title: Magnetic hyperthermia enhances cell toxicity with respect to exogenous heating.
abstract: Magnetic hyperthermia is a new type of cancer treatment designed for overcoming resistance to chemotherapy during the treatment of solid, inaccessible human tumors. The main challenge of this technology is increasing the local tumoral temperature with minimal side effects on the surrounding healthy tissue. This work consists of an in vitro study that compared the effect of hyperthermia in response to the application of exogenous heating (EHT) sources with the corresponding effect produced by magnetic hyperthermia (MHT) at the same target temperatures. Human neuroblastoma SH-SY5Y cells were loaded with magnetic nanoparticles (MNPs) and packed into dense pellets to generate an environment that is crudely similar to that expected in solid micro-tumors, and the above-mentioned protocols were applied to these cells. These experiments showed that for the same target temperatures, MHT induces a decrease in cell viability that is larger than the corresponding EHT, up to a maximum difference of approximately 45% at T = 46 °C. An analysis of the data in terms of temperature efficiency demonstrated that MHT requires an average temperature that is 6 °C lower than that required with EHT to produce a similar cytotoxic effect. An analysis of electron microscopy images of the cells after the EHT and MHT treatments indicated that the enhanced effectiveness observed with MHT is associated with local cell destruction triggered by the magnetic nano-heaters. The present study is an essential step toward the development of innovative adjuvant anti-cancer therapies based on local hyperthermia treatments using magnetic particles as nano-heaters.
authors.affiliation: Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, C/Mariano Esquillor S/N, CP 50018, Zaragoza, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Sanz
authors.affiliation: Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, C/Mariano Esquillor S/N, CP 50018, Zaragoza, Spain; Departamento de Física de la Materia Condensada, Facultad de Ciencias, C/ Pedro Cerbuna 12, 50009, Zaragoza, Spain.
authors.forename: M Pilar
authors.initials: MP
authors.lastname: Calatayud
authors.affiliation: Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, C/Mariano Esquillor S/N, CP 50018, Zaragoza, Spain; Departamento de Física de la Materia Condensada, Facultad de Ciencias, C/ Pedro Cerbuna 12, 50009, Zaragoza, Spain; Laboratorio de Microscopias Avanzadas (LMA), Universidad de Zaragoza, C/Mariano Esquillor S/N, CP 50018, Zaragoza, Spain.
authors.forename: Teobaldo E
authors.initials: TE
authors.lastname: Torres
authors.affiliation: Grupo de Nanomedicina-IDIVAL, Universidad de Cantabria, Herrera Oria s/n, CP 39011 Santander, Spain.
authors.forename: Mónica L
authors.initials: ML
authors.lastname: Fanarraga
authors.affiliation: Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, C/Mariano Esquillor S/N, CP 50018, Zaragoza, Spain; Departamento de Física de la Materia Condensada, Facultad de Ciencias, C/ Pedro Cerbuna 12, 50009, Zaragoza, Spain.
authors.forename: M Ricardo
authors.initials: MR
authors.lastname: Ibarra
authors.affiliation: Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, C/Mariano Esquillor S/N, CP 50018, Zaragoza, Spain; Departamento de Física de la Materia Condensada, Facultad de Ciencias, C/ Pedro Cerbuna 12, 50009, Zaragoza, Spain. Electronic address: goya@unizar.es.
authors.forename: Gerardo F
authors.initials: GF
authors.lastname: Goya
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000528:radiation effects; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods*; D055909:Magnetic Field Therapy / Q000379:methods*; D060526:Magnetic Fields; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000627:therapeutic use*; D009374:Neoplasms, Experimental / Q000473:pathology* / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D058185:Magnetite Nanoparticles
keywords: Cell viability; Human neuroblastoma; Magnetic hyperthermia; Magnetic nanoparticles; Specific power absorption