Ashley R. Davis

In the United States, ∼30,000 units of red blood cells (RBCs) are transfused daily to patient recipients. These RBCs are stored in one of multiple variations of media known as additive solutions, all of which contain glucose at concentrations well above physiological levels. Recently, strategies for storage of the RBCs in normoglycemic versions of the additive solutions whose glucose levels are maintained with periodic boluses of glucose were developed, resulting in benefits to the stored RBCs. Here, we describe a system capable of semiautonomous, Wi-Fi-enabled control of glucose delivery using a microperistaltic pump for maintenance of physiological concentrations of glucose in a closed RBC storage system. The RBCs stored in these normoglycemic conditions demonstrated reduced lysis and reduced hemoglobin glycation in comparison to those of the currently used hyperglycemic additive solutions. Furthermore, a novel single cell technique using pressure-induced conductivity mapping showed an improved Young’s modulus for those RBCs stored in normoglycemic solutions. These quantitative measurements of the RBCs’ chemical and physical properties coincide with improvements in cell functionality. Specifically, determinations of RBC-derived ATP using a 3D-printed microfluidic device show an increased release of ATP for RBCs stored in normoglycemic solutions in comparison to hyperglycemic storage, even for cells that were 2 weeks past a storage expiration of 42 days.

Gene targeting applied to totipotent embryonic stem (ES) cells is a very powerful means of creating highly specific mutations of genes in the mouse. The successful application of this technology is however constrained by both the types of mutations that can be generated at a target locus and the ability to reconstruct a germline chimera from the manipulated cells. We have developed two cell lines that can be routinely transmitted through the germline of chimeras after cloning and prolonged selection in tissue culture. We have also established a variety of methods for generating non-selected mutations at the X-linked hprt locus in ES cells. Our observations at this locus have enabled us to generate successfully a subtle mutation at the non-selectable Hox-2.6 locus.