Evaluation of vitrification for cryopreservation of teeth

Abstract

PurposeThe aim of this study was to investigate whether vitrification in the cryopreservation of periodontal ligament (PDL) cells could be useful for tooth banking.MethodsIn step 1, primary cultured human PDL cells were cryopreserved in 100% conventional cryopreservation media and 100% vitrification media (ESF40 media) in different temperatures for 2 weeks. In step 2, a series of modified vitrification formulae named T1 (75% vitrification media + 25% F-media), T2 (50% vitrification media + 50% F-media) and T3 (25% vitrification media + 75% F-media) were used to store PDL cells for 2 weeks and 4 weeks in liquid nitrogen. MTT assay was performed to examine the viability of PDL cells.ResultsMaximum cell viability was achieved in cells stored in 100% conventional cryopreservation media at -196℃ (positive control group) in step 1. Compared to the positive control group, viability of the cells stored in 100% vitrification media was very low as 10% in all test conditions. In step 2, as the percentage of vitrification media decreased, the cell viability increased in cells stored for 2 weeks. In 4-week storage of cells in step 2, higher cell viability was observed in the T2 group than the other vitrification formulae while the positive control group had the highest viability. There was no statistically significant difference in the cell viability of 2-week and 4-week stored cells in the T2 group.ConclusionsThese observations indicate 100% vitrification media is not successful in PDL cell cryopreservation. Conventional cryopreservation media is currently the most appropriate media type for this purpose while T2 media would be interesting to test for long-term storage of PDL cells.

Research progress on optimization of in vitro isolation, cultivation and preservation methods of dental pulp stem cells for clinical application

“…Another important aspect of cryopreservation is the cooling rate. A precise balance between the concentration of cryoprotectants and the cooling rate required for cryopreservation must be maintained ( Dissanayake et al, 2010 ). Osmotic pressure causes cells to dry and shrink when they are cooled too slowly, while intracellular ice production may result from rapid cooling ( Chen et al, 2011b ; Marquez-Curtis et al, 2015 ).…”

Does Cryopreservation Affect the Biological Properties of Stem Cells from Dental Tissues? A Systematic Review

“…Cryopreservation relies on a complex balance established by a well-controlled cooling rate and the cryoprotectant agent's (CA) concentration (7,8). Thus, a proper CA should allow water to leave the cell slowly enough to avoid impairment on cells' membranes, but sufficiently fast to avoid ice crystals formation inside the cell.…”

Effects of Slow Programmable Cryopreservation on Preserving Viability of the Cultured Periodontal Ligament Cells from Human Impacted Third Molar

“…However, we must evaluate various types of injuries to the cells during each step of the process, including ice injury during cooling to -196 o C, chemical toxicity, and osmotic changes due to cryoprotectants. Numerous studies have been conducted to establish a cryoprofile, including rate-controlled freezing 10) , application of magnetic fields 11) , and vitrification 12) . To date, previous studies have focused on replantation of mature premolars after cryopreservation mainly for orthodontic purposes 6,10,13) .…”