Supramolecular “Trojan Horse” for Nuclear Delivery of Dual Anticancer Drugs

Bioinspired Supramolecular Lubricating Hydrogel Induced by Shear Force

Bioinspired lubricating materials are great challenge toward artificial joints. In this contribution, we synthesize a bioinspired hydrogel by combining a thixotropic supramolecular network and polymer double network, exhibiting a unique shear-responsive lubricating property. The disassembly of the N-fluorenylmethoxycarbonyl-l-tryptophan supramolecular network triggered by shear force will endow lubricating function to the hydrogel; meanwhile PAAm and PVA double network acts as the supporting skeleton with high mechanical property. This work will bring new insight on the design of artificial lubricating joint.

Porous metal–organic gel assisted by l-tartaric acid ligand for efficient and controllable drug delivery

The synthetic route for drug carriers based on porous Al-MOG.

Carboplatin-loaded SMNDs to reduce GSH-mediated platinum resistance for prostate cancer therapy

Glutathione (GSH)-mediated drug resistance can strongly weaken the therapeutic efficiency of platinum(ii).

A supramolecular hydrogel for spatial-temporal release of auxin to promote plant root growth

An auxin-based hydrogelator linked by a hydrolysable ester bond enabled spatial-temporal release of the plant hormone and significantly promoted root growth.

Left-handed helical polymer resin nanotubes prepared by using N-palmitoyl glucosamine

Although the preparation of single-handed helical inorganic and hybrid organic-inorganic nanotubes is well developed, approaches to the formation of single-handed organopolymeric nanotubes are limited. Here, left-handed helical m-phenylenediamine-formaldehyde resin and 3-aminophenol-formaldehyde resin nanotubes were prepared by using N-palmitoyl glucosamine that can self-assemble into left-handed twisted nanoribbons in a mixture of methanol and water. In the reaction mixture, the helical pitch of the nanoribbons decreased with increasing reaction time. The resin nanotubes were obtained after removing the N-palmitoyl glucosamine template, and circular dichroism spectroscopy indicated that the organopolymeric nanotubes had optical activity. Carbonaceous nanotubes were then prepared by carbonization of the 3-aminophenol-formaldehyde resin nanotubes.

Intracellular coassembly boosts the anti-inflammation capacity of dexamethasone

Dexamethasone (Dex) is one of the essential medicines used to treat inflammation diseases but an overdose of Dex leads to severe adverse effects. The development of a new strategy to boost the anti-inflammation efficacy of Dex is, therefore, important but remains challenging. Herein, by employing an enzyme-instructed self-assembly system, we developed an intracellular coassembly strategy to boost the anti-inflammation efficacy of Dex. Under the catalysis of alkaline phosphatase (ALP), the hydrogelator precursor Nap-Phe-Phe-Tyr(H₂PO₃)-OH (1p) self-assembled to form Gel 1 but dexamethasone sodium phosphate (Dp) only yielded Dex precipitates. However, subjecting equivalent amounts of 1p and Dp together to ALP-triggered coassembly was found to result in the formation of Gel 2. Cell experiments indicated that intracellular ALP-triggered coassembly of Dp with 1p extensively boosted the anti-inflammation efficacy of Dex on two types inflammatory cell models. We envision that, in the near future, our strategy of intracellular coassembly could be widely employed to boost the therapeutic effects of more drugs, while in the meantime used to alleviate the undesired adverse effects of these drugs.

Aggregation-Induced Chirality: Twist and Stacking Handedness of the Biphenylene Groups of n-C12H25O-BP-CO-Ala-Ala Dipeptides

In mixtures of water and dimethyl sulfoxide, 4'-(n-dodecyloxy)-1,1'-biphenyl-4-carbonyl Ala-Ala dipeptides can self-assemble into tubular structures that are formed by coiled nanoribbons. The twist and stacking handedness of biphenylene groups were studied using circular dichroism and confirmed by theoretical chemical calculations. The handedness of the coiled nanoribbons and the stacking handedness of biphenylene groups are controlled by the chirality of alanine at the C-terminus, whereas the twist handedness of biphenylene groups is determined by the chirality of alanine at the N-terminus. ¹H NMR spectra indicated that the hydrogen bond formed by the N-H group of alanine at the N-terminus plays an important role in the formation of organic self-assemblies. On the basis of small-angle X-ray scattering characterization, a dimer structure was proposed to form through the terminal COOH groups.

Fabrication of self-assembling nanofibers with optimal cell uptake and therapeutic delivery efficacy

Effective strategies to fabricate finite organic nanoparticles and understanding their structure-dependent cell interaction is highly important for the development of long circulating nanocarriers in cancer therapy. In this contribution, we will capitalize on our recent development of finite supramolecular nanofibers based on the self-assembly of modularly designed cationic multidomain peptides (MDPs) and use them as a model system to investigate structure-dependent cell penetrating activity. MDPs self-assembled into nanofibers with high density of cationic charges at the fiber-solvent interface to interact with the cell membrane. However, despite the multivalent charge presentation, not all fibers led to high levels of membrane activity and cellular uptake. The flexibility of the cationic charge domains on self-assembled nanofibers plays a key role in effective membrane perturbation. Nanofibers were found to sacrifice their dimension, thermodynamic and kinetic stability for a more flexible charge domain in order to achieve effective membrane interaction. The increased membrane activity led to improved cell uptake of membrane-impermeable chemotherapeutics through membrane pore formation. In vitro cytotoxicity study showed co-administering of water-soluble doxorubicin with membrane-active peptide nanofibers dramatically reduced the IC50 by eight folds compared to drug alone. Through these detailed structure and activity studies, the acquired knowledge will provide important guidelines for the design of a variety of supramolecular cell penetrating nanomaterials not limited to peptide assembly which can be used to probe various complex biological processes.

Enzyme-assisted peptide folding, assembly and anti-cancer properties

The α-helix is the most prevalent conformation in proteins. However, formation of the α-helical conformation remains a challenge for short peptides with less than 5 amino acids. We demonstrated in this study that enzyme-instructed self-assembly (EISA) provides a unique pathway to assist the self-assembly of peptides into the α-helical conformation, while a heating-cooling process leads to a conformation more similar to a β-sheet. The same peptide with different conformations self-assembled into different nanostructures. The peptide with α-helical conformation self-assembled into stable nanofibers and hydrogels, while the other one assembled into an unstable nanoparticle suspension. The nanofiber solution exhibited better stability against proteinase K digestion and an enhanced cellular uptake compared to the nanoparticle solution. Therefore, the nanomedicine formed by the α-helical peptide showed a better inhibition capacity against cancer cells in vitro and significantly inhibited tumor growth in vivo compared to the one formed by the β-sheet peptide. Our study demonstrates the unique advantages of EISA to assist peptide folding and self-assembly into biofunctional nanomaterials.

Probing Gelation and Rheological Behavior of a Self-Assembled Molecular Gel

Molecular gels have been investigated over the last few decades; however, mechanical behavior of these self-assembled gels is not well understood, particularly how these materials fail at large strain. Here, we report the gelation and rheological behavior of a molecular gel formed by self-assembly of a low molecular weight gelator (LMWG), di-Fmoc-l-lysine, in 1-propanol/water mixture. Gels were prepared by solvent-triggered technique, and gelation was tracked using Fourier transform infrared (FTIR) spectroscopy and shear rheology. FTIR spectroscopy captures the formation of hydrogen bonding between the gelator molecules, and the change in IR spectra during the gelation process correlates with the gelation kinetics results captured by rheology. Self-assembly of gelator molecules leads to a fiber-like structure, and these long fibers topologically interact to form a gel-like material. Stretched-exponential function can capture the stress-relaxation data. Stress-relaxation time for these gels have been found to be long owing to long fiber dimensions, and the stretching exponent value of 1/3 indicates polydispersity in fiber dimensions. Cavitation rheology captures fracture-like behavior of these gels, and critical energy release rate has been estimated to be of the order 0.1 J/m². Our results provide new understanding of the rheological behavior of molecular gels and their structural origin.

Molecular packing and the handedness of the self-assemblies of C17H35CO-Ala-Phe sodium salts

Molecular packing structure dominates the handedness of the self-assemblies of a series of lipodipeptide sodium salts.

Cancer vaccines using supramolecular hydrogels of NSAID-modified peptides as adjuvants abolish tumorigenesis

We demonstrated in this study that supramolecular hydrogels of NSAID-modified peptides are promising adjuvants for cancer vaccine development.