Implantation of a Small Intestinal Submucosa Scaffold Combined With Adipose-derived Stem Cells to Evaluate Its Potential to Form an Adipocyte-containing Hypodermis

Human adipose tissues were obtained from five healthy adult women who underwent abdominal liposuction. They were aged 28 to 45 years (mean, 32.15±4.8 years) and had no infectious or endocrine diseases. All protocols using human samples were approval by the Institutional Review Board of Nanfang Hospital (no.18502), and samples were obtained with written informed consent. Ten millilitres of discarded adipose tissue from the humans was washed extensively with equal volumes of phosphate-buffered saline (PBS); minced into a fine, homogeneous preparation; and digested at 37°C for 30 min with 0.125% type I collagenase. Enzyme activity was neutralized with Dulbecco's modified Eagle's medium (DMEM) containing 10% FBS. Then, the sample was filtered through a 200-mm nylon mesh to remove cellular debris and was centrifuged at 1500 revolutions per minute (rpm) for 5 min. The precipitate was resuspended in 6~10 ml NH4Cl and incubated at room temperature for 10 min to lyse contaminating red blood cells. The compound was centrifuged at 1500 rpm for an additional 5 min. The ASCs were collected via centrifugation as described above, resuspended in 2 ml of control medium (DMEM containing 10% FBS and 1% antibiotic/antimycotic solution) and incubated at 37°C in a humidified chamber containing 5% CO2 for 48 h. Next, the plates were washed extensively with PBS to remove residual non-adherent red blood cells and debris. The resulting cell population was termed ASCs, and the cultures were expanded with media changes at 3-day intervals. Cells at passage 1 through 6 were used for all experiments.