A biodegradable porous composite scaffold of PGA/beta-TCP for bone tissue engineering.
Polyglycolic acid (PGA) and beta-tricalcium phosphate (beta-TCP) each have many applications as tissue repair materials. In this study, three-dimensional (3D) porous composite scaffolds of PGA/beta-TCP (in 1:1 and 1:3 weight ratios) were fabricated using the solvent casting and particulate leaching method. PGA/beta-TCP scaffolds with high porosity, interconnected 3D pores and rough surfaces were obtained and were observed using scanning electron microscopy (SEM) and micro-computed tomography (micro-CT). The PGA/beta-TCP scaffolds were investigated during the repair of critical bone defects (3 mm diameter, 2 mm depth) in rat femoral medial-epicondyles, compared with hydroxylapatite (HAP) and no implant as controls. Quantitative imageology analysis (volume and density of new bone) and qualitative histological evaluations (hematoxylin and eosin staining; tartrate-resistant acid phosphatase-hematoxylin counterstaining) were characterized using in vivo micro-CT images and histological sections at 0, 14, 30 and 90 days after surgery. Significant differences of all variables were tested by multivariate analysis (p<0.05). The results showed that the bone reformation by using the PGA/beta-TCP scaffolds began within 14 days of surgery, and were healing well at 30 days after surgery. By 90 days after surgery, the bone replacement was almost completed and presented a healthy bone appearance. The new bone mineral densities (mg/cm(3)) with HAP, PGA/beta-TCP (1:1) and PGA/beta-TCP (1:3) at 90 days after surgery were: 390.4+/-18.1, 563.8+/-26.9 and 606.3+/-26.9, respectively. The new bone mineral density with the PGA/beta-TCP scaffold was higher than with HAP (p<0.001), and with the PGA/beta-TCP (1:3) scaffold was higher than with the PGA/beta-TCP (1:1) scaffold at each time examined (p<0.05). The biodegradation percents (%) of HAP, PGA/beta-TCP (1:1) and PGA/beta-TCP (1:3) at 90 days after surgery were: 35.1+/-5.5, 99.0+/-1.0 and 96.2+/-3.3, respectively. The biodegradation percents of the PGA/beta-TCP scaffolds were higher than HAP at each time examined (p<0.01), and matched the osteogenesis rates. The PGA/beta-TCP scaffolds were almost replaced by new growing bone within 90 days after surgery. Thus the PGA/beta-TCP composite scaffold, especially weight ratio 1:3, exhibited a strong ability for osteogenesis, mineralization and biodegradation for bone replacement.
Department of Pediatric Dentistry, Nihon University School of Dentistry at Matsudo, Japan. laura-hong@hotmail.co.jp
Hong
H
Cao
Noboru
N
Kuboyama
D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D015519:Bone Density / Q000187:drug effects; D001861:Bone Regeneration / Q000187:drug effects; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000503:physiopathology; D002130:Calcium Phosphates / Q000494:pharmacology*; D005269:Femur / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D006416:Hematoxylin / Q000378:metabolism; D020007:Implants, Experimental; D007527:Isoenzymes / Q000378:metabolism; D008297:Male; D008855:Microscopy, Electron, Scanning; D009929:Organ Size / Q000187:drug effects; D011100:Polyglycolic Acid / Q000494:pharmacology*; D016062:Porosity / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013194:Staining and Labeling; D000071681:Tartrate-Resistant Acid Phosphatase; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*; D055114:X-Ray Microtomography
D001672:Biocompatible Materials; D002130:Calcium Phosphates; D007527:Isoenzymes; C485817:beta-tricalcium phosphate; D011100:Polyglycolic Acid; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D006416:Hematoxylin