Guarino V, Ambrosio L
Institute of Composite and Biomedical Materials (IMCB), P. le Tecchio 80, 80125 Naples, Italy.
Acta Biomater. 2008 Nov;4(6):1778-87. doi: 10.1016/j.actbio.2008.05.013. Epub 2008 Jun 11.
In this work, three-dimensional porous composite scaffolds, based on poly(epsilon-caprolactone) (PCL), were fabricated through the combination of a filament winding technique and a phase inversion/salt leaching process. Sodium chloride crystals were used as the porogen agent, and poly(lactic acid) (PLA) fibers and calcium phosphates as reinforcement. The aim of the current work is to assess the effective synergistic role of bioactive particles (i.e. alpha-tricalcium phosphates (alpha-TCP)) and PLA fibers on the morphology and mechanical response of the final scaffold. Morphological investigations performed on fiber-reinforced composite scaffolds with different PCL/alpha-TCP volume ratios (0%, 13%, 20% and 26%) show a high porosity degree (ca. 80%), pore interconnection and a homogeneous distribution of pores within the scaffold. More specifically, a bimodal pore size distribution was observed. This comprised microporosity (pores with radii ranging from 0.1 to 10 microm, which were strictly related to solvent extraction) and macroporosity (pores with radii from 10 to 300 microm, which were ascribable to the leaching of porogen elements). Static compressive tests showed that the effect of alpha-TCP on the mechanical response was to increase the elastic modulus up to a maximum value of 2.21+/-0.24 MPa, depending on the concentration of alpha-TCP added. This effect may be explained through the interaction of calcium-deficient hydroxyapatite crystals, formed as a consequence of a hydrolysis reaction of alpha-TCP, and the fiber-reinforced polymer matrix. The correct balance between chemical composition and spatial organization of reinforcement systems allows the attainment of an ideal compromise between mechanical response and bioactive potential, facilitating the development of composite scaffolds for bone tissue engineering applications.
在这项工作中,基于聚己内酯(PCL)的三维多孔复合支架通过纤维缠绕技术与相转化/盐沥滤工艺相结合的方法制备而成。氯化钠晶体用作致孔剂,聚乳酸(PLA)纤维和磷酸钙用作增强材料。当前工作的目的是评估生物活性颗粒(即α-磷酸三钙(α-TCP))和PLA纤维对最终支架的形态和力学响应的有效协同作用。对具有不同PCL/α-TCP体积比(0%、13%、20%和26%)的纤维增强复合支架进行的形态学研究表明,支架具有高孔隙率(约80%)、孔互连以及孔在支架内的均匀分布。更具体地说,观察到了双峰孔径分布。这包括微孔(半径范围为0.1至10微米的孔,与溶剂萃取密切相关)和大孔(半径为10至300微米的孔,归因于致孔剂元素的沥滤)。静态压缩试验表明,α-TCP对力学响应的影响是根据添加的α-TCP浓度将弹性模量提高到最大值2.21±0.24MPa。这种效应可以通过α-TCP水解反应形成的缺钙羟基磷灰石晶体与纤维增强聚合物基体之间的相互作用来解释。增强系统的化学成分与空间组织之间的正确平衡使得能够在力学响应和生物活性潜力之间实现理想的折衷,从而促进用于骨组织工程应用的复合支架的开发。