Biomanufacturing of biomimetic three-dimensional nanofibrous multicellular constructs for tissue regeneration

Biomanufacturing of functional tissue analogues is of great importance in regenerative medicine. However, this is still highly challenging due to extreme difficulties in recreating/recapitulating complicated anatomies of body tissues that have both well-defined three-dimensional (3D) multicellular organizations and bioactive nanofibrous extracellular matrix (ECM). In the current investigation, a biomanufacturing approach via concurrent emulsion electrospinning and coaxial cell electrospraying was developed, which could fabricate 3D nanofibrous multi-cellular constructs that resemble both the multicellular organizations and bioactive nanofibrous microenviron-ments of body tissues. In the proof-of-concept study, endothelial cells (ECs) and smooth muscle cells (SMCs) were placed in respective layers of multilayer-structured constructs. The two different construct layers consisted of nanofibers providing different topographies (randomly oriented nanofibers or aligned nanofibers) and contained different growth factors (vascular endothelial growth factor or platelet-derived growth factor). The ECs and SMCs in the different construct layers showed high cell densities (> 4 x105 cells/cm2 after 4-day incubation) and high cell viabilities (> 95%). Owing to the contact guidance/stimulation by different fibrous topographies and sequential release of different growth factors, ECs and SMCs exhibited distinct morphologies (uniformly stretched plaque-shaped or directionally elongated) and displayed enhanced proliferative activities. Our bio-manufacturing approach is shown to be effective and efficient in reconstituting/replicating cell-ECM organiza-tions as well as their interactions similar to those in body tissues such as blood vessels, indicating the great promise to produce a range of tissue analogues with biomimetic structures and functions for modeling or regenerating body tissues.