Vascularization is crucial for implantation of engineered tissues in reconstructive surgery. Polypeptides encapsulated in microspheres can be efficiently transported to their site of action and released in a sustained dosage. We evaluated the effect of delivering vascular endothelial growth factor (VEGF)–encapsulated microspheres in a lipoaspirate scaffold on vascularization and tissue survival. The VEGF-loaded (n = 6) and empty (n = 6) poly(lactic-co-glycolic acid) microspheres in human lipoaspirate and the human lipoaspirate alone (n = 6) were injected subcutaneously into the flanks of athymic nude mice. Three mice from each group were killed, and grafts were explanted at weeks 3 and 6. Increases in mass and volume of VEGF samples, as well as decreases in empty and lipoaspirate-only samples, were observed at 3 and 6 weeks, reaching statistical significance at 6 weeks. Hematoxylin and eosin and CD31+ imaging demonstrated significantly greater vascularization in VEGF samples than in both the empty and lipoaspirate-only groups at both 3 and 6 weeks.
From the *Division of Plastic Surgery, Department of Surgery, and †McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA.
Received March 11, 2012, and accepted for publication, after revision, March 25, 2012.
Conflicts of interest and sources of funding: Supported by the National Institutes of Health grant R01CA114246-01A1 (to J.P.R.).
Reprints: J. Peter Rubin, MD, Division of Plastic Surgery, Department of Surgery, University of Pittsburgh, 3380 Blvd of the Allies, Suite 180, Pittsburgh, PA 15213. E-mail: firstname.lastname@example.org.