Two component hydrogel with γ-amino butyric acid as potential receptor and neurotransmitter delivery system

Assembly of a Tripeptide and Anti-Inflammatory Drugs into Supramolecular Hydrogels for Sustained Release

Supramolecular hydrogels offer interesting opportunities for co-assembly with drugs towards sustained release over time, which could be achieved given that the drug participates in the hydrogel nanostructure, and it is not simply physically entrapped within the gel matrix. dLeu-Phe-Phe is an attractive building block of biomaterials in light of the peptide's inherent biocompatibility and biodegradability. This study evaluates the assembly of the tripeptide in the presence of either of the anti-inflammatory drugs ketoprofen or naproxen at levels analogous to commercial gel formulations. Fourier-transformed infrared (FT-IR), circular dichroism, Thioflavin T fluorescence, transmission electron microscopy (TEM), and oscillatory rheometry are used. Drug release over time is monitored by means of reverse-phase high performance liquid chromatography, and shows different kinetics for the two drugs.

Heterotypic Supramolecular Hydrogels

Supramolecular hydrogels, formed via intermolecular interactions in water, are emerging as a new type of versatile soft materials to be applied in many areas, such as biomedical applications, catalysis, food additives, and cosmetics. While most of the supramolecular hydrogels are homotypic (i.e., one type of building blocks), heterotypic supramolecular hydrogels are less explored, but may offer unique advantages. This review discribes supramolecular hydrogels that consist of more than one type building blocks (i.e., heterotypic) to illustrate the promises and challenges of heterotypic supramolecular hydrogels as soft biomaterials. First, we discuss the driving force for producing heterotypic supramolecular hydrogels. Second, we introduce the general methods for triggering heterotypic supramolecular hydrogels. Third, we summarize the examples of heterotypic supramolecular hydrogels made of hydrogelators with or without containing amino acid residues. Fourth, we describe the applications of heterotypic supramolecular hydrogels up-to-date. Finally, we give the outlook and propose a few future directions that likely worth to be explored.

Self-assembled peptide microspheres for sustainable release of sulfamethoxazole

Porous peptide microspheres have been used for the loading and sustained release of the bacteriostatic antibiotic sulfamethoxazole.

Supramolecular Hydrogelators and Hydrogels: From Soft Matter to Molecular Biomaterials

In this review we intend to provide a relatively comprehensive summary of the work of supramolecular hydrogelators after 2004 and to put emphasis particularly on the applications of supramolecular hydrogels/hydrogelators as molecular biomaterials. After a brief introduction of methods for generating supramolecular hydrogels, we discuss supramolecular hydrogelators on the basis of their categories, such as small organic molecules, coordination complexes, peptides, nucleobases, and saccharides. Following molecular design, we focus on various potential applications of supramolecular hydrogels as molecular biomaterials, classified by their applications in cell cultures, tissue engineering, cell behavior, imaging, and unique applications of hydrogelators. Particularly, we discuss the applications of supramolecular hydrogelators after they form supramolecular assemblies but prior to reaching the critical gelation concentration because this subject is less explored but may hold equally great promise for helping address fundamental questions about the mechanisms or the consequences of the self-assembly of molecules, including low molecular weight ones. Finally, we provide a perspective on supramolecular hydrogelators. We hope that this review will serve as an updated introduction and reference for researchers who are interested in exploring supramolecular hydrogelators as molecular biomaterials for addressing the societal needs at various frontiers.

The effect of meta versus para substitution on the aggregation of bis-cholesteryl appended 2,6-disubstituted pyridine-based gelators

The self assembly of bent core isomers comprising pyridine-cholesteryl units connected through meta- and para-substituted benzene as linkers were studied and their gelation and aggregation phenomena were compared with respect to the substitution effect.

Synthesis and characterization of lysine-modified SBA-15 and its selective adsorption of scandium from a solution of rare earth elements

A novel lysine-functionalized mesoporous material was synthesized using a facile two-step post-grafting method, selectively adsorbing scandium from aqueous solution.

Fabrication of hollow self-assembled peptide microvesicles and transition from sphere-to-rod structure

This paper presents the construction of hollow peptide microspheres and the mechanism of transition of microspheres to rod-like vesicles at low concentration. The tripeptides Boc-Phe-Maba-Phe-OMe 1 and Boc-Phe-Maba-Tyr-OMe 2, each of them containing a rigid m-aminobenzoic acid (Maba) template at the central position, forms microspheres at a concentration of 1.6 mM in methanol. At low concentration, these vesicular structures are fused through neck formation, and this leads to sphere-to-rod transition of vesicles. Sizes of these microspheres increase with increasing concentration. We have successfully characterized this transition by fluorescence spectroscopy, DLS, and electron microscopic study. The scanning electron microscopy clearly shows that these spheres are hollow. One important property of these microvesicular structures is the encapsulation of a potent anticonvulsant and mood stabilizing drug carbamazepine, which holds future promise to use these microvesicles as delivery vehicles.

Molecular hydrogels of therapeutic agents

This tutorial review aims to introduce a new kind of biomaterials-molecular hydrogels of therapeutic agents. Based on the molecular self-assembly in water, it is possible to transform therapeutic agents into analogues that form hydrogels without compromising their pharmacological efficacy. This transformation can be beneficial in three aspects: (i) the therapeutic agents become "self-deliverable" in the form of hydrogels; (ii) the self-assembly of hydrogelators of drugs might confer new and useful properties such as multivalency or high local densities; (iii) the exploration of molecular hydrogels of drugs may ultimately lead to bioactive molecules that have dual or multiple roles. By summarizing the reports on the molecular hydrogels made from clinical used drugs or other bioactive molecules, this article presents representative molecular hydrogels of therapeutics and outlines the promises and challenges for developing this new class of biomaterials.