Tissue engineering, gene therapy, drug screening, and emerging regenerative medicine therapies are fundamentally reliant on high‐quality adherent cell culture, but current methods to cryopreserve cells in this format can give low cell yields and require large volumes of solvent “antifreezes”. Herein, we report polyproline as a minimum (bio)synthetic mimic of antifreeze proteins that is accessible by solution, solid‐phase, and recombinant methods. We demonstrate that polyproline has ice recrystallisation inhibition activity linked to its amphipathic helix and that it enhances the DMSO cryopreservation of adherent cell lines. Polyproline may be a versatile additive in the emerging field of macromolecular cryoprotectants.

In superconducting spin valves of the type S/F1/N/F2 or F1/S/F2 with a superconducting layer S, two ferromagnetic layers F1 and F2, and a normal metallic layer N, the superconducting transition temperature T S depends on the relative magnetization direction of the ferromagnetic layers F1 and F2. The difference of the transition temperature ⌬T S = T s AP − T s P with the magnetization direction of F1 and F2 either antiparallel or parallel is called the superconducting spin valve effect. We have prepared both types of spin valves by growing Fe/V thin-film heterostructures with epitaxial quality on MgO͑001͒ substrates. In the S/F1/N/F2-type spin valves the ferromagnetic layers were the first two Fe layers of a ͓Fe/V͔ superlattice coupled antiferromagnetically via the interlayer exchange interaction. Here we observed a superconducting spin valve shift of up to ⌬T S Ϸ 200 mK when aligning the sublattice magnetization in an external magnetic field. In the F1/S/F2-type spin valves the ferromagnetic layer F1 was either a ͓Fe/V͔ or a ͓Fe x V 1−x / V͔ superlattice, the F2 layer was a Fe-, a Co-, or a Fe x V 1−x film. Using weakly ferromagnetic Fe x V 1−x alloy layers as F1 and F2 we find a spin valve effect of up to ⌬T S Ϸ 20 mK, which is more than a factor of 2 larger than reported in the literature before for spin valves with comparable transition temperatures. Our results indicate that a high interface transparency and a large superconducting correlation length are prerequisites for the observation of a sizable superconducting spin valve effect.

Time-resolved X-ray solution scattering is an increasingly popular method to measure conformational changes in proteins. Extracting structural information from the resulting difference X-ray scattering data is a daunting task. We present a method in which the limited but precious information encoded in such scattering curves is combined with the chemical knowledge of molecular force fields. The molecule of interest is then refined toward experimental data using molecular dynamics simulation. Therefore, the energy landscape is biased toward conformations that agree with experimental data. We describe and verify the method, and we provide an implementation in GROMACS.