Uso de la matriz extracelular como material para ingeniería de tejidos

Abstract

Introduction: Evaluation of small intestine submucosa vascular grafts for the regeneration of blood vessels has produced variable patency (0-100%) that has been concurrent with variability in fabrication techniques. Methodology: We herein investigated the effects of fabrication on patency and regeneration in a 22 factorial experimental design that combined: 1) preservation (P) or removal (R) of the stratum compactum layer of the intestine and 2) dehydrated (D) or hydrated (H) state, into four study groups (PD, RD, PH, RH). Grafts were implanted in the carotid arteries of swine (ID 4.5 mm, n=4, 7d). Patency, thrombogenicity, inflammatory reaction, vascularization, fibroblast infiltration, macrophage polarization profile and biaxial tensile mechanics were assessed. Results: All PD grafts remained patent (4/4) but had scarce vascularization and fibroblast infiltration. RD had sustained patency (4/4), extensive vascularization and fibroblast infiltration and the highest number of regeneration-associated phenotype macrophages (M2). RH had lower patency (3/4), extensive vascularization and fibroblast infiltration, an M2 dominant profile but less M2 macrophages compared to RD. PH had the lowest patency (2/4), and in spite of higher cellular infiltration than PD, they exhibited a dominant adverse macrophage phenotype. Elasticity of R grafts evolved towards that of native carotids (particularly RD), while P grafts kept their initial stiffness. Discussion: We concluded that fabrication parameters drastically affected the outcome criteria, with the best result produced by RD grafts.