Bone-like nanocomposites

Kikuchi, M. Ikoma, T. Itoh, S. Matsumoto, H.N. Koyama, Y. Takakuda, K. Shinomiya, K. Tanaka, J. Biomimetic synthesis of bone-like nanocomposites using the self-organization mechanism of hydroxyapatite and collagen. Composites Sciences and Technology 2004, 64, 819-825. 

M, Kikuchi, T. Ikoma, S. Itoh, H, N, Matsumoto, Y, Koyama, K, Takakuba, K. Shinomiya and J, Tanaka, Biomimetic Synthesis of Bone-like Nanocomposites using the Self-organization Mechanism of Hydroxyapatite and Collagen, Composites Science and Technology, 64, 819-825(2004)... 

Kikuchi, M., Itoh, S., Ichinose, S., Shinomiya, K., Tanaka, J. Self-Organization Mechanism in a Bone-like Hydroxyapatite/Collagen Nanocomposite Synthesized in vitro and Its Biological Reaction in vivo. Biomaterials. 22, 1705—1711 (2001)... 

Kikuchi M, Itoh S, Ichinose S, Shinomiya K, Tanaka J. Self-organization mechanism in a bone-like hydroxyapatite/collagen nanocomposite synthesized in vitro and its biological reaction in vivo. Biomaterials 2001 22 1705-11. 

Bernhardt et al. [234] obtained a synthetic material that mimics the composition and structure of the extracellular bone matrix, which mainly consists of Coll fibrils, mineralized with HAp (nano)crystals. This nanocomposite material was produced in a biomimetic process, in which Col fibril assembly and mineralization with HAp occur simultaneously. The authors observed that the membranes from biomimetically mineralized Coll show a substantial influence on the osteogenic differentiation of human bone-marrow-derived stromal cells (hBMSCs). The bone-like composition of the material, combined with its stimulating effect on the osteogenic differentiation of hBMSC, makes it appropriate for human bone regeneration. 

Li, X., Chang, J., 2008. Prqraration of bone-like apatite-collagen nanocomposites by a biomimetic process with phosphorylated coUagen. Journal of Biomedical Materials Research. Part A 85 (2), 293-300. Available at http //www.ncbi.nlm.nih.gov/pubmed/17688292 (accessed 10.10.14.). 

Figure 2.17 Representative histological sections of scaffolds implanted in femoral condyle defects (a and b) a PPF scaffold 4 weeks after implantation, (c and d) a US-tube-PPF scaffold after 4 weeks, (e andf) a PPF scaffold after 12 weeks, and (g and h) a US-tube-PPF scaffold after 12weeks implantation. The images are presented at 1.6A and 10A magnification. The PPF scaffold (P) appears as white areas in all images. The original defect edge (DE) is visible in the low-magnification images. Bone-like tissue (BT) appears red direct bone implant contact (BIC) occurred with the US-tube-PPF nanocomposite scaffold 12 weeks after implantation. US tubes (UST), connective tissue (CT), adipose cells (AC), and inflammatory cells (IC) are also shown. Adapted from Sitharaman B, Shi X, Walboomers XF, Liao H, Cuijpers V, Wilson LJ, et al.

Schneider OD, Weber F, Brunner TJ, Loher S, Ehrbar M, Schmidlin PR, et al. In vivo and in vitro evaluation of flexible, cottonwool-like nanocomposites as bone substitute material for complex defects. Acta Biomater 2009 5(5) 1775-84. 

Li X, Chang J. Preparation of bone-like apatite-coUagen nanocomposites by a biomimetic process with phosphorylated collagen. J Biomed Mater Res A 2008 85(2) 293-300. 

Schneider, O. D., et al., / vivo and in vitro Evaluation of Flexible, Cotton wool-like Nanocomposites as Bone Substitute Material for Complex Defects. Acta Biomateria-lia, 2009, 5(5), 1775-1784. 

It is important to emphasize that many natural tissues are essentially composed of nanoscale biopolymers or biocomposites with hierarchical architectures. Therefore, by mimicking the structure and property of their natural counterparts, synthetic nanopoiymers and nanocomposites are very likely to enhance/regulate the functions of specific cells or tissues. This principle has been demonstrated by the success of bioinspired polymers and composites in both clinical practice and in laboratory research. In particular, bone is the hierarchical tissue that has inspired a myriad of biomimetic materials, devices, and systems for decades. This chapter focuses on this well-developed area of biomimetic or bioinspired nanopoiymers and nanocomposites for bone substitution and regeneration, especially those with high potentials for clinical applications in the near future. 

Eventually, regarding the nano-hydro)yapatite filler, like the polymer/ clay nanocomposites, the good dispersion of inorganic fillers in the PHBV inevitably benefits the improvement of the mechanical properties of the materials. Furthermore, the study also pointed out the enhanced material bioactivity since this specific property is expected for the repair and replacement of bone. 

---