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Order Articulavirales
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
For purification of influenza VLPs, a nitrocellulose membrane-based filtration system (Park and Song 2017) and a cascade of ultrafiltration and diafiltration steps, followed by a sterile filtration step (Geisler and Jarvis 2018; Carvalho et al. 2019), were used successfully. The bioprocessing of influenza VLPs was recently reviewed (Durous et al. 2019).
Manufacturing arthropod and mammalian allergen extracts
Published in Richard F. Lockey, Dennis K. Ledford, Allergens and Allergen Immunotherapy, 2020
Enrique Fernández-Caldas, Eva Abel Fernández, Jonathan Kilimajer, Seong H. Cho
A general guide for the preparation of allergen extracts of mites and insects follows: Weigh the desired amount of source material in a 1:20 weight/volume ratio of a specific buffer, i.e., phosphate buffer saline (PBS), at 4°C for 4–8 hours under continuous stirring conditions. Other weight/volume ratios can also be used. Afterward, adjust the pH between 7.5 and 8.5 by the addition of NaOH or HCl. The careful selection of the extraction buffer is a key issue, as has been previously demonstrated [40]. In some cases, a double extraction of the source material can be performed. Once the extraction is completed, centrifuge the recovered extract volume in a centrifuge at 10,000 rpm for 30 minutes at 4°C (the centrifuge must be cooled down in advance). Afterward, carefully separate the supernatant and discard the pellet. Filtrate the obtained extract in a filter cascade until going through a 0.2 μm pore size filter. A diafiltration (dialysis) step is now performed in a Pellicon tangential flow filtration system (Pellicon, Merck Millipore), using a cassette of 5 kDa cutoff. The dialysis process should be performed with five times the same volume of ultrapure. The conductivity in the last step must be lower than 500 ppm (approximately 800 μS/cm). Once the extract is dialyzed, aliquot the extract in 50 mL freeze-drying vials (previously cleaned and labeled) and freeze-dry it according to the program selected. After the freeze-drying cycle is completed, the extract is ready to be diluted to the desired concentration, and after several manufacturing steps, it is ready to be used.
Bioprocess Parameters of Production of Cyanobacterial Exopolysaccharide
Published in Gokare A. Ravishankar, Ranga Rao Ambati, Handbook of Algal Technologies and Phytochemicals, 2019
Onkar Nath Tiwari, Sagnik Chakraborty, Indrama Devi, Abhijit Mondal, Biswanath Bhunia, Shen Boxiong
Ramus (Ramus 1972) reported segregation of the “encapsulating polysaccharide” from Porphyridium biomass. Red microalgae produces sulfated polysaccharides dissolvable within the nutrient media. The removal of color from biomass was achieved by applying the acetone along with ethanol, further solubilization of exopolysaccharide glue from porphyridium cells was achieved using warm water. Another study also reports the use of absolute alcohol or isopropanol (Liu et al. 2015; Patel et al. 2013). The yield of polysaccharide is influenced by temperature of precipitation and polarity of alcohol. This technique robustly yields EPS. The method possesses specific merits like further recycling the alcohol via distillation to modify extremely viscid solution. Patel et al. (Patel et al. 2013) delineated the extraction and salting out of EPS from Porphyridium cruentum applying the alcoholic precipitation, separation via membrane method. Furthermore, they have inferred the application of diafiltration employing 300 kDa membrane as a highly effective technique. Occasionally, an additional refinement phase is necessary to remove the undesired molecules like proteins, pigments, salts and another compounds via trichloroacetic acid modification, peripheral ultrafiltration, or precipitation by using alcohol (Li et al. 2011; Patel et al. 2013).
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.
Dissecting the molecular basis of high viscosity of monospecific and bispecific IgG antibodies
Published in mAbs, 2020
Cholpon Tilegenova, Saeed Izadi, Jianping Yin, Christine S. Huang, Jiansheng Wu, Diego Ellerman, Sarah G. Hymowitz, Benjamin Walters, Cleo Salisbury, Paul J. Carter
Antibodies are the largest class of biologic drugs, with over 80 antibodies approved1 for the treatment of a broad range of human diseases.2 Most approved antibody drugs are delivered by either intravenous (IV) infusion or subcutaneous (SC) injection.2 SC delivery is increasingly used because it can potentially decrease administration time from hours to minutes, increase patient convenience by enabling at-home injection and reduce associated health-care costs.3,4 A notable challenge with SC administration is injection volumes, which are typically small (up to 1.5 mL) and necessitate the formulation of antibodies at high concentration (>150 mg/mL) to deliver the required dose. Non-covalent interactions of antibodies at high concentrations can lead to high viscosity, making injection difficult and painful.5 Furthermore, elevated viscosity of antibody solutions can lead to problems in manufacturing, including ultrafiltration and diafiltration steps, as well as vialing.5–7
Systematic determination of the relationship between nanoparticle core diameter and toxicity for a series of structurally analogous gold nanoparticles in zebrafish
Published in Nanotoxicology, 2019
Lisa Truong, Tatiana Zaikova, Brandi L. Baldock, Michele Balik-Meisner, Kimberly To, David M. Reif, Zachary C. Kennedy, James E. Hutchison, Robert L. Tanguay
Chemicals. Hydrogen tetrachloroaurate (HAuCl4·H2O) was purchased from Strem (Newburyport, MA) and used as received. Dichloromethane (DCM) and chloroform (CHCl3) was purchased from Fisher Scientific. Chloroform was filtered through the plug of basic alumina to remove acidic impurities. Thiocholine (N,N,N-trimethylammonium ethanethiol trifluoroacetate) (TMAT) was synthesized according to the published procedure (Kim et al. 2013; Warner and Hutchison 2003). All other compounds were purchased from Sigma-Aldrich (St. Louis, MO) and used as received. Nanopure water (18.2 MΩ·cm resistivity) was prepared with a Barnstead Nanopure filtration system and used for all aqueous samples. The samples synthesized were purified either by diafiltration (Sweeney, Woehrle and Hutchison, 2006) using polyethersulfone diafiltration membranes (OmegaTM 10 kDa or 100 kDa PES ultrafiltration membrane) obtained from Pall Life Sciences (Port Washington, NY) or by size exclusion chromatography (Sephadex G-50 Fine, GE Healthcare). Carboxyl-functionalized SMART grids for TEM imaging were purchased from Dune Sciences (Eugene, OR).