Kim Sang-Soo, Ahn Kang-Min, Park Min Sun, Lee Jong-Ho, Choi Cha Yong, Kim Byung-Soo
Department of Bioengineering, Hanyang University, Seoul 133-791, Korea.
J Biomed Mater Res A. 2007 Jan;80(1):206-15. doi: 10.1002/jbm.a.30836.
Biodegradable polymer/ceramic scaffolds can overcome the limitations of conventional ceramic bone substitutes. However, the conventional methods of polymer/ceramic scaffold fabrication often use organic solvents, which might be harmful to cells or tissues. Moreover, scaffolds fabricated with the conventional methods have limited ceramic exposure on the scaffold surface since the polymer solution envelopes the ceramic particles during the fabrication process. In this study, we developed a novel fabrication method for the efficient exposure of ceramic onto the scaffold surface, which would enhance the osteoconductivity and wettability of the scaffold. Poly(D,L-lactide-co-glycolide)/nanohydroxyapatite (PLGA/HA) scaffolds were fabricated by the gas foaming and particulate leaching (GF/PL) method without the use of organic solvents. Selective staining of ceramic particles indicated that HA nanoparticles exposed to the scaffold surface were observed more abundantly in the GF/PL scaffold than in the conventional solvent casting and particulate leaching (SC/PL) scaffold. Both types of scaffolds were implanted to critical size defects in rat skulls for 8 weeks. The GF/PL scaffolds exhibited significantly enhanced bone regeneration when compared with the SC/PL scaffolds. Histological analyses and microcomputed tomography of the regenerated tissues showed that bone formation was more extensive on the GF/PL scaffolds than on the SC/PL scaffolds. Compared with the SC/PL scaffolds, the enhanced bone formation on the GF/PL scaffolds may result from the higher exposure of HA nanoparticles to the scaffold surface. These results show that the biodegradable polymer/ceramic composite scaffolds fabricated with the novel GF/PL method can enhance bone regeneration compared with those fabricated with the conventional SC/PL method.
可生物降解的聚合物/陶瓷支架能够克服传统陶瓷骨替代物的局限性。然而，聚合物/陶瓷支架的传统制造方法通常使用有机溶剂，这可能对细胞或组织有害。此外，由于在制造过程中聚合物溶液包裹着陶瓷颗粒，用传统方法制造的支架在支架表面的陶瓷暴露有限。在本研究中，我们开发了一种新的制造方法，可使陶瓷有效地暴露于支架表面，这将提高支架的骨传导性和润湿性。聚（D，L-丙交酯-共-乙交酯）/纳米羟基磷灰石（PLGA/HA）支架通过气体发泡和颗粒沥滤（GF/PL）法制造，无需使用有机溶剂。对陶瓷颗粒的选择性染色表明，与传统的溶剂浇铸和颗粒沥滤（SC/PL）支架相比，在GF/PL支架中观察到更多暴露于支架表面的HA纳米颗粒。将两种类型的支架植入大鼠颅骨的临界尺寸缺损处8周。与SC/PL支架相比，GF/PL支架的骨再生显著增强。对再生组织的组织学分析和微型计算机断层扫描显示，GF/PL支架上的骨形成比SC/PL支架上更广泛。与SC/PL支架相比，GF/PL支架上增强的骨形成可能是由于HA纳米颗粒在支架表面的更高暴露。这些结果表明，与用传统SC/PL方法制造的支架相比，用新型GF/PL方法制造的可生物降解聚合物/陶瓷复合支架可增强骨再生。
