Marchant R, Hiltner A, Hamlin C, Rabinovitch A, Slobodkin R, Anderson J M
J Biomed Mater Res. 1983 Mar;17(2):301-25. doi: 10.1002/jbm.820170209.
A cage implant system has been utilized to examine the in vivo biocompatibility of a biodegradable hydrogel, poly(2-hydroxy-ethyl-L-glutamine) (PHEG). This system permits the quantitative determination of the components of the inflammatory exudate which surrounds the implanted polymer within the cage system. This system permits the serial examination of exudate components without sacrificing the animal. In addition, this system allows the subsequent removal of the polymer for surface and mechanical studies. Following implantation of the biodegradable hydrogel, quantitative and differential white cell counts of the exudates were determined over a 21-day period. In addition, concomitant extracellular enzyme analyses for alkaline phosphatase, acid phosphatase, prostatic acid phosphatase, leucine amino-peptidase, and Cathepsin B1 were determined. Corresponding control samples from exudates of the cage implant without the polymer were also determined. The two-tailed Student's t-test for unpaired samples was used to statistically compare the control and implanted polymer values for these respective analyses at the various time periods. A comparison of the cellular response for the control system and the PHEG system did not show statistically significant differences during the first 7 days following implantation. The acute inflammatory response, polymorphonuclear leukocyte predominant, was followed by a mild chronic inflammatory response, macrophage and lymphocyte predominant, and during this time period, 8-14 days, macrophages were present in significantly larger numbers for the PHEG system when compared to the control values. Enzymic analysis of the exudates revealed statistically significant differences between control and PHEG values at time intervals where no differences were noted in cell density or population. These results are discussed in terms of cell-polymer interactions leading to cellular activation and enhanced enzyme exocytosis by the inflammatory cells. Stress-strain measurements on implanted PHEG samples showed that significant in vivo degradation had occurred during the acute inflammatory phase of the response, i.e., the first 7 days.
一种笼式植入系统已被用于研究可生物降解水凝胶聚（2-羟乙基-L-谷氨酰胺）（PHEG）的体内生物相容性。该系统能够对笼式系统内植入聚合物周围的炎性渗出液成分进行定量测定。该系统允许在不牺牲动物的情况下对渗出液成分进行系列检查。此外，该系统还能在后续取出聚合物进行表面和力学研究。在植入可生物降解水凝胶后，在21天的时间内对渗出液进行了定量和分类白细胞计数。此外，还对碱性磷酸酶、酸性磷酸酶、前列腺酸性磷酸酶、亮氨酸氨肽酶和组织蛋白酶B1进行了伴随的细胞外酶分析。还测定了来自没有聚合物的笼式植入物渗出液的相应对照样品。使用双尾非配对样本的学生t检验对不同时间段这些各自分析的对照值和植入聚合物值进行统计学比较。对照系统和PHEG系统的细胞反应比较在植入后的前7天没有显示出统计学上的显著差异。急性炎症反应以多形核白细胞为主，随后是轻度慢性炎症反应，以巨噬细胞和淋巴细胞为主，在这个时间段，即8 - 14天，与对照值相比，PHEG系统中巨噬细胞的数量明显更多。渗出液的酶分析显示，在细胞密度或细胞群体没有差异的时间间隔内，对照值和PHEG值之间存在统计学上的显著差异。这些结果根据细胞与聚合物的相互作用进行了讨论，这种相互作用导致细胞活化和炎性细胞增强酶的胞吐作用。对植入的PHEG样品进行的应力-应变测量表明，在反应的急性炎症阶段，即前7天内发生了显著的体内降解。
