020                        eng d  a0168-165600aEnhancing titers and productivity of rCHO clones with a combination of an optimized fed-batch process and ER-stress adaptation0 aEnhancing titers and productivity of rCHO clones with a combinat  cMAR  a49-580 v3113 a<p>To increase the productivity of rCHO cells, many cell engineering approaches have been demonstrated that over-express or knockout a specific gene to achieve increased titers. In this work, we present an alternate approach, based on the concept of evolutionary adaptation, to achieve cells with higher titers. rCHO cells, producing a monoclonal antibody, are adapted to ER-stress, by continuous culturing under increasing concentration of tunicamycin. A sustained higher productivity of at-least 2-fold was achieved in all the clones, in a concentration-dependent manner. Similarly, a 1.5-2 fold increase in final titers was also achieved in the batch culture. Based on metabolic analysis of the adapted cells, a fed-batch process was designed where significantly higher titersare achieved as compared to control. Metabolic flux analysis is employed in addition with gene expression analysis of key genes to understand the basis of increased performance of the adapted cells. Overall, this work illustrates how process modifications and cellular adaptation can be used in synergy to drive up product titers.</p>
10aAdaptive laboratory evolution10aCHO cells10aER-stress10aFed-batch10aIncreased productivity and titers10aRecombinant protein production10aUPR pathway1 aChandrawanshi, Vikas1 aKulkarni, Rohan1 aPrabhu, Anuja1 aMehra, Sarika  uhttp://library.ncl.res.in/content/enhancing-titers-and-productivity-rcho-clones-combination-optimized-fed-batch-process-and-er02237nas a2200229   4500008004100000022001400041245012200055210006900177260000900246300001100255490000800266520144400274653001601718653001401734653001801748653001401766653003601780653002901816100001701845700001901862856012601881       2020                        eng d  a1369-703X00aTowards in situ continuous feeding via controlled release of complete nutrients for fed-batch culture of animal cells0 aTowards in situ continuous feeding via controlled release of com  cFEB   a1074360 v1543 a<p>Small-scale culture of animal cells in suspension is of importance for many applications. At a small-scale, fed-batch is achieved either by manual bolus feeding or the use of liquid handling robots. In this study, we report an alternate application of a hydrogel for in situ continuous delivery of a nutrient feed comprising 18 amino acids, vitamins, antioxidants, and trace elements. We show that amino acid release is sustained for at least seven days. Importantly, release rates of individual amino acids can be independently modulated by changing their loading. We demonstrate the application of this hydrogel for complete in situ feeding of nutrients to a suspension adapted CHO cell line expressing IgG leading to 2.7-fold and 4-fold improvement in integral viable cell density (IVCD) and volumetric productivity respectively. This is similar to improvements obtained by bolus liquid feeding. Further, supplying glucose from the same hydrogel to eliminate manual feeding led to a 1.8-fold increase in IVCD accompanied by a 3-fold increase in volumetric productivity as compared to batch culture. In summary, this study provides a proof-of-concept that hydrogels can enable completely closed in situ feeding for mammalian cell culture requiring no external intervention. Such continuous in situ delivery can potentially enable closed culture systems maintaining nutrients at low levels mimicking physiological concentrations.</p>
10aAmino acids10aCHO cells10aClosed system10aFed-batch10aHydrogel for continuous feeding10aIn situ nutrient release1 aRawat, Jyoti1 aGadgil, Mugdha  uhttp://library.ncl.res.in/content/towards-situ-continuous-feeding-controlled-release-complete-nutrients-fed-batch-culture