In-situ preparation of amino-terminated dendrimers on TiO2 films by generational growth for potential and efficient surface functionalization

Abstract

Dendrimers, with their unique structure and polyfunctionality, have shown excellent performance in many biomedicinal applications, such as drug carriers and gene transfection. In this study, titanium dioxide (TiO2) films with four generations (G1, G2, G3, G4) of amino-terminated dendrimers were prepared in situ using a simple iterative Michael addition and aminolysis reaction for generational growth. The TiO2 films with different generations of dendrimers were characterized using X-ray diffraction, water contact angle measurements, and scanning electron microscopy. The chemical compositions of these films were confirmed by Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy. Blood compatibility was evaluated using platelet adhesion and activation assays utilizing platelet-rich plasma. The results indicated that the dendrimers immobilized on the surface of the TiO2 films effectively reduced platelet adhesion and aggregation. Endothelial cell culturing on the dendrimer-immobilized surfaces showed that the amino-terminated dendrimers exhibited a certain degree of cytotoxicity due to the positive charges of the amino groups. These results indicated that amino-terminated dendrimers immobilized on TiO2 films provided numerous functional groups for the future immobilization of specific biological molecules and may be used for manufacturing future blood-contacting implants.