Papers by Author: Chong Pyong Chung

Abstract: In this study, we find out the possibilities to make conduit for nerve regeneration using biodegradable polymers, which have enough mechanical strength in surgery. Cell adhesion (PC12) behaviors about various nerve conduits have not great difference compared to control. This is regarded due to specific structure of nerve conduits formed nano-fibers. In the case of PPD, we observed better phenotype of adhered cell than PLGA samples. Also, PPD-PLGA bi-layered nerve conduits were more effective than PLGA nerve conduit for in vitro evaluation.

Abstract: The method which gives a low crystalline hydroxyl carbonated apatite forming ability to originally non-bioactive high crystalline hydroxyapatite surface was newly developed. The granules of trabecular bovine bone, which had a size range from 212 to 1000 μm, were defatted, deproteinized, and then heat-treated at 1000 oC for 3 hours to remove organics completely. They were treated with the mixed solution of calcium chloride and calcium hydroxide in Soxhlet’s apparatus at 100 oC for 3 days and then dried completely. Low crystalline hydroxyl carbonated apatite was observed to occur on the surface of high crystalline hydroxyapatite granules after soaking them into the simulated body fluid (SBF) for 1 week. This method is likely to have a potential to be used as a new process to give a bioactivity to originally non-bioactive materials.

Abstract: Effect of heat-treatment temperature on the osteoconductivity of the apatite derived from bovine trabecular bone was investigated. Three different heat-treatment temperatures (600, 800 and 1000 oC) were adopted in the experiment and their effects on the physical properties of apatite granules, which could affect on the osteoconductivity, were evaluated. The content of carbonate ions in the apatite structure was assessed by FT-IR and its crystallinity was evaluated by X-ray diffractometry. The microstructure was assessed by field emission electron microscopy. Apatite granules heat-treated at 600 oC and 1000 oC were implanted into the calvaria of New Zealand White rabbit for 4 weeks, respectively, and the undecalcified ground histologic specimens stained with multiple staining method was observed. As increasing the heat-treatment temperature, the crystal size and crystallinity of the apatite increased while the content of carbonate ions decreased. The apatite granules heat-treated at 600 oC showed much better osteoconductivity comparing to that heat-treated at 1000 oC. The results were explained in terms of the physical properties of apatite which could affect to the osteoconductivity.