  A critical step in tissue engineering is the design and synthesis of 3D
biocompatible matrices (scaffolds) to support and guide the proliferation of
cells and tissue growth. Most existing techniques rely on the processing of
scaffolds under controlled conditions and then implanting them \textit{in
vivo}, with questions related to biocompatibility and the implantation process
that are still challenging. As an alternative, it was proposed to assemble the
scaffolds \textit{in loco} through the self-organization of colloidal particles
mediated by cells. In this study, we combine experiments, particle-based
simulations, and mean-field calculations to show that, in general, the size of
the self-assembled scaffold scales with the cell-to-particle ratio. However, we
found an optimal value of this ratio, for which the size of the scaffold is
maximal when cell-cell adhesion is suppressed. These results suggest that the
size and structure of the self-assembled scaffolds may be designed by tuning
the adhesion between cells in the colloidal suspension.
