Adipose tissue engineering of the breast with adipose-derived stem cells and collagen sponge scaffolds in rats

Abstract

Objective To explore the feasibility of building the tissue-engineered adipose tissue of breast with adipose- derived stem cells (ASCs) and collagen sponge scaffolds.Methods Enzymatic digestion and centrifugalization were used to isolate ASCs from the inguinal fat pad in adult female Sprague Dawley rats (n=6).After expansion in culture medium,ASCs underwent adipogenic and osteogenic induction and were identified with oil red O staining and yon Kossa staining.For in vitro study,ASCs were seeded onto collagen scaffolds and cultured for 14 days.For in vivo study,ASCs were combined with collagen type Ⅰ sponge scaffolds before implantation.The 6 SD rats underwent implantation of autologous ASCs with collagen sponge into the right side of the upper breast (experimental group),and implantation of collagen sponge into the left side of the upper breast (control group).Twelve weeks later the rats were euthanatized to harvest the implants for wet weight measurement.HE and oil red O staining were used for morphological observation.Results Adipose tissue-like new-born tissues were found in the implantation sites in the experimental group,while collagen sponge-like new-born tissues were found in the implantation sites in the control group.The average wet-weight of the new-born tissue in the experimental group was (121 ±9) mg,significantly heavier than that in the control group [ (77±6) mg,P＜0.05].HE staining and oil red O staining confirmed that most of the new-born tissues in the experimental group were mature adipose tissues,while most of the new-born tissues in the control group were collagen fibers.Conclusion Autologous ASCs combined with collagen type Ⅰ scaffolds can be implanted into the breast to build mature adipose tissue in rats. Key words: Adipose-derived stem cells; Tissue engineering; Type Ⅰ collagen; Rat