title: In vitro and animal study of novel nano-hydroxyapatite/poly(epsilon-caprolactone) composite scaffolds fabricated by layer manufacturing process.
abstract: 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.
authors.affiliation: Team of BK21, First Project Team, Department of Biomedical Engineering, Inje University, Gimhae, Gyeongnam, Republic of Korea.
authors.forename: Su-Jin
authors.initials: SJ
authors.lastname: Heo
authors.forename: Seung-Eon
authors.initials: SE
authors.lastname: Kim
authors.forename: Jie
authors.initials: J
authors.lastname: Wei
authors.forename: Dong Hwa
authors.initials: DH
authors.lastname: Kim
authors.forename: Young-Taek
authors.initials: YT
authors.lastname: Hyun
authors.forename: Hui-Suk
authors.initials: HS
authors.lastname: Yun
authors.forename: Hyung Keun
authors.initials: HK
authors.lastname: Kim
authors.forename: Taek Rim
authors.initials: TR
authors.lastname: Yoon
authors.forename: Su-Hyang
authors.initials: SH
authors.lastname: Kim
authors.forename: Su-A
authors.initials: SA
authors.lastname: Park
authors.forename: Ji Won
authors.initials: JW
authors.lastname: Shin
authors.forename: Jung-Woog
authors.initials: JW
authors.lastname: Shin
mesh_terms: 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
chemical_list: D018786:Bone Substitutes; D006882:Hydroxyapatites; D011091:Polyesters; C016240:polycaprolactone; D000469:Alkaline Phosphatase; D002118:Calcium