Abstracts Book - IMRC 2018

• SB6-P091
THERMAL ABLATION OF TUMORS BY ANISOTROPIC AUNPS
FUNCTIONALIZED WITH BSA
Clara de la Luz Carreón Álvarez 1 , José Luis Rodríguez López 2 , Rubén López Revilla 1
1 Instituto Potosino de Investigación Científica y Tecnológica A.C., Molecular Biology, Mexico.
2 Instituto Potosino de Investigación Científica y Tecnológica A.C., Advanced Materials, Mexico.
Since hyperthermia to remove tumors is ineffective and affects cancer and
normal cells, the plasmonic effect of anisotropic gold nanoparticles (MBAuNPs,
Multi-branched Gold Nanoparticles) is being explored for thermal ablation of
tumors. Our aim was to synthesize MBAuNPs for thermal ablation of tumors of
diameter ~ 100 nm, maximum light absorption near the mid-infrared region,
functionalized with bovine serum albumin (BSA) to direct them to the surface
receptors of endothelial cells that abound in vascularized superficial tumors and
to induce controlled hyperthermia by irradiation with a laser of 808 nm of
variable power, in gels that simulate the skin and contain the selected
MBAuNPs.
MBAuNPs were synthesized spherical auric seeds (diameter ~18 nm and
ultraviolet-visible spectrum (UV-VIS) with maximum absorbance (Amax) at 520
nm), and functionalized with BSA. These MBAuNPs present average diameters
around ~100 nm and Amax = 775 nm, while those functionalized with BSA
(MBAuNPs-BSA) show Amax = 825 nm and an estimated number of ~100,000 BSA
molecules per nanoparticle. For the complex MBAuNPs-BSA, X-ray
photoelectron spectroscopy (XPS) demonstrated the Au—BSA chemical
interaction, and by means of dynamic scattering of light (DLS), this system
presents a decrease, but still being negative, in the Z-potential. Transmission
electron microscopy evidenced that MBAuNPs acquired an additional surface
layer of BSA with 5-10 nm thick; also by DLS indicated an increase of 14 nm in
the hydrodynamic radius and by circular dichroism (CD) a slight decrease in the
proportion of α-helices, inversely proportional to the concentration of BSA.
Our results suggest that MBAuNPs-BSA acquired a protein-corona constituted
by two parts: an internal film of one to two layers of BSA molecules covalently
bound to the surface of each nanoparticle and a loose external portion given by
the agglomeration of protein molecules linked together by non-covalent bonds.
These results show that these MBAuNPs are potential, non-toxic nanostructured
systems for thermal ablation treatment of tumors, since irradiation with the 808