| AVS 57th International Symposium & Exhibition | |
| Nanometer-scale Science and Technology | Tuesday Sessions |
| Session NS-TuP |
| Session: | Nanometer-Scale Science and Technology Poster Session |
| Presenter: | A. Liberman, University of California, San Diego |
| Authors: | A. Liberman, University of California, San Diego S. Sandoval, University of California, San Diego J. Yang, University of California, San Diego S. Aschemeyer, University of California, San Diego J.G. Alfaro, University of California, San Diego D. Martin, University of California, San Diego M. Makale, University of California, San Diego A.C. Kummel, University of California, San Diego W.C. Trogler, University of California, San Diego |
| Correspondent: | Click to Email |
An important area of biomedical nanotechnology is based on the interaction of living systems with inorganic and organic materials at the nanoscale. Silica nanospheres (NS) are attractive biomaterials because of their advantages as readily functionalized transport and imaging devices: the porous amorphous structure of silica colloid allows small molecule storage; the surface of silica can be modified easily with trimethoxysilyl reagents; silica has low biotoxicity and good biocompatibility. Silica nanospheres potentially have multiple biomedical applications as imaging agents, targeted drug delivery agents or gene transferring motherships. A simple method to fabricate hollow silica nanospheres with 100 nm or 200 nm diameters has been developed and tested. Amino polystyrene beads were used as templates and a 5-10 nm thick silica gel coating was formed by the sol-gel reaction. After removing template by calcinations, porous dehydrated silica gel nanoshells of uniform size were obtained. The porous structure of silica shell wall was characterized by transmission electron microscopy measurements, while particle size and zetapotentials of the particles suspended in aqueous solution were characterized by dynamic light scattering. The surfaces of the NS have been functionalized with folic acid in order to specifically target cancer cells. Folic acid, also known as vitamin B9 or Folate, is essential for the synthesis of nucleotide bases and binds with high affinity to Folate receptors, which are frequently over-expressed in tumor cells and epithelial lineaged tumors such as ovarian carcinomas. With the use of confocol and two-photon microscopy, it was found that as the amount of folate on the surface of the NS was increased, a higher amount of NS endocytose into HeLa cancer cells, a cervical cancer cell line. Cytotoxicity studies will quantify the effectiveness of using folate coated siica shells for enhancing endocytosis of chemotherapy drugs in cell lines and in animal studies.