Angiogenesis

FIGURE 1.5. Unusual prominent vasculature at the base of a primary cutaneous malignant melanoma. Courtesy of G. E. Pierard. For a color representation of this figure, see Plate 1A facing this page. 

The complex process of angiogenesis includes the recruitment of nearby endothelial cells, their activation, degradation of the vascular basement membrane, proliferation and 

However, certain aspects of the concept of vasculogenic mimicry have been questioned by McDonald et al. (2000). They indicate that PAS-stained channels do not 

A large number of tumor blood vessels increases the opportunity of the tumor cells to enter the circulation. In fact, the newly formed capillaries usually have a fragmented basement membrane, facilitating easier invasion. In the prevascular phase, with little or no angiogenic activity, the tumor is unable to expand beyond a few cubic millimeters, but once angiogenic factors are released in sufficient number, the onset of angiogenic activity stimulates rapid expansion of the tumor. 

Tissue engineering scaffold for DNA delivery by cationic polymers. Biomimetic scaffolds can be encapsulated with growth factors and MSCs are seeded onto their surface [top]. Polymeric release bottom left) consists in the entrapment of the complexes between cationic polymers and DNA within the biomaterial for release into the environment. Conversely, substrate-mediated delivery bottom right), also termed reverse transfection delivery, employs the immobilization of complexes to the biomaterial. MSCs can internalize the complexes either directiy or by degrading the linkage between the biomaterial and DNA complexes. 

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Angiogenesis and Vascular Morphogenesis. Table 1 Positive and negative endogenous regulators of angiogenesis (noncomprehensive list)... 

Interference with specific cell-cell and cell-matrix adhesion mechanisms is another rapidly advancing approach to therapeutically interfere with angiogenesis. Antagonistic antibodies (Vitaxin) to the integrin heterodimer av 33 have been shown to act on the blood vessels of tumors but not on the resting organ vasculature. Vitaxin demonstrated some promise in Phase II clinical trials. 

The growing list of endogenous inhibitors of angiogenesis holds great promise for therapeutic applications (Table 2). Substances most advanced in clinical development include Endostatin, Angiostatin, Interleukin-12, Thrombospondin, and Tumstatin. As... 

Antiangiogenesis research has driven the field. Yet, there are a number of indications which may benefit from an induction of angiogenesis, including wound... 

Direct laser-assisted myocardial revascularization (DMR) is an approved technique in the US, Europe, and parts of Asia to create numerous myocardial channels. This results in the induction of a massive inflammatory reaction, which in turn induces angiogenesis. The other FDA-approved pro-angiogenic therapy is the use of recombinant human platelet-derived growth factor (Regranex) for use in the treatment of diabetic neuropathic foot ulcer s. 

Carmeliet P (2005) Angiogenesis in life, disease and medicine. Nature 438(7070)... 

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