scholarly journals A novel one-step purification of human α-thrombin after direct activation of crude prothrombin enriched from plasma

1991 ◽  
Vol 280 (3) ◽  
pp. 805-808 ◽  
Author(s):  
P K Ngai ◽  
J Y Chang
Keyword(s):  
Specific Activity ◽  
Single Step ◽  
National Institutes Of Health ◽  
Long Term Storage ◽  
Freeze Dried ◽  
Specific Affinity ◽  
One Step ◽  
Term Storage ◽  
Laser Densitometry

Crude prothrombin enriched from human plasma was directly activated to generate alpha-thrombin without prior exhaustive purification of the proenzyme using a combination of several different types of chromatographic techniques, as in all previously described methodologies. Activated thrombin was separated from other components in a single step by taking advantage of its highly specific affinity to heparin immobilized on a matrix support of Sepharose CL-6B. On the basis of the data presented herein, we have demonstrated the ease with which at least 25 mg of a highly purified enzyme (greater than 97% homogeneous by laser densitometry) can be obtained per litre of plasma. Our product exhibits a specific activity of at least 4000 National Institutes of Health units/mg and is stable after being freeze-dried for the purpose of long-term storage.

Purification of Glycerol Kinase by "Dye-Ligand" Chromatography and Hydrophobic Interaction Chromatography on Bead-Cellulose Derivatives

1993 ◽  
Vol 58 (2) ◽  
pp. 445-451 ◽  
Author(s):  
Vladimír Žúbor ◽  
Albert Breier ◽  
Marta Horváthová ◽  
Dagmar Hagarová ◽  
Peter Gemeiner ◽  
...  
Keyword(s):  
Hydrophobic Interaction ◽  
Specific Activity ◽  
Hydrophobic Interaction Chromatography ◽  
Glycerol Kinase ◽  
Enzymic Activity ◽  
Cellulose Derivatives ◽  
Long Term Storage ◽  
Bead Cellulose ◽  
Term Storage

The crude extract of cytosole enzymes was obtained from homogenized cells of Saccharomyces cerevisiae by partition. The enzyme was then isolated from the lower aqueous phase displaying higher glycerol kinase activity by dye-ligand chromatography on Cibacron Blue (CB) or Remazol Brilliant Blue R (RB)-derivatized bead-cellulose, ATP being the eluent. The specific activity of glycerol kinase rised more than 10 and 7-times after affinity dye-ligand chromatography and hydrophobic interaction chromatography, respectively. Glycerol kinase obtained by the latter method was purified by CB-bead cellulose. The final preparation maintained its enzymic activity without noticeable losses during a long-term storage at 4 °C in dark.

scholarly journals Long-Term Nanoleakage Depth and Pattern of Cervical Restorations Bonded With Different Adhesives

2012 ◽  
Vol 37 (1) ◽  
pp. 45-53 ◽  
Author(s):  
EH Mobarak ◽  
LE Daifalla
Keyword(s):  
Clinical Relevance ◽  
Adhesive System ◽  
Single Step ◽  
Short Term ◽  
Long Term Storage ◽  
Term Storage

Clinical Relevance A mild acetone-based single-step self-etched adhesive system may reveal less nanoleakage in the short-term interval, but unfortunately, this was not sustained after long-term storage.

scholarly journals Design of a new lyoprotectant increasing freeze-dried Lactobacillus strain survival to long-term storage

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Aurore Bodzen ◽  
Audrey Jossier ◽  
Sébastien Dupont ◽  
Pierre-Yves Mousset ◽  
Laurent Beney ◽  
...  
Keyword(s):  
Water Content ◽  
Water Activity ◽  
Freeze Drying ◽  
Sucrose Solution ◽  
Bound Water ◽  
Long Term Storage ◽  
Freeze Dried ◽  
Micellar Casein ◽  
Term Storage

Abstract Background Stabilization of freeze-dried lactic acid bacteria during long-term storage is challenging for the food industry. Water activity of the lyophilizates is clearly related to the water availability and maintaining a low aw during storage allows to increase bacteria viability. The aim of this study was to achieve a low water activity after freeze-drying and subsequently during long-term storage through the design of a lyoprotectant. Indeed, for the same water content as sucrose (commonly used lyoprotectant), water activity is lower for some components such as whey, micellar casein or inulin. We hypothesized that the addition of these components in a lyoprotectant, with a higher bound water content than sucrose would improve lactobacilli strains survival to long-term storage. Therefore, in this study, 5% whey (w/v), 5% micellar casein (w/v) or 5% inulin (w/v) were added to a 5% sucrose solution (w/v) and compared with a lyoprotectant only composed of 5% sucrose (w/v). Protective effect of the four lyoprotectants was assessed measuring Lactiplantibacillus plantarum CNCM I-4459 survival and water activity after freeze-drying and during 9 months storage at 25 °C. Results The addition whey and inulin were not effective in increasing Lactiplantibacillus plantarum CNCM I-4459 survival to long-term-storage (4 log reduction at 9 months storage). However, the addition of micellar casein to sucrose increased drastically the protective effect of the lyoprotectant (3.6 log i.e. 0.4 log reduction at 9 months storage). Comparing to a lyoprotectant containing whey or inulin, a lyoprotectant containing micellar casein resulted in a lower water activity after freeze-drying and its maintenance during storage (0.13 ± 0.05). Conclusions The addition of micellar casein to a sucrose solution, contrary to the addition of whey and inulin, resulted in a higher bacterial viability to long-term storage. Indeed, for the same water content as the others lyoprotectants, a significant lower water activity was obtained with micellar casein during storage. Probably due to high bound water content of micellar casein, less water could be available for chemical degradation reactions, responsible for bacterial damages during long-term storage. Therefore, the addition of this component to a sucrose solution could be an effective strategy for dried bacteria stabilization during long-term storage.

scholarly journals Effect of Dentin Biomodification Using Naturally Derived Collagen Cross-Linkers: One-Year Bond Strength Study

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Carina S. Castellan ◽  
Ana K. Bedran-Russo ◽  
Alberto Antunes ◽  
Patricia N. R. Pereira
Keyword(s):  
Bond Strength ◽  
Adhesive System ◽  
Grape Seed ◽  
Seed Extract ◽  
Long Term Storage ◽  
Acetone Water ◽  
One Step ◽  
One Year ◽  
Term Storage

Purpose.This study investigated the long-term resin-dentin bond strength of dentin biomodified by proanthocyanidin-rich (PA) agents.Materials and Methods.Forty molars had their coronal dentin exposed, etched, and treated for 10 minutes with 6.5% grape seed extract (GSE), 6.5% cocoa seed extract ethanol-water (CSE-ET), 6.5% cocoa seed extract acetone-water (CSE-AC), and distilled water (CO). Samples were restored either with One-Step Plus (OS) or Adper Single-Bond Plus (SB). Bond strength test was performed immediately or after 3, 6, and 12 months.Results.HigherμTBS were observed for GSE immediately (SB- 62.9 MPa; OS- 51.9 MPa) when compared to CSE-ET (SB- 56.95 MPa; OS- 60.28 MPa), CSE-AC (SB- 49.97 MPa; OS- 54.44 MPa), and CO (SB- 52.0 MPa; OS- 44.0 MPa) (P<0.05). CSE outcomes were adhesive system and solvent dependant. After 12 months storage SB results showed no difference among treatment types (GSE- 57.15 MPa; CSE/ET- 54.04 MPa; CSE/AC- 48.22 MPa; CO- 51.68 MPa;P=0.347),while OS results where treatment dependent (GSE- 42.62 MPa; CSE/ET- 44.06 MPa; CSE/AC- 41.30 MPa; CO- 36.85 MPa;P=0.036).Conclusions.GSE and CSE-ET agents provided enhanced immediate adhesion and stabilization to demineralized dentin after long-term storage, depending on adhesive system.

40 Comparison of slow and rapid freezing in freeze-dried ram spermatozoa

2020 ◽  
Vol 32 (2) ◽  
pp. 146
Author(s):  
L. Palazzese ◽  
D. A. Anzalone ◽  
P. Toschi ◽  
P. Loi
Keyword(s):  
Liquid Nitrogen ◽  
Rapid Freezing ◽  
Cell Stage ◽  
Food Industries ◽  
Long Term Storage ◽  
Freeze Dried ◽  
Cheap Alternative ◽  
Group 2 ◽  
Term Storage

Semen lyophilisation is an interesting technique that might be a cheap alternative to long-term storage in liquid nitrogen. The first significant result of this method was achieved by Wakayama and Yanagimachi in the 1998 and demonstrated, for the first time, the birth of healthy mouse pups from epididymal freeze-dried (mouse) spermatozoa. The authors follow the lyophilisation technique, commonly used in the pharmaceutical and food industries, namely, deep freezing, which requires direct immersion of the semen sample into liquid nitrogen before vacuum drying. In this work, we focused on the freezing phase to improve and make the technique more reliable. We compared two protocols: 1) rapid freezing, where the semen is plunged directly into liquid nitrogen (LN group), and 2) slow freezing, where the sample is frozen with a freezing rate of 1°C min−1 until −50°C (SL group). Then, both frozen samples were lyophilized. Subsequently, after an interval ranging between 1 and 3 months, dry spermatozoa from LN and SL groups were used for intracytoplasmic sperm injection (ICSI), and the embryo development was evaluated at 24h (2-cell stage) and 7 days (expanded blastocyst) post-ICSI. Moreover, acrosome integrity was evaluated with Pisum sativum agglutinin (PSA) staining on part of the semen, immediately after freezing. The LN-group semen showed the acrosome completely melted, whereas the SL group showed better integrity of the acrosome, which was comparable to that of the normal frozen (vital) spermatozoa. At 24h post-ICSI the number of cleaved embryos in the SL group was higher than in the LN group (42/100 (42%) vs. 19/75 (25.3%), SL and LN, respectively; P=0.0253). The blastocyst rate 7 days after ICSI in the SL group was higher (7/100 (7%) than that in the LN group (2/75 (2.7%); P=0.0238). Our data show that lyophilisation can be conveniently achieved in ram spermatozoa without liquid nitrogen, thus simplifying the procedure. These data support the idea that lyophilisation might be a valuable and cheaper alternative to liquid nitrogen for long-term storage of ram semen.

scholarly journals Lyophilization Preserves the Intrinsic Cardioprotective Activity of Bioinspired Cell-Derived Nanovesicles

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1052
Author(s):  
Yub Neupane ◽  
Chenyuan Huang ◽  
Xiaoyuan Wang ◽  
Wei Heng Chng ◽  
Gopalakrishnan Venkatesan ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Ischemia Reperfusion Injury ◽  
Biological Activities ◽  
Ischemia Reperfusion ◽  
Target Cells ◽  
Residual Moisture ◽  
Long Term Storage ◽  
Freeze Dried ◽  
Term Storage

Recently, bioinspired cell-derived nanovesicles (CDNs) have gained much interest in the field of nanomedicine due to the preservation of biomolecular structure characteristics derived from their parent cells, which impart CDNs with unique properties in terms of binding and uptake by target cells and intrinsic biological activities. Although the production of CDNs can be easily and reproducibly achieved with any kind of cell culture, application of CDNs for therapeutic purposes has been greatly hampered by their physical and chemical instability during long-term storage in aqueous dispersion. In the present study, we conceived a lyophilization approach that would preserve critical characteristics regarding stability (vesicles’ size and protein content), structural integrity, and biological activity of CDNs for enabling long-term storage in freeze-dried form. Compared to the lyoprotectant sucrose, trehalose-lyoprotected CDNs showed significantly higher glass transition temperature and lower residual moisture content. As assessed by ATR-FTIR and far-UV circular dichroism, lyophilization in the presence of the lyoprotectant effectively maintained the secondary structure of cellular proteins. After reconstitution, lyoprotected CDNs were efficiently associated with HeLa cells, CT26 cells, and bone marrow-derived macrophages at a rate comparable to the freshly prepared CDNs. In vivo, both lyoprotected and freshly prepared CDNs, for the first time ever reported, targeted the injured heart, and exerted intrinsic cardioprotective effects within 24 h, attributable to the antioxidant capacity of CDNs in a myocardial ischemia/reperfusion injury animal model. Taken together, these results pave the way for further development of CDNs as cell-based therapeutics stabilized by lyophilization that enabled long-term storage while preserving their activity.

scholarly journals Assessing the tolerance to room temperature and viability of freeze-dried mice spermatozoa over long-term storage at room temperature under vacuum

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Yuko Kamada ◽  
Sayaka Wakayama ◽  
Ikue Shibasaki ◽  
Daiyu Ito ◽  
Satoshi Kamimura ◽  
...  
Keyword(s):  
Room Temperature ◽  
Long Term Storage ◽  
Freeze Dried ◽  
Term Storage
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