A new bone-inducing biodegradable porous beta-tricalcium phosphate.
A new type of degradable biomaterial with bone-inducing capacity was made by combining porous beta-tricalcium phosphate (beta-TCP) with a delivery system for recombinant human bone morphogenetic protein-2 (rhBMP-2). The BMP delivery system consisted of a block copolymer composed of poly-D,L-lactic acid with random insertion of p-dioxanone and polyethylene glycol (PLA-DX-PEG), a known biocompatible and biodegradable material. The efficacy of this biomaterial in terms of its bone-inducing capacity was examined by ectopic bone formation in the dorsal muscles of the mouse. In the beta-TCP implants coated with the PLA-DX-PEG polymer containing more than 0.0025% (w/w) of rhBMP-2, new ectopic bone tissues with marrow were consistently found on the surface of implants. The radiographic density of beta-TCP was diminished in a time-dependent manner. On histological examination, numerous multinucleated osteoclasts with positive tartrate-resistant acid-phosphatase (TRAP) staining were noted on the surface of the beta-TCP. These experimental results indicate that beta-TCP implants coated with synthetic rhBMP-2 delivery system might provide effective artificial bone-graft substitutes with osteoinductive capacity and biodegradable properties. In addition, this type of biomaterial may require less rhBMP-2 to induce significant new bone mass.
Department of Orthopaedic Surgery, Osaka City University School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585 Japan.
Naofumi
N
Matsushita
Hidetomi
H
Terai
Takao
T
Okada
Kazutoshi
K
Nozaki
Hikaru
H
Inoue
Shimpei
S
Miyamoto
Kunio
K
Takaoka
D020341:Absorbable Implants; D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001861:Bone Regeneration / Q000502:physiology*; D001842:Bone and Bones / Q000166:cytology / Q000000981:diagnostic imaging / Q000473:pathology; D002130:Calcium Phosphates / Q000737:chemistry* / Q000378:metabolism*; D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000378:metabolism; D004146:Dioxanes / Q000737:chemistry; D016503:Drug Delivery Systems; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D019344:Lactic Acid / Q000737:chemistry; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008855:Microscopy, Electron, Scanning; D011091:Polyesters; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D011859:Radiography; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013499:Surface Properties; D000071681:Tartrate-Resistant Acid Phosphatase; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
C525718:BMP2 protein, human; C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; D004146:Dioxanes; D007527:Isoenzymes; D011091:Polyesters; D011108:Polymers; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C485817:beta-tricalcium phosphate; C499469:recombinant human bone morphogenetic protein-2; D019344:Lactic Acid; D011092:Polyethylene Glycols; C033616:poly(lactide); D000135:Acid Phosphatase; C000605511:Acp5 protein, mouse; D000071681:Tartrate-Resistant Acid Phosphatase; C059814:4-dioxanone