Glutaraldehyde cross-linked hydroxyapatite/collagen self-organized nanocomposites.
To control the mechanical properties and biodegradability of self-organized hydroxyapatite/collagen (HAp/Col) nanocomposites, cross-linkage was introduced into the composites with glutaraldehyde (GA). The HAp/Col composite suspensions, prepared by a simultaneous titration method and aged for 3h, were cross-linked with the reagents for 10min under vigorous stirring. The precipitates obtained were filtrated and compacted by dehydration under a uniaxial pressure. The particle size distribution, 3-point bending strength, contained water amount and swelling ratio of the composites were examined as a function of cross-linkage amount; the biodegradability was estimated by animal tests using rabbits. As regards the cross-linked composites, no long-rage alignment of HAp crystals along collagen molecules was found with a transmission electron microscope, suggesting that the cross-linking reagents suppressed their long-range self-organization mechanism. The 3-point bending strength increased with the GA content and took a maximal value at 1.35mmol/g(col). The animal tests indicated no toxicity and osteoclastic resorption with good osteoconductivity. The resorption rate was decreased with increasing GA concentration. These results suggest that GA cross-linkage controls mechanical properties and resorption rate without reducing high biocompatibility of the composite.
Biomaterials Center, National Institute for Materials Science, 1-1, Namiki, Tsukuba, Ibaraki, 305-0044, Japan. kikuchi.masanori@nims.go.jp
Masanori
M
Kikuchi
Hiroko N
HN
Matsumoto
Takeki
T
Yamada
Yoshihisa
Y
Koyama
Kazuo
K
Takakuda
Junzo
J
Tanaka
D000818:Animals; D001665:Binding Sites; D018786:Bone Substitutes / Q000138:chemical synthesis / Q000737:chemistry*; D003094:Collagen / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000138:chemical synthesis / Q000737:chemistry; D003460:Crystallization / Q000379:methods*; D017886:Durapatite / Q000737:chemistry*; D005976:Glutaral / Q000737:chemistry*; D008420:Manufactured Materials / Q000032:analysis; D008422:Materials Testing; D036103:Nanotechnology / Q000379:methods; D016348:Osseointegration / Q000502:physiology; D019736:Prostheses and Implants; D011485:Protein Binding; D011487:Protein Conformation; D011817:Rabbits; D013977:Tibia / Q000166:cytology* / Q000502:physiology* / Q000601:surgery
D018786:Bone Substitutes; D003432:Cross-Linking Reagents; D003094:Collagen; D017886:Durapatite; D005976:Glutaral