Biocompatible, biodegradable and sterically stabilized phospholipid nanomicelles improve cryopreservation of oral keratinocytes: a preliminary investigation.

In this proof-of principle study, we determined whether biocompatible, biodegradable and sterically stabilized phospholipid nanomicelles (SSNMs) improve viability and membrane integrity of cryopreserved oral keratinocytes. Cultured chemically transformed hamster oral keratinocytes were frozen gradually with and stored in liquid nitrogen in the presence of 10% dimethylsulfoxide (DMSO) or SSNMs composed of distearoylphosphatidyl-ethanolamine-N-poly(ethylene glycol) 2000 (size, 17+/-1nm; 0.1 and 1.0nmol). Forty-eight hours later, cells were thawed and their viability was determined. Lactate dehydrogenase (LDH) activity in cell lysates and supernatants was quantified as well. SSNMs evoked a significant, concentration-dependant increase in cell viability in comparison to 10% DMSO (p<0.05). There was also a significant decrease in LDH activity in the supernatant of cells cryopreserved with SSNMs in comparison to 10% DMSO (p<0.05). These data indicate that SSNMs improve cryopreservation of oral keratinocyte by promoting cell viability and plasma membrane integrity. We suggest that SSNMs should be further developed as a novel nanocryopreservative for keratinocytes.