RESUMO
Our purpose was to develop a human epidermal growth factor receptor-2 (HER-2) targeted nanotechnology-based radiosensitizer. HER-2 is overexpressed in 20-30% of all breast cancers and up to 2-fold higher in locally advanced disease (LABC). Trastuzumab was derivatized with a polyethylene glycol (OPSS-PEG-SVA) cross-linker to produce trastuzumab-PEG-OPSS. These immunoconjugates were analyzed by SDS-PAGE, and their immunoreactivity was assessed by flow cytometry using HER-2 overexpressing SK-BR-3 breast cancer cells. Reacting trastuzumab with increasing ratios of PEG resulted in an increase in molecular weight from approximately 148 kDa to 243 kDa, associated with increasing PEG substitution (0.6 to 18.9 PEG chains per trastuzumab). Attachment of approximately 7 PEG chains per trastuzumab resulted in 56% retention in immunoreactivity assessed by flow cytometry. The conjugates were then linked to 30 nm AuNPs. Using a novel (123)iodine-radiotracer based assay that overcomes the current limitations of spectrophotometric quantification of biological molecules on AuNPs we estimate 14.3 ± 2.7 antibodies were attached to each AuNP when 2 × 10(11) AuNPs were reacted with 20 µg of trastuzumab-PEG-OPSS. Specificity of trastuzumab-PEG-AuNPs for HER-2 and internalization in SK-BR-3 cells was demonstrated by comparing the uptake of trastuzumab-PEG-AuNPs or PEG-AuNPs by darkfield microscopy. The ability of trastuzumab-PEG-AuNPs in combination with 300 kVp X-rays to enhance DNA double strand breaks (DSBs) in SK-BR-3 cells was assessed by immunofluorescence using the γ-H2AX assay. γ-H2AX assay results revealed 5.1-fold higher DNA-DSBs with trastuzumab-PEG-AuNPs and X-radiation as compared to treatment with X-radiation alone. The trastuzumab-PEG-AuNPs are a promising targeted nanotechnology-based radiosensitizer for improving LABC therapy. The design and systematic approaches taken to surface modify and characterize trastuzumab-PEG-AuNPs described in this study would have application to other molecularly targeted AuNPs for cancer treatment.
Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/terapia , Desenho de Fármacos , Ouro/farmacologia , Nanopartículas Metálicas/química , Recidiva Local de Neoplasia/terapia , Radiossensibilizantes/farmacologia , Anticorpos Monoclonais/química , Anticorpos Monoclonais Humanizados , Antineoplásicos/síntese química , Antineoplásicos/química , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Progressão da Doença , Relação Dose-Resposta à Radiação , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Ouro/química , Humanos , Modelos Biológicos , Nanotecnologia , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Polietilenoglicóis/química , Radiossensibilizantes/síntese química , Radiossensibilizantes/química , Receptor ErbB-2/genética , Trastuzumab , Raios XRESUMO
Semiconducting polymer nanoparticles (SPNs) emerge as attractive molecular imaging nanoagents in living animals because of their excellent optical properties including large absorption coefficients, tunable optical properties and controllable dimensions, high photostability, and the use of organic and biologically inert components without toxic metals. This review summarizes the recent advances of these new organic nanoparticles in in vivo molecular imaging. The in vivo biocompatibility of SPNs is discussed first in details, followed by examples of their applications ranging from sentinel lymph node mapping and tumor imaging to long-term cell tracking, to drug toxicity and bacterial infection imaging for fluorescence, bioluminescence, chemiluminescence and photoacoustic imaging in living animals. The utility of SPNs for designing smart activatable probes for real-time in vivo imaging is also discussed.
Assuntos
Materiais Biocompatíveis/química , Imagem Molecular/métodos , Polímeros/química , Pontos Quânticos/química , Animais , Sondas Moleculares , Estrutura Molecular , Técnicas FotoacústicasRESUMO
Diketopyrrolopyrrole-based semiconducting polymer nanoparticles with high photostability and strong photoacoustic brightness are designed and synthesized, which results in 5.3-fold photoacoustic signal enhancement in tumor xenografts after systemic administration.