The efficient purification and analysis of topological DNA variants is mandatory for many state-of-the-art molecular medicine technologies, like gene- and cancer-therapy as well as plasmid vaccination. In this work, we exploit dielectrophoresis (DEP) for a fast and efficient continuous-flow separation and analysis that goes beyond the standard methods of gel electrophoresis and capillary electrophoresis. The aim of this work was to reach for the limits in dielectrophoretic analysis of DNA regarding the size resolution and the topological conformation. A continuous-flow analytical separation of analyte mixtures of small linear DNA-fragments (10.0 kbp, 8.0 kbp, 6.0 kbp, and 5.0 kbp) and topological DNA variants (linear and supercoiled conformation) was investigated. We present a world record in the minimal size difference of 16.7% of DNA samples that can be resolved in a dielectrophoretic continuous-flow separation. Moreover, we demonstrate for the first time a microfluidic continuous-flow separation of DNA molecules based on their topological conformation. Since dielectrophoresis is virtually label-free, it offers a fast in-process quality control with low consumption, e.g. for the production of gene vaccines.

Carbon dioxide (CO 2 ) is a renewable carbon source that is easily available in high purity and is utilized as a co-monomer in the direct ring-opening polymerization of epoxides to obtain aliphatic polycarbonates. In this work, degradable aliphatic polycarbonate diblock copolymers (mPEG-b-PBC) are synthesized via catalytic copolymerization of CO 2 and 1,2-butylene oxide, starting from monomethoxy poly(ethylene glycol) (mPEG) as a chain transfer reagent. The polymerization proceeds at low temperatures and high CO 2 pressure, utilizing the established binary catalytic system (R,R)-Co(salen)Cl/[PPN]Cl. Amphiphilic nonionic diblock copolymers with varying PBC block lengths and hydrophilic−lipophilic balance values between 9 and 16 are synthesized. The polymers are characterized via NMR and Fourier transform infrared spectroscopies as well as size exclusion chromatography, exhibiting molecular weights ranging from 2400 to 4100 g mol −1 with narrow dispersities (Đ = M w /M n ) from 1.07 to 1.18. Furthermore, the thermal properties, i.e., T g , T m , and T d , are determined. Surface tension measurements prove that the amphiphilic polymers form micelles above the critical micelle concentration, whereas small-angle neutron scattering shows that they are of nearly spherical shape. Adding small amounts of the synthesized mPEG-b-PBC polymers to different microemulsion systems, we found that the polymers were able to strongly increase the efficiency of medium-chain surfactants to solubilize polar oils.

Carbon dioxide (CO2) is an easily available, renewable carbon source and can be utilized as a comonomer in the catalytic ring‐opening polymerization of epoxides to generate aliphatic polycarbonates. Dodecyl glycidyl ether (DDGE) is copolymerized with CO2 and propylene oxide (PO) to obtain aliphatic poly(dodecyl glycidyl ether carbonate) and poly(propylene carbonate‐co‐dodecyl glycidyl ether carbonate) copolymers, respectively. The polymerization proceeds at 30 °C and high CO2 pressure utilizing the established binary catalytic system (R,R)‐Co(salen)Cl/[PPN]Cl. The copolymers with varying DDGE:PO ratios are characterized via NMR, FT‐IR spectroscopy, and SEC, exhibiting high molecular weights between 11 400 and 37 900 g mol−1 with dispersities (Р= M w/M n) in the range of 1.37–1.61. Copolymers with T gs of −11 °C or T ms from 5 to 15 °C and thermal decomposition >200 °C depending on the comonomer ratio, are obtained as determined by differential scanning calorimetry/TGA.