Zhao O H, Anderson J M, Hiltner A, Lodoen G A, Payet C R
Department of Macromolecular Science, Case Western Reserve University, Cleveland, Ohio 44106.
J Biomed Mater Res. 1992 Aug;26(8):1019-38. doi: 10.1002/jbm.820260805.
The nature of in vivo leukocyte adhesion and foreign-body giant cell (FBGC) formation on polyurethanes was studied through theoretical and statistical analyses in terms of cell size distribution, density changes, and kinetics of FBGC formation. The results showed that the size distribution of FBGCs followed a "most probable" distribution. During FBGC formation, the densities of FBGCs changed with time. At an early stage, the number of FBGCs increased with time to a maximum at the expense of macrophages. As more FBGCs were formed and less macrophages were present, the fusion of FBGCs among themselves became significant. This, in turn, caused a gradual decrease of FBGC density with time. The rate of FBGC formation was characterized by a rate constant that represented certain characteristics of cell fusion and FBGC formation and the density of initial FBGC-forming macrophages that were a small fraction of leukocytes adhering to the surface. The direct correlations of surface cracking and pitting and adherent FBGCs demonstrated the influence of phagocytic actions of FBGCs on the biostability of implanted polyurethanes. While the cracking was thought to be caused by oxidative degradation facilitated by oxygen ion/radical release of FBGCs, the pitting appeared to result from the Methacrol 2138F aggregates diffusing out of the polymer in an acidic microenvironment under FBGCs, which in turn could be enhanced by the surface degradation and cell phagocytosis. The added Santowhite powder in polyurethane had a significant influence on FBGC formation: It reduced FBGC density and rate of FBGC formation by reducing leukocyte adhesion and the number of macrophages participating in FBGC formation.
通过理论和统计分析，从细胞大小分布、密度变化以及异物巨细胞（FBGC）形成动力学方面，研究了聚氨酯材料上体内白细胞粘附和异物巨细胞形成的性质。结果表明，FBGC的大小分布遵循“最可几”分布。在FBGC形成过程中，其密度随时间变化。在早期阶段，FBGC的数量随时间增加至最大值，这是以巨噬细胞数量减少为代价的。随着更多FBGC形成且巨噬细胞数量减少，FBGC之间的融合变得显著。这反过来又导致FBGC密度随时间逐渐降低。FBGC形成速率的特征在于一个速率常数，该常数代表了细胞融合和FBGC形成的某些特征以及最初形成FBGC的巨噬细胞的密度，这些巨噬细胞是粘附在表面的白细胞中的一小部分。表面裂纹和点蚀与粘附的FBGC之间的直接相关性证明了FBGC的吞噬作用对植入聚氨酯生物稳定性的影响。虽然认为裂纹是由FBGC释放氧离子/自由基促进的氧化降解引起的，但点蚀似乎是由于甲基丙烯酸2138F聚集体在FBGC下方的酸性微环境中从聚合物中扩散出来导致的，而这又可能因表面降解和细胞吞噬作用而增强。聚氨酯中添加的Santowhite粉末对FBGC形成有显著影响：它通过减少白细胞粘附和参与FBGC形成的巨噬细胞数量，降低了FBGC密度和FBGC形成速率。
