Increasing robustness, reliability and storage stability of critical reagents by freeze-drying

Bioanalysis ◽  
2021 ◽  
Author(s):  
Thomas Emrich ◽  
Jan Olaf Stracke ◽  
Xiaoying Guo ◽  
Kari Damhjell ◽  
Joerg Moelleken ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Functional Performance ◽  
Attractive Alternative ◽  
Drying Process ◽  
Ambient Temperatures ◽  
Model Protein ◽  
Stable Performance ◽  
And Storage ◽  
Generic Process

Aim: Stabilization of critical reagents by freeze-drying would facilitate storage and transportation at ambient temperatures, and simultaneously enable constant reagent performance for long-term bioanalytical support throughout drug development. Freeze-drying as a generic process for stable performance and storage of critical reagents was investigated by establishing an universal formulation buffer and lyophilization process. Results: Using a storage-labile model protein, formulation buffers were evaluated to preserve reagent integrity during the freeze-drying process, and to retain functional performance after temperature stress. Application to critical reagents used in pharmacokinetics and anti-drug antibodies assays demonstrated stable functional performance of the reagents after 11 month at +40°C. Conclusion: Stabilization and storage of critical assay reagents by freeze-drying is an attractive alternative to traditional deep freezing.

scholarly journals Stability of pseudorabies virus during freeze-drying and storage: effect of suspending media

1976 ◽  
Vol 4 (1) ◽  
pp. 1-5
Author(s):  
E M Scott ◽  
W Woodside
Keyword(s):  
Freeze Drying ◽  
Pseudorabies Virus ◽  
Storage Effect ◽  
Drying Process ◽  
Sodium Glutamate ◽  
Degree Of Protection ◽  
The Stability ◽  
Subsequent Storage ◽  
And Storage ◽  
Lactalbumin Hydrolysate

The effect of suspending media on the stability of pseudorabies virus upon freeze-drying and subsequent storage was studied. A variety of media was tested, including: sodium glutamate; sucrose; lactose; lactalbumin hydrolysate; peptone; a combination of sucrose, dextran, and glutamate; and various combinations of sucrose, glutamate, and potassium phosphates. Suspending media containing glutamate, either alone or in combination with sucrose and either dextran or phosphates, afforded the greatest degree of protection during the freeze-drying process and upon storage. Some possible functions of these additives in preventing injury to the virus during freezing and drying have been suggested.

Greenhouse Heating With a Fresh Water Floating Collectors Solar Pond: A Feasibility Study

1991 ◽  
Vol 113 (2) ◽  
pp. 66-72 ◽  
Author(s):  
A. Arbel ◽  
M. Sokolov
Keyword(s):  
Fresh Water ◽  
Heating System ◽  
Radiation Absorption ◽  
Attractive Alternative ◽  
Solar Absorption ◽  
Solar Pond ◽  
Radiation Properties ◽  
And Storage ◽  
Conventional Oil

The fresh water floating collectors solar pond was investigated both experimentally and theoretically in a previous work, and it is now matched, by simulation, with the heat load requirements of a greenhouse. Results of the simulation indicate that such a pond is a potential energy source for greenhouse heating. This is especially true when the material properties are such that solar absorption and storage are enhanced. To demonstrate this point, three sets of collectors constructed with materials of different physical (radiation) properties were tested. One set is constructed of common materials which are readily available and are normally used as covers for greenhouses. The second set is made of improved materials which are also available but have a smaller long-wave transmittance. The last set is made of “ideal” material which additionally possesses selective radiation absorption properties. Collectors made of “ideal” materials make a superior solar pond; thus, manufacturing films with improved properties should become a worthwhile challenge for the agricultural polyethylene-films industry. Preliminary economic studies indicate that even with the low oil (< $20/Bbl) prices which exist between 1986-1989, the fresh water floating collectors solar pond provides an economically attractive alternative to the conventional oil-burning heating system. This is especially true in mild climate areas and when the large initial investment is justified by long-term greenhouse utilization planning.

scholarly journals Taking Advantage of Nature’s Benefits: Soluble and Stable Antigen Straight Out of the Pathogen

Proceedings ◽  
2020 ◽  
Vol 50 (1) ◽  
pp. 137
Author(s):  
Didier Clénet ◽  
Léna Clavier ◽  
Benoit Strobbe ◽  
Christel Le Bon ◽  
Manuela Zoonens ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Process Development ◽  
Storage Conditions ◽  
Full Length ◽  
Soluble Form ◽  
Drying Process ◽  
Liquid Form ◽  
Freeze Dried

Integral membrane proteins (MP) exhibit specific tridimensional conformation and topology that define their various functions. Pathogen surface antigens, encompassing many MP, are at the forefront of the viral strategy which is broadly targeted by the host immune response. These antigens are present in equilibrium under different oligomeric forms with distinctive epitopes, and to obtain them in a soluble form and/or stable constitutes a real risk. The solubilization of a full-length MP directly from a pathogen to rapidly obtain a native antigen mimicking the original conformation of the MP at the pathogen surface is the process development reported in this work. Rabies virus (RABV) was used as a model for this demonstration and its full-length glycoprotein (G) was stabilized in amphiphatic polymers (A8-35 amphipols). The stability of the soluble RABV-G was evaluated under various stress conditions (temperatures, agitation and light exposures) and a long-term stable RABV-G formulation, suitable for the freeze-drying process, was defined using a design of experiment approach. RABV-G/A8-35 in liquid form was shown to be antigenically stable at 5 °C and 25 °C for one month, and a dedicated kinetic model predicted its stability up to 1 year at 5 °C. To mitigate the RABV-G/A8-35 sensitivity to mechanical stress, a solid form of RABV-G/A8-35 and a freeze-drying process were considered, resulting in a 2-year thermally stable product at 5 °C, 25 °C and 37 °C. To the best of our knowledge, this is the first time that a natural full-length MP, extracted from a virus and trapped in amphipols, was kept antigenically stable in the long term, in a defined freeze-dried form out of any refrigerated storage conditions. These results described an easy process to obtain a pure, well conformed native-like antigen of interest, from a circulating pathogen which is of concern for diagnostic (quantification/characterization assays), therapeutic and vaccine strategies. After the physical characterization of the protein, the identification of RABV G/A8-35 neutralizing epitopes has been underway before in vivo testing.

Development of a freeze-drying protocol for the long-term storage of S9-fraction at ambient temperatures

Cryobiology ◽  
2009 ◽  
Vol 58 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Sebastian Buchinger ◽  
Elisabeth Campen ◽  
Eckard Helmers ◽  
Valeri Morosow ◽  
Marianne Krefft ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Ambient Temperatures ◽  
Long Term Storage ◽  
Term Storage ◽  
S9 Fraction

scholarly journals Reconstitution properties of biologically active polymersomes after cryogenic freezing and a freeze-drying process

RSC Advances ◽  
2018 ◽  
Vol 8 (45) ◽  
pp. 25436-25443 ◽  
Author(s):  
Robert Ccorahua ◽  
Silvia Moreno ◽  
Hannes Gumz ◽  
Karin Sahre ◽  
Brigitte Voit ◽  
...  
Keyword(s):  
Membrane Permeability ◽  
Freeze Drying ◽  
Chemical Properties ◽  
Biologically Active ◽  
Enzymatic Reactions ◽  
Drying Process ◽  
Physico Chemical ◽  
And Storage

Polymersomes can retain their physico-chemical properties and membrane permeability for enzymatic reactions after lyophilization or cryogenic freezing and storage.

scholarly journals Flow-cytometric assessment of damages to Acetobacter senegalensis during freeze-drying process and storage

2013 ◽  
Vol 2 (1s) ◽  
pp. 10 ◽  
Author(s):  
Rasoul Shafiei ◽  
Frank Delvigne ◽  
Phillipe Thonart
Keyword(s):  
Freeze Drying ◽  
Storage Temperature ◽  
Culture Media ◽  
Cell Envelope ◽  
Storage Conditions ◽  
Cell Multiplication ◽  
Drying Process ◽  
Log Reduction ◽  
Downstream Processes ◽  
And Storage

Downstream processes have great influences on bacterial starter production. Different modifications occur to cellular compounds during freeze-drying process and storage of bacterial starters. Consequently, viability and culturability (multiplication capacity) undergo some changes. In this study, the effects of freeze-drying process and storage conditions were examined on cell envelope integrity, respiration and culturability of <em>Acetobacter senegalensis</em>. Freezing of cells protected with mannitol (20% w/w) did not affect cell multiplication and respiration considerably; however, 19% of cells showed compromised cell envelope after freezing. After drying, 1.96&times;10<sup>11</sup> CFU/g were enumerated, indicating that about 34% of the cells could survive and keep their culturability. Drying of the cells induced further leakage in cell envelope and finally 81% of cells appeared as injured ones; however, 87% of the dried cells maintained their respiration capacity. Storage temperature had significant effect on cell multiplication ability; higher storage temperature (35&deg;C) caused 8.59-log reduction in cell culturability after nine-month period of storage. Collapse of cell envelop integrity and respiration was observed at 35&deg;C. At lower storage temperature (4&deg;C), the culturability decreased about one-log reduction after nine months. Cell envelope integrity was subjected to minor changes during a period of nine month-storage at 4&deg;C whereas a heterogeneous population of cells with different respiration capacity emerged at 4&deg;C. These results indicate that a major part of cells undergone drying process and storage entered into viable but non-culturable state. In addition, usage of different culture media didn&rsquo;t improve resuscitation. Besides, it seems that sub-lethal damages to cell envelope caused uptake of propidium iodide, however these kinds of injuries could not impress cell multiplications and respiration.

A Study of Enthalpic Relaxation of Trehalose-Water Glasses

2004 ◽  
Author(s):  
James Green ◽  
Alex Fowler ◽  
Mehmet Toner ◽  
Sankha Bhowmick
Keyword(s):  
Molecular Mobility ◽  
Physical Aging ◽  
Glassy Matrix ◽  
Relaxation Kinetics ◽  
Ambient Temperatures ◽  
Enthalpic Relaxation ◽  
Long Term Storage ◽  
And Storage ◽  
Kinetics Of

Trehalose has been shown to be an effective biostabilizer, one explanation for this is that it can easily form glass at near ambient temperatures. Enthalpic relaxation is a physical aging process that occurs in glasses held near, but below, their Tg and is an indicator of the amount of molecular mobility of a particular glass. Since molecular mobility is key to long-term storage biologics in a glassy matrix this study was developed to gain a fundamental understanding of the enthalpic relaxation kinetics of trehalose-water glasses. Through the use of DSC, enthalpic peaks were quantitatively measured for water-trehalose glasses as a function of aging time and aging temperature for three different mass percentages (Mwater/Mtrehalose%, ~0%, ~1.5%, & ~10%). From this data the total amount of relaxation and the relaxation time have been determined using the Cowie-Ferguson equation. Understanding the effects of water on enthalpic relaxation kinetics will help lead to optimized drying protocols and storage parameters.

scholarly journals PREPARATION OF POWDER FROM BROWN SEAWEED (SARGASSUM PLAGYOPHYLLUM) BY FREEZE-DRYING WITH MALTODEXTRIN AS A STABILIZER

2018 ◽  
Vol 10 (1) ◽  
pp. 348
Author(s):  
Effionora Anwar ◽  
Hilmia Erianto ◽  
Kurnia Sari Setio Putri
Keyword(s):  
Water Content ◽  
Freeze Drying ◽  
Storage Time ◽  
Storage Temperature ◽  
Brown Seaweed ◽  
Drying Process ◽  
Dextrose Equivalent ◽  
The Stability ◽  
And Storage ◽  
Lower Water Content

Objective: The aim of this study was to prepare powder from liquid extract with maltodextrin dextrose equivalent 10–15 as a stabilizer using a freezedryingmethod to maintain stability during drying process and extend storage time.Methods: Powders were prepared for four formulas: F1 (without maltodextrin), F2 (2.5% maltodextrin), F3 (5% maltodextrin), and F4 (10%maltodextrin). Powder from the four formulas was characterized by its phlorotannin concentration, antioxidant activity, water content, morphology,particle size distribution, pH, and organoleptic activities.Results: F4 was the best formula because it contained the highest phlorotannin concentration (113.06±1.36) or 0.25%, highest percentage ofinhibition concentration50 (IC50) (4.06% at a concentration of 5000 ppm), and lowest water content (5.16%); moreover, in a stability test, F4 exhibiteda more stable phlorotannin concentration and lower water content than F1, with an optimal storage temperature of 4°C.Conclusion: Maltodextrin can improve the stability bioactive compounds during the freeze-drying process and storage time.

Effect of ginseng polysaccharide on the stability of lactic acid bacteria during freeze-drying process and storage

2006 ◽  
Vol 29 (9) ◽  
pp. 735-740 ◽  
Author(s):  
Seung-Hyun Yang ◽  
Sung-Hoon Seo ◽  
Sang-Wook Kim ◽  
Seung-Ki Choi ◽  
Dong-Hyun Kim
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Freeze Drying ◽  
Drying Process ◽  
Ginseng Polysaccharide ◽  
The Stability ◽  
And Storage

The Critical Point Drying Method Applied to Scanning Electron Microscopy of L-929 Cells

1970 ◽  
Vol 28 ◽  
pp. 278-279
Author(s):  
Charles TurnbiLL ◽  
Delbert E. Philpott
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Surface Tension ◽  
Critical Point ◽  
Freeze Drying ◽  
Attractive Alternative ◽  
Crystal Formation ◽  
Critical Point Drying ◽  
Time Required ◽  
Scanning Electron

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.

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