The target of the t-PA released fro

从水凝胶中释放出的t-PA的靶标是新生的凝块，即最初形成的纤维蛋白。因此，纤维蛋白原-凝血酶凝块测定法47用于研究纤维蛋白原的纤溶活性。<br>释放。简而言之，在存在/不存在凝血酶的条件下，将纤溶酶原溶液中的t-PA负载水凝胶孵育。（纤溶酶原被t-PA激活并转化为纤溶酶，其纤溶活性形式）。然后加入在凝血酶存在下产生纤蛋白的纤溶酶原溶液。然后随时间测量溶液在340 nm处的吸光度。对于仅在缓冲液中（无凝血酶）温育的水凝胶，在吸光度测量之前立即添加凝血酶。如图4a所示，纤维蛋白原溶液中凝血酶引发的血凝块形成由吸光度的急剧增加指示。对于在PBS（无凝血酶）中温育的水凝胶释放物，几分钟后达到吸光度的平稳状态，表明完全形成了稳定的凝块。相反，在凝血酶溶液中温育的水凝胶中的释放物显示出初始实验室吸光度增加，随后在30分钟内恢复到基线，表明开始凝结，然后溶解了新生凝块。对于两个样品，在2分钟时都观察到了类似的高浊度，而在测定结束时，在凝血酶溶液中温育的水凝胶中的释放物是清晰的。可以得出结论，响应于凝血酶，t-PA从水凝胶中释放出来，将纤溶酶原转化为溶液中的纤溶酶，导致血块溶解。在测定结束时，在凝血酶溶液中温育的水凝胶中的释放物是清晰的。可以得出结论，响应于凝血酶，t-PA从水凝胶中释放出来，将纤溶酶原转化为溶液中的纤溶酶，导致血块溶解。在测定结束时，在凝血酶溶液中温育的水凝胶中的释放物是清晰的。可以得出结论，响应于凝血酶，t-PA从水凝胶中释放出来，将纤溶酶原转化为溶液中的纤溶酶，导致血块溶解。

The target of the t-PA released from the hydrogel is the nascent clot, i.e. initially formed fibrin. Thus, a fibrinogen–thrombin clot assay47 was used to investigate the fibrinolytic activity of <br>the releasate. Briefly, the t-PA-loaded hydrogels were incubated in plasminogen solution in the presence/absence of thrombin. (Plasminogen is activated by t-PA and transformed into plasmin, its fibrinolytically-activeform.)Fibrinogen solution, whichinthe presence of thrombin produces fibrin, was then added. The absorbance of the solutions at 340 nm was then measured over time. For the hydrogel incubated in buffer only (no thrombin), thrombin was added immediately before the absorbance measurements. As seen in Fig. 4a, thrombin-initiated clot formation in the fibrinogen solution is indicated by a steep increase in absorbance. For the releasate from the hydrogel incubated in PBS (no thrombin), a plateau in absorbance was reached after a few minutes, indicating a fully formed, stable clot. In contrast, the releasate from the hydrogel incubated in thrombinsolutionshowedaninitialabsorbanceincreasefollowed by a return to the baseline within 30 min, indicating that clotting was initiated and the nascent clot then lysed. A similar high turbidity was observed at 2 min for both samples, whereas the releasate from the hydrogel incubated in thrombin solution was clear at the end of the assay. It may be concluded that t-PA released from the hydrogel in response to thrombin converted plasminogen to plasmin in the solution, leading to clot lysis.

水凝胶释放t-PA的靶点是新生的血块，即最初形成的纤维蛋白。因此，使用纤维蛋白原-凝血酶凝块测定47来研究<br>释放。简单地说，在有/无凝血酶的情况下，将载t-PA的水凝胶在纤溶酶原溶液中培养。（纤溶酶原被t-PA激活并转化为纤溶酶，其纤溶酶的活性形式）然后添加纤维蛋白原溶液，在凝血酶存在下产生纤维蛋白。然后随时间测量340nm处溶液的吸光度。对于仅在缓冲液中培养的水凝胶（无凝血酶），在测量吸光度之前立即添加凝血酶。如图4a所示，纤维蛋白原溶液中凝血酶引发的凝块形成可通过吸光度的急剧增加来表示。对于在PBS（无凝血酶）中培养的水凝胶释放物，几分钟后吸收率达到一个稳定的平台，表明血栓完全形成，稳定。相反，在凝血酶溶液中培养的水凝胶释放物显示初始吸附量增加，然后在30分钟内恢复到基线水平，这表明凝血开始，新生的血块随后溶解。在2分钟时，两个样品都观察到类似的高浊度，而凝血酶溶液中培养的水凝胶释放物在检测结束时是清晰的。这可能是由于凝血酶引起的水凝胶释放的t-PA在溶液中将纤溶酶原转化为纤溶酶，导致血栓溶解。<br>