Supramolecular Materials最新文献

Searching chemical space and expanding the structural diversity of supramolecular self-assembly based on the development of combinatorial libraries is significant to the guided design of bio-inspired materials. Here we discuss the peptide self-assembly into a diversity of nanostructures, as well as their network organization into macroscopic hydrogel using secondary structures of α-helix, β-sheet, and coiled-coil peptides. In particular, we highlight the recent advances in developing computational and experimental tools to explore the vast combinatorial space, uncover structure-activity relationships and identify the factors that determine peptide self-assembly. We envision that the integration of newly developed techniques such as high throughput screening, automated flow chemistry, and machine learning into the screening of peptide libraries will offer new opportunities to discover peptide-based functional materials.

Photodynamic therapy (PDT) has been considered as a therapeutic method based on non-invasiveness and lower side effect. However, photosensitizers (PS), as a major component of PDT, suffer from aggregation and limit reactive oxygen species (ROS) generation in the delivery process, thus causing unsatisfactory therapeutic effect of PDT. Herein, we demonstrate a multicomponent coordination coassembly strategy based on the combination of metal-binding protein (ovalbumin, OVA), metal ions (Zn²⁺) and a photosensitive drug (pheophorbide a, PheoA) for constructing supramolecular photosensitive nanodrugs towards antitumor PDT. The resulting photosensitizer nanodrugs exhibit well-defined nanorod structures, good colloidal dispersity, and high encapsulation efficiency. Most importantly, multicomponent coassembled nanorods possess favorable stability of physiological environment and on-demand release of PS in response to an acidic ambient in tumor cells. These features result in the high level of ROS generation in tumor cells, benefiting for enhanced therapeutic effect of in vitro PDT.

Supramolecular polymers based on supramolecular coordination complexes (SCCs) have received extensive attention because of their good stimulus responsiveness, processability and other properties. Herein, we report metallacycle-crosslinked supramolecular polymers via amino–yne click reaction, which were employed as well-performing elastomer materials. The supramolecular polymers cross-linked by the metallacycle not only maintained the aggregation induced emission (AIE) properties of the metallacycle, which were used to detect nitroaromatic explosives, but also had enhanced mechanical strength and toughness and exhibited elastomeric properties. This study provides a feasible strategy for the preparation of metallacycle-based supramolecular polymers with better mechanical properties.

The infections and diseases caused by harmful bacteria are regarded as the worldwide health-threatening issue. The most antibiotics-based delivery systems restricted the controlled drug release at specific infection sites due to the stable chemical conjugation, thus largely compromising the treatment effectiveness. Herein, we report the construction of light controlled drug-based supramolecular polymer (LDSP), which is endowed the “switch on” function for realizing the controllable antibiotics released in specific sites. LDSP was first formed based on the host-guest interaction between β-cyclodextrin units grafted hyaluronic acid chain (HA-CD) and azobenzene moiety linked by two enoxacin units (Azo-(Eno)₂), and could further self-assemble into light controlled drug-based supramolecular polymer self-assemblies (LDSPSAs). Under the UV light irradiation, the “switch on” function of LDSPSAs could be effectively turned on at the specific infected tissues due to the smartly dissociated host-guest interaction, facilitating the controlled release of the hydrophobic Azo-(Eno)₂ to interact with bacteria for efficient antibacterial effect. The biological evaluation demonstrated that LDSPSAs achieved good antibacterial efficiency and well biosafety.

With the increasing requirement for antibacterial surface especially in biomedical apparatus, constructing the new material surface with bactericidal activity for combating the infection caused by multi-resistant microbials possesses great significance. The surface sterilization in traditional way cannot remove the bacteria completely, and new strategy which could kill the bacteria with high efficiency, safety and convenience is urgently needed. In this review, we recapitulate the commonly used approaches about surface modification technology for combating the bacteria on material surface. According to different mechanism of disinfectant, we first list two widely used bactericidal manners on surface, contacting killing and releasing killing, and summarize its characterizations. Then, the antibacterial surface with these killing factors are concluded, and further categorized into the form of covalent polymer brushes coatings and non-covalent supramolecular coatings. Besides, smart responsive surface adjusted by light, pH or salt, and surface morphology structure such as physical puncture are superficially discussed. We hope this review can provide a comprehensive knowledge in preparing for antibacterial surface.

Converting linear to rotary motion is a typical and enabling task for macroscale machinery, but the process is not yet established at the nano- and microscale. Linear motion is generated by the motor proteins kinesin and dynein as they move along microtubules, and a microtubule immobilized on the circumference of a microsphere could create rotary motion as it is propelled by surface-adhered motors, enabling microscale machines such as “active ball bearings”. This paper describes the attachment of microtubules to microspheres and the resulting types of motion as the microtubule-microsphere assemblies interact with a surface covered with kinesin-1 motor proteins. Dragging, pushing, spinning and rotating motions are observed and analyzed, demonstrating a pathway to microscale rotations driven by linear biomolecular motors.

Cholestasis is defined as an impairment of bile acid flow leading to intrahepatic retention of toxic bile acids (BAs), which induce apoptosis or necrosis of hepatocytes and liver inflammation. Ursodeoxycholic acid (UDCA), a FDA-approved drug to treat cholestasis, has limited therapeutic effects due to its poor specificity. Herein, we report a targeted therapeutic platform (namely, MAP) based upon co-assembly of macrophage membrane and amphiphilic calix[4]arene on PLGA nanoparticles. With UDCA loaded into calix[4]arene on the surface, MAP exhibited long-term stability, excellent biocompatibility, prolonged retention in the inflammatory liver due to the homing effects of macrophage membrane, and effective therapy of cholestasis via the specific action of UDCA and efficient sequestration of toxic BAs and inflammatory cytokines by the artificial receptor and membrane receptors, respectively. This study not only provides an artificial receptor coupled macrophage-mimetic nanomedicine platform to conquer cholestasis but also offers new insights into the design of improved versions of biomimetic nanomaterials that harness the power of both the natural and artificial receptors.

Integrating the advantages of terpyridine (tpy) ligands with excellent chromophoric sensitization ability and lanthanides (Lns) with characteristic luminescent and magnetic properties, discrete terpyridine-lanthanide (tpy-Ln) molecular and supramolecular complexes are of great value in many fields and have drawn significant attention from the community of supramolecular chemistry, coordination chemistry and materials science. Compared to the well-documented coordination behavior between transition metals and tpy, the construction of tpy-Ln molecular and supramolecular complexes remains a longstanding challenge due to the high coordination diversity and the lack of stereochemical preference of Lns. Nevertheless, with the advancement of self-assembly strategies, i.e., employing diverse anions as capping components and utilizing secondary auxiliary ligands as well as engineering of tpy ligands, diverse tpy-Ln molecular and supramolecular complexes have been constructed and their potential applications have been explored. This review comprehensively summarizes the progress of discrete tpy-Ln molecular and supramolecular complexes in the past decades, covering the structures of mononuclear, binuclear and multinuclear architectures. Beyond structures, the potential applications of these tpy-Ln complexes are also introduced. This review aims to shed more light on the design and construction of novel discrete tpy-Ln supramolecular complexes and materials with molecular level precision and multiple functions through coordination-driven self-assembly.

Self-healing hydrogels are attractive to extend material lifetime by rapid recovery from damage; the underlying healing mechanism regarding polymer diffusion are of broad research interest. However, intuitive and convenient characterization of polymer diffusion remains challenging due to the complex and dynamic features of hydrogels. Herein, we have constructed a dually-crosslinked hydrogel system to decouple complex factors for direct visualization of polymer diffusion and quantified study of healing dynamics. The successively formed dually-crosslinked hydrogel networks are designated for purposes of self-healing/visualization and tunable constraining effects (varied crosslinking density), respectively. As a result, we observed direct polymer diffusion across the crack interface and calculated the diffusion speed ranging from 0.51 to 0.04 μm/s depending on varied constraining degree. The corresponding self-healing performance is consistent with other conventional characterizations (e.g., dynamic mechanical properties, surface morphology changes). The above method has enabled facile visualization of dynamic healing processes with flexible adjustment of polymeric systems, which could inspire novel designs of high-performance self-healing materials.

The creation of nano- or micro-particles with separated domains has generated significant attention in the field of biomedicine, cosmetics, and chemical synthesis. Compared with phospholipid-based multicompartment vesicles, the introduction of polymers into multicompartment capsules can enhance their mechanical stability and broaden their applications. In this review, we highlight recent advances in polymer-based multicompartment capsules, including construction strategies (e.g., self-assembly, layer-by-layer assembly, and emulsion-mediated assembly) as well as their applications (e.g., drug delivery and micro-reactors). In addition, we also summarize the challenges associated with controllability and functionality of multicompartment capsules as well as future directions and developments in the field. This review is expected to help unravel fundamental understandings in artificial cells and guide the design of polymer multicompartment capsules for tailored applications.