A Co<sup>2+</sup>-selective and chirality-sensitive supermolecular metallohydrogel with a nanofiber network skeleton

Self-assembling natural drug hydrogels formed without structural modification and able to act as carriers are of interest for biomedical applications. A lack of knowledge about natural drug gels limits there current application. Here, we report on rhein, a herbal natural product, which is directly self-assembled into hydrogels through noncovalent interactions. This hydrogel shows excellent stability, sustained release and reversible stimuli-responses. The hydrogel consists of a three-dimensional nanofiber network that prevents premature degradation. Moreover, it easily enters cells and binds to toll-like receptor 4. This enables rhein hydrogels to significantly dephosphorylate IκBα, inhibiting the nuclear translocation of p65 at the NFκB signalling pathway in lipopolysaccharide-induced BV2 microglia. Subsequently, rhein hydrogels alleviate neuroinflammation with a long-lasting effect and little cytotoxicity compared to the equivalent free-drug in vitro. This study highlights a direct self-assembly hydrogel from natural small molecule as a promising neuroinflammatory therapy.

show abstract

“…1h) 32 . The excellent thixotropy and thermo-reversibility indicate that the rhein hydrogel can serve as an injectable hydrogel 33 .…”

Section: Resultsmentioning

confidence: 99%

Directed self-assembly of herbal small molecules into sustained release hydrogels for treating neural inflammation

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…Amino‐acid derivatives are regarded as effective candidates to form ionically cross‐linked gels. Wang et al designed and synthesized a serial of amino‐acid derivatives, all of which exhibited specific metal‐ion‐induced gelation property. The gelator 2‐((4‐(hydroxymethyl)benzyl)amino)‐3‐(1 H ‐indol‐3‐yl)propanoic acid (HAIP) (Figure , compound 2) can specifically be cross‐linked by Pb 2+ ions to form stable gels over a broad pH range from 4 to 8 .…”

Section: Design Rationalementioning

confidence: 99%

“…Incorporation of metal components (metal ions, metal–organic molecules, and metal nanoparticles) is an effective way to locally establish extra interactions among the building blocks and consequently trigger gel formation, weaken or enhance gel strength, and modify gel morphology . Moreover, addition of metal components is a straightforward way to integrate the specific properties of metals with the properties of organic matrix, therefore to tune properties like conductivity, color, rheological behavior, adsorption, emission, photophysical properties, magnetism, antibacterial activities, catalytic activities, redox activities, and self‐healing properties .…”

Section: Introductionmentioning

confidence: 99%

Metallogels: Availability, Applicability, and Advanceability

et al. 2019

Self Cite

View full text Add to dashboard Cite

amount of cross-linked solid. According to the nature of solvents, gels are categorized into hydrogel and organogel to indicate whether the solvent is water or organic solvent(s), respectively. As to the gelation driving forces, gels can be classified into physical gels in which intermolecular interactions are responsible for gel formation, and chemical gels in which the gel skeleton is cross-linked by covalent bonds.Incorporation of metal components (metal ions, metal-organic molecules, and metal nanoparticles) is an effective way to locally establish extra interactions among the building blocks and consequently trigger gel formation, [2][3][4] weaken [5] or enhance [6] gel strength, and modify gel morphology. [7,8] Moreover, addition of metal components is a straightforward way to integrate the specific properties of metals with the properties of organic matrix, therefore to tune properties like conductivity, [9] color, [10,11] rheological behavior, [12] adsorption, [13] emission, [14] photophysical properties, [15] magnetism, [16,17] antibacterial activities, [18,19] catalytic activities, [20][21][22][23] redox activities, [24,25] and selfhealing properties. [26][27][28] Therefore, a broad response range to physical and chemical stimuli can be achieved. For instance, the incorporation of multivalence ions such as Fe 2+ /Fe 3+ , [25,29] Co 2+ / Co 3+ , [30] Cu + /Cu 2+ , [31] results in redox reactive hydrogels; the incorporation of magnetic nanoparticles like Fe 3 O 4[17] causes the gel to respond to external magnetic fields. In addition to the abovementioned intrinsically functional superiorities, metallogels can also serve as ideal templates to generate new materials, [13,22,23,32,33] such as 3D networks, [34] porous structures, [35] chiral materials, [36][37][38] quantum dots, [39] and nanorods. [40] Following the rapid advancement of exploration on the knowledge acquisition toward the major roles that metallogels are playing in catalysis, sensing, biomedicine, electronics, and optical devices, the focus of research has been transferred to the design principles of metallogels in the last decade. Owing to the advancements in the instrumental characterizations and theoretical calculations, [41] a number of pioneering efforts on metallogel design have been made and several innovative reviews have summarized these inspiring contributions. [32,[42][43][44] Despite their extensively acknowledged application advantages in many fields, the discovery of new metallogels with expected functionalities is still highly dependent on experimental screening and serendipity. The challenge stems from the susceptible balance among those complicated intermolecular interactions and the elaborate structure requirements of metallogels.Another research niche that needs to be clarified before discussing recent development of metallogels is: how to sort Introducing metal components into gel matrices provides an effective strategy to develop soft materials with advantageous properties such as: optical activity, conductivity, magn...

show abstract

“…To date, although considerable progress has been achieved in metallohydrogels containing metal ions such as Cu 2+ , Fe 3+ , Zn 2+ and Hg 2+ , as well as La 3+ , etc . it is still desirable to develop convenient approaches for the design of metal‐selective hydrogels . The formation of the 3D networks of metallohydrogels requires not only the metal‐ligand coordination interactions, but also the non‐covalent interactions, such as hydrogen bonds, π‐π stacking, vander waals force, and hydrophobic interactions .…”

Section: Figurementioning

confidence: 99%

Assembly of (l+d)‐Tryptophan Derivatives Containing an Imidazole Group Selectively Forms a Rare Purple Ni²⁺‐Hydrogel

et al. 2019

View full text Add to dashboard Cite

Design of metal‐selective hydrogels is attractive due to potential applications in materials and biological sciences. Although much progress has been made, assembly of both l‐ and d‐amino acid derivatives was less explored for design of metallohydrogels. In this study, we synthesized a facile and small tryptophan derivative containing an imidazole ligand with both l‐ and d‐ configurations (denoted as l/d‐ImW). Intriguingly, the assembly of (l+d)‐ImW gelators was found to selectively form a Ni2+‐hydrogel in aqueous medium at room temperature, which shows a rare purple color and exhibits excellent multi‐responsiveness. In addition to insights into the gelation mechanism, this study provides a novel approach to the design of metallohydrogels, by the assembly of (l+d)‐amino acid derivatives containing both aromatic rings and multiple metal coordination sites.

show abstract

A Co²⁺-selective and chirality-sensitive supermolecular metallohydrogel with a nanofiber network skeleton

Cited by 34 publications

References 47 publications

Directed self-assembly of herbal small molecules into sustained release hydrogels for treating neural inflammation

Directed self-assembly of herbal small molecules into sustained release hydrogels for treating neural inflammation

Metallogels: Availability, Applicability, and Advanceability

Assembly of (l+d)‐Tryptophan Derivatives Containing an Imidazole Group Selectively Forms a Rare Purple Ni²⁺‐Hydrogel

Contact Info

Product

Resources

About

A Co2+-selective and chirality-sensitive supermolecular metallohydrogel with a nanofiber network skeleton

Cited by 34 publications

References 47 publications

Directed self-assembly of herbal small molecules into sustained release hydrogels for treating neural inflammation

Directed self-assembly of herbal small molecules into sustained release hydrogels for treating neural inflammation

Metallogels: Availability, Applicability, and Advanceability

Assembly of (l+d)‐Tryptophan Derivatives Containing an Imidazole Group Selectively Forms a Rare Purple Ni2+‐Hydrogel

Contact Info

Product

Resources

About

A Co²⁺-selective and chirality-sensitive supermolecular metallohydrogel with a nanofiber network skeleton

Assembly of (l+d)‐Tryptophan Derivatives Containing an Imidazole Group Selectively Forms a Rare Purple Ni²⁺‐Hydrogel