Abstract
At present, intensive investigation aims at the creation of optimal valvular prostheses. We introduced
and tested the applicability and functionality of two advanced cell-plus-matrix seeding technologies,
spray-assisted bioprocessing (SaBP) and laser-assisted bioprocessing (LaBP), for autologous tissue
engineering (TE) of bioresorbable artificial grafts. For SaBP, human mesenchymal stem cells (HMSCs),
umbilical cord vein endothelial cells (HUVECs) and fibrin were simultaneously spray-administered on
poly(«-caprolactone) (PCL) substrates. For LaBP, HUVECs and HMSCs were separately laser-printed in
stripes, followed by fibrin sealing. Three-leaflet valves were manufactured following TE of electrospun
PCL tissue equivalents. Graftsweremonitored in vitro under static and dynamic conditions in bioreactors.
SaBP and LaBP resulted in TE of grafts with homogeneous cell distribution and accurate cell pattern,
respectively. The engineered valves demonstrated immediate sufficient performance, complete cell
coating, proliferation, engraftment, HUVEC-mediated invasion, HMSC differentiation and extracellular
matrix deposition. SaBP revealed higher efficiency,with at least 12-fold shorter processing time than the
applied LaBP set-up. LaBP realized coating with higher cell density and minimal cell–scaffold distance.
Fibrin and PCL stability remain issues for improvement. The introduced TE technologies resulted in
complete valvular cell-plus-matrix coating, excellent engraftment and HMSCs differentiation. SaBP
might have potential for intraoperative table-side TE considering the procedural duration and ease of implementation. LaBP might accelerate engraftment with precise patterns.