title: Targeting neural stem cells with titanium dioxide nanoparticles coupled to specific monoclonal antibodies.
abstract: Aiming to characterize the use of biomaterials in cancer therapy, we took advantage of the n-type semiconductor properties, which upon irradiation excite their electrons into the conduction band to induce photoelectrochemical reactions generating oxygen reactive species (ROS). Indeed, photoactivated TiO(2) nanoparticles have been shown to kill in vitro either bacteria or tumor cells in culture following UV irradiation, as a consequence of the ROS levels generated; the killing was highly effective although devoid of specificity. In this report, we have directed the TiO(2) nanoparticles to particular targets by coupling them to the monoclonal antibody (mAb) Nilo1, recognizing a surface antigen in neural stem cells within a cell culture, to explore the possibility of making this process specific. TiO(2) nanoparticles generated with particular rutile/anatase ratios were coupled to Nilo1 antibody and the complexes formed were highly stable. The coupled antibody retained the ability to identify neural stem cells and upon UV irradiation, the TiO(2) nanoparticles were activated, inducing the selective photokilling of the antibody-targeted cells. Thus, these data indicate that antibody-TiO(2) complexes could be used to specifically remove target cell subpopulations, as demonstrated with neural stem cells. The possible applications in cancer therapy are discussed.
authors.affiliation: Cellular and Molecular Medicine Department, Centro de Investigaciones Biológicas, Madrid, Spain.
authors.forename: Gema
authors.initials: G
authors.lastname: Elvira
authors.forename: Berta
authors.initials: B
authors.lastname: Moreno
authors.forename: Ignacio Del
authors.initials: ID
authors.lastname: Valle
authors.forename: Jose A
authors.initials: JA
authors.lastname: Garcia-Sanz
authors.forename: María
authors.initials: M
authors.lastname: Canillas
authors.forename: Eva
authors.initials: E
authors.lastname: Chinarro
authors.forename: José R
authors.initials: JR
authors.lastname: Jurado
authors.forename: Augusto
authors.initials: A
authors.lastname: Silva
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D005434:Flow Cytometry; D007150:Immunohistochemistry; D053768:Metal Nanoparticles; D051379:Mice; D008810:Mice, Inbred C57BL; D058953:Neural Stem Cells / Q000166:cytology / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D014025:Titanium / Q000737:chemistry* / Q000276:immunology; D014466:Ultraviolet Rays; D014961:X-Ray Diffraction
chemical_list: D000911:Antibodies, Monoclonal; D017382:Reactive Oxygen Species; C009495:titanium dioxide; D014025:Titanium