Research On Vitrification Preservation Method Of Biological Tissue Slices

Cryopreservation is an effective method for long-term preservation of biological materials,which has important applications in clinical medicine and scientific research.Vitrification preservation method can effectively avoid the ice crystal damage existing in the traditional cryopreservation method.Because the existing methods for vitrification preservation of biological materials have the disadvantages,such as low heat transfer efficiency,low volume sample,and high risk of contamination,as a result,the application range and effects are very limited.In order to solve these problems and break through the bottleneck of vitrification preservation methods,this study mainly made the following research:(1)Based on the micro-scale enhanced heat transfer principle,a set of biomaterial vitrification preservation system was successfully constructed from the micro-scale enhanced heat transfer of the working fluids,sample and carrier surface structure.First,the micro-jet impact enhanced heat transfer technology was introduced to realize the micro-scale reduction of the rewarming working fluids.Second,a special sample carrier was designed and fabricated to realize the thin film formation,which constructed the micro-scale heat transfer path of the sample.Third,series of microstructure structures were built on the surface of the carrier to realize the surface of the carrier features.In addition to this,the vitrification storage system also has an automatic clamping function to clamp sample.(2)Study the micro-scale heat transfer characteristics of the vitrification heat transfer system.Through simulation,reference parameters are provided for the vitrification system to simulate the sensitivity and influence law of the analysis parameters,and the experimental verification is carried out;experimental design was used to optimize different design schemes.The micro-scale heat transfer characteristics of the vitrification preservation system were studied.The results confirmed that the micro-scale of the working fluids,the thinning of the heat transfer path and the micro-scale of the surface characteristics of the carrier enhanced the heat transfer effect.As the jet impact hole diameter decreases and the thickness of the sample decreases,the rate of decrease and rewarming increases.When the jet impact hole diameter is 1mm and the sample thickness is 0.2 mm,the rate of cooling and rewarming reaches a maximum of 11900 ° C / min and 9620 ° C / min,respectively.The surface of the aluminum foil carrier can be treated to enhance the heat transfer enhancement effect.In various surface microstructure treatments,the cooling and rewarming rate is up to 15% and 30%.(3)Through the toxicity comparison experiment and vitrification experiment of cryoprotectant,the cryopreservation agents are selected,which are suitable for jet vitrification.It was finally determined that 17.5% glycerin + 2% sorbitol,14% glycerol + 1.5% mannitol,and 6 M glycerol could be used as a cryoprotectant for vitrification preservation by jet vitrification.Taking 6M glycerol as an example,the RBCs vitrification was preserved.After the cooling-storage-rewarming process,the survival rate of the cells reached 96% or more.We performed vitrification of rat liver sections with a survival rate of over 94%.This phenomenon successfully proved the vitrification effect of the vitrification preservation system of this design.