Evaluación de la actividad crioprotectora de dos almidones de yuca sobre células mononucleadas de sangre de cordón umbilical
Ortiz Trujillo, Bibiana | 2007-07
This research determined the possibility to change the hydroxyethyl starch (HES), conventional crioprotector, for two sorts of mandioca starches made by national industry. The study verified the influence of the mandioca starches on the hidrogenions amount in blood and confirmed the estability of starches in umbilical cord blood envelop and established its molecular stability inside a medium with amylases enzymes and mononuclear cells such as the umbilical cordon blood. The mononuclear cells viability six months after being criopreservated with each starch at –80ºC, using HES as a reference or standard, was also assessed. Results showed that the umbilical cord blood, outside the organism for 30 minutes is more affected by the mandioca starches than by HES. In spite of the similar structure of the mandioca starch and HES, the latter one is more resistant in the blood environment to the enzymatic attack of amylases because of its modified structure, therefore it is more resistance to withstand the blood conditions. It was corroborated that HES was able to keep the mononuclear cell viability over 70%, but mandioca starches did not, because of their influence on the pH which became lethal to cells. It was concluded, that the amilopectine of mandioca starches with some modifications in its molecular structure such as hydroxyethylation could work as a crioprotector for mononuclear blood cells, provided that the pH is controlled.