Particles are provided for use in therapeutic and/or diagnostic procedures. The particles include poly[bis(trifluoroethoxy)phosphazene] and/or a derivatives thereof which may be present throughout the particles or within an outer coating of the particles. The particles may also include a core having a hydrogel formed from an acrylic-based polymer. Such particles may be provided for placement within defects in bone within the body of a mammal to augment structural support and facilitate osteogenesis without causing adverse reactions therein. The hydrogel core may further be used as a delivery vehicle for therapeutic agents to treat or retard pathologic processes within the bone defect during healing.