Histological changes induced by Polyglycolic-Acid (PGA) scaffolds seeded with autologous adipose or muscle-derived stem cells when implanted on rabbit bladder

Purpose: To evaluate the morphological and histological changes induced by PGA scaffold seeded with autologous adipose or muscle derived stem cells implanted on rabbit bladder wall. Material and Methods: Adipose derived stem cells (ADSC s) were obtained from the inguinal fat of eight rabbits and muscle derived stem cells (MDSC s) from the anterior tibial muscle of other eight rabbits. After culture and isolation, the cells were stained with Vybrant Red CM DiI and then implanted at third passage. Two PGA scaffolds were implanted on the bladder submucosa of each animal. On the right bladder side was implanted unseeded PGA scaffold while on the left side was implanted ADSC s or skeletal MDSC s seeded PGA scaffold. ADSC s were implanted in eight animals and MDSC in other eight animals. The animals were sacrificed at four and eight weeks. Histological evaluation was performed with Hematoxylin and Eosin, Masson's Trichrome and smooth muscle a-actin. Results: We observed a mild inflammatory response in all the three groups. Seeded scaffolds induced higher lymphocytes and lower polimorphonuclear migration than controls. Fibrosis was more pronounced in the control groups. Smooth muscle a-actin was positive only in ADSC and MDSC seeded scaffolds. At four and eight weeks ADCS s and skeletal MDSC s labeled cells were found at the implant sites. Conclusions: The implantation of PGA scaffolds seeded with ADSC and MDSC induced less fibrosis than control and smooth muscle regeneration.