A biodegradable porous composite scaffold of PGA/beta-TCP for bone tissue engineering

Bone. 2010 Feb;46(2):386-95. doi: 10.1016/j.bone.2009.09.031. Epub 2009 Sep 30.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acid Phosphatase / metabolism
  • Animals
  • Biocompatible Materials / pharmacology*
  • Bone Density / drug effects
  • Bone Regeneration / drug effects
  • Bone and Bones / diagnostic imaging
  • Bone and Bones / drug effects*
  • Bone and Bones / physiopathology
  • Calcium Phosphates / pharmacology*
  • Femur / diagnostic imaging
  • Femur / drug effects
  • Femur / pathology
  • Femur / physiopathology
  • Hematoxylin / metabolism
  • Implants, Experimental
  • Isoenzymes / metabolism
  • Male
  • Microscopy, Electron, Scanning
  • Organ Size / drug effects
  • Polyglycolic Acid / pharmacology*
  • Porosity / drug effects
  • Rats
  • Rats, Sprague-Dawley
  • Staining and Labeling
  • Tartrate-Resistant Acid Phosphatase
  • Tissue Engineering / methods*
  • Tissue Scaffolds / chemistry*
  • X-Ray Microtomography

Substances

  • Biocompatible Materials
  • Calcium Phosphates
  • Isoenzymes
  • beta-tricalcium phosphate
  • Polyglycolic Acid
  • Acid Phosphatase
  • Tartrate-Resistant Acid Phosphatase
  • Hematoxylin