Publications by authors named "Guizhi Shen"

The morphology of nanodrugs is of utmost importance in photothermal therapy because it directly influences their physicochemical behavior and biological responses. However, clarifying the inherent relationship between morphology and the resultant properties remains challenging, mainly due to the limitations in the flexible morphological regulation of nanodrugs. Herein, we created a range of morphologically controlled nanoassemblies based on poly(ethylene glycol)--poly(d,l-lactide) (PEG-PLA) block copolymer building blocks, in which the model photosensitizer phthalocyanine was incorporated.

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Triple-negative breast cancer (TNBC) is known for its poor prognosis and aggressive behavior, being highly prone to recurrence and metastasis, and currently has limited effective treatment options. Photothermal therapy (PTT) is an emerging, minimally invasive, low-drug-resistance, and precisely controllable therapeutic method for cancer treatment, offering hope to break through the bottleneck in TNBC therapy. The antitumor efficiency of PTT is predominantly contingent upon the performance of the photothermal drugs.

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Therapeutic peptides have attracted significant attention in clinical applications due to their advantages in biological origination and good biocompatibility. However, the therapeutic performance of peptides is usually hindered by their short half-lives in blood and inferior activity. Herein, supramolecular nanodrugs of therapeutic peptides are constructed by covalent assembly of chemotherapeutic peptides through genipin cross-linking.

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Nanoassemblies based on self-assembly of biological building blocks are promising in mimicking the nanostructures, properties, and functionalities of natural enzymes. However, it remains a challenge to design of biomimetic nanozymes with tunable nanostructures and enhanced catalytic activities starting from simple biomolecules. Herein, the construction of nanoassemblies through coassembly of an amphiphilic amino acid and hemin is reported.

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Photothermal nanodrugs based on biomolecules are critically important for advancing photothermal therapy (PTT). However, constructing photothermal nanodrugs from biomolecules is highly challenging because most biomolecules are inherently nonpigmented. Herein, we synthesize well-defined, uniform photothermal nanodrugs through a covalent assembly approach by using nonpigmented peptides and iridoids as building blocks.

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Cyclic dipeptides (CDPs), the smallest naturally occurring cyclic peptides, have attracted tremendous attention due to their exceptional biological and pharmacological activities such as antitumor, antimicrobial, and immune regulation. However, controlled fabrication of CDPs nanostructures to address the problem of poor aqueous solubility and low bioavailability existing in therapeutic application is still in challenging, due to their remarkable structural rigidity and superior hydrogen-bonding-forming capability. Herein, a simple but robust and universal strategy for the construction of CDP nanoribbons based on the amphiphilic dye-mediated hydrophobic self-assembly is presented.

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We report the construction of erythrocyte membrane-cloaked Janus polymeric motors (EM-JPMs) which are propelled by near-infrared (NIR) laser irradiation and are successfully applied in thrombus ablation. Chitosan (a natural polysaccharide with positive charge, CHI) and heparin (glycosaminoglycan with negative charge, Hep) were selected as wall materials to construct biodegradable and biocompatible capsules through the layer-by-layer self-assembly technique. By partially coating the capsule with a gold (Au) layer through sputter coating, a NIR-responsive Janus structure was obtained.

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How to reduce the resistance of certain tumor cells to paclitaxel (PTX) and related taxoid anticancer drugs is a major challenge for improving cure rates. An oligo(p-phenylenevinylene) unit with thiol groups and a PTX unit (OPV-S-PTX), which enhances drug efficacy and reverses resistance is thus designed. The mechanism involves diffusion of OPV-S-PTX into the cell, where π-π interactions lead to aggregation.

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We present the preparation of a new multicolor emission system constructed from two complementary conjugated materials that are highly photoluminescent, that is, phenyl-modified carbon nitride (PhCN) colloids as the core and water-soluble conjugated polymers (WSCPs) adsorbed as the shell. The fluorescence bands of the PhCN and WSCPs effectively complement each other and the overall emission can be simply adjusted to fully cover the visible light spectrum with white light emission also accessible. Photophysical insights imply that the interactions between PhCN and WSCPs preserve the binary system from emission distortion and degradation, which is essential to delicately tune the overall fluorescence bands.

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Self-assembled peptide hydrogels are particularly appealing for drug delivery, tissue engineering, and antitumor therapy due to various advantageous features including excellent biocompatibility and biodegradability, defined molecular and higher organized structures, and easy availability. However, the poor mechanical and rheological properties of assembled peptide hydrogels cause difficulties in injection, thus limiting further applications. Herein, injectable peptide-based hydrogels with tunable mechanical and rheological properties were obtained by combination with a positively charged poly peptide (poly-l-lysine, PLL).

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A lot of efforts have been devoted to engineering the delivery of hydrophobic drugs due to the high demand of chemotherapy against cancer. While early developed liposomes and polymeric nanoparticles did not meet the requirements of high drug loading efficiency, pure drug nanoparticles appeared to meet these together with high stability. Current drug delivery systems demand an improved performance over the whole aspects of stability, loading capacity, and therapeutic effects.

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Nanoengineering of hydrophobic photosensitizers (PSs) is a promising approach for improved tumor delivery and enhanced photodynamic therapy (PDT) efficiency. A variety of delivery carriers have been developed for tumor delivery of PSs through the enhanced permeation and retention (EPR) effect. However, a high-performance PS delivery system with minimum use of carrier materials with excellent biocompatibility is highly appreciated.

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Photothermal agents can harvest light energy and convert it into heat, offering a targeted and remote-controlled way to destroy carcinomatous cells and tissues. Inspired by the biological organization of polypeptides and porphyrins in living systems, here we have developed a supramolecular strategy to fabricate photothermal nanodots through peptide-modulated self-assembly of photoactive porphyrins. The self-assembling nature of porphyrins induces the formation of J-aggregates as substructures of the nanodots, and thus enables the fabrication of nanodots with totally inhibited fluorescence emission and singlet oxygen production, leading to a high light-to-heat conversion efficiency of the nanodots.

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Self-assembling peptide-based materials are playing an important role in fabricating drug delivery carriers; however, they are often limited by several challenges, such as precise structure modulation, desirable nanoscale size, and sufficient circulation lifetime in the body. To address this issue, herein one type of injectable dipeptide-based nanocarriers with well-modulated size and structure has been developed by adjusting glutaraldehyde (GA)-assisted cationic dipeptide (CDP) assembly. After loading a model photosensitive drug (Ce6) and further decorating CDP nanoparticles (NPs) with heparin polymers (Hep), the desired dipeptide-based NPs are achieved with an average diameter of 100 nm and surface charge of -25 mV, which are favorable for the enhanced permeability and retention effects.

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Concave nanospheres based on the self-assembly of simple dipeptides not only provide alternatives for modeling the interactions between biomacromolecules, but also present a range of applications for purification and separation, and delivery of active species. The kinetic control of the peptide assembly provides a unique opportunity to build functional and dynamic nanomaterials, such as concave nanospheres. In this work, we report dipeptide-based concave nanospheres with structures from crescent-like to solid interior by interfacially controlled self-assembly in combination with covalent formation of building blocks, driven by synergistic thermodynamic and kinetic control.

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The majority of anticancer drugs are poorly water-soluble and thus suffer from rather low bioavailability. Although a variety of delivery carriers have been developed for bioavailability improvement, they are severely limited by low drug loading and undesired side effects. The optimum delivery vehicle would be a biocompatible and biodegradable drug nanoparticle of uniform size with a thin but stable shell, making it soluble, preventing aggregation and enabling targeting.

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Nanoengineering of anticancer therapeutic drugs including photosensitizers is highly desired and extremely required for improved therapeutic efficacy. It remains a formidable challenge to achieve nanostructured colloidal particles directly starting from hydrophobic drugs due to their hydrophobic nature and ready aggregation in aqueous ambient. In this work, we report a facile method for a one-pot preparation of hydrophobic photosensitizer nanoparticles by coating with different types of polyelectrolyte as stabilizing agents.

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Long-range structural order and alignment over different scales are of key importance for the regulation of structure and functionality in biology. However, it remains a great challenge to engineer and assemble such complex functional synthetic systems with order over different length scales from simple biologically relevant molecules, such as peptides and porphyrins. Herein we describe the successful introduction of hierarchical long-range order in dipeptide-adjusted porphyrin self-assembly by a thermodynamically driven self-orienting assembly pathway associated with multiple weak interactions.

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Here, we present an Au@Pt core-shell multibranched nanoparticle as a new substrate capable of in situ surface-enhanced Raman scattering (SERS), thereby enabling monitoring of the catalytic reaction on the active surface. By careful control of the amount of Pt deposited bimetallic Au@Pt, nanoparticles with moderate performance both for SERS and catalytic activity were obtained. The Pt-catalyzed reduction of 4-nitrothiophenol by borohydride was chosen as the model reaction.

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We present a general strategy to nanoengineer protein-based colloidal spheres (biomimetic protocells) as versatile delivery carriers with stimuli responsiveness by the electrostatic assembly of binary components (proteins and polypeptides) in association with intermolecular disulfide cross-linking. The size of the colloidal spheres, ranging from nanoscale to microscale, is readily tuned through parameters like protein and polypeptide concentration, the ratio between both, pH, and so on. Moreover, such colloidal spheres show versatile encapsulation of various guest molecules including small organic molecules and biomacromolecules.

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