title: Technetium-99m radiolabeled paclitaxel as an imaging probe for breast cancer in vivo.
abstract: The high incidence and mortality of breast cancer supports efforts to develop innovative imaging probes to effectively diagnose, evaluate the extent of the tumor, and predict the efficacy of tumor treatments while concurrently and selectively delivering anticancer agents to the cancer tissue. In the present study we described the preparation of technetium-99m (99mTc)-labeled paclitaxel (PTX) and evaluated its feasibility as a radiotracer for breast tumors (4T1) in BALB/c mice. Thin Layer Chromatography (TLC) was used to determine the radiochemical purity and in vitro stability of99mTc-PTX. PTX micelles showed a unimodal distribution with mean diameter of 13.46±0.06nm. High radiochemical purity (95.8±0.3%) and in vitro stability (over than 95%), up to 24h, were observed. Blood circulation time of99mTc-PTX was determined in healthy BALB/c mice.99mTc-PTX decays in a one-phase manner with a half-life of 464.3 minutes. Scintigraphic images and biodistribution were evaluated at 4, 8 and 24h after administration of99mTc-PTX in 4T1 tumor-bearing mice. The data showed a significant uptake in the liver, spleen and kidneys, due to the importance of these routes for excretion. Moreover, high tumor uptake was achieved, indicated by high tumor-to-muscle ratios. These findings indicate the usefulness of99mTc-PTX as a radiotracer to identify 4T1 tumor in animal models. In addition,99mTc-PTX might be used to follow-up treatment protocols in research, being able to provide information about tumor progression after therapy.
authors.affiliation: Department of Pharmaceutical Products, Faculty of Pharmacy, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Liziane O F
authors.initials: LOF
authors.lastname: Monteiro
authors.affiliation: Department of Pharmaceutical Products, Faculty of Pharmacy, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Renata S
authors.initials: RS
authors.lastname: Fernandes
authors.affiliation: Department of Pharmaceutical Products, Faculty of Pharmacy, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Luciano C
authors.initials: LC
authors.lastname: Castro
authors.affiliation: Department of Clinical and Toxicological Analyses, Faculty of Pharmacy, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Valbert N
authors.initials: VN
authors.lastname: Cardoso
authors.affiliation: Department of Pharmaceutical Products, Faculty of Pharmacy, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Mônica C
authors.initials: MC
authors.lastname: Oliveira
authors.affiliation: Department of Drug Discovery and Pharmaceutical Sciences, Medical University of South Carolina, USA.
authors.forename: Danyelle M
authors.initials: DM
authors.lastname: Townsend
authors.affiliation: Department of Nuclear Medicine, Molecular Imaging, Radiology, Neuro Radiology, Medical Physics, Clinical Laboratory, Microbiology & Pathology, Santa Maria de la Misericordia Hospital, Rovigo, Italy.
authors.forename: Alice
authors.initials: A
authors.lastname: Ferretti
authors.affiliation: Department of Nuclear Medicine, Molecular Imaging, Radiology, Neuro Radiology, Medical Physics, Clinical Laboratory, Microbiology & Pathology, Santa Maria de la Misericordia Hospital, Rovigo, Italy. Electronic address: Domenico.rubello@libero.it.
authors.forename: Domenico
authors.initials: D
authors.lastname: Rubello
authors.affiliation: Department of Pharmaceutical Products, Faculty of Pharmacy, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Elaine A
authors.initials: EA
authors.lastname: Leite
authors.affiliation: Department of Clinical and Toxicological Analyses, Faculty of Pharmacy, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil. Electronic address: brancodebarros@yahoo.com.br.
authors.forename: André L B
authors.initials: ALB
authors.lastname: de Barros
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D005260:Female; D006207:Half-Life; D006801:Humans; D007553:Isotope Labeling; D051379:Mice; D008807:Mice, Inbred BALB C; D009928:Organ Specificity; D017239:Paclitaxel / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D013667:Technetium; D014018:Tissue Distribution
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D019275:Radiopharmaceuticals; D013667:Technetium; D017239:Paclitaxel
keywords: 4T1 tumor; Biodistribution profile; Breast cancer; Paclitaxel; Scintigraphic images