ABSTRACT
Surfaces of materials that promote cell adhesion, proliferation, and growth are critical for new generation of implantable biomedical devices. These films should be able to coat complex geometrical shapes very conformally, with smooth surfaces to produce hermetic bioinert protective coatings, or to provide surfaces for cell grafting through appropriate functionalization. Upon performing a survey of desirable properties such as chemical inertness, low friction coefficient, high wear resistance, and a high Young's modulus, diamond films emerge as very attractive candidates for coatings for biomedical devices. A promising novel material is ultrananocrystalline diamond (UNCD) in thin film form, since UNCD possesses the desirable properties of diamond and can be deposited as a very smooth, conformal coating using chemical vapor deposition. In this paper, we compared cell adhesion, proliferation, and growth on UNCD films, silicon, and platinum films substrates using different cell lines. Our results showed that UNCD films exhibited superior characteristics including cell number, total cell area, and cell spreading. The results could be attributed to the nanostructured nature or a combination of nanostructure/surface chemistry of UNCD, which provides a high surface energy, hence promoting adhesion between the receptors on the cell surface and the UNCD films.
Subject(s)
Cell Culture Techniques/instrumentation , Diamond/chemistry , Membranes, Artificial , Nanostructures/chemistry , Nanostructures/ultrastructure , Tissue Engineering/instrumentation , Biomedical Engineering/instrumentation , Biomedical Engineering/methods , Cell Adhesion , Cell Culture Techniques/methods , Cell Proliferation , Equipment Design , Equipment Failure Analysis , Materials Testing , Surface Properties , Tissue Engineering/methodsABSTRACT
Nanoparticles and bacteria can be used, independently, to deliver genes and proteins into mammalian cells for monitoring or altering gene expression and protein production. Here, we show the simultaneous use of nanoparticles and bacteria to deliver DNA-based model drug molecules in vivo and in vitro. In our approach, cargo (in this case, a fluorescent or a bioluminescent gene) is loaded onto the nanoparticles, which are carried on the bacteria surface. When incubated with cells, the cargo-carrying bacteria ('microbots') were internalized by the cells, and the genes released from the nanoparticles were expressed in the cells. Mice injected with microbots also successfully expressed the genes as seen by the luminescence in different organs. This new approach may be used to deliver different types of cargo into live animals and a variety of cells in culture without the need for complicated genetic manipulations.
