The surface markers and survival rate of platelets during storage at 4°C: The influence of sodium octanoate

Background: Storage of platelet concentrates (PCs) at room temperature (20-24°C) limits its storage time to 5 days due to the destructive effects of platelet storage lesion (PSL) and bacterial contamination. Although prolonged storage of platelets (PLTs) at 4°C reduces the likelihood of bacterial contamination and PSL levels, it is accompanied by an increase in the clearance rate and changes in the surface markers of PLTs. The goal of this study was to evaluate the effects of sodium octanoate (SO) as a stabilizer on PLTs during storage at 4°C. Materials and Methods: In this experimental study, PCs were divided into three portions and stored for 5 days at 3 different conditions, including 20-24°C, 4°C temperature, and 4°C in presence of SO. PLTs enumeration was performed using an automated hematology analyzer. To measure the metabolic activity and survival rate of PLTs, the water-soluble tetrazolium salt (WST-1) assay was performed. The activity of lactate dehydrogenase enzyme (LDH) was measured by a biochemical analyzer. Additionally, the levels of PLT glycoprotein Ibα (GPIbα) and CD62P (P-selectin) were measured on PLTs by flow cytometry technique. Results: PLTs count was higher in SO-treated (4°C) PLTs than two other studied samples. Additionally, the viability was higher in the SO-treated PLTs than that in other groups. LDH amount was lower in the SO-treated PLTs than that in other groups (P>0.05). GPIbα expression was significantly higher in SO-treated PLTs than that other groups (P<0.05). On the other hand, the expression of CD62P was lower at 4°C in PLTs in the presence of SO (P>0.05). Conclusions: SO could modulate the effects of cold temperatures on PLTs. Furthermore, we found that the survival of platelets was better maintained in the presence of SO at 4°C.

Ultrafiltration of Aqueous Solutions of Food Dye in the Presence of Surfactants

The objective of the study is the low-pressure membrane process for treating aqueous solutions containing food dyes and surfactants. The influence of surfactants (SDS � sodium dedecil sulphate, SO � sodium octanoate) in the separation of synthetic food dyes (E104 � quinoline yellow) was analyzed. Polysulfone and polysulfone-polyaniline membranes were used. Dye and surfactant concentrations used were 10% (equivalent to 100g/m3). The pressures used in the ultrafiltration process were 0.1, 0.2 and 0.3 MPa. When dye containing solutions were passed through the membranes, an increase in their flux was observed. The presence of surfactants in the solutions lead to a decline in flux when pressures of 0.1 and 0.2 MPa were used, but an improvement could be seen as the pressure increased to 0.3 MPa, for both dead-end and cross-flow filtration. Using only dead-end alternative, higher fluxes were achieved for both membranes, but it decreases with time due to accumulation on the membrane surface. The use of cross-flow filtration did not allow accumulation on the membrane surface so that the flux was constant in time.The use of anionic surfactants improved the food dye retention. The interactions between membranes and surfactants can be an important factor supporting the efficiency of the ultrafiltration.