Growth Factors Adsorbed on Polyglycolic Acid Mesh Augment Growth of Bioengineered Intestinal Neomucosa

Production of tissue engineered small intestine (TESI) has been limited by the relatively large amount of native tissue required to generate neomucosa. The influence of growth factors and three-dimensional (3D) extracellular matrices on TESI has been studied both in vitro and in vivo, and positive growth effects on tissue mass and differentiation were noted. The present study investigates the impact of single doses of glucagon-like peptide-2 (GLP-2), hepatocyte growth factor (HGF), or holo-transferrin adsorbed onto a polyglycolic (PGA) mesh scaffold using a rat small-intestinal organoid transplant model. In Experiment I, intestinal organoids were seeded onto PGA mesh discs, suspended in either Matrigel (n = 8) or a vehicle control (n = 8), and implanted into syngenic recipients. In Experiment II, GLP-2 (n = 8), HGF (n = 8), or transferrin (n = 8) were adsorbed onto PGA mesh discs. Intestinal organoids were then suspended in Matrigel and seeded onto each growth factor-loaded PGA disc or onto control discs without growth factors (n = 12). In addition, organoids were suspended in vehicle and seeded onto control discs (n = 12). All discs were implanted into syngenic recipients. After 4 wk, histologic analysis of the samples revealed significantly greater neomucosal surface area (3.62 ± 0.33 mm2versus 0.92 ± 0.11 mm2, P < 0.0001) and cyst diameter (2.83 ± 0.14 mm versus 2.06 ± 0.07 mm, P < 0.0001) in groups treated with Matrigel compared with vehicle controls. The addition of holo-transferrin to the scaffolds further augmented neomucosal surface area (9.11 ± 0.66 mm2versus 3.01 ± 0.22 mm2, P < 0.01), whereas that of GLP-2 stimulated the formation of increased numbers of cysts (8.88 ± 0.46 versus 4.18 ± 0.25, P < 0.01). These data suggest that Matrigel and growth factors adsorbed to polymer scaffolds can be used to manipulate the morphology of TESI.