Surface-Functionalized Polymeric Nanoparticles as Templates for Biomimetic Mineralization of Hydroxyapatite

The use of polymeric nanoparticles as templates for producing inorganic materials is an intriguing approach, as it offers the feasibility of synthesizing organic/inorganic hybrid materials for several interesting applications. Here, polymeric nanoparticles synthesized via the miniemulsion process are employed as templates for biomimetic mineralization of hydroxyapatite in the aqueous phase. The versatile miniemulsion technique allows the fabrication of surface-functionalized polymeric nanoparticles with varying amounts of surface-bound functional groups by use of different types of surfactants. Hybrid nanoparticles were formed by performing crystallization outside on the surface of the polymer nanoparticles by varying the amount of surface functional groups and were studied by high-resolution scanning electron microscopy (HRSEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). These hydroxyapatite/polymer hybrid nanoparticles have great potential to be used as filler or as scaffold for nucleation and growth of new bone material. They offer the feasibility of being injected directly into the damaged part in addition to being applied as coatings on implants. The use of polymeric nanoparticles coated with hydroxyapatite (HAP) for bone repair applications in addition opens new doors for realizing the potential of using the polymeric nanoparticles as carriers of drugs and growth factors to better treat bone defects and promote wound healing.