Abstract
Chemically modified silk fibroin (SF) with an enzyme, Proteinase K, has been incorporated into hydroxyapatite (HAp)-based nanocomposite attempting to strengthen the interfacial bonding between the mineral phase and the organic matrix. Particular emphasis is laid on the microstructure and microhardness of the composite along with the crystallographic properties of HAp. The whisker-like HAp crystallites of nanometer size show the preferential self-assembly and anisotropic crystal growth along c-axis. There appears porous microstructure with 70% of open porosity and pore size distribution of 10–115 um in the composite. Attributed to the enzyme modification, the crosslinkage between HAp clusters and SF matrix is improved to form an enhanced three-dimensional network extending throughout the composites and an increase of 35% in microhardness of the composite is achieved as well.
Similar content being viewed by others
References
Bigi A., S. Panzavolta & N. Roveri, 1998. Hydroxyapatite-gelatin films: A structural and mechanical characterization. Biomaterials 19, 739-744.
Chang M.C., T. Ikoma, M. Kikuchi & J. Tanaka, 2002. The cross-linkage effect of hydroxyapatite/collagen nanocomposites on a self-organization phenomenon. J. Mater. Sci. Mater. Med. 13, 993-997.
Chang M.C., C.C. Ko & W.H. Douglas, 2003. Preparation of hydroxyapatite-gelatin nanocomposite. Biomaterials 24, 2853-2862.
Chen F., Z.C. Wang & C.J. Lin, 2002. Preparation and characterization of nano-sized hydroxyapatite particles and hydroxyapatite/chitosan nano-composite for use in biomedical materials. Mater. Lett. 57, 858-861.
Du C., F.Z. Cui, W. Zhang, Q.L. Feng, X.D. Zhu & K. De Groot, 2000. Formation of calcium phosphate/collagen composites through mineralization of collagen matrix. J. Biomed. Mater. Res. 50, 518-527.
Evans G.P., J.C. Behiri, J.D. Currey & W. Bonfield, 1990. Micro-hardness and Young's modulus in cortical bone exhibiting a wide range of mineral volume fractions, and in a bone analogue. J. Mater. Sci. Mater. Med. 1, 38-43.
Freddi G., P. Monti, M. Nagura, Y. Gotoh & M. Tsukada, 1997. Structure and molecular conformation of tussah silk fibroin films: Effect of heat treatment. J. Polym. Sci. B: Polym. Phys. 35, 841-847.
Furuzono T., T. Taguchi, A. Kishida, M. Akashi & Y. Tamada, 2000. Preparation and characterization of apatite deposited on silk fabric using an alternate soaking process. J. Biomed. Mater. Res. 50, 344-352.
Ikoma T., A. Yamazakai, S. Nakamura & M. Akao, 1999. Preparation and structure refinement of monoclinic hydroxy-apatite. J. Solid State Chem. 144, 272-276.
Ito M., Y. Hidaka, M. Nakajima, H. Yagasaki & A.H. Kafrawy, 1999. Effect of hydroxyapatite content on physical properties and connective tissue reactions to a chitosan-hydroxyapatite composite membrane. J. Biomed. Mater. Res. 45, 204-208.
Izumi F. & T. Ikeda, 2000. ARietveld-analysis program RIETAN-98 and its applications to zeolites. Mater. Sci. Forum 321, 198-203.
Kikuchi M., S. Itoh, S. Ichinose, K. Shinomiya & J. Tanaka, 2001. Self-organization mechanism in a bone-like hydroxy-apatite/ collagen nanocomposite synthesized in vitro and its biological reaction in vivo. Biomaterials 22, 1705-1711.
Liu D.M., 1996. Fabrication and characterization of porous hydroxyapatite granules. Biomaterials 17, 1955-1957.
Park S.J., K.Y. Lee, W.S. Ha & S.Y. Park, 1999. Structural changes and their effect on mechanical properties of silk fibroin/chito-san blends. J. Appl. Polym. Sci. 74, 2571-2575.
Petsch D., W.D. Deckwer & F.B. Anspach, 1998. Proteinase K digestion of proteins improves detection of bacterial endo-toxins by the limulus amebocyte lysate assay: Application for endotoxin removal from cationic proteins. Anal. Biochem. 259, 42-47.
Rhee S.H. & J. Tanaka, 2002. Self-assembly phenomenon of hydroxyapatite nanocrystals on chondroitin sulfate. J. Mater. Sci.: Mater. Med. 13, 597-600.
Sepulveda P., J.G.P. Binner, S.O. Rogero, O.Z. Higa & J.C. Bressiani, 2000. Production of porous hydroxyapatite by the gel-casting of foams and cytotoxic evaluation. J. Biomed. Mater. Res. 50, 27-34.
Tamai N., A. Myoui, T. Tomita, T. Nakase, J. Tanaka & T. Ochi, 2002. Novel hydroxyapatite ceramics with an interconnective porous structure exhibit superior osteoconduction in vivo. J. Biomed. Mater. Res. 59, 110-117.
Tampieri A., G. Celotti, S. Sprio, A. Delcogliano & S. Franzese, 2001. Porosity-graded hydroxyapatite ceramics to replace natural bone. Biomaterials 22, 1365-1370.
TenHuisen K.S. & P.W. Brown, 1994. The formation of hydroxyapatite-gelatin composites at 381/4ñêôœ'C. J. Biomed. Mater. Res. 28, 27-33.
Wang L., R. Nemoto & M. Senna, 2002. Microstructure and chemical states of hydroxyapatite/silk fibroin nanocomposites synthesized via a wet-mechanochemical route. J. Nanoparticle Res. 4, 535-540.
Wang L., R. Nemoto & M. Senna, 2003a. Changes in microstruc-ture and physico-chemical properties of hydroxyapatite-silk fibroin nanocomposite with varying silk fibroin content. J. Eur. Ceram. Soc. (in press).
Wang L., R. Nemoto & M. Senna, 2003b. Effects of alkali pretreatment of silk fibroin on microstructure and properties of hydroxyapatite-silk fibroin nanocomposite. J. Mater. Sci.: Mater. Med. (in press).
Yamaguchi I., K. Tokuchi, H. Fukuzaki, Y. Koyama, K. Takakuda, H. Monma & J. Tanaka, 2001. Preparation and microstructure analysis of chitosan/hydroxyapatite nanocomposites. J. Biomed. Mater. Res. 55, 20-27.
Zhao F., Y.J. Yin, W.W. Lu, J.C. Leong, W.Y. Zhang, J.Y. Zhang, M.F. Zhang & K.D. Yao, 2002. Preparation and histological evaluation of biomimetic three-dimensional hydroxyapatite/chitosan-gelatin network composite scaffolds. Biomaterials 23, 3227-3234.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Wang, L., Nemoto, R. & Senna, M. Three-Dimensional Porous Network Structure Developed in Hydroxyapatite-Based Nanocomposites Containing Enzyme Pretreated Silk Fibroin. Journal of Nanoparticle Research 6, 91–98 (2004). https://doi.org/10.1023/B:NANO.0000023228.49670.86
Issue Date:
DOI: https://doi.org/10.1023/B:NANO.0000023228.49670.86