The Use of Gamma Ray Perturbed Angular Correlation Technique for the Study of Liposomal Integrity In Vitro and In Vivo

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.

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PENGARUH IRADIASI SINAR GAMMA [60Co] TERHADAP BACTROCERA CARAMBOLAE DREW & HANCOCK IN VITRO DAN IN VIVO

JURNAL HAMA DAN PENYAKIT TUMBUHAN TROPIKA ◽

10.23960/j.hptt.11517-25 ◽

2015 ◽

Vol 15 (1) ◽

pp. 17

Author(s):

Endang Sri Ratna ◽

Kemas Usman ◽

Indah Arastuti ◽

Dadan Hindayana

Keyword(s):

Gamma Ray ◽

Lethal Dose ◽

Fruit Fly ◽

Probit Analysis ◽

Adult Survival ◽

Significance Level ◽

Bactrocera Carambolae ◽

Gamma Ray Irradiation

Effect of gamma irradiation [60Co] against Bactrocera carambolae Drew & Hancock in vitro and in vivo. Bactrocera carambolae Drew & Hancock is one of the most important pests on guava fruit. According to a quarantine regulation in export-import commodities, irradiation treatment is a suitable methods for eradicating infested organism, which is relatively safe for the environment. The aim of this research was to determine mortality doses and an effective dose of [60Co] gamma ray irradiation for the eradication purpose, and its implication on the survival of fruit fly B. carambolae. Two irradiation methods of in vitro dan in vivo were carried out, by exposing egg and 3rd instar larvae of B. carambolae obtained from the laboratory reared insect. Eleven doses of gamma ray irradiation of 0, 30, 50, 75, 100, 125, 150, 175, 200, 300, 450, and 600 Gy were applied, respectively. The level of 99% fruit fly mortality was estimated by the value of LD99 using probit analysis and the number of larvae, pupae and adult survival were evaluated by analysis of variance (ANOVA), and the means compared by Tukey’s test, at 5% of significance level. These result showed that the effective lethal dose (LD99) of irradiation that could be successful to eradicate eggs and 3rd instar larvae in vitro were 2225 and 2343 Gy and in vivo were 3165 dan 3177 Gy, respectively. Almost all of the treated larvae survived and developed to pupae, therefore only the minimum irradiation dose of 30 Gy allowed the pupae to develop into adults.

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