Papers by Author: S.J. Heo

Paper TitlePage

Authors: Seung Eon Kim, Yong Taek Hyun, Dong June Chung, S.J. Heo, Jung Woog Shin, J.H. Lee
Abstract: Poly ε-caprolactone(PCL)/hydroxyapatite(HA) composite scaffolds were fabricated by particulate leaching and freeze drying routes with different HA content. Porosity was decreased with HA addition, while mean pore size was maintained at around porogen size regardless of HA content. Compressive modulus was increased with increasing HA content. In this study, the optimum content of HA was around 40% in weight against PCL to obtain the highest compressive modulus with keeping porosity above 85%. HA apparently enhanced proliferation of osteoblast-like MG63 cells in PCL/HA composite scaffolds. Typical adhesion, migration and aggregation procedure of MG63 cells were found on PCL, while spreading morphology only was found on HA even at the early stage of adhesion without migration or aggregation.
Authors: Yong Taek Hyun, Seung Eon Kim, S.J. Heo, Jung Woog Shin
Abstract: Porous and bioactive composite scaffolds based on poly ε-caprolactone(PCL) and hydroxyapatite(HA) were successfully fabricated by solvent casting and salt leaching method. The scaffolds have interconnected pore structure with pore size ranging from 10μm to 500μm. The pore size of PCL scaffold and PCL/HA scaffold were similar to that of the salt particles. The pore walls became thick and the small pores on the surface of macropores were formed as the HA increased. MTT assay showed that HA content did not affect initial cell attachment in both PCL scaffolds and PCL/HA scaffolds. The osteoblasts proliferated in both scaffolds, but the cell number was higher in the PCL/HA composite scaffolds. It was found that the incorporation of hydroxyapatite enhances bone cell proliferation rather than initial cell attachment in PCL/HA composite scaffolds. The results suggest that the PCL/HA composite scaffolds have a potential for the bone tissue engineering applications.
Authors: S.J. Heo, S.A. Park, H.J. Shin, Y.J. Lee, T.R. Yoon, H.Y. Seo, K.C. Ahn, S.E. Kim, Jung Woog Shin
Abstract: PMMA remains the most popular material of bone cement for orthopaedic surgeries. However, conventional PMMA bone cement still has some problems. For this, we suggested new composite material (BBC) consisting of hydroxyapatite (45%), chitosan (10%) and PMMA. The purpose of this study was to evaluate the bonding stress at the interface of PMMA with additives and host bone using a rabbit model. After 6, 12 weeks of operation, the bonding stresses were evaluated by measuring shear stress through push-out test. The results of the tests showed that after 6 weeks the shear stress of the BBC was 2.65±0.29MPa and the PMMA was 1.21±0.31MPa (p<0.05). However, after 12 weeks, there were no significant differences between BBC and conventional PMMA bone cement. In SEM analysis, bone surface of BBC showed higher roughness than that of conventional PMMA bone cement after push-out test. From the study we conducted, addition of HA particles and chitosan to conventional PMMA bone cement showed promising results. The BBC has clinical potential of bone substitutes replacing conventional PMMA.
Authors: S.J. Heo, S.E. Kim, Yong Taek Hyun, D.H. Kim, Hyang Mi Lee, Yeong Maw Hwang, S.A. Park, Jung Woog Shin
Abstract: This study evaluated the potential of the PCL (poly -caprolactone)/HA(Hydroxyapatite) composite materials as a scaffold for bone regeneration. For this, we fabricated scaffolds utilizing salt leaching method. The PCL/HA composite scaffolds were prepared with various HA contents (20wt%, 40wt%, 60 wt %). To ensure the potential for the scaffolds, porosity tests were conducted along with SEM observations. The porosity decreased with the increase of the contents of HA particles. The porosity of the composite with the highest contents of HA was still adoptable (~85%). In addition, the PCL/HA composite scaffolds were evaluated for their ability of osteogenic differentiation with human bone marrow stromal cell (hBMSC) in vitro. Alkaline phosphatase (ALP) activity, markers for osteoblastic differentiation, and total protein contents were evaluated in hBMSCs following 14 days of cultivation. The addition of HA particles enhanced proliferation of hBMSC during the test. Also, the differentiation ability of the cells was increased as HA particles were added. In this study, we concluded that PCL/HA composite scaffolds has great potential as a scaffold for bone tissue engineering.
Showing 1 to 4 of 4 Paper Titles