Katarzyna Adamala and Jack Szostak at Massachusetts General Hospital report in Science this week that citrate appears to enable RNA replication in protocells made of fatty acid vesicles. Researchers trying to construct such protocells have found that high levels of magnesium ion within the vesicles would halt RNA replication. The duo screened a number of compounds to search for small molecules that protect the vesicles from Mg2+ leakage. Citrate, they found, does both that and protects RNA from Mg2+-catalyzed degradation. "In the absence of a prebiotic citrate synthesis pathway, it is of interest to consider prebiotically plausible alternatives to citrate that could potentially confer similar effects, such as short acidic peptides," they note.
University of California, Santa Barbara-led researchers report in Science Translational Medicine on a device they developed to monitor the levels of certain molecules in patient's blood. Their sensor, dubbed microfluidic electrochemical detector for in vivo continuous monitoring, or MEDIC, can detect a number of molecules, depending on the apatamer probe used. The researchers tested their system out, monitoring doxorubicin and kanamycin levels in live rats and in human whole blood at high sensitivity and specificity. "We believe that MEDIC could offer a general framework for achieving closed-loop control of numerous different in vivo biological processes, thereby yielding more effective treatments for a broad range of medical conditions," the researchers say. They add that such monitoring may better enable personalized medicine.