Algal Polysaccharides
Gokare A. Ravishankar, Ranga Rao Ambati in Handbook of Algal Technologies and Phytochemicals, 2019
Filtration techniques seem well suited for initial extraction and purification steps at industrial scale as they can be automated; and permit to treat large volumes of samples (Patel et al. 2013). However, the widespread application of membranes has been hindered due to excessive membrane fouling which could result in reduced performance, severe flux decline, high energy consumption and frequent membrane cleaning or replacement (Feng et al. 2009). Recent studies focused on achieving a better understanding of anti-fouling agents (Feng et al. 2009) and other strategies to reduce fouling. For example the addition of an initial high-molecular weight cut-off membrane before the ultrafiltration step reduces the fouling of the membranes when extracting bacterial oligosaccharides (Mellal et al. 2008).
Understanding Fragrance: From Chemistry to Emotion
Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters in Cosmetic Formulation, 2019
Other fragrance ingredients that are now routinely produced synthetically are lilial (lilly aldehyde), linalool, geraniol, musk derivatives (musk ketone, musk xylene, moskene, etc.), civetone (a macrocyclic ketone and main scent of civet) and muscone (15-membered ring ketone that provides the odour of musk). The goal is to develop a synthetic pathway with the minimum number of synthetic steps, a high process yield and minimum residue molecules. This will also simplify the purification process. Compared to the isolation of a single molecule from a natural source, there is considerable skill required to develop the best chemical reaction pathway with the lowest number of steps and high process yield to form a few different residue molecules. In addition the purification process should not be time-consuming or costly, but it is essential that impurities are removed, as even small amounts of these will incur regulatory restrictions or have a health/environmental impact. Whilst there are many benefits in terms of control of supply of the material, the final cost of the molecule should not be significantly more expensive compared to natural sources.
CMC Requirements for Biological Products
Shein-Chung Chow in Analytical Similarity Assessment in Biosimilar Product Development, 2018
The goals for fermentation are to increase the expression level of a deficiency without compromising the correct amino acid sequence and post-translational modification. Achieving high expression requires optimizing culture medium and growth conditions, and efficient extraction and recovery procedures. The correct amino acid sequence and post-translation modification will need to be verified. Solubilization and refolding of insoluble proteins are sometimes necessary for proteins which have a tendency to aggregate under the processing conditions. Differences in the cell bank and production processes may create impurities that are different from the innovator’s product. The purification process needs to remove impurities such as host-cell proteins, DNA, medium constituents, viruses, and metabolic by-products as much as possible. It is important for biosimilar manufacturers to accept appropriate yield losses to achieve high purity, because any increase in yield at the expense of purity is unacceptable and can have clinical consequences. The final product is produced by going through formulation, sterile-filtration, and fill/finish into the final containers. Selection of formulation components starts from basic buffer species for proper pH control and salt for isotonicity adjustment. Surfactants may be needed to prevent proteins from being absorbed onto container surfaces or water-air interface or other hydrophobic surfaces. Stabilizers are required to inhibit aggregation, oxidation, deamidations and other degradations. The container and closure system can be glass vials, rubber stoppers, and aluminum seals or pre-filled syringes or IV bags. The container and closure integrity need to be verified by sterility or dye-leak tests.
Virus-like particle-based nanocarriers as an emerging platform for drug delivery
Published in Journal of Drug Targeting, 2023
Bingchuan Yuan, Yang Liu, Meilin Lv, Yilei Sui, Shenghua Hou, Tinghui Yang, Zakia Belhadj, Yulong Zhou, Naidan Chang, Yachao Ren, Changhao Sun
To produce VLPs for clinical use, purification is required. The main purpose of purification is to remove host cell proteins and process-derived impurities from the VLP concentrate [129]. Super-centrifugal purification methods in sucrose or CsCl gradients are usually sufficient to obtain suitable VLPs for subsequent application, especially on a laboratory-scale or using small-scale processes. Hillebrandt et al. reported a new purification method known as crossflow filtration [143]. The application of a super-centrifugal method is limited in industrial production because of the risk of VLP aggregation, high labour intensity and the lack of scalability [138]. Therefore, it is necessary to purify VLPs using special chromatography techniques rather than super-centrifugation. Depending on the VLP properties, different ion exchange-, affinity- and size-exclusion columns can be used for purification. Diafiltration and tangential flow filtration are also used to scale up VLP production.
Development of an algorithm for effective design of respirator half-masks and encapsulated particle filters
Published in International Journal of Occupational Safety and Ergonomics, 2022
Serhii Cheberyachko, Yurii Cheberyachko, Mykola Naumov, Oleg Deryugin
As a result of the performed work, the algorithm for designing and manufacturing filter masks of the dust respirator, which consists of several stages, was worked out and improved. In the first stage, the dimensions of faces of potential consumers were defined, and then the dimensions obtained were applied to a 3D head model on which the contour of a half-mask obturator was constructed. We paid attention to the difficulties that were associated with different thickness and elasticity of different parts of the face, which could affect the obturator design to ensure uniformity of clamping forces and minimal impact on blood circulation in the soft tissues of the worker’s face. Then, we selected the appropriate dust respirator structure (number of particle filter layers, needed respiration valve) depending on the concentration and properties of aerosols and operating conditions and the type of particle filter material depending on the characteristics of harmful aerosols (diameter of aerosol particles, toxicity, hazard class). This process was described in detail by Makowski and Okrasa [23] and by Hayashi and Tokura [24]. It should be noted that the modern development level of particle filter materials allows for a high degree of air purification.
Regenerative responses of rabbit corneal endothelial cells to stimulation by fibroblast growth factor 1 (FGF1) derivatives, TTHX1001 and TTHX1114
Published in Growth Factors, 2021
Jessica Weant, David D. Eveleth, Amuthakannan Subramaniam, Jennifer Jenkins-Eveleth, Michael Blaber, Ling Li, David M. Ornitz, Asaf Alimardanov, Trevor Broadt, Hui Dong, Vinay Vyas, Xiaoyi Yang, Ralph A. Bradshaw
TTHX1001, containing K12V, C117V, and P134V substitutions was expressed as the N-Phe, 140 amino acid form of human FGF1 as described (Xia et al. 2012). Some preparations also had an N-terminal extension containing a His-tag sequence for purification purposes (Brych et al. 2001). TTHX1114, which is characterised by C16S, A66C and C117V mutations, where an intrachain disulphide bond is also formed between C83 and the substituted cysteine at 66, was prepared as the N-Phe 140 residue structure as above and as the N-Met-FGF1 (141-amino acid form) by the Frederick National Laboratory for Cancer Research, Biopharmaceutical Development Program, and supplied to Trefoil through a CRADA collaboration with the NCATS TRND program. Both derivatives are annotated as the 140-residue sequence (Jaye et al. 1986). TTHX1001 has the most sensitive cysteine at 117 (Ortega et al. 1991) replaced while TTHX1114 has no free thiols.
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