Collagen fibers matrices

Silk fibers or monolayers of silk proteins have a number of potential biomedical applications. Biocompatibility tests have been carried out with scaffolds of fibers or solubilized silk proteins from the silkworm Bombyx mori (for review see Ref. [38]). Some biocompatibility problems have been reported, but this was probably due to contamination with residual sericin. More recent studies with well-defined silkworm silk fibers and films suggest that the core fibroin fibers show in vivo and in vivo biocompatibility that is comparable to other biomaterials, such as polyactic acid and collagen. Altmann et al. [39] showed that a silk-fiber matrix obtained from properly processed natural silkworm fibers is a suitable material for the attachment, expansion and differentiation of adult human progenitor bone marrow stromal cells. Also, the direct inflammatory potential of silkworm silk was studied using an in vitro system [40]. The authors claimed that their silk fibers were mostly immunologically inert in short and long term culture with murine macrophage cells. 

Figure 2. Diagram of two osteocytes (1) in the lamellar bone of calcified bone matrix (3). Two neighboring lamellae (2) with different collagen fiber orientations (7) are visible. The osteocytic cell bodies are located in lacunae and are surrounded by a thin layer of uncalcified matrix (4). Their cell processes (5) are housed in canaliculi (6). Some of the gap junctions between the cell processes are indicated (arrows). Modified from Krstic (1978).

The lower layer of Yannas s artificial skin consists of a 2-mm thick matrix of collagen fibers, obtained from bovine tendons, and... 

Figure 7. Portion of an intimal smooth muscle cell and the adjacent intercellular matrix from a primate artery (Macaca nemestrina) stained with ruthenium red. The ruthenium red stains numerous polygonal granules associated with each other through 30-60 A diameter filamentous projections which, based on studies with chondroitinases, must represent dermatan sulfate-containing proteoglycans (X 40,000). As shown in the insert, the 30-60 A filaments interconnect granules, collagen fibers, elastin, and the surfaces of cells (X 140,000). Reproduced from Proteoglycans in Primate Arteries. I. Ultrastructural Localization and Distribution in the Intima, by Thomas N. Wight and Russell Ross, J. Cell Biol. (1975) 67,...

The reticular layer of basement membrane in a tissue such as the skin contains a variety of matrix structures. Strands of basement membrane may project down to type I collagen fibers. Anchoring fibers, banded fibers composed of type VII collagen, extend into the basement mem-... 

Figure 3.20. Structure of hyaline cartilage. Hyaline cartilage contains chondrocytes within lacunae separated by a matrix containing collagen fibers and proteoglycans.

Descemet s membrane is the basement membrane of the endothelial cells. It is comprised of collagen fibers arranged in a hexagonal pattern and embedded in a matrix. 

Bone is an anisotropic and viscoelastic ceramic matrix composite and is distinct from conventional ceramics. Its mechanical properties depend on its porosity, degree of mineralization, collagen fiber orientation, and other structural details. The data in Table 18.1 may be used to compare the physical and mechanical properties of bone, hydroxyapatite (the major mineral in bone, and hence, the most relevant material as a bioceramic), and CBPCs. 

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