The following inquiries and reflections summarized in this work are intended to be a contribution to the field of tissue engineering. The task is three fold: firstly to provide a view of the present scientific state at the interface of drug delivery, biomaterials, bioreactors, stem cells, and tissue engineering of mesenchymal tissues (Chapter 1). Secondly, and by employment of multisdisciplinary approaches, it is to provide novel ways of controlling the engineering of bone-like and autologous tissues to match complex bone geometries as found within our skeletons and for their functional replacement (Chapters 2-5). Thirdly, approaches of providing regulator molecule supply, as needed for the guidance of directed and selective stem cell differentiation are provided, by means of protein drug delivery from scaffold materials (Chapters 6), decorating of scaffolds (Chapter 7), physical adsorption (Chapter 7, 8) or using adenovirally transformed stem cells, transiently releasing regulatory molecules which in return trigger their differentiation in an autocrine and paracrine manner (Chapter 9), or employing genetically modified and stably transfected embryonic stem cells, which continuously release regulatory molecules (Chapter 11). The main target tissue of this contribution is on the engineering of bone-like tissues from mesenchymal stem cells (Chapters 2-9) but exemplarily other tissues were engineered such as cartilagelike tissue (Chapter 10), or neural differentiation of embyonic stem cells (Chapter 11).