Theranostics 2013; 3(9):687-691. doi:10.7150/thno.6381

Research Paper

Tumor Spheroids as an In Vitro Model for Determining the Therapeutic Response to Proton Beam Radiotherapy and Thermally Sensitive Nanocarriers

Lakmini K. Senavirathna1, Ruchika Fernando1, Danny Maples1, Yuanshui Zheng2, Jerimy C. Polf 3, Ashish Ranjan1✉

1. Laboratory of Nanomedicine and Targeted Therapy, Department of Physiological Sciences, Center for Veterinary Health Sciences Oklahoma State University
2. Procure Proton Therapy Center, Oklahoma City
3. Department of Physics, College of Arts and Sciences, Oklahoma State University

Abstract

Multicellular Tumor Spheroids (MCTS) strongly resemble tumor tissues, which makes them useful tools for radiation biology studies and screening of various chemotherapeutics. The goal of this pilot study was to use MCTS as an in vitro model to determine the response of cells to low temperature-sensitive liposomes (LTSLs) encapsulating doxorubicin (Dox) and proton beam radiotherapy (PBRT). Prior to treatment, MCTS were characterized for morphology and LTSLs were characterized for size, encapsulation efficiency, and ability to thermally release Dox (a model anticancer agent). Two groups of MCTS were treated with LTSL in combination with mild hyperthermia (40-42 °C) or PBRT alone in the presence of appropriate controls. Cytotoxic response was assessed after 48-72 h using an acid phosphatase assay. At 72 h, LTSL in combination with heat significantly reduced the viability of MCTS (15-30%) compared to the control (P < 0.05). A similar cytotoxic response was observed with PBRT treatment. The data suggest that like a monolayer cell culture, MCTS can be used to determine cytotoxic outcomes of thermal and proton therapy.

Keywords: Tumor spheroids, Liposomes, Proton beam radiotherapy, Drug delivery

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How to cite this article:
Senavirathna LK, Fernando R, Maples D, Zheng Y, Polf JC, Ranjan A. Tumor Spheroids as an In Vitro Model for Determining the Therapeutic Response to Proton Beam Radiotherapy and Thermally Sensitive Nanocarriers. Theranostics 2013; 3(9):687-691. doi:10.7150/thno.6381. Available from http://www.thno.org/v03p0687.htm