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Zwitterionic near-infrared fluorophore-conjugated epidermal growth factor for fast, real-time, and target-cell-specific cancer imaging
摘要： Epidermal growth factor receptor (EGFR) is overexpressed in many types of cancers, which is associated with metastatic potential and poor prognosis in cancer patients. Therefore, development of EGFR-targeted sensitive imaging probes has been a challenge in tumor targeting, image-guided cancer surgery, patient-selective anti-EGFR therapy, and efficient targeted therapies. Methods: We synthesized a zwitterionic near-infrared fluorophore (ATTO655)-conjugated epidermal growth factor (EGF) as a novel activatable molecular probe. Fluorescence OFF/ON property and EGFR-targeting specificity of EGF-ATTO655 as well as its utility in real-time near-infrared (NIR) fluorescence imaging of EGFR-positive cancers were evaluated using in vitro and in vivo studies. Results: When conjugated to EGF, the fluorescence of ATTO655 quenched efficiently by photo-induced electron transfer (PET) mechanism between the conjugated dyes and nearby amino acid quenchers (tryptophan/tyrosine residues), which was stably maintained at physiological pH and in the presence of serum for at least 17 h. The fluorescence of EGF-ATTO655 turned on by receptor-mediated endocytosis and subsequent disintegration of EGF in EGFR-positive A431 cancer cells, thereby enabling specific and real-time fluorescence imaging of EGFR-positive cancer cells. Consequently, EGFR-positive tumors could be clearly visualized 3 h post-injection with a significantly high tumor-to-background ratio (TBR = 6.37). Conclusion: This PET mechanism-based OFF/ON type of EGF probe showed great potential for rapid, real-time, and target-cell-specific imaging of EGFR-overexpressing cancers in vitro and in vivo.
关键词： photo-induced electron transfer,Epidermal growth factor,real-time cancer imaging,tumor-specific targeting
更新于2025-11-21 11:24:58
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Chitosan-based hydrogels prepared by UV polymerization for wound dressing
摘要： Chitosan-based hydrogels were prepared by grafting with poly(acrylic acid) (PAA) and poly(hydroxyethyl methacrylate) (pHEMA) through ultraviolet polymerization to further improve its hydrophilic nature and enhance its mechanical properties. The epidermal growth factor (EGF) was incorporated inside the hydrogels to stimulate the wound healing. The physical characterization of chitosan-PAA-pHEMA hydrogel indicates that it is highly hydrophilic with adequate properties for wound dressing purpose. The biological characterization shows that chitosan-based hydrogel retains its thrombogenic and antibacterial properties. The in vivo wound healing experiment demonstrates that the hydrogel-incorporated EGF has better wound healing rate than other dressings.
关键词： hydrogel,Chitosan,2-hydroxyethyl methacrylate,epidermal growth factor,wound dressing,acrylic acid
更新于2025-09-23 15:22:29
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Synthesis and analysis of 64Cu-labeled GE11-modified polymeric micellar nanoparticles for EGFR-targeted molecular imaging in a colorectal cancer model
摘要： Polymeric micellar nanoparticles represent versatile and biocompatible platforms for targeted drug delivery. However, tracking their biodistribution, stability, and clearance profile in vivo is challenging. The goal of this study was to prepare surface-modified micelles with peptide GE11 for targeting the epidermal growth factor receptor (EGFR). In vitro fluorescence studies demonstrated significantly higher internalization of GE11-micelles into EGFR-expressing HCT116 colon cancer cells versus EGFR-negative SW620 cells. Azo coupling chemistry of tyrosine residues in the peptide backbone with aryl diazonium salts was used to label the micelles with radionuclide 64Cu for positron emission tomography (PET) imaging. In vivo analysis of 64Cu-labeled micelles showed prolonged blood circulation and predominant hepatobiliary clearance. The biodistribution profile of EGFR-targeting GE11-micelles was compared with non-targeting HW12-micelles in HCT116 tumor-bearing mice. PET revealed increasing tumor-to-muscle ratios for both micelles over 48 h. Accumulation of GE11-containing micelles in HCT116 tumors was higher compared to HW12-decorated micelles. Our data suggest that the efficacy of image-guided therapies with micellar nanoparticles could be enhanced by active targeting, as demonstrated with cancer biomarker EGFR.
关键词： polymeric micelles,epidermal growth factor receptor (EGFR),64Cu,GE11 peptide,Colorectal cancer,positron emission tomography (PET)
更新于2025-09-23 15:21:01
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PACAP through EGFR transactivation preserves human corneal endothelial integrity
摘要： The corneal endothelium is composed of a single hexagonal‐shaped cells layer adherent to the Descemet's membrane. The primary function of these cells is maintaining of tissue clarity by regulating its hydration. Trauma, aging or other pathologies cause their loss, counterbalanced by enlargement of survived cells fluid pumping to and from the stroma. unable to guarantee an efficient Regenerative medicine using human corneal endothelial cells (HCECs) isolated from peripheral corneal‐scleral tissue of a donor could be an attractive solution, overcoming transplantation problems. In a previous study, we have demonstrated that HCECs treatment with pituitary adenylate cyclase–activating polypeptide following growth factors deprivation prevents their degeneration. (PACAP) However, the molecular mechanism mediating this effect has not been clarified, yet. Here, we have shown for the first time the expression of PACAP and its receptor (PAC1R) in human corneal endothelium and demonstrated that this peptide, selectively binding to PAC1R, induces epidermal growth factor receptor (EGFR) phosphorylation and the MAPK/ERK1/2 signaling pathway activation. In conclusion, our data have suggested that PACAP could represent an important trophic factor in maintaining human corneal endothelial integrity through EGFR transactivation. Therefore, PACAP, as well as epidermal growth factor and fibroblast growth factor, could co‐operate to guarantee tissue physiological functioning by supporting corneal endothelial barrier integrity.
关键词： epidermal growth factor receptor,human corneal endothelial cells,mitogen‐activated protein kinase,pituitary adenylate cyclase–activating polypeptide
更新于2025-09-23 15:19:57
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Single-molecule F?rster Resonance Energy Transfer Measurement Reveals Dynamic Partially Ordered Structure of the Epidermal Growth Factor Receptor C-tail Domain
摘要： Intrinsically disordered proteins (IDPs) or regions (IDRs) are thought to exhibit unique functionalities without forming ordered structures. However, these molecular mechanisms are not easily elucidated, partly because of the difficultly of measuring structural information. In this study, we applied the alternative laser excitation (ALEX) method and circular dichroism (CD) spectroscopy to investigate the structure of the C-terminal tail (CTT) domain of the human epidermal growth factor receptor (EGFR). The single-molecule distributions of F?rster resonance energy transfer (FRET) obtained by ALEX under solution conditions modified by the addition of potassium chloride (KCl), urea or guanidinium chloride (GdmCl) allowed us to separately examine the influences of charge interactions and secondary structure formation. The CD spectrum analyses indicated the types of included secondary structure. The results suggested that the structure of the CTT is influenced by secondary structure formation, which is principally antiparallel β-sheet, rather than by charge interactions, and that phosphorylation of the major Grb2-binding sites partially denature that secondary structure. Our findings suggest that the EGFR CTT might regulate ligand binding kinetics by local β-sheet formation or by the disruption associated with phosphorylation states.
关键词： Circular dichroism,Epidermal Growth Factor Receptor,F?rster resonance energy transfer,Secondary structure,Intrinsically disordered proteins
更新于2025-09-23 15:19:57
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Real-time molecular optical micro-imaging of EGFR mutations using a fluorescent erlotinib based tracer
摘要： Background: EGFR mutations are routinely explored in lung adenocarcinoma by sequencing tumoral DNA. The aim of this study was to evaluate a fluorescent-labelled erlotinib based theranostic agent for the molecular imaging of mutated EGFR tumours in vitro and ex vivo using a mice xenograft model and fibred confocal fluorescence microscopy (FCFM). Methods: The fluorescent tracer was synthesized in our laboratory by addition of fluorescein to an erlotinib molecule. Three human adenocarcinoma cell lines with mutated EGFR (HCC827, H1975 and H1650) and one with wild-type EGFR (A549) were xenografted on 35 Nude mice. MTT viability assay was performed after exposure to our tracer. In vitro imaging was performed at 1 μM tracer solution, and ex vivo imaging was performed on fresh tumours excised from mice and exposed to a 1 μM tracer solution in PBS for 1 h. Real-time molecular imaging was performed using FCFM and median fluorescence intensity (MFI) was recorded for each experiment. Results: MTT viability assay confirmed that addition of fluorescein to erlotinib did not suppress the cytotoxic of erlotinib on tumoral cells. In vitro FCFM imaging showed that our tracer was able to distinguish cell lines with mutated EGFR from those lines with wild-type EGFR (p < 0.001). Ex vivo FCFM imaging of xenografts with mutated EGFR had a significantly higher MFI than wild-type (p < 0.001). At a cut-off value of 354 Arbitrary Units, MFI of our tracer had a sensitivity of 100% and a specificity of 96.3% for identifying mutated EGFR tumours. Conclusion: Real time molecular imaging using fluorescent erlotinib is able to identify ex vivo tumours with EGFR mutations.
关键词： Lung cancer,Erlotinib,Theranostic,EGFR,Epidermal growth factor,Fibred confocal fluorescence microscopy,Molecular imaging
更新于2025-09-19 17:15:36
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Two-dimensional porphyrin-based covalent organic framework: A novel platform for sensitive epidermal growth factor receptor and living cancer cell detection
摘要： A porphyrin-based covalent organic framework (denoted as p-COF) was synthesized by a simple oil-bath method and exploited as a novel sensing layer for immobilizing epidermal growth factor receptor (EGFR)-targeting aptamer strands to detect trace EGFR and living michigan cancer foundation-7 (MCF-7) cells for the first time. p-COF presented a nanosheet-like structure, large cavities, rich nitrogen-bearing groups, high electrochemical activity, excellent bioaffinity, low toxicity, and good stability in aqueous solution; the microstructural features of this material enabled strong immobilization of the aptamer strands. Interactions between the aptamer strands and EGFR significantly changed the electrochemical signals of the modified electrode due to the formation of an aptamer-EGFR complex. The p-COF-based aptasensor exhibited an extremely low detection limit (LOD) of 5.64 fg?mL?1 obtained from differential pulse voltammetry and 7.54 fg?mL?1 originated from electrochemical impedance spectroscopy with a broad linear detection range of 0.05–100 pg?mL?1 of the EGFR concentration. When detecting living MCF-7 cells, the p-COF-based aptasensor showed an LOD of 61 cell?mL?1 with a linear detection range of 500 × 105 cell?mL?1. The fabricated aptasensor exhibited high selectivity, good stability, reproducibility, acceptable recyclability, and favorable applicability in human serum samples. We believe that the developed p-COF-based aptasensor is a potential candidate for the sensitive detection of target cancer markers or living cells.
关键词： Detection of epidermal growth factor receptor,Living cancer cell detection,Porphyrin-based covalent organic framework,Electrochemical aptasensor
更新于2025-09-09 09:28:46
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Treatment of erlotinib induced acneiform eruption with chromophore?gel‐assisted?phototherapy
摘要： A 49-year-old female presented with an acneiform eruption induced by erlotinib. She had been diagnosed with Stage IV (T1N3M1) EGFR mutant adenocarcinoma of the lung and commenced on erlotinib 150mg daily. Within three days she developed an acneiform eruption prompting empiric treatment with topical hydrocortisone and systemic doxycycline 100mg daily. The acneiform eruption progressed with evolution to widespread pustules and papules with proud erythema involving the entire face with minor extension to the scalp, décolletage and back (Fig.1). Treatment was escalated to daily washes with benzoyl peroxide and transition to topical methylprednisolone aceponate and minocycline 100mg daily, met with modest response (Supplementary Fig 1). The patient was demonstrating a reduction in tumour burden on erlotinib but significant cutaneous toxicity recalcitrant to standard therapy. Given the significant burden on her quality of life (QOL), it was decided to continue erlotinib but trial adjuvant chromophore gel-assisted phototherapy (CGAP). The patient received twelve treatment sessions over six weeks involving application of a 2mm layer of the photoconverter chromophore gel (Kleresca? SKR-treatment) followed by irradiation with a multi-LED lamp (447nm) (Kleresca?, Balerup, Denmark). Within three weeks of treatment, the acneiform eruption was arrested and topical treatment was withdrawn one week after. The patient completed a further three weeks of CGAP as per standard protocol and maintained on minocycline 50mg daily thereafter. The severity of her acneiform eruption decreased from an Investigator’s Global Assessment (IGA) of 5 to 0. Scoring of the patient reported outcomes of the Acne Quality of Life Index decreased from 78 to 23 and increased on the Acne-specific Quality of Life Questionnaire (Acne-QOL) from 49 to 109 demonstrating marked improvement in quality of life.1, 2 She continues treatment with erlotinib maintaining tumour arrest without any active cutaneous toxicity; only post-inflammatory erythema, hyperpigmentation and ice-pick scarring as sequelae of the initial acneiform eruption (Fig.2).
关键词： Lung cancer,Epidermal growth factor receptor,Acne,Erlotinib,Phototherapy
更新于2025-09-09 09:28:46