RESUMO
BACKGROUND: The in vitro interactions of esophageal smooth muscle cells (SMCs) with synthetic absorbable polymers were tested and artificial muscle tissues harvested from subcutaneous implantation were examined. MATERIAL/METHODS: Esophageal tissue samples from adult and fetal (25-day gestational age) rabbits were cut into small pieces and cultured in Dulbecco's Modified Eagle Medium supplemented with 10% fetal bovine serum. Growing cells were identified as SMCs by immunostaining for anti-actin and anti-myosin antibodies. Equal volumes of agar gel and medium were mixed and used for 3-D culture. 5x10(5) cells and 1 mg polyglycolic acid (PGA) and poly-lactide-co-glycolide acid (PLGA) fibers were seeded in six-well tissue culture plates. On days 2 and 7 growing cells were counted by a hemocytometer and cell-polymer interactions were evaluated with light microscopy. Adult and fetal SMCs were seeded onto the PGA and PLGA scaffolds, cultivated for two weeks, and implanted subcutaneously on the backs of the rabbits. Cell-polymer implants were retrieved after four weeks and muscle formation was evaluated histologically and immunohistochemically. RESULTS: Growing cells stained positive for actin and myosin proteins. Cell-polymer interactions were poor after 24 hours, whereas intensive attachment to the fibers was detected 48 hours following cultivation. Both fiber materials supported cell proliferation. PLGA scaffolds improved muscle formation more efficiently than PGA, and fetal and adult SMCs showed similar mass quality. CONCLUSIONS: Scaffolds are important as cell-carrying vehicles, and material-cell interactions should be tested before application. A 3-D culture prepared with agar gel and medium is practical for testing material toxicity.
