scholarly journals Polymers as Encapsulating Agents and Delivery Vehicles of Enzymes

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4061
Author(s):  
Adejanildo da S. Pereira ◽  
Camila P. L. Souza ◽  
Lidiane Moraes ◽  
Gizele C. Fontes-Sant’Ana ◽  
Priscilla F. F. Amaral

Enzymes are versatile biomolecules with broad applications. Since they are biological molecules, they can be easily destabilized when placed in adverse environmental conditions, such as variations in temperature, pH, or ionic strength. In this sense, the use of protective structures, as polymeric capsules, has been an excellent approach to maintain the catalytic stability of enzymes during their application. Thus, in this review, we report the use of polymeric materials as enzyme encapsulation agents, recent technological developments related to this subject, and characterization methodologies and possible applications of the formed bioactive structures. Our search detected that the most explored methods for enzyme encapsulation are ionotropic gelation, spray drying, freeze-drying, nanoprecipitation, and electrospinning. α-chymotrypsin, lysozyme, and β-galactosidase were the most used enzymes in encapsulations, with chitosan and sodium alginate being the main polymers. Furthermore, most studies reported high encapsulation efficiency, enzyme activity maintenance, and stability improvement at pH, temperature, and storage. Therefore, the information presented here shows a direction for the development of encapsulation systems capable of stabilizing different enzymes and obtaining better performance during application.

1963 ◽  
Vol 09 (01) ◽  
pp. 030-052 ◽  
Author(s):  
Eberhard Mammen

SummaryIn this paper an inhibitor is described that is found in hemophilic plasma and serum different from any till now described inhibitor. The inhibitor only inhibits prothrombin activation in the “intrinsic clotting systems”. This inhibitor is probably not present in normal human plasma or serum. It is destroyed by ether and freeze drying, is labile to acid and storage at room temperature. It is stable upon dialysis and has not been adsorbed on barium sulfate, aluminum hydroxide or kaolin. It precipitates at 50% v/v saturation with alcohol. The nature of this inhibitor seems to be a protein or lipoprotein.Factor VIII was isolated from hemophilic plasma. The amount isolated was the same as from normal plasma and the activity properties were not different. Hemophiliacs have normal amounts of factor VIII.


2010 ◽  
Vol 150 ◽  
pp. 352-352 ◽  
Author(s):  
F. Darvishi ◽  
J. Destain ◽  
I. Nahvi ◽  
P. Thonart ◽  
H. Zarkesh-Esfahani

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alice F. Charteris ◽  
Karina A. Marsden ◽  
Jess R. Evans ◽  
Harry A. Barrat ◽  
Nadine Loick ◽  
...  

AbstractIn grazing systems, urine patches deposited by livestock are hotspots of nutrient cycling and the most important source of nitrous oxide (N2O) emissions. Studies of the effects of urine deposition, including, for example, the determination of country-specific N2O emission factors, require natural urine for use in experiments and face challenges obtaining urine of the same composition, but of differing concentrations. Yet, few studies have explored the importance of storage conditions and processing of ruminant urine for use in subsequent gaseous emission experiments. We conducted three experiments with sheep urine to determine optimal storage conditions and whether partial freeze-drying could be used to concentrate the urine, while maintaining the constituent profile and the subsequent urine-derived gaseous emission response once applied to soil. We concluded that filtering of urine prior to storage, and storage at − 20 °C best maintains the nitrogen-containing constituent profile of sheep urine samples. In addition, based on the 14 urine chemical components determined in this study, partial lyophilisation of sheep urine to a concentrate represents a suitable approach to maintain the constituent profile at a higher overall concentration and does not alter sheep urine-derived soil gaseous emissions.


2012 ◽  
Vol 168 (5) ◽  
pp. 1101-1107 ◽  
Author(s):  
Farshad Darvishi ◽  
Jacqueline Destain ◽  
Iraj Nahvi ◽  
Philippe Thonart ◽  
Hamid Zarkesh-Esfahani

1976 ◽  
Vol 4 (1) ◽  
pp. 1-5
Author(s):  
E M Scott ◽  
W Woodside

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.


Author(s):  
Rodica Sturza

The presented results reflect the researches carried out over the last decade, having as their object the soil, water, vegetal raw materials, and wines from the Republic of Moldova. The analysis of the possible anthropogenic contamination (NAA method) demonstrated the absence of systematic soil pollution. A total of 30 elements were determined in soil samples and the soil-leaves-fruit transfer factors were calculated. Approximately 3000 samples of local wines have been analysed to determine the residual quantities of pesticides. POPs were not found in any of the wine samples. In most of the examined cases (> 60% of samples), the lack of organic pesticide residues was observed. The migration of phthalates into different solutions from polymeric materials (PVC, rubber) and the influence of the temperature on the extraction rate were investigated. It has been shown that the contamination with phthalate residues occurs predominantly at the stage of grape processing, technological treatment, and storage.


2007 ◽  
Vol 17 (3-4) ◽  
pp. 173-182 ◽  
Author(s):  
Jan Wilschut ◽  
Jørgen de Jonge ◽  
Anke Huckriede ◽  
Jean-Pierre Amorij ◽  
Wouter L. J. Hinrichs ◽  
...  

2010 ◽  
Vol 58 (3) ◽  
pp. 1726-1731 ◽  
Author(s):  
Michael Wenzel ◽  
Ingrid Seuss-Baum ◽  
Elmar Schlich

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