One of the most important ideas ever produced by the application of materials science to the medical field is the notion of biomaterials. The nanostructured biomaterials play a crucial role in the development of new treatment strategies including not only the replacement of tissues and organs, but also repair and regeneration. They are designed to interact with damaged or injured tissues to induce regeneration, or as a forest for the production of laboratory tissues, so they must be micro-environmentally sensitive. The existing materials have many limitations, including impaired cell attachment, proliferation, and toxicity. Nanotechnology may open new avenues to bone tissue engineering by forming new assemblies similar in size and shape to the existing hierarchical bone structure. Organic and inorganic nanobiomaterials are increasingly used for bone tissue engineering applications because they may allow to overcome some of the current restrictions entailed by bone regeneration methods. This review covers the applications of different organic and inorganic nanobiomaterials in the field of hard tissue engineering.

Spinel NiFe ₂ O ₄ nanoparticles have been synthesized via hydrothermal route using Mangifera indica flower extract (MIFE) as a green surfactant and reducing agent. X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy techniques have been used to determine the structure and morphology. The formation of single-phase, monodispersed NiFe ₂ O ₄ with mixed morphology, the predominant shape being of equi-axed nanoparticles having an average particle size ≲45 nm, is observed. The thermal magnetization of as-synthesized NiFe ₂ O ₄ nanoparticles shows ferromagnetic to paramagnetic phase transition at T _c ∼ 825 K. These nanoparticles show a very high saturation magnetization ( M _s ) value of 55 emu g ⁻¹ close to the bulk material and amongst the highest reported values for green synthesized NiFe ₂ O4 nanoparticles. This material has a coercivity ( H _c ) of 0.15 kOe and remanent magnetization ( M _r ) of 8.5 emu g ⁻¹ . The as-synthesized NiFe ₂ O ₄ nanoparticles show bandgap energy of 2.02 eV, derived from UV–vis absorption measurement, which is suitable for effective solar photocatalytic reactions. When exposed to sunlight in the presence of as-synthesized NiFe ₂ O ₄ nanoparticles, 93% of MB-dye degradation is measured in 80 min, indicating excellent photocatalytic properties. Based on the as-synthesized NiFe ₂ O ₄ nanoparticles’ observed properties, the effectiveness of MIFE as an environmentally friendly surfactant, and the low-cost dye-degradation prospects of green synthesized NiFe ₂ O ₄ nanoparticles are affirmed.