Navegando por Assunto "Epidermal growth factor"

Agora exibindo 1 - 2 de 2
  • Imagem de Miniatura
    Item
    Chlorin e6-EGF conjugated gold nanoparticles as a nanomedicine based therapeutic agent for triple negative breast cancer
    (Elsevier) Castilho, Maiara Lima; Jesus, Viviane Paula dos Santos; Vieira, Paula Fonseca Antunes; Hewitt, Kevin Cecil; Raniero, Leandro José
    To develop a treatment modality for triple-negative breast cancer, we investigated the efficacy of a bifunctional theranostic nanoprobes (BN) during Photodynamic Therapy (PDT) on human breast carcinoma and normal human cells. The BN is a 21 nm gold nanoparticles functionalized with Chlorin e6 (Ce6) and Epidermal Growth Factor (EGF). Attachment to gold nanoparticle stabilizes Ce6 while EGF acts as a cancer cell targeting agent. Fluorescence Spectroscopy and Confocal Fluorescence Microscopy revealed a gradual uptake of nanoprobes into cancer cells at an average rate of 63 BN/min. Cell viability assays showed that 0.2 μg/mL BN concentration was highly cytotoxic to cancer cells (86 %), but not normal cells. At this concentration, 58 % cancer cells were necrotic and 38 % apoptotic, while the reactive oxygen species (ROS) was 9-fold higher in cancer cells compared to normal. Overall, results suggest that BN mediated PDT can achieve targeted cancer cell death with high efficiency.
  • Imagem de Miniatura
    Item
    Gold nanoparticles conjugated with epidermal growth factor and gadolinium for precision delivery of contrast agents in magnetic resonance imaging
    (Springer-Verlag London Ltd.) Queiroz, Marinho de; Veriato, Thaís da Silva; Raniero, Leandro José; Castilho, Maiara Lima
    The utilization of contrast agents in magnetic resonance imaging (MRI) has become increasingly important in clinical diagnosis. However, the low diagnostic specificity of this technique is a limiting factor for the early detection of tumors. To develop a new contrast agent with a specific target for early stage tumors, we present the synthesis and characterization of a nanocontrast composed of gold nanoparticles (AuNPs), gadopentetic acid (Gd-DTPA), and epidermal growth factor (EGF). Carbodiimide-based chemistry was utilized to modify Gd-DTPA for functionalization with AuNPs. This resulted in the formation of the Au@Gd-EGF nanocontrast. The relaxation rate (1/T1) of the nanocontrast was analyzed using MRI, and cytotoxicity was determined based on cell viability and mitochondrial activity in a human breast adenocarcinoma cell line. Fourier-transform infrared spectroscopy analysis confirmed the effectiveness of carbodiimide in the formation of the Gd-DTPA-cysteamine complex in the presence of bands at 930, 1042, 1232, 1588, and 1716 cm-1. The complexes exhibited good interactions with the AuNPs. However, the signal intensity of the Au@Gd-EGF nanocontrast was lower than that of the commercial contrast agent because the r1/r2 relaxivities of the Gd-DTPA-based contrast agents were lower than those of the gadoversetamide-based molecules. The Au@Gd-EGF nanocontrast agent exhibited good biocompatibility, low cytotoxicity, and high signal intensity in MRI with active targeted delivery, suggesting significant potential for future applications in the early diagnosis of tumors.