Development of multilayer constructs for tissue engineering.

The rapidly developing field of tissue engineering produces living substitutes that restore, maintain or improve the function of tissues or organs. In contrast to standard therapies, the engineered products become integrated within the patient, affording a potentially permanent and specific cure of the disease, injury or impairment. Despite the great progress in the field, development of clinically relevantly sized tissues with complex architecture remains a great challenge. This is mostly due to limitations of nutrient and oxygen delivery to the cells and limited availability of scaffolds that can mimic the complex tissue architecture. This study presents the development of a multilayer tissue construct by rolling pre-seeded electrospun sheets [(prepared from poly (l-lactic acid) (PLLA) seeded with C2C12 pre-myoblast cells)] around a porous multibore hollow fibre (HF) membrane and its testing using a bioreactor. Important elements of this study are: 1) the medium permeating through the porous walls of multibore HF acts as an additional source of nutrients and oxygen to the cells, which exerts low shear stress (controllable by trans membrane pressure); 2) application of dynamic perfusion through the HF lumen and around the 3D construct to achieve high cell proliferation and homogenous cell distribution across the layers, and 3) cell migration occurs within the multilayer construct (shown using pre-labeled C2C12 cells), illustrating the potential of using this concept for developing thick and more complex tissues.

Single-market regulation and innovation in Europe's medical devices industry.

In this article we analyze the influence of the legal regulatory framework in Europe, established by the two directives on medical devices and active implantable devices, on the performance of innovation in a single European market. First, we describe in general the possible influence of a single European market on innovation and the institutional features of the particular harmonization approach ("New Approach") we are looking at here. The empirical results presented derive from a survey investigation involving 150 firms that we defined as best innovators in the European medical devices industry from a pre-survey. The results confirm that the total impact of the New Approach regulation on firms' innovation in the long term is positive. However, it also becomes clear that the impact of regulation on innovation is limited if the factors are looked at individually and that there is a clear difference regarding short-term effects. To improve the regulatory framework, several policy actions are recommended.