In vivo evaluation of a porous hydroxyapatite/poly-DL-lactide composite for use as a bone substitute.
We investigated the biocompatibility, osteoconductivity, and biodegradability of a porous composite of hydroxyapatite (HA) and poly-DL-lactide (PDLLA) implanted into rabbit femoral condyles and compared it with porous HA. Six weeks after implantation, the HA/PDLLA was covered with bone and contacted the bone directly. The amount of newly formed bone in the pores was similar in both materials during the examined period. The newly formed bone in the HA/PDLLA tended to increase over 26 weeks, but that in the HA did not show a significant increase after 12 weeks. By 26 weeks, remodeling of the newly formed bone in the pores was seen and bone marrow tissue was found in the pores of the HA/PDLLA. The porous HA/PDLLA was resorbed much faster than the porous HA. Porous HA/PDLLA was resorbed continuously through bone formation and remodeling. Conversely, porous HA was scarcely resorbed throughout the period. HA/PDLLA is thought to be degraded almost completely after about 1 year, and in this study, porous HA/PDLLA showed excellent osteoconductivity and faster resorption than HA. Therefore, HA/PDLLA might be a desirable material for bone substitutes.
Hasegawa
Shin
S
Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan. shinhase@kuhp.kyoto-u.ac.jp
Tamura
Jiro
J
Neo
Masashi
M
Goto
Koji
K
Shikinami
Yasuo
Y
Saito
Makoto
M
Kita
Masakazu
M
Nakamura
Takashi
T
D000818:Animals; D001672:Biocompatible Materials; D001673:Biodegradation, Environmental; D018786:Bone Substitutes; D006882:Hydroxyapatites; D008297:Male; D008855:Microscopy, Electron, Scanning; D008970:Molecular Weight; D011091:Polyesters; D011817:Rabbits
D001672:Biocompatible Materials; D018786:Bone Substitutes; D006882:Hydroxyapatites; D011091:Polyesters; C033616:poly(lactide)