James A. Hayward

Polymerized liposomes as stable oxygen‐carriers

We have produced a surrogate erythrocyte (‘hemosomes’) by encapsulating human hemoglobin in polymerized vesicles composed of diacetylenic phospholipids plus or minus cholesterol. Hemoglobin (in the presence or absence of allosteric effectors) was encapsulated by a freeze‐thaw method in large, unilamellar vesicles composed of monomeric lipids. Entrapment was demonstrated by molecular‐sieve chromatography. Brief irradiation with ultraviolet light produced polymeric hemosomes with polymerization kinetics and conversions similar to liposomes in the absence of protein. Photo‐induced oxidation of the heme was eliminated or severly limited by a combination of prior ligation with CO and the maintenance of high intravesicular hemoglobin concentrations (5–10 mM internal hemoglobin). The inclusion of allosteric effectors within polymerized hemosomes facilitated near‐quantitative conversion to the oxy‐HbA form. Gas permeability of monomeric and polymeric hemosomes was demonstrated by spectroscopic methods. Reversible spectral shifts, corresponding to oxygenation‐deoxygenation, were obtained after brief evacuation and exposure to oxygen or nitrogen. The gas permeability of polymerized hemosomes appears sufficient for the vesicles to act as oxygen carriers in vivo, a notion that is strengthened by their apparent hemocompatibility.

The Role of DNA-Stained Currency in Gang Robberies within the United Kingdom†

Cash‐and‐valuables‐in‐transit (CViT) robberies have become a substantial problem—especially in the current global economy. Over £19.4 million were stolen in 2008 and £17.1 million in 2009 in the United Kingdom alone. The transportation of cash and valuable items between financial institutions has long been a target of robberies in the U.K. After a robbery has occurred, police collect evidence in the form of ink‐stained currency. These stained notes are submitted for analysis. Samples are subjected to polymerase chain reaction in order to amplify any possible botanically derived DNA markers present on the notes. After amplification, capillary electrophoresis allows for the deciphering of the “DNA profile.” The DNA profile is then linked to a particular cash box, and this information is compared with records of whether or not that box had been stolen. The cases below are three such instances where botanically marked currency was used to help solve robberies.