In vitro and animal study of novel nano-hydroxyapatite/poly(epsilon-caprolactone) composite scaffolds fabricated by layer manufacturing process.
The purpose of this study was to propose a computer-controllable scaffold structure made by a layer manufacturing process (LMP) with addition of nano- or micro-sized particles and to investigate the effects of particle size in vitro. In addition, the superiority of this LMP method over the conventional scaffolds made by salt leaching and gas forming process was investigated through animal study. Using the LMP, we have created a new nano-sized hydroxyapatite/poly(epsilon-caprolactone) composite (n-HPC) scaffold and a micro-sized hydroxyapatite/poly(epsilon-caprolactone) composite (m-HPC) scaffold for bone tissue engineering applications. The scaffold macropores were well interconnected, with a porosity of 73% and a pore size of 500 microm. The compressive modulus of the n-HPC and m-HPC scaffolds was 6.76 and 3.18 MPa, respectively. We compared the cellular responses to the two kinds of scaffolds. Both n-HPC and m-HPC exhibited good in vitro biocompatibility. Attachment and proliferation of mesenchymal stem cells were better on the n-HPC than on the m-HPC scaffold. Moreover, significantly higher alkaline phosphatase activity and calcium content were observed on the n-HPC than on the m-HPC scaffold. In an animal study, the LMP scaffolds enhanced bone formation, owing to their well-interconnected pores. Radiological and histological examinations confirmed that the new bony tissue had grown easily into the entire n-HPC scaffold fabricated by LMP. We suggest that the well-interconnected pores in the LMP scaffolds might encourage cell attachment, proliferation, and migration to stimulate cell functions, thus enhancing bone formation in the LMP scaffolds. This study shows that bioactive and biocompatible n-HPC composite scaffolds prepared using an LMP have potential applications in bone tissue engineering.
Heo
Su-Jin
SJ
Team of BK21, First Project Team, Department of Biomedical Engineering, Inje University, Gimhae, Gyeongnam, Republic of Korea.
Kim
Seung-Eon
SE
Wei
Jie
J
Kim
Dong Hwa
DH
Hyun
Young-Taek
YT
Yun
Hui-Suk
HS
Kim
Hyung Keun
HK
Yoon
Taek Rim
TR
Kim
Su-Hyang
SH
Park
Su-A
SA
Shin
Ji Won
JW
Shin
Jung-Woog
JW
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001861:Bone Regeneration; D018786:Bone Substitutes; D002118:Calcium / Q000378:metabolism; D002448:Cell Adhesion; D002454:Cell Differentiation; D049109:Cell Proliferation; D019245:Compressive Strength; D006882:Hydroxyapatites; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites; D036103:Nanotechnology; D010316:Particle Size; D011091:Polyesters; D011817:Rabbits; D013977:Tibia / Q000293:injuries / Q000378:metabolism / Q000502:physiology; D023822:Tissue Engineering / Q000295:instrumentation / Q000379:methods*; D054457:Tissue Scaffolds; D014057:Tomography, X-Ray Computed
D018786:Bone Substitutes; D006882:Hydroxyapatites; D011091:Polyesters; C016240:polycaprolactone; D000469:Alkaline Phosphatase; D002118:Calcium