HBMSCs cells

Figure 21.13. A) High power microscope image showing that polysaccharide nanoparticles selectively associate with primary human bone marrow stromal cells in a 3D cell suspensions (n=12). The alginate nanocapsule core is stained with a fluorescent dye (Cell Tracker Red) which in white transmitted light is blue. B) TEM image showing presence of nanocapsules (i) at the surface of a primary hBMSC cell membrane and (ii) internalized within vacuoles. The yellow arrows denote position of nanocapsules.

Capsules of this kind were immersed in a primary hBMSC cell suspension to test the potential of peptide decorated capsules to attach cells to the external surface. It was found that within 7 days metabolically active/viable primary hBMSC preferentially adhered to chitosan-GGRGD complexed capsules (Figure 14B,D). In capsules without chitosan conjugated GGRGD ligands only a few cells were seen to be attached (Figure 14A,C). 

Figure 21.3. In vivo osteoid (mineralized) bone formation within capsules and nested capsules containing a physiologically relevant concentration of BBMP-2 (200ng/mL) and primary hBMSC inside a diffusion chamber. Capsules are loaded in triplicate inside a diffusion chamber which prevents ingress of host cells into the capsules. Thus, all tissue generated comes from seeded primary hBMSC.

Figure 21.4. Immuno-staining for cartilage specific collagen lype 11 molecules within matrix synthesized by embedded cultured human articular chondrocyte cells (500,000 cells per capsule). Staining of new matrix is strong throughout each sampled capsule. Individual cells are located in well-defined lacuane at a high density. New matrix is not formed in capsules containing primary hBMSC.

Figure 1.8 Combined in vitro culture of hBMSC. The cell mass is stained red for ALP secretion (a primary marker of bone formation). Nacre chips of various sizes can clearly be seen.

Bernhardt et al. [234] obtained a synthetic material that mimics the composition and structure of the extracellular bone matrix, which mainly consists of Coll fibrils, mineralized with HAp (nano)crystals. This nanocomposite material was produced in a biomimetic process, in which Col fibril assembly and mineralization with HAp occur simultaneously. The authors observed that the membranes from biomimetically mineralized Coll show a substantial influence on the osteogenic differentiation of human bone-marrow-derived stromal cells (hBMSCs). The bone-like composition of the material, combined with its stimulating effect on the osteogenic differentiation of hBMSC, makes it appropriate for human bone regeneration. 

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