Carbon nanotube-gelatin-hydroxyapatite nanohybrids with multilayer core–shell structure for mimicking natural bone

• Published in: Carbon (New York) Vol. 77; pp. 379 - 389
• Main Authors: Yoon, Il-Kyu, Hwang, Ji-Young, Seo, Jae-won, Jang, Won-Cheoul, Kim, Hae-Won, Shin, Ueon Sang
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.10.2014; Elsevier
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Elasticity, elastic constants; Exact sciences and technology; Materials science; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Nanoscale materials and structures: fabrication and characterization; Nanotubes; Physics; Nanohybrid; Multilayer; Core shell structure; Crystals; Carbon nanotubes; Hydroxyapatite; Multilayers; Chemical modification; Gelatin; Collagen; Bone; Nanostructured materials; Elongation (mechanics)
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2014.05.041

We attempted to mimic collagen fibrils bearing apatite crystals in natural bone, using gelatin, carboxylic acid functionalized carbon nanotubes (f-CNTs), and hydroxyapatite (HA). Gelatin molecules were covalently grafted on the surface of f-CNTs by the formation of amide linkages. HA crystals were then assembled onto the gelatin-grafted f-CNTs in a highly concentrated CaP solution, resulting a multilayered core–shell structure, consisting of a f-CNT core and gelatin-HA shells (as a fibrous multilayered f-CNT/Gel/HA nanohybrid), and in a similar formation to the collagen fibers of natural bone. The tensile strength, elastic modulus, and elongation rate of the new hybrid material were significantly improved compared to both pure (f-CNT free) gelatin and a mixture of f-CNT and gelatin, by 4.6–8.8, 9–10, and 28–42 times, respectively. Cell viability studies of the f-CNT/Gel/HA nanohybrid also suggest a higher degree of biocompatibility compared to pure gelatin.