Exploratory in Vitro Study of Red Blood Cell Storage Container with An Alternative Plasticizer.

The plasticizer di-2-ethylhexyl phthalate (DEHP) is a common component in medical plastics. Unique to the storage of RBC, DEHP is a necessary component of these storage bags, and is required to prevent excessive hemolysis over storage. Due to concerns related to the long term effects of DEHP exposure and issues related to disposal of these materials, there is a drive to replace this component. Our objective is to evaluate a candidate replacement plasticizer (Hexamoll ^TM DINCH, Cyclohexane-1,2-dicarboxylic acid, dinonylester, branched and linear) compared to control DEHP in an in vitro feasibility study. We hypothesize that the candidate will provide at least equivalent protection against hemolysis for RBC stored in additive solution for 42 days, and periodic mixing of RBC stored in additive solution for 42 days will add additional protection against hemolysis.

Whole blood was collected into CPD in standard collection sets (Terumo), combined into pools of 2 ABO identical RBC, divided, leukocyte-reduced, centrifuged and separated into plasma and packed RBC, then additive solution (AS-5) was added to the RBC, and the RBC/AS-5 were transferred into 2 study bags (matched pair) for storage up to 42 days under standard blood bank conditions of 4°C. In the first part, both study bags were Hexamoll ^TM DINCH, and one bag of each pair was mixed once per week, the other was held undisturbed. In the second part, DEHP bags were used as control held 42 days undisturbed, and the DINCH test bag was mixed once per week during storage. Standard in vitro RBC characteristics were determined at days 0 and 42.

DINCH bags mixed weekly retained RBC morphology better, had lower extracellular potassium and had lower hemolysis compared to static storage. There were no detectable differences between DEHP static stored bags and DINCH bags mixed weekly when comparing in vitro parameters.

Periodic mixing of RBC stored in DINCH bags provides additional protection against hemolysis over 42 days of storage. DINCH plasticizer provided at least equivalent protection against hemolysis and potassium leakage for RBC stored in additive solution for 42 days. These initial observations should be extended to larger sample sizes and to in vivo autologous RBC recovery studies. The need for periodic mixing will need to be evaluated further. The plasticizer DINCH may be a viable candidate for replacement DEHP in RBC storage bags.

Dumont: BASF: Research Funding. Baker:BASF: Research Funding. Waters:BASF: Research Funding. Herschel:BASF: Research Funding. Dumont:BASF: Research Funding. David:BASF: Employment. Otter:BASF: Employment.