Three-dimensional sprayed active biological gels and cells for tissue engineering application.

Complex three-dimensional structures can "a priori" be built layer-by-layer with a large number of different components, including various cell types, polyelectrolytes, drugs, proteins, peptides or DNA. Our approach is based on the spraying of such elements in order to form a highly functionalized and structured biomaterial. The proposed route will allow the control at the surface and in depth the distribution of the different included elements (matrix and cells).The main objective of this work concerns the buildup of biomaterials aimed to reconstruct biological tissue. The proposed ways are highly innovative and consist in a simple and progressive spraying of all the elements constituting finally the biomaterial.We report here that it is possible (i) to build an alginate gel by alternate spraying of alginate and Ca(2+); (ii) to spray active alginate gel and cells; (iii) to build layer-by-layer an active reservoir under and on the top of this sprayed gel and cells; (iv) to follow the activity of these sprayed cells with time; (v) to propose a three-dimensional sprayed structure for tissue engineering application.