02238nas a2200229   4500008004100000022001400041245012200055210006900177260000900246300001100255490000800266520144400274653001601718653001401734653001801748653001401766653003601780653002901816100001701845700001901862856012701881       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  uhttps://library.ncl.res.in/content/towards-situ-continuous-feeding-controlled-release-complete-nutrients-fed-batch-culture02437nas a2200253   4500008004100000022001400041245012000055210006900175260000800244490000700252520159800259653001601857653002401873653001401897653001601911653000901927100001701936700002101953700001901974700002301993700001802016700001902034856013002053       2023                        eng d  a8756-793800aAmino acid abundance and composition in cell culture medium affects trace metal tolerance and cholesterol synthesis0 aAmino acid abundance and composition in cell culture medium affe  cJAN0 v393 a<p>
	Amino acid compositions of cell culture media are empirically designed to enhance cell growth and productivity and vary both across media formulations and over the course of culture due to imbalance in supply and consumption. The interconnected nature of the amino acid transporters and metabolism suggests that changes in amino acid composition can affect cell physiology. In this study, we explore the effect of a step change in amino acid composition from a DMEM: F12-based medium to a formulation varying in relative abundances of all amino acids, evaluated at two amino acid concentrations (lean LAA vs. rich HAA). Cell growth was inhibited in LAA but not HAA. In addition to the expected effects on expression of the cell cycle, amino acid response and mTOR pathway genes in LAA, we observed an unanticipated effect on zinc uptake and efflux genes. This was accompanied by a lower tolerance to zinc supplementation in LAA but not in the other formulations. Histidine was sufficient but not necessary to prevent such zinc toxicity. Additionally, an unanticipated downregulation of genes in the cholesterol synthesis pathway was observed in HAA, accompanied by an increase in cellular cholesterol content, which may depend on the relative abundances of glutamine and other amino acids. This study shows that changes in the amino acid composition without any evident effect on growth may have profound effects on metabolism. Such analyses can help rationalize the designing of medium and feed formulations for bioprocess applications beyond replenishment of consumed components.</p>
10aAmino acids10acell culture medium10aCHO cells10aCholesterol10azinc1 aRawat, Jyoti1 aBhambri, Aksheev1 aPandey, Ujjiti1 aBanerjee, Sanchita1 aPillai, Beena1 aGadgil, Mugdha  uhttps://library.ncl.res.in/content/amino-acid-abundance-and-composition-cell-culture-medium-affects-trace-metal-tolerance-and