Spray- and laser-assisted biomaterial processing for fast and efficient autologous cell-plus-matrix tissue engineering

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(ε-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. Grafts were monitored 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.

Tissue-Engineered Heart Valve with a Tubular Leaflet Design for Minimally Invasive Transcatheter Implantation

“…6,7 Historically, TEHVs have been designed to mimic the shape of the native valve in the attempt to recreate the natural hemodynamics. [8][9][10][11][12][13][14][15][16] This implies to the fabrication of leaflets to ensure the unidirectional blood flow. However, it is the inadequate leaflets' functionality that ultimately determined the failure of TEHVs in preclinical studies, independently whether a conventional 9,[17][18][19][20] or a minimally invasive implantation was performed.…”

Spraying Respiratory Epithelial Cells to Coat Tissue-Engineered Constructs

“… 7 , 13 , 14 , 25 Still, some studies were focused on the development of tissue-engineered constructs: The team of Steinhoff has spray-applied stem cells or stem cell/endothelial cell mixtures in a fibrin glue for coating of heart valve scaffolds and report the desired homogeneous cell distribution. 8 , 26 Farhat et al were already able to demonstrate tissue engineering of porcine urothelium successfully in vivo. 15 In addition to better cell adhesion, fibrin supports cell growth by enhanced diffusion of growth factors and by acting as a nutrient.…”

Laser-Based Cell Printing

“…By moving the substrate and repositioning the laser focus, every desired two-dimensional pattern can be printed, and layer by layer also 3D patterns can be generated. Cells have been printed onto different objects like glass slides, sheets of different materials (see below), and heart valve leaflets (Klopsch et al 2012) and into scaffolds (Ovsianikov et al 2010).…”