Surface properties of collagen-functionalized aluminosilicate particles embedding iron and dysprosium designed for cancer therapy

Simultaneous radiotherapy and hyperthermia yield synergistic improvement of therapeutic efficacy in cancer therapy. The study is focussed on sol-gel derived particles of 60SiO2•20Al2O3•10Fe2O3•10Dy2O3 (mol%) system functionalized with type I collagen. The addition to aluminosilicate matrix of Fe2O3•was thought for hyperthermia and of Dy2O3 for internal radiation therapy after neutron activation of dysprosium to 165Dy radioisotope. The collagen functionalization of these particles aimed to make them well accepted in the body and to contribute to destruction of reactive oxygen species, what has to be taken into account when nanoparticles are used for cancer therapy. The XRD, FTIR and XPS investigations were carried out on Fe-Dy-aluminosilicate particles of average size around tens of nanometers, before and after their incubation in collagen solution in order to prove the protein functionalization particles and to assess the changes in secondary structure of protein following this process. The results show the anchoring of the protein on particles surface in a few nanometers thin layer as well as some relative changes of protein secondary structure. After interface processes with particles surface, the secondary structure of amide I in collagen consists overwhelmingly of α-helices and only about 12 % of β-turns structure.