(a) a colonization chamber for biological cells, the colonization chamber comprising a recess that is open toward a top side of the 3D scaffold and extends along an X axis, a Y axis,

and a Z axis where the Y axis is orthogonal to and defines an X-Y plane with the X axis

and where the Z axis is orthogonal to both the X axis and the Y axis, the entire outer perimeter of the recess in planes parallel to the X-Y plane being defined by a recess lateral surface that extends continuously from a bottom surface of the recess along the entire dimension of the recess in the direction of the Z axis;

(b) a canal vessel in an interior of the 3D scaffold, the canal vessel at least partially surrounding the colonization chamber in planes parallel to the X-Y plane so as to be positioned between the colonization chamber and the periphery of the 3D scaffold in planes parallel to the X-Y plane;

(c) a filling opening for the canal vessel;

(d) an outlet opening for the canal vessel;

(e) wherein the 3D scaffold is comprised of biocompatible polymer; and

(f) wherein the colonization chamber and the canal vessel are spatially separated from each other in planes parallel to the X-Y plane by a separation structure, the separation structure having an inner surface comprised of at least a portion of the recess lateral surface and an outer surface facing the canal vessel, and the separation structure including a-separation structure biocompatible polymer that is permeable to nutrients in a direction from the canal vessel to the colonization chamber to facilitate diffusion of nutrients from the canal vessel into the colonization chamber.