Adipose tissue engineering with human adipose-derived stem cells and fibrin glue injectable scaffold

Abstract

To explore the possibility of building tissue-engineered adipose tissue and find a new approach for repairing soft tissue defects. Using enzymatic digestion, adipose tissue-derived stem cells (ASCs) were extracted from the lipid part of human liposuction aspirate, cultured, and underwent adipogenic induction or not. The adipogenic-induced and non-adipogenic-induced ASCs were labeled with 3, 3, 3', 3'-tetramethylindo-carbocyanine perchlorate (DiI), a fluorescent marker, in vitro to be used as seed cells. Then, they were combined with injectable fibrin glue scaffold at 1 x 10(7)/ml cell density. Six athymic BALB/C mice underwent subcutaneous injection of adipogenic-induced ASCs with fibrin glue scaffold at the density of 1 x 10(7) cells/ml into the left side of the low back (induced group), subcutaneous injection of non-adipogenic-induced ASCs into the right side of the low back (non-induced group), and subcutaneous injection of injectable fibrin glue scaffold into the middle part of the neck (blank control group), with 0.2 ml per injection. Twelve weeks later the mice were killed and the implants were taken out. The wet weight was measured. HE and oil red O staining and light and fluorescence microscopy were used for morphological observation. Adipose tissue-like new-born tissues were found in the injection sites of the induced and un-induced groups. The average wet-weight of the induced group new-born tissue was (28 +/- 15) mg, significantly heavier than that of the un-induced group [(22 +/- 16) mg, P < 0.01]. HE staining and oil red O staining confirmed that the new-born tissue of the induced group was mature adipose tissue and DiI fluorescent staining approved its exogenousness. Most part of the new-born tissues of the un-induced group was fibroid tissue with only a few mature adipose tissues. ASCs extracted from the lipid part after liposuction can be used as seed cells, mixed, after adipose-induction, with injectable scaffold of fibrin glue, and injected into the body to build mature adipose tissue.