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A Fluorescent Supramolecular Biosensor for Bacterial Detection via Binding-Induced Changes in Coiled-Coil Molecular Assembly
摘要： The essential elements required for any sensors are a receptor, a signal converter, and a detector. Here, we report the construction of bacterial biosensors in which all of the required biosensor elements are furnished in one supramolecular assembly. The supramolecular biosensor is based on a double-layered octa-helical coiled-coil peptide assembly that contains tetravalent bioreceptors on the outer surface and environment-sensitive fluorophores in the core. The signal conversion takes advantage of the noncovalent and reversible nature of the self-assembled system, i.e., the multivalent binding of bacteria induces conformational changes in the supramolecular state, which is translated into differential fluorescence emissions. We show that fluorescent supramolecular biosensors (fSBs) can selectively detect E. coli over other bacteria. Because the fSBs were resistant to heat-induced denaturation, they retained their bacterial-sensing capability even at an elevated temperature (50 ℃). Biosensors based on responsive supramolecular assemblies can be further developed to detect various large and flat biological objects and biomacromolecules.
关键词： Escherichia coli,Supramolecule,Biosensor,Bacteria,Self-assembly,Peptide-based probe
更新于2025-11-21 11:08:12
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Improved in vivo targeting of BCL-2 phenotypic conversion through hollow gold nanoshell delivery
摘要： Although new cancer therapeutics are discovered at a rapid pace, lack of effective means of delivery and cancer chemoresistance thwart many of the promising therapeutics. We demonstrate a method that confronts both of these issues with the light-activated delivery of a Bcl-2 functional converting peptide, NuBCP-9, using hollow gold nanoshells. This approach has shown not only to increase the efficacy of the peptide 30-fold in vitro but also has shown to reduce paclitaxel resistant H460 lung xenograft tumor growth by 56.4%.
关键词： Bcl-2,Resistant cancer,Apoptosis,Hollow gold nanoshells,NuBCP,Peptide delivery
更新于2025-11-21 11:08:12
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Peptic Fluorescent “Signal-On” and “Signal-Off” Sensors Utilized for the Detection Protein Post-Translational Modifications
摘要： Protein post-translational modifications (PTMs) are typically enzyme-catalyzed events generating functional diversi?cation of proteome; thus, multiple PTM enzymes have been validated as potential drug targets. We have previously introduced energy-transfer-based signal-modulation method called quenching resonance energy transfer (QRET), and utilize it to monitor PTM addition or removal using the developed peptide-break technology. Now we have reinvented the QRET technology, and as a model, we introduced the tunable ?uorescent “signal-on” and “signal-o?” detection scheme in the peptide-break PTM detection. Taking the advantage of time-resolved ?uorescence-based single-label detection technology, we were able to select the signal direction upon PTM addition or removal by simply introducing di?erent soluble Eu3+-signal-modulating molecule. This enables the selection of positive signal change upon measurable event, without any additional labeling steps, changes in assay condition or Eu3+-reporter. The concept functionality was demonstrated with four Eu3+-signal modulators in a high-throughput compatible kinase and phosphatase assays using signal-on and signal-o? readout at 615 nm or time-resolved Fo?rster resonance energy transfer at 665 nm. Our data suggest that the introduced signal modulation methodology provides a transitional ?uorescence-based single-label detection concept not limited only to PTM detection.
关键词： time-resolved fluorescence,signal-off,high-throughput screening,peptide-break technology,protein post-translational modifications,FRET,signal-on
更新于2025-11-19 16:56:35
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Silver Nanoparticles - Fabrication, Characterization and Applications || Synthesis and Optical Properties of Highly Stabilized Peptide- Coated Silver Nanoparticles
摘要： The interaction between the silver nanoparticle and peptide surfaces has been of increased interest for the applications of bionanotechnology and tissue engineering. In order to completely understand such interactions, we have examined the optical properties of peptide-coated silver nanoparticles. However, the effect of peptide binding motif upon the silver nanoparticles surface characteristics and physicochemical properties of these nanoparticles remains incompletely understood. Here, we have fabricated sodium citrate stabilized silver nanoparticles and coated with peptide IVD (ID3). The optical properties of these peptide-capped nanomaterials were characterized by UV-visible, transmission electron microscopy (TEM), and z-potential measurement. The results indicate that the interface of silver nanoparticles (AgNP)-peptide is generated using ID3 peptide and sug-gested that the reactivity of peptide is governed by the conformation of the bound pep-tide on the silver nanoparticle surface. The interactions of peptide-nanoparticle would potentially be used to fabricate specific functionality into the various peptide-capped nanomaterials and antibacterial applications.
关键词： Z-potential,silver nanoparticles,peptide,physicochemical properties
更新于2025-11-14 17:04:02
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Codelivery of a cytotoxin and photosensitiser <i>via</i> a liposomal nanocarrier: a novel strategy for light-triggered cytosolic release
摘要： Endosomal entrapment is a key issue for the intracellular delivery of many nano-sized biotherapeutics to their cytosolic or nuclear targets. Photochemical internalisation (PCI) is a novel light-based solution that can be used to trigger the endosomal escape of a range of bioactive agents into the cytosol leading to improved efficacy in pre-clinical and clinical studies. PCI typically depends upon the endolysosomal colocalisation of the bioactive agent with a suitable photosensitiser that is administered separately. In this study we demonstrate that both these components may be combined for codelivery via a novel multifunctional liposomal nanocarrier, with a corresponding increase in the biological efficacy of the encapsulated agent. As proof of concept, we show here that the cytotoxicity of the 30 kDa protein toxin, saporin, in MC28 fibrosarcoma cells is significantly enhanced when delivered via a cell penetrating peptide (CPP)-modified liposome, with the CPP additionally functionalised with a photosensitiser that is targeted to endolysosomal membranes. This innovation opens the way for the efficient delivery of a range of biotherapeutics by the PCI approach, incorporating a clinically proven liposome delivery platform and using bioorthogonal ligation chemistries to append photosensitisers and peptides of choice.
关键词： photosensitiser,codelivery,cell penetrating peptide,photochemical internalisation,saporin,liposomal nanocarrier,endosomal escape
更新于2025-11-14 15:32:45
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Peptide-Functionalized Quantum Dots for Rapid Label-Free Sensing of 2,4,6-Trinitrotoluene
摘要： Explosive compounds, such as 2,4,6-trinitrotoluene (TNT), pose a great concern in terms of both global public security and environmental protection. There are estimated to be hundreds of TNT contaminated sites all over the world, which will affect the health of humans, wildlife, and the ecosystem. Clearly, the ability to detect TNT in soils, water supplies, and wastewater is important for environmental studies but also important for security, such as in ports and boarders. However, conventional spectroscopic detection is not practical for on-site sensing because it requires sophisticated equipment and trained personnel. We report a rapid and simple chemical sensor for TNT by using TNT binding peptides which are conjugated to fluorescent CdTe/CdS quantum dots (QDs). QDs were synthesized in the aqueous phase, and the peptide was attached directly to the surface of the QDs by using thiol groups. The fluorescent emission from the QDs was quenched in response to the addition of TNT. The response could even be observed by the naked eye. The limit of detection from fluorescence spectroscopic measurement was estimated to be approximately 375 nM. In addition to the rapid response (within a few seconds), selective detection was demonstrated. We believe this label-free chemical sensor contributes to progress for the on-site explosive sensing.
关键词： quantum dots (QDs),explosive detection,2,4,6-trinitrotoluene (TNT),label-free sensing,peptide-functionalized
更新于2025-11-14 15:23:50
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A novel peptide targets CD105 for tumour imaging in?vivo
摘要： Non-antibody-binding proteins (nABPs) have attracted attention in the field of alternative antibody approaches due to their ability to penetrate cell membranes. CD105 has been demonstrated to be a useful marker for identifying angiogenic endothelial, mesenchymal stem and osteosarcoma cells. In the present study, a novel non-antibody-binding protein (namely nABP296) with a high affinity for recombinant human CD105 was identified by M13 phage biopanning. Fluorescence microscopy, flow cytometry and in vivo animal imaging were used to confirm the visualization effect of the novel peptide to the CD105-positive MNNG/HOS cell line in vivo and in vitro. Immunofluorescence of tissue sections was also used to identify the target efficiency of the peptide in tumour sections derived from an MNNG/HOS xenograft tumour model and osteosarcoma patients. This peptide specifically was found to bind to the CD105-positive osteosarcoma MNNG/HOS cell line and the osteosarcoma cells in the histological sections derived from an MNNG/HOS xenograft model and osteosarcoma patients in vitro. This peptide also successfully labelled an animal osteosarcoma xenograft model in vivo. Taken together, a novel peptide that can be used as a potent agent for CD105 molecular targeting was identified, and this peptide can be applied for osteosarcoma visualization in vitro and in vivo.
关键词： CD105,peptide,biomarker,osteosarcoma,diagnosis
更新于2025-09-23 15:23:52
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Antimicrobial-Peptide-Conjugated MoS2 Based Nanoplatform for Multimodal Synergistic Inactivation of Superbugs
摘要： Development of new antibacterial therapeutics material is becoming increasingly urgent due to the huge threat of superbugs, which are responsible for more than half million death each year in this world. Here, we report the development of novel nano-biomaterial based on melittin antimicrobial peptide (AMP) attached transition metal dichalcogenide MoS2 based theranostic nanoplatform. Reported nanoplatform has capability for targeted identification and synergistic inactivation of 100% multidrug-resistant superbugs by combined photo thermal therapy (PTT), photodynamic therapy (PDT) and AMP process. A novel approach for the design of melittin antimicrobial peptide attached MoS2 based nanoplatform is reported, which emits very bright and photo stable fluorescence. It also generates heat as well as reactive oxygen species (ROS) in the presence of 670 nm near infrared light, which allow it to be used as PTT & PDT agent. Due to the presence of AMP, multifunctional AMP exhibits significantly improved antibacterial activity for superbugs via multimodal synergistic killing mechanism. Reported data demonstrate that nanoplatforms are capable of identification of multidrug-resistant superbugs via luminescence imaging. Experimental results show that it is possible to kill only ~45% of superbugs via MoS2 nanopaltform based on PTT & PDT processes together. On the other hand, killing of less than 10% of superbugs is possible using melittin antimicrobial peptide alone. Whereas, 100% Methicillin-resistant Staphylococcus aureus (MRSA), drug resistance Escherichia coli (E. coli) and drug resistance Klebsiella pneumoniae (KPN) superbugs can be killed using antimicrobial peptide attached MoS2 QDs, via synergistic killing mechanism. Mechanisms for possible synergistic killing of multidrug-resistant superbugs have been discussed.
关键词： theranostic transition metal dichalcogenide,photodynamic therapy,multimodal therapy for multidrug-resistant superbugs,Melittin antimicrobial peptide attached MoS2 based nanoplatform,photo thermal therapy
更新于2025-09-23 15:23:52
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Peptide-based ratiometric fluorescent probe for highly selective detection of Cd (II) and its application in bioimaging
摘要： This work reported a new peptide fluorescent probe L including dansyl group (acceptor) and tryptophan (donor) via imitated the binding sites of natural protein. L exhibited exclusively selective ratiometric fluorescence response towards Cd2+ ions over other metal ions based on fluorescent resonance energy transfer (FRET) effects. As designed, L showed exciting sensitivity to Cd2+ ions in aqueous media, and the detection limits are less than 27.5 nM. In addition, the binding pattern of L and Cd2+ was confirmed by fluorescence titration analysis which was found to be 2:1 and further it was confirmed by Job's plot. What' more, L exhibited very low biotoxicity and exciting cell infiltration, and have been successfully used for fluorescence imaging of Cd2+ ions in living HeLa cells.
关键词： Cell imaging,Fluorescent probe,Peptide,Cadmium ion,Ratiometric
更新于2025-09-23 15:23:52
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Functional chlorin gold nanorods enable to treat breast cancer by photothermal/photodynamic therapy
摘要： Background: The existing chemo/radiotherapy fail to eliminate cancer cells due to the restriction of either drug resistance or radio tolerance. The predicament urges researchers to continuously explore alternative strategy for achieving a potent curative effect. Methods: Functional chlorin gold nanorods (Ce6-AuNR@SiO2-d-CPP) were fabricated aiming at treating breast cancer by photothermal/photodynamic therapy (PTT/PDT). The nanostructure was developed by synthesizing Au nanorods as the photothermal conversion material, and by coating the pegylated mesoporous SiO2 as the shell for entrapping photosensitizer Ce6 and for linking the D-type cell penetrating peptide (d-CPP). The function of Ce6-AuNR@SiO2-d-CPP was verified on human breast cancer MCF-7 cells and MCF-7 cells xenografts in nude mice. Results: Under combinational treatment of PTT and PDT, Ce6-AuNR@SiO2-d-CPP demonstrated a strong cytotoxicity and apoptosis inducing effects in breast cancer cells in vitro, and a robust treatment efficacy in breast cancer-bearing nude mice. The uptake mechanism involved the energy-consuming caveolin-mediated endocytosis, and Ce6-AuNR@SiO2-d-CPP in PTT/PDT mode could induce apoptosis by multiple pathways in breast cancer cells. Conclusion: Ce6-AuNR@SiO2-d-CPP demonstrated a robust efficacy in the treatment of breast cancer by photothermal/photodynamic therapy. Therefore, the present study could offer a new promising strategy to treat the refractory breast cancer.
关键词： PTT/PDT,apoptosis,cellular uptake,functional chlorin gold nanorods,cell penetrating peptide,cytotoxicity
更新于2025-09-23 15:23:52