RESUMO
Nanometer-scale architectures assembled on cell surface receptors from smaller macromolecular constituents generated a large amplification of fluorescence. A targeted dendrimer was synthesized from a cystamine-core G4 PAMAM dendrimer, and contained an anti-BrE3 monoclonal antibody as the targeting group, several fluorophores and an average of 12 aldehyde moieties as complementary bio-orthogonal reactive sites for the covalent assembly. A cargo dendrimer, derived from a PAMAM G4 dendrimer, contained several fluorophores as the cargo for delivery and five hydrazine moieties as complimentary bio-orthogonal reactive sites. The system is designed to be flexible and allow for facile incorporation of a variety of targeting ligands.
Assuntos
Dendrímeros/química , Portadores de Fármacos/química , Nylons/química , Receptores de Superfície Celular/metabolismo , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Linhagem Celular Tumoral , Corantes Fluorescentes/química , Corantes Fluorescentes/metabolismo , Humanos , Receptores de Superfície Celular/química , Rodaminas/química , Rodaminas/metabolismoRESUMO
OBJECTIVES/HYPOTHESIS: In this article we describe a methodology for obtaining high-quality dynamic magnetic resonance imaging (MRI) sequences of the swallow sequence in healthy volunteers. The study includes comparison to previous work done in our lab using a 1.5 Tesla (T) magnet. STUDY DESIGN: Case series. METHODS: Three healthy volunteers underwent turbo-fast low angle shot MRI at 3T while swallowing liquid boluses delivered via intravenous tubing to the oral cavity. Imaging was performed in the sagittal and axial planes. RESULTS: Imaging provided by this sequence provided high temporal resolution, with the ability to depict deglutition in the axial and sagittal planes. Comparison with imaging at 1.5 T demonstrated benefits in temporal resolution and signal-to-noise. Anatomic information provided differed from comparative videofluoroscopy. CONCLUSIONS: MRI of swallowing using the described technique is reliable and provides a unique evaluation of the swallowing sequence.
Assuntos
Deglutição/fisiologia , Imageamento por Ressonância Magnética/métodos , Faringe/fisiologia , Adulto , Feminino , Humanos , Masculino , Valores de Referência , Reprodutibilidade dos TestesRESUMO
OBJECTIVE: To evaluate and compare image quality between flat-panel volumetric computed tomography (fpVCT) and multislice CT (msCT) in temporal bones with cochlear implants (CIs), and to evaluate fpVCT imaging for accuracy in determining CI electrode positioning. METHODS: Six cadaveric temporal bones were imaged prior to CI using fpVCT. Each bone was implanted with an electrode array and rescanned in order to create radial reformatted images through each electrode contact. Electrode-modiolar interval (EMI) distances were measured. The bones were fixed and cut in order to grossly evaluate for CI intrascalar positioning and insertional trauma. MAIN OUTCOME MEASURE: To compare image quality between fpVCT and msCT in temporal bones with CI, and to evaluate the utility of fpVCT in post-implantation temporal bone analysis. RESULTS: The mean EMI distances did not differ significantly between fpVCT and msCT images, while the image quality was significantly better for fpVCT. Furthermore, information about intracochlear trauma and intrascalar electrode array positioning can be ascertained using this radiographic technique. CONCLUSION: fpVCT and msCT do not differ significantly in the evaluation of EMI distances in implanted temporal bones, but the image quality is significantly better using fpVCT. Additionally, useful information regarding intracochlear trauma, electrode depth of insertion, and intrascalar positioning can be gained from fpVCT imaging. Given the ease of use, superior image quality, improved convenience, reduced levels of radiation, and agreement with histology, fpVCT is a valuable option for post-implantation temporal bone imaging.
Assuntos
Implante Coclear , Implantes Cocleares , Tomografia Computadorizada por Raios X/instrumentação , Implante Coclear/métodos , Humanos , Tomografia Computadorizada Multidetectores , Período Pós-Operatório , Tomografia Computadorizada por Raios X/métodosRESUMO
A nanoparticle magnetic resonance imaging (MRI) contrast agent was developed by conjugation of more than 500 gadolinium chelate groups onto a viral capsid. The high density of paramagnetic centers and slow tumbling rate of modified MS2 capsids provided enhanced T1 relaxivities up to 7200 mM-1s-1 per particle. A bimodal imaging agent was generated by sequential conjugation of fluorescein and Gd3+ chelate. These results illustrate the potential for engineering natural protein assemblies to address bionanotechnology applications.
