Polymer-inorganic hybrid nanospheres have attracted increasing attention in recent years because of the synergic properties arising from both the polymeric nanospheres and inorganic nanomaterials. Especially, the nanospheres composed by the polymers that have desirable plasticity and biocompatibility, and the inorganic materials with unique optical, magnetic and electric properties are greatly useful in diagnosis and therapy disease. The combinations of functional polymers, inorganic nanomaterials and bioactive molecules can offer synergetic multifunctional nanomedical platforms, which make it possible to accomplish multimodal imaging and monitoring therapy. This article provides a review on the synthetic methodologies for building hybrid nanospheres, and their applications in targeted drug delivery, bio-imaging, cell separation, biosensing and hyperthermia. Perspective and challenges in nanomedical fields are discussed to provide the reference information for development of novel theranostic hybrid nanospheres.

Contents
1 Introduction
2 Preparation of polymer-inorganic hybrid nanospheres
2.1 Encapsulation method
2.2 In situ synthesis of inorganic nanoparticles
2.3 Surface-initiated polymerization coated method
2.4 Hole-doping method
2.5 Layer-by-layer method
2.6 Film rehydration method
3 Theranostic applications of polymer-inorganic hybrid nanospheres
3.1 Magnetic resonance imaging
3.2 CT imaging and surface enhanced raman imaging
3.3 Optical imaging in vivo
3.4 Triggered drug release and monitoring of therapy
3.5 Targeted drug delivery and hyperthermia treatment
3.6 Photothermal therapy
3.7 Cell separation
4 Conclusion and outlook