Characterization of Different Nanostructured Bone Substitute Biomaterials

Bone biomaterials and interactions with stem cells

Bone biomaterials play a vital role in bone repair by providing the necessary substrate for cell adhesion, proliferation, and differentiation and by modulating cell activity and function. In past decades, extensive efforts have been devoted to developing bone biomaterials with a focus on the following issues: (1) developing ideal biomaterials with a combination of suitable biological and mechanical properties; (2) constructing a cell microenvironment with pores ranging in size from nanoscale to submicro- and microscale; and (3) inducing the oriented differentiation of stem cells for artificial-to-biological transformation. Here we present a comprehensive review of the state of the art of bone biomaterials and their interactions with stem cells. Typical bone biomaterials that have been developed, including bioactive ceramics, biodegradable polymers, and biodegradable metals, are reviewed, with an emphasis on their characteristics and applications. The necessary porous structure of bone biomaterials for the cell microenvironment is discussed, along with the corresponding fabrication methods. Additionally, the promising seed stem cells for bone repair are summarized, and their interaction mechanisms with bone biomaterials are discussed in detail. Special attention has been paid to the signaling pathways involved in the focal adhesion and osteogenic differentiation of stem cells on bone biomaterials. Finally, achievements regarding bone biomaterials are summarized, and future research directions are proposed.

N, Camargo NHA, Dallabrida AL, da Costa BD, Gil OG, Cambra-Moo O, Rodríguez MA, Canillas M. An in vivo study on bone formation behavior of microporous granular calcium phosphate

This study was developed based on in vivo investigation of microporous granular biomaterials based on calcium phosphates.

Hydration study from different calcium phosphate biocements with microstructure and nanostructure

Important features of biocements include easy molding and good wettability, hydration, and setting time during its application in biological tissue. Interest in calcium phosphate biocements is directly related to its characteristics of bioactivity, biocompatibility, and crystallographic similarity to bone apatite. This experimental study aimed to understand hydration behavior of calcium phosphate biocements with microstructure and nanostructure, with molar ratios Ca/P = 1.5; 1.6; 1.67; and 1.7 and hydration times of 5 and 30 min. The hydration tests were performed on the same solid/liquid ratio for the four Ca/P compositions. The morphology was observed via scanning electron microscopy and phases were identified with help from X-ray diffraction. The biocements showed similar effects of hydration and gelling for the periods of 5 and 30 min. The results show that these biocements can offer favorable wettability, hydration, and easy molding during the surgical procedure, which could be an innovation in implant fixation and bone tissue repair. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 820-827, 2017.