Research Article For reprint orders, please contact: reprints@futuremedicine.com Therapeutic potential of low-cost nanocarriers produced by green synthesis: macrophage uptake of superparamagnetic iron oxide nanoparticles Brunno RF Verc ¸oza 1,2,3 , Robson R Bernardo 1,4 , Arb´ elio Pent ´ on-Madrigal 5 , Jo˜ ao P Sinnecker 6 , Juliany CF Rodrigues** ,1,2,3 & Luiz Augusto S de Oliveira* ,1,4 1 N´ ucleo Multidisciplinar de Pesquisas em Biologia, Campus Prof. Geraldo Cidade, Universidade Federal do Rio de Janeiro, Rodovia Washington Luiz, km 105. 25240-005, Duque de Caxias, RJ, Brazil 2 Instituto Nacional de Ci ˆ encia e Tecnologia de Biologia Estrutural e Bioimagem, Rio de Janeiro, RJ, 21941-902, Brazil 3 Laborat ´ orio de Ultraestrutura Celular Hertha Meyer, Instituto de Biof´ ısica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, RJ, 21941-170, Brazil 4 N´ ucleo Multidisciplinar de Pesquisas em Nanotecnologia, Campus Prof. Geraldo Cidade, Universidade Federal do Rio de Janeiro, Rodovia Washington Luiz, km 105. 25240-005, Duque de Caxias, RJ, Brazil 5 Facultad de F´ ısica, IMRE, Universidad de La Habana, San Lazaro y L, C. Habana, CP 10400, Cuba 6 Centro Brasileiro de Pesquisas F´ ısicas, Rua Xavier Sigaud 150, Rio de Janeiro, RJ, 22290-180, Brazil *Author for correspondence: Tel.: +55 21 2679 1018; laso@ufrj.br **Author for correspondence: Tel.: +55 21 2679 1018; julycola@biof.ufrj.br Aim: The primary goal of this work was to synthesize low-cost superparamagnetic iron oxide nanoparticles (SPIONs) with the aid of coconut water and evaluate the ability of macrophages to internalize them. Our motivation was to determine potential therapeutic applications in drug-delivery systems associated with magnetic hyperthermia. Materials & methods: We used the following characterization techniques: X-ray and electron diffractions, electron microscopy, spectrometry and magnetometry. Results: The synthesized SPIONs, roughly 4 nm in diameter, were internalized by macrophages, likely via endocytic/phagocytic pathways. They were randomly distributed throughout the cytoplasm and mainly located in membrane- bound compartments. Conclusion: Nanoparticles presented an elevated intrinsic loss power value and were not cytotoxic to mammalian cells. Thus, we suggest that low-cost SPIONs have great therapeutic potential. Graphical abstract: 10,000 8000 6000 4000 2000 0 Counts (a.u.) 8 Energy (keV) 10 12 14 16 6 N 4 2 Os Os S Fe Fe Cu Cu Os Os As 0 2 nm 1 μm Os First draft submitted: 18 December 2018; Accepted for publication: 24 May 2019; Published online: 15 August 2019 Nanomedicine (Lond.) (Epub ahead of print) ISSN 1743-5889 10.2217/nnm-2018-0500 C  2019 Future Medicine Ltd