| The cryopreservation technology has made great progress in theory and practice.The long-term preservation of human red blood cells plays an important role in regulating the balance of blood supply and demand,carrying out normal blood transfusion and maintaining rare blood types.Till now,the development of cryopreservation methods of red blood cells has been relatively mature and successfully applied in clinical practice,which mainly include low-temperature refrigeration at 4℃ and high-glycerin(Gly)slow-freezing method.The storage time of the low temperature refrigeration method is too short,and the transportation cost of cold chain is high,which is not suitable for some special areas.The slow freezing method requires Gly high concentration of as a cryoprotectant(CPA),which increases the complexity and difficulty of clinical operation and brings many inconveniences to the cryopreservation and transfusion of red blood cells in clinical practice.Therefore,it is still a research focus to find a new method for cryopreservation of red blood cells to reduce the concentrations of CPA.In this project:(1)Red blood cells are cryopreserved using the low-Gly quick-freezing method to explore the effects of CPA type and concentration on the cryopreservation.The experimental results showed that adding trehalose(Tre)could improve the red blood cell recovery.(2)Alginate hydrogels,which have been widely used in preservation research,were selected.In addition,a new method of cryopreservation of red blood cell-laden hydrogel microfibers was proposed.The experimental results showed that hydrogel microfiber encapsulation enhanced cryopreservation of human red blood cells with low concentrations of Gly(≤5%(w/v)).When 5%Gly+0.3 mol/L Tre were used as CPAs,the red blood cell recovery increased to about 80%.And Gly can be removed by washing directly with a 0.9%sodium chloride solution.(3)When 10%Gly was used as CPA in the experiments,the proposed new method had no positive effect on the red blood cell recovery rate.The differential scanning calorimetry test of hydrogel microfiber showed that there was a threshold value for the permeability of alginate hydrogel to Gly.According to the crystallization of alginate,the possible protective mechanism of cryopreservation based on hydrogel encapsulation technology was proposed.Therefore,exploring a suitable composite CPAs,or finding a more permeable and biocompatible hydrogel material may be a potential measure to improve red blood cell recovery.It is hoped that a feasible strategy for the cryopreservation of red blood cells can be provided,which has certain significance for the study of biological cryopreservation. |
