As a control, they did something similar using matrices of collagen (a protein abundant in bone) instead of ersatz marrow.
In contrast, MMP activity was required for invasion into 3D matrices of collagen I reconstituted from acid-soluble rat-tail collagen I, but not from pepsin-extracted collagen I (Vitrogen/Purecol), which lacks telopeptide regions.
A well-established hallmark of VM is the ability of established cancer cells to form tube-like structures resembling those formed by endothelial cells, when seeded on three-dimensional (3D) matrices of collagen I.
MMP 14 and MMP 2 are key proteinases in branching morphogenesis during epidermal-growth-factor-mediated lung development [ 74], and MMP 14, independent of pro-MMP 2 activation, can confer invasion and tubulogenesis of noninvasive MDCK cells in matrices of collagen type I, while MMPs 1, 2, 3, 7, 9, 11, and 13 cannot [ 75].
Similarly, it was shown that highly aggressive melanoma cells, when seeded on three-dimensional matrices of collagen I, form extracellular matrix-rich patterned networks that surround clusters of tumor cells; however, under the same culture conditions, poorly aggressive melanoma cells did not form the patterned networks [ 38].
We performed this study to ascertain the results of the foregoing animal experiments and to demonstrate the influence of phospholipids to three different ECM components, even though matrices of collagen IV, laminin and fibronectin alone may not be predictive of peritoneal membrane nidation.
Bone is composed of an organic phase that contains (i) bone forming cells (osteoblasts and osteocytes), (ii) bone resorbing cells (osteoclasts) and (iii) a matrix of collagen and non-collagenous proteins (osteoid), and a mineral phase of inorganic salts.
To her surprise, she found that it still contained a matrix of collagen fibres, a protein that gives bone its structure and flexibility.
The second layer, the dermis, is thicker and is composed of loosely packed connective tissue cells in a watery matrix of collagen and elastin fibres, as well as sweat glands, hair follicles, capillaries, and lymphatic vessels.
Cartilage is an intricate balance of water, chondrocytes, and a rich extracellular matrix of collagen fibers and proteoglycan molecules.
Parchment artefacts can therefore be described structurally, as a matrix of collagen fibres interfaced with a gelatine exterior.
