Shanpeng Qiao

Enzymetically Regulating the Self‐Healing of Protein Hydrogels with High Healing Efficiency

Enzyme-mediated self-healing of dynamic covalent bond-driven protein hydrogels was realized by the synergy of two enzymes, glucose oxidase (GOX) and catalase (CAT). The reversible covalent attachment of glutaraldehyde to lysine residues of GOX, CAT, and bovine serum albumin (BSA) led to the formation and functionalization of the self-healing protein hydrogel system. The enzyme-mediated protein hydrogels exhibit excellent self-healing properties with 100% recovery. The self-healing process was reversible and effective with an external glucose stimulus at room temperature.

Enzyme-Triggered Defined Protein Nanoarrays: Efficient Light-Harvesting Systems to Mimic Chloroplasts

The elegance and efficiency by which chloroplasts harvest solar energy and conduct energy transfer have been a source of inspiration for chemists to mimic such process. However, precise manipulation to obtain orderly arranged antenna chromophores in constructing artificial chloroplast mimics was a great challenge, especially from the structural similarity and bioaffinity standpoints. Here we reported a design strategy that combined covalent and noncovalent interactions to prepare a protein-based light-harvesting system to mimic chloroplasts. Cricoid stable protein one (SP1) was utilized as a building block model. Under enzyme-triggered covalent protein assembly, mutant SP1 with tyrosine (Tyr) residues at the designated sites can couple together to form nanostructures. Through controlling the Tyr sites on the protein surface, we can manipulate the assembly orientation to respectively generate 1D nanotubes and 2D nanosheets. The excellent stability endowed the self-assembled protein architectures with promising applications. We further integrated quantum dots (QDs) possessing optical and electronic properties with the 2D nanosheets to fabricate chloroplast mimics. By attaching different sized QDs as donor and acceptor chromophores to the negatively charged surface of SP1-based protein nanosheets via electrostatic interactions, we successfully developed an artificial light-harvesting system. The assembled protein nanosheets structurally resembled the natural thylakoids, and the QDs can achieve pronounced FRET phenomenon just like the chlorophylls. Therefore, the coassembled system was meaningful to explore the photosynthetic process in vitro, as it was designed to mimic the natural chloroplast.

Cucurbit[8]uril-Based Giant Supramolecular Vesicles: Highly Stable, Versatile Carriers for Photoresponsive and Targeted Drug Delivery

Highly stable giant supramolecular vesicles were constructed by hierarchical self-assembly of cucurbit[8]uril (CB[8])-based supra-amphiphiles for photoresponsive and targeted intracellular drug delivery. These smart vesicles can encapsulate the model drugs with high loading efficiencies and then release them by manipulating photoswitchable CB[8] heteroternary complexation to regulate the formation and dissociation of supra-amphiphiles that cause dramatic morphological changes of the assemblies to achieve remote optically controlled drug delivery. More importantly, the confocal microscopy analysis, cellular uptake experiment, and cell viability assay have shown that the giant vesicles are able to maintain the structural integrity and stability within actual cellular environments and exhibit obvious advantages for intracellular drug delivery such as low toxicity, easy surface modification for tumor-targeting selectivity, and rapid internalization into different human cancer cell lines. A synergistic mechanism that integrates multiple pathways including energy-dependent endocytosis, macropinocytosis, cholesterol-dependent endocytosis, and microtubule-related endocytosis was determined to facilitate the internalization process. Moreover, cytotoxicity experiments and flow cytometric analysis have demonstrated that the doxorubicin hydrochloride-loaded vesicles exhibited a significant therapeutic effect for tumor cells upon UV light irradiation, which makes the photoresponsive system more promising for potential applications in pharmaceutically relevant fields.

Protein self-assembly: technology and strategy

Proteins, as the premier building blocks in nature, exhibit extraordinary ability in life activities during which process proteins mostly self-assemble into large complexes to exert prominent functions. Inspired by this, recent chemical and biological studies mainly focus on supramolecular self-assembly of proteins into high ordered architectures, especially the assembly strategy to unravel the formation and function of protein nanostructures. In this review, we summarize the progress made in the engineering of supramolecular protein architectures according to the strategies used to control the orientation and the order of the assembly process. Furthermore, potential applications in biomedical areas of the supramolecular protein nanostructures will also be reviewed.

Covalently assembled polymer nanocapsules: a novel scaffold for light-harvesting

A nanocapsule with an ultrathin shell designed for mimicking natural light-harvesting systems was successfully constructed based on the covalent assembly of donor molecules called 4,4′,4′′-(1,3,5-triazine-2,4,6-triyl)trianiline (Tta). When tetra(4-aminophenyl)porphyrin (Tapp), another building block, which acted as the acceptor was covalently coassembled into the nanocapsule, a novel artificial light-harvesting system was successfully constructed.

Photocontrolled protein assembly for constructing programmed two-dimensional nanomaterials

Precise self-assembly of proteins with structural heterogeneity, flexibility, and complexity into programmed arrays to mimic the exquisite architectures created by Nature is a great challenge for the development of protein-based functional nanomaterials. Herein, we present a strategy that integrates light stimuli and covalent coupling to prepare size-tunable two-dimensional (2D) protein nanostructures by remote photocontrol. Using Ru(bpy)3 2+ as a photosensitizer, stable protein one (SP1) was redesigned and self-assembled into nanosheets in the presence of ammonium persulfate (APS) through a rapid and efficient oxidative protein crosslinking reaction. In the design, only a serine-to-tyrosine mutation at position 98 was introduced into SP1 by combining computer simulation and genetic engineering for specific covalent coupling under white light illumination. The chemical and topographical specificities of the photosensitized crosslinking reaction allow control of the direction of protein assembly to form extended 2D nanosheets, which are packed in an orderly manner along the lateral surface of ring-shaped SP1S98Y. Notably, the growth of SP1 nanosheets exhibited isotropical characteristics and can be dynamically mediated by illumination time to achieve precise control of the size of the assembled architectures. The subsequent heat treatment further revealed the excellent thermostability of the 2D periodic SP1 nanostructures, which may find promising applications in the fabrication of various nanobiomaterials after functionalization. The present work demonstrates that the visible light-triggered crosslinking strategy is a facile and environmentally friendly method for constructing advanced protein architectures through hierarchical self-assembly.

Reductive-Responsive Single Molecular Layer Polymer Nanocapsules Prepared by Lateral Functionalized Pillar[5]arenes for Targeting Anticancer Drug Delivery

Herein, a new reductive-responsive pillar[5]arene-based, single-molecule-layer polymer nanocapsule is constructed for drug delivery. The functionalized system shows good biocompatibility, efficient internalization into targeted cells and obvious triggered release of entrapped drugs in a reducing environment such as cytoplasm. Besides, this smart vehicle loaded with anticancer drug shows excellent inhibition for tumor cell proliferation and exhibits low side effect on normal cells. This work not only demonstrates the development of a new reductive-responsive single molecular layer polymer nanocapsule for anticancer drug targeting delivery but also extends the design of smart materials for biomedical applications.