Harrison D, Johnson R, Tucci M, Puckett A, Tsao A, Hughes J, Benghuzzi H
University of Mississippi Medical Center, Jackson 39216, USA.
Biomed Sci Instrum. 1997;34:41-6.
Several reports have suggested that encapsulation of orthopaedic and dental implants with fibrous tissue can lead to implant failure. The binding of cells to the surface of the implants is specific to amino-acid sequences, typically RGD. The specific objective of this study was to investigate the interaction of cultured human peripheral macrophages with specific amino-acid sequences to determine if adherence is due to the specificity of such sequence. Macrophages were seeded at a density of 1 x 10(5) cells on ultra high molecular weight polyethylene (UHMWPE) coated with either amino-acid heteropolymers of RGE, RGD, or amino-acid homopolymer Poly-L-Lysine. Cells were observed daily and morphology was recorded. The results showed that cells growing in the presence of RGD had significantly (p < 0.05) higher numbers of cells adhering and remaining viable, in comparison to cells growing on Poly-L-lysine or RGE. Cells growing on UHMWPE coated with RGE appeared irregularly (elongated and spindle) shaped and unevenly spaced. The cells growing in the presence of Poly-L-Lysine showed cellular disruption and lysis, whereas cells growing on the RGD appeared intact, regularly spaced and began fusing into giant cells. Lactate dehydrogenase activity was used as a measure of membrane integrity, and cells grown on UHMWPE coated with Poly-L-lysine showed a two-fold increase in activity over control and peptide treated groups. Immunochemical analysis for cytokine (IL-1) release as a measure of cellular reactivity revealed an increase level in the experimental groups after 24 hours and remained measurable over the duration of the experiment. Cells incubated on uncoated polyethylene showed no evidence of increased cytokine response. Overall, the results show macrophages can interact with specific coating on the material surface, and these surfaces can affect the adhesion process adherence. Use of RGE, which inhibits binding of the cells, may be a factor that can be used to coat implants to increase their longevity.
多项报告表明，骨科和牙科植入物被纤维组织包裹会导致植入物失效。细胞与植入物表面的结合对氨基酸序列具有特异性，通常为RGD。本研究的具体目的是研究培养的人外周巨噬细胞与特定氨基酸序列的相互作用，以确定粘附是否归因于此类序列的特异性。将巨噬细胞以1×10⁵个细胞的密度接种在涂有RGE、RGD氨基酸杂聚物或氨基酸均聚物聚-L-赖氨酸的超高分子量聚乙烯（UHMWPE）上。每天观察细胞并记录形态。结果表明，与在聚-L-赖氨酸或RGE上生长的细胞相比，在RGD存在下生长的细胞粘附并保持存活的数量显著更高（p<0.05）。在涂有RGE的UHMWPE上生长的细胞呈不规则（细长和纺锤形）形状且间距不均匀。在聚-L-赖氨酸存在下生长的细胞显示出细胞破裂和溶解，而在RGD上生长的细胞看起来完整、间距规则并开始融合成巨细胞。乳酸脱氢酶活性用作膜完整性的指标，在涂有聚-L-赖氨酸的UHMWPE上生长的细胞活性比对照组和肽处理组增加了两倍。作为细胞反应性指标的细胞因子（IL-1）释放的免疫化学分析显示，实验组在24小时后水平升高，并在实验期间一直可测量。在未涂层的聚乙烯上孵育的细胞没有细胞因子反应增加的迹象。总体而言，结果表明巨噬细胞可以与材料表面的特定涂层相互作用，并且这些表面可以影响粘附过程的粘附。使用抑制细胞结合的RGE可能是一种可用于涂覆植入物以延长其寿命的因素。
