Torsten (2019) 'Heliconical-layered nanocylinders (HLNCs) hierarchical self-assembly in a unique B4 phase liquid crystal morphology.', Materials horizons., 6 (5). 959968. Further information on publisher's website:https://doi.org/10.1039/C9MH00089EPublisher's copyright statement:Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details.

Tissue regeneration requires 3-dimensional (3D) smart materials as scaffolds to promote transport of nutrients. To mimic mechanical properties of extracellular matrices, biocompatible polymers have been widely studied and a diverse range of 3D scaffolds have been produced. We propose the use of responsive polymeric materials to create dynamic substrates for cell culture, which goes beyond designing only a physical static 3D scaffold. Here, we demonstrated that lactone- and lactide-based star block-copolymers (SBCs), where a liquid crystal (LC) moiety has been attached as a side-group, can be crosslinked to obtain Liquid Crystal Elastomers (LCEs) with a porous architecture using a salt-leaching method to promote cell infiltration. The obtained SmA LCE-based fully interconnected-porous foams exhibit a Young modulus of 0.23 ± 0.07 MPa and a biodegradability rate of around 20% after 15 weeks both of which are optimized to mimic native environments. We present cell culture results showing growth and proliferation of neurons on the scaffold after four weeks. This research provides a new platform to analyse LCE scaffold-cell interactions where the presence of liquid crystal moieties promotes cell alignment paving the way for a stimulated brain-like tissue.

3D liquid crystal elastomer (3D‐LCE) foams are used to support long‐term neuronal cultures for over 60 days. Sequential imaging shows that cell density remains relatively constant throughout the culture period while the number of cells per observational area increases. In a subset of samples, retinoic acid is used to stimulate extensive neuritic outgrowth and maturation of proliferated neurons within the LCEs, inducing a threefold increase in length with cells displaying morphologies indicative of mature neurons. Designed LCEs' micro‐channels have a similar diameter to endogenous parenchymal arterioles, ensuring that neurons throughout the construct have constant access to growth media during extended experiments. Here it is shown that 3D‐LCEs provide a unique environment and simple method to longitudinally study spatial neuronal function, not possible in conventional culture environments, with simplistic integration into existing methodological pipelines.

The range of possible morphologies for bent‐core B4 phase liquid crystals has recently expanded from helical nanofilaments (HNFs) and modulated HNFs to dual modulated HNFs, helical microfilaments, and heliconical‐layered nanocylinders. These new morphologies are observed when one or both aliphatic side chains contain a chiral center. Here, the following questions are addressed: which of these two chiral centers controls the handedness (helicity) and which morphology of the nanofilaments is formed by bent‐core liquid crystals with tris‐biphenyl diester core flanked by two chiral 2‐octyloxy side chains? The combined results reveal that the longer arm of these nonsymmetric bent‐core liquid crystals controls the handedness of the resulting dual modulated HNFs. These derivatives with opposite configuration of the two chiral side chains now feature twice as large dimensions compared to the homochiral derivatives with identical configuration. These results are supported by density functional theory calculations and stochastic dynamic atomistic simulations, which reveal that the relative difference between the para‐ and meta‐sides of the described series of compounds drives the variation in morphology. Finally, X‐ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM) data also uncover the new morphology for B4 phases featuring p2/m symmetry within the filaments and less pronounced crystalline character.

The development of appropriate materials that can make breakthroughs in tissue engineering has long been pursued by the scientific community. Several types of material have been long tested and re-designed for this purpose. At the same time, liquid crystals (LCs) have captivated the scientific community since their discovery in 1888 and soon after were thought to be, in combination with polymers, artificial muscles. Within the past decade liquid crystal elastomers (LCE) have been attracting increasing interest for their use as smart advanced materials for biological applications. Here, we examine how LCEs can potentially be used as dynamic substrates for culturing cells, moving away from the classical two-dimensional cell-culture nature. We also briefly discuss the integration of a few technologies for the preparation of more sophisticated LCE-composite scaffolds for more dynamic biomaterials. The anisotropic properties of LCEs can be used not only to promote cell attachment and the proliferation of cells, but also to promote cell alignment under LCE-stimulated deformation. 3D LCEs are ideal materials for new insights to simulate and study the development of tissues and the complex interplay between cells.

Composites based on ε-caprolactone-d,l-lactide-based elastomer with cellulose nanocrystals (CNC) are investigated to understand how matching cells with appropriate mechanical environments can provide important insights into fundamental cell behaviors.

The coupling between molecular conformation and chirality is a cornerstone in the construction of supramolecular helical structures of small molecules across various length scales. Inspired by biological systems, conformational preselection and control in artificial helical molecules, polymers, and aggregates has guided various applications in optics, photonics, and chiral sorting among others, which are frequently based on an inherent chirality amplification through processes such as templating and self-assembly. The so-called B4 nano- or microfilament phase formed by some bent-shaped molecules is an exemplary case for such chirality amplification across length scales, best illustrated by the formation of distinct nano- or microscopic chiral morphologies controlled by molecular conformation. Introduction of one or more chiral centers in the aliphatic side chains led to the discovery of homochiral helical nanofilament, helical microfilament, and heliconical-layered nanocylinder morphologies. Herein, we demonstrate how a priori calculations of the molecular conformation affected by chiral side chains are used to design bent-shaped molecules that self-assemble into chiral nano- and microfilament as well as nanocylinder conglomerates despite the homochiral nature of the molecules. Furthermore, relocation of the chiral center leads to formation of helical as well as flat nanoribbons. Self-consistent data sets from polarized optical as well as scanning and transmission electron microscopy, thin-film and solution circular dichroism spectropolarimetry, and synchrotron-based X-ray diffraction experiments support the progressive and predictable change in morphology controlled by structural changes in the chiral side chains. The formation of these morphologies is discussed in light of the diminishing effects of molecular chirality as the chain length increases or as the chiral center is moved away from the core-chain juncture. The type of phase (B1-columnar or B4) and morphology of the nano- or microfilaments generated can further be controlled by sample treatment conditions such as by the cooling rate from the isotropic melt or by the presence of an organic solvent in the ensuing colloidal dispersions. We show that these nanoscale morphologies can then organize into a wealth of two- and three-dimensional shapes and structures ranging from flower blossoms to fiber mats formed by intersecting flat nanoribbons.

Aggregation-induced emission (AIE)-based circularly polarized luminescence (CPL) has been recognized as a promising pathway for developing chiroptical materials with high luminescence dissymmetry factors (|g lum |). Here, we propose a method for the construction of a thermally tunable CPL-active system based on a supramolecular self-assembly approach that utilizes helical nano-or microfilament templates in conjunction with an AIE dye. The CPL properties of the ensuing ensembles are predominantly determined by the intrinsic geometric differences among the various filament templates such as their overall dimensions (width, height, and helical pitch) and the area fraction of the exposed aromatic segments or sublayers. The proposed mechanism is based on the collective data acquired by absorption, steady state and timeresolved fluorescence, absolute quantum yield, and CPL measurements. The highest |g lum | value for the most promising dual-modulated helical nanofilament templates in the present series was further enhanced, reaching up to |g lum | = 0.25 by confinement in the appropriate diameter of anodized aluminum oxide (AAO) nanochannels. It is envisioned that this methodology will afford new insights into the design of temperature-rate indicators or anti-counterfeiting tags using a combination of structural color by the nano-and microfilament templates and the AIE property of the guest dye.