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Instruments / Technical Area	Publication Details	Published
B21-High Throughput SAXS	3D-printed SAXS chamber for controlled in situ dialysis and optical characterization Tamara Ehm , Julian Philipp , Martin Barkey , Martina Ober , Achim Theo Brinkop , David Simml , Miriam Von Westphalen , Bert Nickel , Roy Beck , Joachim O. Rädler Journal Of Synchrotron Radiation 29 DOI: 10.1107/S1600577522005136 Diamond Proposal Number(s): [24693, 21971] Open Access Show Abstract ▼ Abstract: 3D printing changes the scope of how samples can be mounted for small-angle X-ray scattering (SAXS). In this paper a 3D-printed X-ray chamber, which allows for in situ exchange of buffer and in situ optical transmission spectroscopy, is presented. The chamber is made of cyclic olefin copolymers (COC), including COC X-ray windows providing ultra-low SAXS background. The design integrates a membrane insert for in situ dialysis of the 100 µl sample volume against a reservoir, which enables measurements of the same sample under multiple conditions using an in-house X-ray setup equipped with a 17.4 keV molybdenum source. The design's capabilities are demonstrated by measuring reversible structural changes in lipid and polymer systems as a function of salt concentration and pH. In the same chambers optical light transmission spectroscopy was carried out measuring the optical turbidity of the mesophases and local pH values using pH-responsive dyes. Microfluidic exchange and optical spectroscopy combined with in situ X-ray scattering enables vast applications for the study of responsive materials.	Jul 2022
B21-High Throughput SAXS I22-Small angle scattering & Diffraction	Order from disorder with intrinsically disordered peptide amphiphiles Guy Jacoby , Merav Segal Asher , Tamara Ehm , Inbal Abutbul Ionita , Hila Shinar , Salome Azoulay-Ginsburg , Ido Zemach , Gil Koren , Dganit Danino , Michael M. Kozlov , Roey J. Amir , Roy Beck Journal Of The American Chemical Society 2010 DOI: 10.1021/jacs.1c06133 Diamond Proposal Number(s): [24693, 21971] Open Access Show Abstract ▼ Abstract: Amphiphilic molecules and their self-assembled structures have long been the target of extensive research due to their potential applications in fields ranging from materials design to biomedical and cosmetic applications. Increasing demands for functional complexity have been met with challenges in biochemical engineering, driving researchers to innovate in the design of new amphiphiles. An emerging class of molecules, namely, peptide amphiphiles, combines key advantages and circumvents some of the disadvantages of conventional phospholipids and block copolymers. Herein, we present new peptide amphiphiles composed of an intrinsically disordered peptide conjugated to two variants of hydrophobic dendritic domains. These molecules, termed intrinsically disordered peptide amphiphiles (IDPA), exhibit a sharp pH-induced micellar phase-transition from low-dispersity spheres to extremely elongated worm-like micelles. We present an experimental characterization of the transition and propose a theoretical model to describe the pH-response. We also present the potential of the shape transition to serve as a mechanism for the design of a cargo hold-and-release application. Such amphiphilic systems demonstrate the power of tailoring the interactions between disordered peptides for various stimuli-responsive biomedical applications.	Jul 2021
B21-High Throughput SAXS	The architectural change of the shell forming block from linear to V-shaped accelerates micellar disassembly but slows the complete enzymatic degradation of the amphiphiles Merav Segal , Lihi Ozery , Gadi Slor , Shreyas Shankar Wagle , Tamara Ehm , Roy Beck , Roey J. Amir Biomacromolecules DOI: 10.1021/acs.biomac.0c00882 Diamond Proposal Number(s): [24693] Show Abstract ▼ Abstract: Tuning the enzymatic degradation and disassembly rates of polymeric amphiphiles and their assemblies is crucial for designing enzyme-responsive nanocarriers for controlled drug delivery applications. The common methods to control the enzymatic degradation of amphiphilic polymers are to tune the molecular weights and ratios of the hydrophilic and hydrophobic blocks. In addition, to these approaches, the architecture of the hydrophilic block can also serve as a tool to tune enzymatic degradation and disassembly. To gain deeper understanding of the effect of the molecular architecture of the hydrophilic block we prepared two types of well-defined PEG-dendron amphiphiles bearing linear or V-shaped PEG chains as the hydrophilic blocks. The high molecular precision of these amphiphiles, which emerges from the utilization of dendrons as the hydrophobic blocks allowed us to study the self-assembly and enzymatic degradation and disassembly of the two types of amphiphiles with high resolution. Interestingly, the micelles of the V-shaped amphiphiles were significantly smaller and disassembled faster than those of the amphiphiles based on linear PEG. However, the complete enzymatic cleavage of the hydrophobic end-groups was significantly slower for the V-shaped amphiphiles. Our results show that the V-shape architecture can stabilize the unimer state and hence plays a double role in the enzymatic degradation and the induced disassembly and how it can be utilized to control the release of encapsulated or bound molecular cargo.	Aug 2020

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