As vascularization represents the rate-limiting step in permanent incorporation of hydrogel-based tissue-regeneration templates, the authors sought to identify the material chemistry that would optimize endothelial cell adhesion and invasion into custom hydrogel constructs. The authors further investigated induction of endothelial tubule formation by growth factor supplementation and paracrine stimulation.
Hydrogel scaffolds consisting of combinations of alginate, collagen type I, and chitosan were seeded with human umbilical vein endothelial cells and maintained under standard conditions for 14 days. Cell density and invasion were then evaluated. Tubule formation was evaluated following basic fibroblast growth factor addition or co-culture with human aortic smooth muscle cells.
Human umbilical vein endothelial cells demonstrated greatest cell-surface density and invasion volumes with alginate and collagen (10:1 weight/weight) scaffolds (p < 0.05). Supplementation with basic fibroblast growth factor increased surface density but neither invasion nor tubule formation. A significant increase in tubule content/organization was observed with increasing human aortic smooth muscle cell–to–human umbilical vein endothelial cell ratio co-culture.
Alginate and collagen 10:1 scaffolds allow for maximal cellularization compared with other combinations studied. Growth factor supplementation did not affect human umbilical vein endothelial cell invasion or morphology. Paracrine signaling by means of co-culture with human umbilical vein endothelial cells stimulated endothelial tubule formation and vascular protonetwork organization. These findings serve to guide future endeavors toward fabrication of prevascularized tissue constructs.
New York, N.Y.
From the Laboratory of Bioregenerative Medicine and Surgery, Division of Plastic Surgery, Weill Cornell Medical College.
Received for publication June 23, 2012; accepted May 13, 2013.
Presented in part at the 80th Annual Meeting of the American Society of Plastic Surgeons, in Denver, Colorado, September 23 through 27, 2011; the 28th Annual Meeting of the Northeastern Society of Plastic Surgeons, in Amelia Island, Florida, October 20 through 23, 2011; the American Society for Reconstructive Microsurgery 2012 Annual Meeting, in Las Vegas, Nevada, January 14 through 17, 2012; and the 57th Annual Meeting of the Plastic Surgery Research Council, in Ann Arbor, Michigan, June 14 through 15, 2012.
Disclosure: None of the authors have any commercial associations or conflicts of interest to disclose.
Jason A. Spector, M.D., Weill Cornell Medical College, Payson 709-A, New York, N.Y. 10065, email@example.com