Dataset Information

The Design and Preclinical Evaluation of a Single-Label Bimodal Nanobody Tracer for Image-Guided Surgery.

ABSTRACT: Intraoperative guidance using targeted fluorescent tracers can potentially provide surgeons with real-time feedback on the presence of tumor tissue in resection margins. To overcome the limited depth penetration of fluorescent light, combining fluorescence with SPECT/CT imaging and/or gamma-ray tracing has been proposed. Here, we describe the design and preclinical validation of a novel bimodal nanobody-tracer, labeled using a "multifunctional single attachment point" (MSAP) label, integrating a Cy5 fluorophore and a diethylenetriaminepentaacetic acid (DTPA) chelator into a single structure. After conjugation of the bimodal MSAP to primary amines of the anti-HER2 nanobody 2Rs15d and ¹¹¹In-labeling of DTPA, the tracer's characteristics were evaluated in vitro. Subsequently, its biodistribution and tumor targeting were assessed by SPECT/CT and fluorescence imaging over 24 h. Finally, the tracer's ability to identify small, disseminated tumor lesions was investigated in mice bearing HER2-overexpressing SKOV3.IP1 peritoneal lesions. [¹¹¹In]In-MSAP.2Rs15d retained its affinity following conjugation and remained stable for 24 h. In vivo SPECT/CT and fluorescence images showed specific uptake in HER2-overexpressing tumors with low background. High tumor-to-muscle ratios were obtained at 1h p.i. and remained 19-fold on SPECT/CT and 3-fold on fluorescence images over 24 h. In the intraperitoneally disseminated model, the tracer allowed detection of larger lesions via nuclear imaging, while fluorescence enabled accurate removal of submillimeter lesions. Bimodal nuclear/fluorescent nanobody-tracers can thus be conveniently designed by conjugation of a single-molecule MSAP-reagent carrying a fluorophore and chelator for radioactive labeling. Such tracers hold promise for clinical applications.

SUBMITTER: Debie P

PROVIDER: S-EPMC7996797 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:The detection of cancer micrometastasis for early diagnosis and treatment poses a great challenge for conventional imaging techniques. The aim of our study was to evaluate the performance of photoacoustic imaging (PAI) in detecting hepatic micrometastases from melanoma at a very early stage and in aiding tumor resection by intraoperative guidance. Methods: In vivo studies were performed by following protocols approved by the Ethical Committee for Animal Research at Xiamen University. First, a mouse model of B16 melanoma metastatic to the liver (n = 10) was established to study the development of micrometastases in vivo. Next, the mice were imaged by a scalable PAI instrument, ultrasound, 9.4-T high-resolution MRI, PET/CT, and bioluminescence imaging. PAI scans acquired with optical wavelengths of 680-850 nm were kept spectrally unmixed by using a linear least-squares method to differentiate various components. Differences in signal-to-background ratios among different modalities were determined with the 2-tailed paired t test. The diagnostic results were assessed with histologic examination. Excised liver samples from patients diagnosed with hepatic cancer were also examined to identify the tumor boundaries. Surgical removal of metastatic melanoma was precisely guided in vivo by the portable PAI system. Results: PAI was able to detect metastases as small as approximately 400 ?m at a depth of up to 7 mm in vivo-a size that is smaller than can be detected with ultrasound and MRI. The tumor-to-liver ratio for PAI at 8 d (4.2 ± 0.2, n = 6) and 14 d (9.2 ± 0.4, n = 5) was significantly higher than for PET/CT (1.8 ± 0.1, n = 5, and 4.5 ± 0.2, n = 5, respectively; P < 0.001 for both). Functional PAI revealed dynamic oxygen saturation changes during tumor growth. The limit of detection was approximately 219 cells/?L in vitro. We successfully performed intraoperative PAI-guided surgery in vivo using the portable PAI system. Conclusion: Our findings offer a rapid and effective complementary clinical imaging application to noninvasively detect micrometastases and guide intraoperative resection.

Dataset Information

The Design and Preclinical Evaluation of a Single-Label Bimodal Nanobody Tracer for Image-Guided Surgery.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets