Peptide‐based materials are one of the most important biomaterials, with diverse structures and functionalities. Over the past few decades, a self‐assembly strategy is introduced to construct ...peptide‐based nanomaterials, which can form well‐controlled superstructures with high stability and multivalent effect. More recently, peptide‐based functional biomaterials are widely utilized in clinical applications. However, there is no comprehensive review article that summarizes this growing area, from fundamental research to clinic translation. In this review, the recent progress of peptide‐based materials, from molecular building block peptides and self‐assembly driving forces, to biomedical and clinical applications is systematically summarized. Ex situ and in situ constructed nanomaterials based on functional peptides are presented. The advantages of intelligent in situ construction of peptide‐based nanomaterials in vivo are emphasized, including construction strategy, nanostructure modulation, and biomedical effects. This review highlights the importance of self‐assembled peptide nanostructures for nanomedicine and can facilitate further knowledge and understanding of these nanosystems toward clinical translation.
The recent progress in peptide‐based nanomaterials from building block peptides and self‐assembly driving forces to application‐directed ex situ and in situ construction of nanomaterials is systematically summarized. The advantages of intelligent in situ construction of peptide‐based nanomaterials in vivo are emphasized. The importance of self‐assembled peptide nanostructures for nanomedicine is highlighted.
An assembly‐induced retention effect for enhanced tumor photoacoustic (PA) imaging and therapeutics is described. A responsive small‐molecule precursor is prepared that simultaneously self‐assembles ...into nanofibers in tumor sites that exhibit an assembly‐induced retention effect, which results in an improved PA imaging signal and enhanced therapeutic efficacy. This successful proof‐of‐concept study paves the way to develop novel supramolecular biomaterials for cancer diagnostics and therapeutics.
A pathology‐adaptive nanosystem, in which nest‐like hosts are built based on nanofibers that are transformed from i.v. injected nanoparticles under the acidic tumor microenvironment. The solid tumor ...is artificially modified by nest‐like hosts readily and firmly, resulting in highly efficient accumulation and stabilization of guest theranostics. This strategy shows great potential for the theranostics delivery to tumors.
A pyropheophorbide‐α‐based building block (Ppa‐PLGVRG‐Van) can be used to construct self‐aggregated superstructures in vivo for highly specific and sensitive diagnosis of bacterial infection by ...noninvasive photoacoustic tomography. This in vivo supramolecular chemistry approach opens a new avenue for efficient, rapid, and early‐stage disease diagnosis with high sensitivity and specificity.
Cerebral amyloid β-peptide (Aβ) accumulation resulting from an imbalance between Aβ production and clearance is one of the most important causes in the formation of Alzheimer's disease (AD). In order ...to preserve the maintenance of Aβ homeostasis and have a notable AD therapy, achieving a method to clear up Aβ plaques becomes an emerging task. Herein, we describe a self-destructive nanosweeper based on multifunctional peptide-polymers that is capable of capturing and clearing Aβ for the effective treatment of AD. The nanosweeper recognize and bind Aβ via co-assembly through hydrogen bonding interactions. The Aβ-loaded nanosweeper enters cells and upregulates autophagy thus promoting the degradation of Aβ. As a result, the nanosweeper decreases the cytotoxicity of Aβ and rescues memory deficits of AD transgenic mice. We believe that this resourceful and synergistic approach has valuable potential as an AD treatment strategy.
To date, numerous nanosystems have been developed as antibiotic replacements for bacterial infection treatment. However, these advanced systems are limited owing to their nontargeting accumulation ...and the consequent side effects. Herein, transformable polymer–peptide biomaterials have been developed that enable specific accumulation in the infectious site and long‐term retention, resulting in enhanced binding capability and killing efficacy toward bacteria. The polymer–peptide conjugates are composed of a chitosan backbone and two functional peptides, i.e., an antimicrobial peptide and a poly(ethylene glycol)‐tethered enzyme‐cleavable peptide (CPC‐1). The CPC‐1 initially self‐assembles into nanoparticles with pegylated coronas. Upon the peptides are cleaved by the gelatinase secreted by a broad spectrum of bacterial species, the resultant compartments of nanoparticles spontaneously transformed into fibrous nanostructures that are stabilized by enhanced chain–chain interaction, leading to exposure of antimicrobial peptide residues for multivalent cooperative electrostatic interactions with bacterial membranes. Intriguingly, the in situ morphological transformation also critically improves the accumulation and retention of CPC‐1 in infectious sites in vivo, which exhibits highly efficient antibacterial activity. This proof‐of‐concept study demonstrates that pathological environment‐driven smart self‐assemblies may provide a new idea for design of high‐performance biomaterials for disease diagnostics and therapeutics.
Transformable chitosan–peptide biomaterials (CPC‐1) initially self‐assemble into nanoparticles with PEGylated coronas. Upon cleavage of the peptides by gelatinase, the resultant compartments of the nanoparticles spontaneously transform into fibrous nanostructures. The in situ morphological transformation critically improves the accumulation and retention of CPC‐1 in infectious sites in vivo, which exhibits highly efficient antibacterial activity.
In this study, the ZnO quantum dots (QDs) water-based fluorescent anti-counterfeiting ink was prepared with the polyvinylpyrrolidone (PVP) content of 0.15-0.17 g/mL, the ZnO QDs concentration of 4% ...and water as the solvent, which has good fluorescence, printability and resistance. According to the halftone technology, fluorescence quenching of the ZnO QDs by acid, and acid resistance of the organic fluorescent ink, a high-quality anti-counterfeiting method of fluorescent discoloration was proposed. The QDs ink has broad application prospects in the field of anti-counterfeiting green packaging.
Worker selection is a key issue in mobile crowd sensing (MCS). While the previous worker selection approaches mainly focus on selecting a proper subset of workers for a single MCS task, a ...multitask-oriented worker selection is essential and useful for the efficiency of large-scale MCS platforms. This paper proposes ActiveCrowd, a worker selection framework for multitask MCS environments. We study the problem of multitask worker selection under two situations: worker selection based on workers' intentional movement for time-sensitive tasks and unintentional movement for delay-tolerant tasks. For time-sensitive tasks, workers are required to move to the task venue intentionally and the goal is to minimize the total distance moved. For delay-tolerant tasks, we select workers whose route is predicted to pass by the task venues and the goal is to minimize the total number of workers. Two greedy-enhanced genetic algorithms are proposed to solve them. Experiments verify that the proposed algorithms outperform baseline methods under different experiment settings (scale of task sets, available workers, varied task distributions, etc.).
Spermatogenic dysfunction caused by cyclophosphamide (CP) chemotherapy has seriously influenced the life quality of patients. Unfortunately, treatments for CP-induced testicular spermatogenic ...dysfunction are limited, and the molecular mechanisms are not fully understood. For the first time, here, we explored the effects of bone marrow mesenchymal stem cell-derived exosomes (BMSC-exos) on CP-induced testicular spermatogenic dysfunction in vitro and in vivo. BMSC-exos could be taken up by spermatogonia (GC1-spg cells). CP-injured GC1-spg cells and BMSC-exos were cocultured at various doses, and then, cell proliferation was measured using 3-4,5-dimethylthiazol-2-yl-2,5 diphenyl tetrazolium bromide (MTT) assay. In addition, photophosphorylation of extracellular-regulated kinase (ERK), p38 mitogen-activated protein kinase (p38MAPK), and protein kinase B (AKT) proteins was evaluated by western blotting as well as apoptosis in GC1-spg cells measured using flow cytometry. Treatment with BMSC-exos enhanced cell proliferation and reduced apoptosis of CP-injured GCI-spg cells. Phosphorylated levels of ERK, AKT, and p38MAPK proteins were reduced in CP-injured spermatogonia when co-treated with BMSC-exos, indicating that BMSC-exos acted against the reproductive toxicity of CP via the p38MAPK/ERK and AKT signaling pathways. In experiments in vivo, CP-treated rats received BMSC-exos by injection into the tail vein, and testis morphology was compared between treated and control groups. Histology showed that transfusion of BMSC-exos inhibited the pathological changes in CP-injured testes. Thus, BMSC-exos could counteract the reproductive toxicity of CP via the p38MAPK/ERK and AKT signaling pathways. The findings provide a potential treatment for CP-induced male spermatogenic dysfunction using BMSC-exos.
Tumor metastasis is one of the big challenges in cancer treatment and is often associated with high patient mortality. Until now, there is an agreement that tumor invasion and metastasis are related ...to degradation of extracellular matrix (ECM) by enzymes. Inspired by the formation of natural ECM and the in situ self-assembly strategy developed in our group, herein, we in situ constructed an artificial extracellular matrix (AECM) based on transformable Laminin (LN)-mimic peptide 1 (BP-KLVFFK-GGDGR-YIGSR) for inhibition of tumor invasion and metastasis. The peptide 1 was composed of three modules including (i) the hydrophobic bis-pyrene (BP) unit for forming and tracing nanoparticles; (ii) the KLVFF peptide motif that was inclined to form and stabilize fibrous structures through intermolecular hydrogen bonds; and (iii) the Y-type RGD-YIGSR motif, derived from LN conserved sequence, served as ligands to bind cancer cell surfaces. The peptide 1 formed nanoparticles (1-NPs) by the rapid precipitation method, owing to strong hydrophobic interactions of BP. Upon intravenous injection, 1-NPs effectively accumulated in the tumor site due to the enhanced permeability and retention (EPR) effect and/or targeting capability of RGD-YIGSR. The accumulated 1-NPs simultaneously transformed into nanofibers (1-NFs) around the solid tumor and further entwined to form AECM upon binding to receptors on the tumor cell surfaces. The AECM stably existed in the primary tumor site over 72 h, which consequently resulted in efficiently inhibiting the lung metastasis in breast and melanoma tumor models. The inhibition rates in two tumor models were 82.3% and 50.0%, respectively. This in vivo self-assembly strategy could be widely utilized to design effective drug-free biomaterials for inhibiting the tumor invasion and metastasis.
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