In the present study, the attempt to synthesize a multibiofunctional polymeric vector to be used for construction of composite scaffolds for bone tissue engineering has been undertaken. The polymers based on 2-deoxy-2-methacrylamido- d-glucose were functionalized by a growth factor (BMP-2), GRGDSP peptide, and poly( l-lysine) using aldehyde chemistry. The covalent modification process was quantitatively studied, and a polymer conjugate containing all these ligands was formed. In addition, the impacts of coupled ligands toward the adsorption of polymers on the commercial mineral macroporous matrix Sponceram used in cell culture applications were studied.

Fracture healing is a complicated process involving many growth factors, cells, and physical forces. In cases, where natural healing is not able, efforts have to be undertaken to improve healing. For this purpose, tissue engineering may be an option. In order to stimulate cells to form a bone tissue several factors are needed: cells, scaffold, and growth factors. Stem cells derived from bone marrow or adipose tissues are the most useful in this regard. The differentiation of the cells can be accelerated using mechanical stimulation. The first part of this chapter describes the influence of longitudinal strain application. The second part uses a sophisticated approach with stem cells on a newly developed biomaterial (Sponceram) in a rotating bed bioreactor with the administration of bone morphogenetic protein-2. It is shown that such an approach is able to produce bone tissue constructs. This may lead to production of larger constructs that can be used in clinical applications.

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The development of bone tissue engineering depends on the availability of suitable biomaterials, a well-defined and controlled bioreactor system, and on the use of adequate cells. The biomaterial must fulfill chemical, biological, and mechanical requirements. Besides biocompatibility, the structural and flow characteristics of the biomaterial are of utmost importance for a successful dynamic cultivation of osteoblasts, since fluid percolation within the microstructure must be assured to supply to cells nutrients and waste removal. Therefore, the biomaterial must consist of a three-dimensional structure, exhibit high porosity and present an interconnected porous network. Sponceram, a ZrO(2) based porous ceramic, is characterized in the presented work with regard to its microstructural design. Intrinsic permeability is obtained through a standard Darcy's experiment, while Young's modulus is derived from a two plates stress-strain test in the linear range. Furthermore, the material is applied for the dynamic cultivation of primary osteoblasts in a newly developed rotating bed bioreactor.

The aim of this study was the transformation of the macroporous zirconium dioxide ceramic Sponceram into a biomimetic composite material. To enhance the adhesion of cells and to induce their differentiation into osteoblasts poly-L-lysine and BMP-2 were coupled to polymers and copolymers based on 2-deoxy-N-methacrylamido-D-glucose (ox.p(MAG) and p(MVA)) used as spacer, which were adsorbed onto the ceramic surface. The development of the composite materials was validated step by step qualitatively and quantitatively. The bioactive potential of the composite materials was tested under static and dynamic conditions using an osteoblastic model cell line and human mesenchymal stem cells. Both composite materials showed potential to enhance the adhesion of cells in the first 10 days of their cultivation. One of the composite materials, namely Sponceram/ox.p(MAG)-BMP-2, was tested into a rotating-bed bioreactor with regard to its osteogenic differentiation-inducing potential. Compared with Sponceram modified with BMP-2 without a polymer spacer, it showed increased expression of osteogenic markers determined by PCR analysis. In summary, the in vitro testing of the developed composite materials demonstrated a promising potential for their application as biomimetic scaffold materials with controllable properties.