Laser-ablative synthesis of novel classes of ultrapure non-toxic nanomaterials for biomedical applications

Andrei V. Kabashin

Aix-Marseille University (AMU), LP3 UMR 7341 CNRS, Campus de Luminy, Case 917, 13288 Marseille Cedex 09, France

Some inorganic nanomaterials demonstrate extremely promising characteristics for biological imaging and therapy, but biomedical prospects of such nanomaterials are complicated by toxicity issues arising as a result of relatively dirty pathways for their fabrication. As an example, Si nanoparticles are biocompatible and even biodegradable in pure state, but conventional chemical and electrochemical routes for their synthesis inevitably lead to a surface contamination by toxic products. As a solution of the toxicity problem, we recently introduced a series of physical nanofabrication methods based on ultrashort laser ablation in aqueous biocompatible solutions. This talk will present the laser synthesis method and overview results of first tests on interaction of some promising laser-synthesized nanomaterials (Si, Au) with biological systems. In particular, our tests in vitro demonstrate excellent safety of nanoparticles, while protein covering after the incubation of nanoparticles in real biological environment suggests potential successful transport of nanoparticles in vivo. In vivo tests in small animal model using systemic administration of Si nanoparticles also do not reveal any sign of toxicity effects, which is confirmed by behaviour of mice, stability of blood content and other biochemical parameters, as well as by histology analyses of all organs and biodistribution of nanoparticles in tissues. Furthermore, the nanoparticles rapidly biodegrade in the organism and are completely cleared 2-3 days after their injection. The talk will also describe optical, photochemical and photo-thermal characteristics of laser-synthesised nanomaterials in the view of their potential cancer theranostic (therapy + diagnostics) applications. As an example, we recently introduced a novel method for mild cancer therapy, in which Si nanoparticles are used as sensitizers of radio-frequency induced hyperthermia. The efficiency of this method is confirmed by successful tests in vitro and in vivo.