Extracellular matrix technique

The surface of the fibril provides the interface between the internal structural and mechanical properties of a fibril, and the rest of the extracellular matrix. The surface, therefore, is the most complex area of the fibril in terms of molecular heterogeneity and structure. Caution has to be taken in the comparison of structural and biochemical evidence from complementary techniques since the extraction, dehydration, and sample preparation can cause variation in observations of fibril surface properties (Raspanti et at, 1996). 

Numerous in vitro and in vivo tests have been developed to study specific steps of the neoangiogenic process. Several of these experimental protocols use the same techniques applied for assessment of tumor cell behavior (Albini, 1998). The activated endothelial cell acts similarly to a metastatic cell in the initial phases of angiogenesis, degrading the capillary basement membrane (BM), extravasating, digesting the extracellular matrix and moving toward the angiogenic stimulus (Liotta et al., 1991). For this reason... 

A possible technique adopted to prevent fibrous capsule formation around the implant is the addition of a tissue intermediary [203,204]. Indeed, if this material has a continuous, interconnected, porous structure (pore diameter >8-10 p-m), macrophages are capable of invading structure voids. Consequently, vascularized tissue can grow in the implant and the foreign body response is avoided as this porous stmcture is able to mimic extracellular matrix. The first example of intermediary tissue use concerns the coating of an implanted catheter by means of a silicone mbber cage [205]. Typically,... 

Three-dimensional brain cell cultures can been obtained from different sources such as cell lines [38], primary cells [39], and stem cells [40]. Depending of the cells used the 3D culturing techniques can vary, e.g., stem cells are commonly forming 3D structures spontaneously, while cell lines and primary cells often need support by for example extracellular matrix, hanging drop, or rotation-mediated culture techniques. 

Early attempts to functionalize biomaterial surfaces with biological molecules were focused on improving blood compatibility of cardiovascular devices, such as the artificial heart and synthetic blood vessels, by immobilizing heparin or albumin on polyurethane or Dacron . To enhance cell adhesion to biomaterial surfaces, entire extracellular matrix (ECM) proteins, such as fibronectin and laminin, have been used directly as coatings. However, because of the nonspecific manner of whole protein adsorption, most of the cell binding capability is often lost. Using a molecular templating technique, it may be possible to select which protein(s) to absorb on biomaterial surfaces. ... 

With the rapid increase in understanding of the mechanisms of cell injury and repair, a number of new substances have been identified that may prove to be useful markers of acute injury or disease activity. These include various cytokines and growth factors, several lipid mediators, a complex array of extracellular matrix components and cell adhesion molecules, plus a variety of miscellaneous compounds. At the present time, the clinical utility of their measurement in biologic samples is unknown, although in selected instances, clinical correlates have emerged. Unfortunately, not all of these markers are present in urine or blood samples. For some, detection involves histologic or histochemical techniques applied to renal tissue samples. Nonetheless, the substances discussed below are intimately involved in the control and modification of cell function, the response to stress and/or the processes of repair. It is anticipated that with proper amplification, one or more may be useful as a marker of susceptibility, exposure or effect. 

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