Now the clinical preservation methods of human red blood cells mainly include hypothermic storage (4 degrees C) and cryopreservation (-80 degrees C or -196 degrees C). The preservation time of hypothermic storage of red blood cells is relatively short and it is easy to be contaminated by microbes. Cryopreservation greatly prolongs the storage time, but it needs heavy storage equipments. Because the protective solutions in cryopreservation contain glycerol, red blood cells need complicated washing in order to remove glycerol. These shortage methods limit their application to some special conditions, such as war or natural disasters. Compared with conventional preservation methods of red blood cells, lyophilization has many advantages such as less weight, convenient transportation, room temperature preservation, prone to be rehydrated. In this review, the progress and challenge in the development of lyophilization of red blood cells, especially application of trehalose and its mechanism in the lyophilization of red blood cells were systematically discussed. This review can provide some theoretic guidance for developing a safe, simple and efficient preservation approach of red blood cells by lyophilization.
Blood Preservation ; Cryopreservation ; Erythrocytes ; Freeze Drying ; Humans ; Trehalose ; pharmacology

Cell freeze-drying can be divided into the freezing and drying processes. Mechanical damage caused by ice crystals and damage from solute during freezing shall not be ignored and lyoprotectants are commonly used to reduce those damages on cells. In order to study the mechanism of lyoprotectants to protect cells and determine an optimal lyoprotectant formula, the thermophysical properties and percentage of unfrozen water of different lyoprotectants in freezing were investigated with differential scanning calorimeter (DSC). The survival rate indicated by trypan blue exclusion test and cell-attachment rate after 24 h using different lyoprotectants to freeze hepatoma Hep-G cells were measured after cell cryopreservation. The results show that 40% (W/V) PVP + 10% (V/V) glycerol + 15% (V/V) fetal bovine serum + 20% (W/V) trehalose formula of lyoprotectant demonstrate the best effect in protecting cells during freezing, for cell-attachment rate after 24 h is 44.56% ± 2.73%. In conclusion, the formula of lyoprotectant mentioned above can effectively protect cells.
Calorimetry, Differential Scanning ; Cryopreservation ; Cryoprotective Agents ; chemistry ; Freeze Drying ; Freezing ; Hep G2 Cells ; Humans ; Trehalose ; chemistry

Lyophilization is the best method for preservation of blood cells at present. Lyophilized blood cells could be stored at room temperature for long periods of time, while maintaining a high degree of viability. Lyophilized blood cells facilitates transportation and the costs are low. However, the membrane of blood cells is damaged and viability of blood cells is decreased in lyophilization. Trehalose has been shown to protect membrane, proteins and nucleic acids during freezing and desiccation. Now, researchers present a methor for loading blood cells with trehalose. In this paper, damage effect of lyophilization on blood cells, the mechanism of trehalose protection and the experimental studies on trehalose were reviewed.
Blood Preservation ; methods ; Cryopreservation ; methods ; Cryoprotective Agents ; pharmacology ; Erythrocyte Membrane ; metabolism ; Erythrocytes ; drug effects ; Freeze Drying ; methods ; Humans ; Trehalose ; pharmacology

This study was aimed to investigate the effect of prefreezing parameters such as freezing rate, annealing, rate, annealing temperature, holding time in annealing before lyophilization on lyophilized platelets by orthogonal tests. The recovery rate, the morphological and ultrastructural changes, the activation and aggregation of lyophilized platelet after rehydratation were detected by cytometer, scan electron microscopy, flow cytometry and aggregation reaction on thrombin, respectively, and complex evaluation was carried out. The results showed that the recovery rate of lyophilized platelets was 91% - 53.5% at different conditions of lyophilization, the size and shape of ice crystals in lyophilized platelets of different test groups were not similar, the expression and distribution of platelet activation markers (PAC-1 and CD62p) after rehydration were relatively similar to fresh platelets, expression rate of PAC-1 was lower (0.03% - 0.22%), meanwhile there were differences of CD62p expression levels between different groups. The optimal theoretic composition of prefreezing conditions obtained on basis of platelet recovery rate was A(2)B(1)C(1)D(3), i.e, first, suspensions of platelets on the program control cooling apparatus were lyophilized with a rate of 20 degrees C/min and maintained at -40 degrees C for 2 hours, then the annealing was conducted at -30 degrees C for 0.5 hours with a heating rate of 1.5 degrees C/min; finally, the freeze-drying program was carried out to the end. It is concluded that the freezing rate, annealing rate, annealing temperature and holding time of annealing all impact on the recovery of lyophilized platelets. The preservation qualities of lyophilized platelets were affected by the various combinations of prefreezing parameters.
Blood Platelets ; Blood Preservation ; methods ; Cell Survival ; Cryopreservation ; methods ; Freeze Drying ; methods ; Humans ; Platelet Activation ; Platelet Aggregation ; Platelet Count

The aim of this research was to study the technology and methods of loading lyoprotectant-trehalose into cytoplasm of human platelets before lyophilization, to optimize experimental conditions of loading trehalose, to investigate the changes of platelets response to agonists and activation after incubation of platelets for 4 hours at 37 degrees C in the presence of lyoprotectant-trehalose, to protract the figures of loading efficiency and intracellular trehalose concentration versus incubation time, temperature and external trehalose concentration, to optimize loading parameters. The response of platelets to different agonists--thrombin, ADP, collagen and ristocetin were measured respectively by APACT2 aggregometer before and after loading trehalose into platelets; the expressions of CD62p and PAC-1 on platelet membranes in the presence and absence of reversible platelets activation inhibitors were measured by flow cytometry respectively before and after loading trehalose into cytoplasm of platelets. The results showed that the loading efficiency was linear to incubation time (2 hours later) and incubation temperature (rang from 30 degrees C to 40 degrees C), respectively. The loading efficiency almost reached 60% when the platelets were incubated at 37 degrees C for 4 hours. The intracellular trehalose concentration was higher with the increase of the extracellular trehalose concentration (< 50 mmol/L). Compared to untreated groups, the values of MPV and aggregation to different agonists in treated groups showed no significant difference, respectively (P > 0.01). After incubation of platelets for 4 hours, the expression of CD62p increased to some extent, however, the expression of CD62p decreased again when the reversible platelets activation inhibitor PGE-1 and adenosine were added to the incubation buffer. It is concluded that 37 degrees C, 4 hours and the extracellular trehalose concentration < 50 mmol/L are the optimal conditions for loading with trehalose. The processing of loading with trehalose before platelet lyophilization has no significant effects on response of platelets to agonists and activation.
Blood Platelets ; cytology ; drug effects ; metabolism ; Blood Preservation ; methods ; Cell Survival ; Cryopreservation ; methods ; Freeze Drying ; Humans ; Trehalose ; blood ; pharmacology

No abstract available.
Cryopreservation* ; Erythrocytes*

No abstract available.
Cryopreservation* ; Trachea*

OBJECTIVETo study the preserve techniques of squeezed juice of Chinese medicinal materials.

METHODThe techniques of refrigeration, rapid freezing, 60Cogamma-ray sterilization, freeze-drying and spray-drying were used for preservation of squeezed juice of Ginger and Glutinous Rehannia. Different results were compared.

RESULTThe period of preservation was half or one year.

CONCLUSIONThe rapid freezing, freeze-drying and spray-drying are suitable for preservation of squeezed juice of Chinese medicinal materials.

Cobalt Radioisotopes ; Cryopreservation ; Drug Storage ; methods ; Freeze Drying ; methods ; Freezing ; Ginger ; chemistry ; Oils, Volatile ; analysis ; Polysaccharides ; analysis ; Refrigeration ; Rehmannia ; chemistry ; Sterilization

This study was aimed to further optimize trehalose loading technique including loading temperature, loading time, loading solution and loading concentration of trehalose, based on the established parameters. Loading efficiency in plasma was compared with that in buffer at 37 degrees C; the curves of intracellular trehalose concentration versus loading time at 37 degrees C and 16 degrees C were measured; curves of mean platelet volume (MPV) versus loading time and loading concentration were investigated and compared. According to results obtained, the loaing time, loading temperature, loading solution and trehalose concentration were ascertained for high loading efficiency of trehalose into human platelet. The results showed that the loading efficiency in plasma was markedly higher than that in buffer at 37 degrees C, the loading efficiency in plasma at 37 degrees C was significantly higher than that at 16 degrees C and reached 19.51% after loading for 4 hours, but 6.16% at 16 degrees C. MPV at 16 degrees C was increased by 43.2% than that at 37 degrees C, but had no distinct changes with loading time and loading concentration. In loading at 37 degrees C, MPV increased with loading time and loading concentration positively. Loading time and loading concentration displayed synergetic effect on MPV. MPV increased with loading time and concentration while trehalose loading concentration was above 50 mmol/L. It is concluded that the optimization parameters of trehalose loading technique are 37 degrees C (temperature), 4 hours (leading time), plasma (loading solution), 50 mmol/L (feasible trehalose concentration). The trehalose concentration can be adjusted to meet the requirement of lyophilization.
Blood Platelets ; cytology ; drug effects ; metabolism ; Blood Preservation ; methods ; Cryopreservation ; methods ; Cryoprotective Agents ; metabolism ; pharmacology ; Dose-Response Relationship, Drug ; Freeze Drying ; Humans ; Trehalose ; metabolism ; pharmacology

No abstract available.
Cryopreservation* ; Humans* ; Spermatozoa*