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A major hurdle in stem cell therapy is the tumorigenic risk of residual undifferentiated stem cells. This report describes the design and evaluation of synthetic hybrid molecules that efficiently reduce the number of human induced pluripotent stem cells (hiPSCs) in cell mixtures. The design takes advantage of Kyoto probe 1 (KP-1), a fluorescent chemical probe for hiPSCs, and clinically used anticancer drugs. Among the KP-1-drug conjugates we synthesized, we found an exceptionally selective, chemically tractable molecule that induced the death of hiPSCs. Mechanistic analysis suggested that the high selectivity originates from the synergistic combination of transporter-mediated efflux and the cytotoxicity mode of action. The present study offers a chemical and mechanistic rationale for designing selective, safe, and simple reagents for the preparation of non-tumorigenic clinical samples.

Thermal analyses of epoxidized soybean oil (ESO) were conducted and showed that it was stable up to temperatures as high as 240–260°C in air-free environment. The solubility and transport characteristics of ESO in poly(vinylchloride) (PVC) were also investigated under various conditions. The absorption study showed that the resin had a void volume of ∼0.3 cm3/g. Furthermore, ESO was found to be sufficiently soluble in the PVC matrix to function as an effective plasticizer, with equilibrium solubility of 72 g/100 g PVC at 80°C and 163 g/100 g PVC at 120°C. The absorption of ESO in PVC grains was a three step process comprising “induction,” “swelling,” and “saturation” periods. Torque rheometer studies showed that higher mixer temperature and/or speed facilitated uptake of plasticizer in PVC and ultimate fusion. Migration studies of plasticized and stabilized PVC compositions showed no change in mass at 40°C, but increasingly greater mass loss as the temperature was raised up to 120°C. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

The efficacy of epoxidized soybean oil (ESO), tri(2-ethylhexyl) trimellitate, and mixtures thereof as plasticizers for poly(vinylchloride) has been studied. At 80°C, the trimellitate was slower to absorb in this polymer than ESO and was also less soluble, but the former exhibited higher solubility at 120°C. Plasticization efficiencies of stabilized polymeric compositions were similar with ESO and the trimellitate (despite their very different molecular weights). The trimellitate yielded greater mass loss during heat aging of the plasticized compositions, but substituting even minor amounts of it with ESO decreased mass loss synergistically. The trimellitate also resulted in more of an increase in hardness than ESO over time at elevated temperatures, but when aged at 120°C, mixtures of the two surprisingly had more deleterious effects. Thus, although ESO can replace part or all of trimellitates in plasticized PVC, using it as sole plasticizer would be preferable when heat aging performance is a requirement. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41966.