ABSTRACT
Adipose-derived stem cells are derived from the nonfat component of adipose tissue termed the stromal vascular fraction (SVF). The use of freshly isolated autologous SVF cells as an alternative to adult stem cells is becoming more common. Repeated SVF administration for improved clinical outcomes is complicated by the need for repeated liposuction. This can be overcome by cryopreservation of SVF cells. The current study aimed to assess whether SVF cells retain their stem cell potency during cryopreservation. METHODS: SVF cells isolated from lipoaspirates (donor age: 46.1 ± 11.7 y; body mass index: 29.3 ± 4.8 kg/m2) were analyzed either immediately after isolation or following cryopreservation at -196°C. Analyses included assessment of nucleated cell counts by methylene blue staining, colony-forming unit fibroblast counts, surface marker expression using a flow cytometric panel (CD45, CD34, CD31, CD73, CD29, and CD105), expansion in culture, and differentiation to fat and bone. RESULTS: While cryopreservation reduced the number of viable SVF cells, stem cell potency was preserved, as demonstrated by no significant difference in the proliferation, surface marker expression in culture, bone and fat differentiation capacity, and the number of colony-forming unit fibroblasts in culture, in cryopreserved versus fresh SVF cells. Importantly, reduced cell counts of cryopreserved cells were due, mainly, to a reduction in hematopoietic CD45+ cells, which was accompanied by increased proportions of CD45-CD34+CD31- stem cell progenitor cells compared to fresh SVF cells. CONCLUSIONS: Cryopreservation of SVF cells did not affect their in vitro stem cell potency and may therefore enable repeated SVF cell administrations, without the need for repeated liposuction.
ABSTRACT
BACKGROUND: Burn injuries are one of the leading causes of morbidity and mortality in the pediatric population. In early childhood, burns have a wide range of adverse long-term consequences ranging from functional impairment to psychological implications. Children from low-income and middle-income countries are at a higher risk of suffering from burn injuries. In the last 10 years the population of asylum seekers from low-income countries in Israel has increased dramatically. About 25,000 or 60% of asylum seekers are living in the Tel Aviv area, making up roughly 6% of the city's total population (about 405,000). AIM: A retrospective study aimed to profile the pediatric burn injuries treated at the Tel Aviv Sourasky Medical Center over the last 9 years in an effort to examine the distinct characteristics of African asylum seekers who suffer burn injuries in comparison with Israeli nationals. PATIENTS & METHODS: Medical records of 876 patients under the age of 18 years presenting between 2007-2015 were retrospectively reviewed. The parameters collected included gender, causality, total body surface area (TBSA), burn depth and patient outcome. CONCLUSIONS: There was no significant difference regarding: age; male-female ratio; scald-types burns; limb involvement. However, hospitalization and length of hospital stay were significantly higher among asylum seekers, as was family burden. Questions may be raised regarding prevention, education & social support. Our research provides a small glimpse into the world of asylum seekers in Israel. We hope it will serve as a window into the much grander problems that this population faces on a daily basis.
