Institute of Orthopedic Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, People's Republic of China.
Biomed Mater. 2011 Feb;6(1):015007. doi: 10.1088/1748-6041/6/1/015007. Epub 2011 Jan 5.
The purpose of this study was to investigate the role of pore size on tissue ingrowth and neovascularization in porous bioceramics under the accurate control of the pore parameters. For that purpose, β-tricalcium phosphate (β-TCP) cylinders with four different macropore sizes (300-400, 400-500, 500-600 and 600-700 µm) but the same interconnection size (120 µm) and unchangeable porosity were implanted into fascia lumbodorsalis in rabbits. The fibrous tissues and blood vessels formed in scaffolds were observed histologically and histomorphometrically. The vascularization of the porous bioceramics was analyzed by single-photon emission computed tomography (SPECT). It is found that pore size as an important parameter of a porous structure plays an important role in tissue infiltration into porous biomaterial scaffolds. The amount of fibrous tissue ingrowth increases with the decrease of the pore size. In four kinds of scaffolds with different macropore sizes (300-400, 400-500, 500-600 and 600-700 µm) and a constant interconnection size of 120 µm, the areas of fibrous tissue (%) were 60.5%, 52.2%, 41.3% and 37.3%, respectively, representing a significant decrease at 4 weeks (P < 0.01). The pore size of a scaffold is closely related to neovascularization of macroporous biomaterials implanted in vivo. A large pore size is beneficial for the growth of blood vessels, and the diameter of a pore smaller than 400 µm limits the growth of blood vessels and results in a smaller blood vessel diameter.
本研究旨在探讨在准确控制孔径参数的条件下，孔径大小对多孔生物陶瓷中组织长入和新生血管形成的作用。为此，我们将具有四种不同大孔尺寸（300-400μm、400-500μm、500-600μm 和 600-700μm）但相同连通尺寸（120μm）和不变孔隙率的β-磷酸三钙（β-TCP）圆柱体植入兔腰背筋膜。通过组织学和组织形态计量学观察支架中形成的纤维组织和血管。采用单光子发射计算机断层扫描（SPECT）分析多孔生物陶瓷的血管化。结果发现，孔径作为多孔结构的一个重要参数，在组织渗透到多孔生物材料支架中起着重要作用。纤维组织长入量随孔径的减小而增加。在四种具有不同大孔尺寸（300-400μm、400-500μm、500-600μm 和 600-700μm）和恒定连通尺寸 120μm 的支架中，纤维组织（%）面积分别为 60.5%、52.2%、41.3%和 37.3%，4 周时显著减少（P<0.01）。支架的孔径与体内植入的大孔生物材料的新生血管密切相关。较大的孔径有利于血管生长，孔径小于 400μm 会限制血管生长并导致血管直径较小。
