Abstract: The invention provides methods of immobilizing an active agent to a substrate surface, including the steps of, depositing a primer compound on a substrate, thereby forming a primed substrate, contacting the primed substrate with a solution of a compound including a trihydroxyphenyl group, thereby forming a trihydroxyphenyl-treated primed substrate, and contacting the trihydroxyphenyl-treated primed substrate with a solution of an active agent, thereby immobilizing the active agent on the substrate. Further provided are methods of immobilizing an active agent on a substrate, including the steps of providing a substrate, combining a solution of a compound including a trihydroxyphenyl group with a solution of an active agent, thereby forming a solution of an active agent-trihydroxyphenyl conjugate, and contacting the primed substrate with the solution of the active agent-trihydroxyphenyl conjugate, thereby immobilizing the active agent on the substrate.

Abstract: A method of inducing mineralization in a bone cell is described. The method comprises contacting a bone cell with a composition comprising nanoparticles. The nanoparticles can be single-walled carbon nanotubes, hydroxyapatite nanoparticles, TiO2 nanoparticles or silver nanoparticles. The bone cell can be an osteoblast cell. A method for increasing bone mass, bone healing or bone formation is also described which comprises administering to a subject in need thereof an effective amount of a composition comprising nanoparticles. The subject can suffer from a bone disease such as osteoporosis. The subject can suffer from a bone fracture and the method can comprise contacting bone cells near the bone fracture site with the composition. The composition can further comprise a pharmaceutically acceptable carrier.