On the effects of organic-acids isomers on temperature-responsiveness in wormlike micelles (WLMs) systems.

Responsive wormlike micelles (WLMs) consisted of cationic surfactants and organic-acids are fascinating due to their reversible molecular recognition properties. However, it is unknown how the structure of organic-acids alters the stimuli-responsiveness of WLMs systems. Herein, the peculiar nature of temperature-responsive behaviors in three WLMs systems were systematically investigated. These were manufactured by combining N-erucamidopropyl-N,N-dimethylamine (UC22AMPM) with isomers of organic-acids: o-phthalic acid (o-PA), m-phthalic acid (m-PA) and p-phthalic acid (p-PA) at molar ratio of 2:1 (named as o-EAPA, m-EAPA and p-EAPA respectively). The phase behaviors, macro- and micro-rheology, as well as the mechanism of temperature-responsiveness were explored by visual inspection, rheological and optical methods. The results showed that the three systems exhibited different responsiveness with increase of temperature. Among them, the viscosity and viscoelasticity of o-EAPA were gradually decreased with temperature increase from 30 °C to 90 °C. On the other hand, those of p-EAPA were firstly increased and subsequently decreased, exhibiting the highest viscosity during the heating process. This peculiar phenomenon was attributed to the hydrophilic difference of organic-acids isomers, leading to variations of micelle transitions upon temperature increase. This study is the first report of aromatic-acids isomers inducing different on temperature-responsiveness, and finding beneficial for the development of responsive WLMs for different applications.

Interaction between polysaccharides and toll-like receptor 4: Primary structural role, immune balance perspective, and 3D interaction model hypothesis.

Various structural types of polysaccharides are recognized by toll-like receptor 4 (TLR4). However, the mechanism of interaction between the polysaccharides with different structures and TLR4 is unclarified. This review summarized the primary structure of polysaccharides related to TLR4, mainly including molecular weight, monosaccharide composition, glycosidic bonds, functional groups, and branched-chain structure. The optimal primary structure for interacting with TLR4 was obtained by the statistical analysis. Besides, the dual-directional regulation of TLR4 signaling cascade by polysaccharides was also elucidated from an immune balance perspective. Finally, the 3D interaction model of polysaccharides to TLR4-myeloid differentiation factor 2 (MD2) complex was hypothesized according to the LPS-TLR4-MD2 dimerization model and the polysaccharides solution conformation. The essence of polysaccharides binding to TLR4-MD2 complex is a multivalent non-covalent bond interaction. All the arguments summarized in this review are intended to provide some new insights into the interaction between polysaccharides and TLR4.

Changes in Protein Non-Covalent Bonds and Aggregate Size during Dough Formation.

This research investigated changes in the amounts and sizes of monomeric proteins and protein aggregates during dough mixing, with a focus on the contribution of non-covalent bonds in the aggregation of gluten proteins. High protein flour (HF) and low protein flour (LF) were used in this study. As dough mixing progressed from flour to overmixed dough, the total amount of protein aggregates increased while the amount of monomeric protein decreased. Omega-gliadin was the major monomeric protein that decreased in quantity. Interestingly, the amount of larger-sized protein aggregates decreased and that of smaller-sized protein aggregates increased. The amount of gluten protein macro-polymer aggregated through strong non-covalent bonds decreased whereas aggregates formed with weaker non-covalent bonds increased. LF dough behaved similar to HF dough. Large-sized gluten protein aggregates disaggregated due to the weakening of non-covalent bonds and became smaller. Omega-gliadin was incorporated into gluten protein aggregates during dough mixing.

[Functionalization of Cyclodextrin Derivatives to Create Supramolecular Pharmaceutical Materials].

Molecular recognition is useful in creating functional supramolecular materials. Non-covalent bond formations, such as host-guest interactions, hydrogen bonding, and electrostatic interaction, are effective tools for introducing various functions and properties into materials. This review focuses on such macroscopic functions as selective molecular adhesion, self-healing, toughness, and the actuation of supramolecular polymeric materials-materials which have potential in pharmaceutical development. These functions have been achieved using reversible bonding between cyclodextrins (CDs; cyclic host molecules) and guest molecules. For example, macroscopic adhesions between host-modified hydrogels and guest-modified hydrogels have been investigated. CD-modified hydrogels were found to show selective adhesion to a guest hydrogel with an appropriate molecular size for the CD cavity, indicating that the host-guest complex formation between the gels led to the adhesive behavior. Surprisingly, polymeric materials having host-guest cross-linking points show both high toughness and flexibility, unlike conventional covalently cross-linked materials. These materials also exhibited self-healing properties, capable of repairing damage to the materials. Furthermore, the supramolecular materials demonstrated macroscopic rapid expansion and contraction driven by external stimuli under wet or semi-dry conditions, in which the supramolecular gels vary the cross-linking density between the polymers accordingly. Different topological gels are able to vary the length of the polymer chain between cross-linking points to show large deformation. Both types of actuators were found to exhibit externally stimulated flexing behaviors. This review summarizes recent advancements in the development of these supramolecular materials, which appear to be promising new components in pharmaceutical science.