An international team led by Felix Lehmkühler from Deutsches Elektronen-Synchrotron DESY in Hamburg has investigated the temperature-induced swelling and collapsing of the polymer poly-N-isopropylacrylamide (PNIPAm) at European XFEL at Schenefeld near Hamburg. Due to its dynamic changes, PNIPAm is used in medicine, e.g. for drug delivery, tissue engineering or sensorics.
PNIPAm is typically dissolved in water. Above a certain temperature, the so-called lower critical solution temperature (LCST), which is around 32 °C, it changes from a hydrophilic, water-loving state to a hydrophobic, water-repellent state. As a consequence, nanogel particles, as investigated by Lehmkühler and co-workers, rapidly change their size above that temperature by expelling water.
This feature is useful for a variety of applications, including the controlled release of drugs in a patient’s body, as a model system for proteins and in tissue engineering, the cultivation of organic tissue for medical applications, or as bio-compatible temperature sensors. However, it was very difficult so far to watch these rapid phase transitions experimentally, and therefore to optimize them for different applications. Therefore, the precise characterisation of the kinetics of the changes of the PNIPAm polymer with temperature is still a lively research topic.
About European XFEL
The European XFEL is a 3.4 km long research facility extending from Hamburg to the neighbouring town of Schenefeld in the German Federal State of Schleswig-Holstein. With its repetition rate of 27,000 pulses per second and a peak brilliance a billion times higher than that of the best synchrotron X-ray radiation sources, the European XFEL enables the investigation of scientific problems in a variety of disciplines, including among many others: Structural Biology, Chemistry, Planetary Science, the study of matter under extreme conditions.
An international team led by Felix Lehmkühler from Deutsches Elektronen-Synchrotron DESY in Hamburg has investigated the temperature-induced swelling and collapsing of the polymer poly-N-isopropylacrylamide (PNIPAm) at European XFEL at Schenefeld near Hamburg. Due to its dynamic changes, PNIPAm is used in medicine, e.g. for drug delivery, tissue engineering or sensorics. PNIPAm is typically dissolved in […]
