During CHO batch shake flask culture, lower fucosylation occurs with increasing glutamine concentration (0-8 mM) and it is thought that the glycolytic flux due to glutamine limitation affects glycosylation. Asparagine concentration has been reported to affect galactosylation levels. Cysteine as well as temperature changes are thought to reduce protein aggregation and increase its stability in the harvest. Oxidized forms of (povidone) cysteine reduce the formation of high molecular weight (HMW) forms and lead to more sialylation and higher protein harvest concentrations.
Polyvinylpyrrolidone is a kind of non-ionic water-soluble polymer fine chemical with excellent performance and wide application. It is polymerized by N-vinylpyrrolidone under certain conditions. It is a kind of fine chemical with characteristics, deep research and wide research among N-vinylamide functional group polymers. Since 1938, when German acetylene chemist Reppe publicly disclosed the method of synthesizing NVP and its polymer PVP using acetylene as raw material, the research on PVP has a history of more than 60 years. So far, PVP has developed into three categories: homopolymer, copolymer and cross-linked polymer. In recent years, ionic PVP has also been developed accordingly and has received more and more attention. PVP products have also developed into three specifications: industrial grade, pharmaceutical grade and food grade, dozens of varieties and hundreds of brands. PVP is widely used in industrial and agricultural production, people's lives and related scientific research departments due to its excellent performance. Now, the literature on the research and application of PVP and its monomer NVP is further developing at a rate of hundreds of articles per year.
PVP was invented as an artificial plasma solubilizer during World War II. Soon after, people found that PVP and its monomer NVP, especially PVP, not only have excellent solubility, chemical stability, film-forming property, low toxicity, physiological inertness, adhesion ability and protective adhesive effect, but also can be combined with many inorganic and chemical compounds. Therefore, since its launch, PVP has been gradually and widely used in medicine, cosmetics, food, brewing, coatings, adhesives, printing and dyeing auxiliaries, separation membranes, photosensitive materials and other fields. For example, in the pharmaceutical industry, PVP-I formed by the combination of PVP and is an excellent solvent, which has the same ability as I-alcohol solution without irritating the skin or being toxic to organisms.
