Diehl Peter, Schauwecker Johannes, Eichelberg Kay, Gollwitzer Hans, Magdolen Ursula, Gerdesmeyer Ludger, Mittelmeier Wolfram, Schmitt Manfred
Department of Orthopedic Surgery, University of Rostock, Rostock, Germany.
Int J Mol Med. 2007 Apr;19(4):667-73.
In orthopedic surgery, sterilization of bone used for reconstruction of osteoarticular defects caused by malignant tumors is carried out in various ways. At present, to devitalize tumor-bearing osteochondral segments, extracorporeal irradiation or autoclaving is mainly used, although both methods have substantial disadvantages, leading to a significant loss of biomechanical and biological integrity of the bone. As an alternative approach, a new technology to achieve bone sterilization, the high hydrostatic pressure (HHP) treatment of bone, has been suggested, which is currently being preclinically tested. This novel technique leads to the inactivation of tumor cells without impairing biomechanical properties of the bone, cartilage, or tendons. HHP may not only exert an effect on tumor and normal cells present in the bone but also on tumor-associated proteases released by these cells, which are conductive to tumor bone turnover. In order to investigate this, proteolytic key enzymes, e.g. MMP-9, uPA, t-PA, plasmin, trypsin, and thrombin were subjected to HHP <or=600 MPa. Thereafter, compared to the non-pressurized enzymes, the proteolytic activity of the pressurized enzymes was determined. The proteases studied showed varying degrees of susceptibility to HHP, depending on the pressure level applied. The latent activity of the inactive zymogens prothrombin, plasminogen, and pro-uPA, in addition to the proteolytically active forms of plasmin, thrombin, HMW-uPA, and trypsin were minimally affected by HHP (10 min, 20 degrees C, 600 MPa) with a reduction of activity up to 13% only, whereas t-PA was significantly impaired by a reduction of activity of 30%. In contrast, for pressurized pro-MMP-9 (10 min, 5 degrees C, 400 MPa) a 3-fold increase in enzymatic activity was observed after activation compared to non-pressurized pro-MMP-9. No activation of pro-MMP-9 due to HHP was observed. These data encourage further exploration of the potential of HHP to sterilize tumor-affected bone segments prior to reimplantation. During this treatment tumor cells are irreversibly impaired, while HHP treatment of proteases may not exert any significant autolytic effect on bone tissue.
在骨科手术中，用于重建恶性肿瘤所致骨关节缺损的骨的灭菌有多种方式。目前，为使含肿瘤的骨软骨段失活，主要采用体外照射或高压灭菌法，尽管这两种方法都有很大缺点，会导致骨的生物力学和生物学完整性显著丧失。作为一种替代方法，有人提出了一种实现骨灭菌的新技术，即对骨进行高静水压（HHP）处理，目前该技术正在进行临床前测试。这种新技术可使肿瘤细胞失活，而不会损害骨、软骨或肌腱的生物力学特性。HHP不仅可能对骨中存在的肿瘤细胞和正常细胞产生影响，还可能对这些细胞释放的与肿瘤相关的蛋白酶产生影响，这些蛋白酶有助于肿瘤骨转换。为了对此进行研究，将蛋白水解关键酶，如基质金属蛋白酶-9（MMP-9）、尿激酶型纤溶酶原激活剂（uPA）、组织型纤溶酶原激活剂（t-PA）、纤溶酶、胰蛋白酶和凝血酶置于HHP≤600兆帕的环境中。此后，与未加压的酶相比，测定加压酶的蛋白水解活性。所研究的蛋白酶对HHP的敏感性程度各不相同，这取决于所施加的压力水平。凝血酶原、纤溶酶原和尿激酶原酶原的潜在活性，以及纤溶酶、凝血酶、高分子量尿激酶型纤溶酶原激活剂（HMW-uPA）和胰蛋白酶的蛋白水解活性形式，受HHP（10分钟，20℃，600兆帕）的影响最小，活性仅降低高达13%，而t-PA的活性则显著受损，降低了30%。相比之下，对于加压的前MMP-9（10分钟，5℃，400兆帕），与未加压的前MMP-9相比，激活后酶活性增加了3倍。未观察到HHP导致前MMP-9的激活。这些数据促使人们进一步探索HHP在重新植入前对受肿瘤影响的骨段进行灭菌的潜力。在这种处理过程中，肿瘤细胞会受到不可逆的损害，而对蛋白酶进行HHP处理可能不会对骨组织产生任何显著的自溶作用。
