Determination of Gas-Phase Ion Structures of Locally Polar Homopolymers Through High-Resolution Ion Mobility Spectrometry-Mass Spectrometry.

The strong synergy arising from coupling two orthogonal analytical techniques such as ion mobility and mass spectrometry can be used to separate complex mixtures and determine structural information of analytes in the gas phase. A tandem study is performed using two systems with different gases and pressures to ascertain gas-phase conformations of homopolymer ions. Aside from spherical and stretched configurations, intermediate configurations formed by a multiply charged globule and a "bead-on-a-string" appendix are confirmed for polyethylene-glycol (PEG), polycaprolactone (PCL), and polydimethylsiloxane (PDMS). These intermediate configurations are shown to be ubiquitous for all charge states and masses present. For each charge state, configurations evolve in two distinctive patterns: an inverse evolution which occurs as an elementary charge attached to the polymer leaves the larger globule and incorporates itself into the appendage, and a forward evolution which reduces the globule without relinquishing a charge while leaving the appendix relatively constant. Forward evolutions are confirmed to form self-similar family shapes that transcend charge states for all polymers. Identical structural changes occur at the same mass over charge regardless of the system, gas or pressure strongly suggesting that conformations are only contingent on number of charges and chain length, and start arranging once the ion is at least partially ejected from the droplet, supporting a charge extrusion mechanism. Configurational changes are smoother for PDMS which is attributed to the larger steric hindrance caused by protruding pendant groups. This study has implications in the study of the configurational space of more complex homopolymers and heteropolymers. Graphical Abstract.

Biopharmaceutical Contact Centers and Combination Products: Results of a Benchmark Survey.

Biopharmaceutical contact centers are expanding core skill sets when it comes to addressing inquiries regarding combination products. An inside look at how biopharmaceutical companies are handling this increasingly common scenario is provided through a benchmark survey, which was conducted between December 2012 and January 2013. The purpose of this survey was to collect and share contact center best practices on the handling of combination products in the biopharmaceutical industry. Eleven biopharmaceutical companies participated in the survey, 10 of which were listed in "The Top 50 Pharmaceutical Companies," by Pharmaceutical Executive. The information gathered from the survey responses is reported anonymously and provides perspectives on the trends and best practices that will serve as a practical resource for those involved in establishing or expanding contact center services.