Factors That Influence Adipose Derived Regenerative Cells' Yield and Viability

Overview

Human adipose tissue has been shown to contain a group of cells that possess extensive proliferative capacity and the ability to differentiate into multiple cell lineages. Cells isolated from the fatty portion are termed processed lipoaspirate cells that contain adipose-derived regenerative cells (ADRCs). ADRCs are most conveniently extracted from tissue during an elective cosmetic liposuction procedure but may also be obtained from resected adipose tissue. This study is aimed to verify if there are differences between the number and viability of cells obtained from patients with different age, sex, Body Mass Index (BMI), smoking and physical activity, within the different amount of processed fat.

Method: We analyzed 46 patients, both sexes, who filled out a questionnaire about their age and habits (sport activity and smoking). They were then divided into two groups. Group 1 consisted of patients with normal BMI range from 18,5 to 24.9 (n=27) and Group 2 had overweight patients with BMI index 25 to 29.9 (n=19). There were no underweight or obese patients. All 46 patients had the ADRCS extracted for therapeutical use, but with different indications. The mixture of 180 mL saline solution, 1mL Epinephrine (1:10,000) and 20 mL of 2% lidocaine is injected in the subcutaneous layer of the abdominal wall to allow the tumescence and to decrease the blood loss. The manual liposuction procedure has been carried out through two or three small incisions using harvester (Tulip® medical products, San Diego, USA). All of them had liposuction done by the author and in the same manner (tumescent technique, same cannula) to obtain 120-200ml of fat. The harvest site is then covered with a pressure dressing for 10 days to reduce swelling and hematoma. The closed system PureGraft® 250mL (PureGraft®, Solana Beach, California, USA) has been used used to collect the specimen. The specimen is transferred within 15 min to the BelPrime Clinic laboratory where the Celution® 800/CRS system (Cytori Therapeutics, Inc. San Diego, California, USA) is applied to process the lipoaspirate in order to obtain ADRCs. The Celution® 800/CRS system is a closed automated medical device that helps to separate blood and fat. The system will then digests fat using the proprietary enzyme reagent Celase 835/CRS (Cytori Therapeutics, Inc. San Diego, California, USA) to release the stromal vascular fraction (SVF). SVF is subsequently concentrated by a short centrifugation and then automated wash cycles to obtain the ADRC fraction. This 90 to 120-minute process provides approximately 5mL of pellet. A few drops of the obtained pellet were immediately used for cell counting (ChemoMetec A/S DK-3450, Allerod, Denmark). Results/Complications: Number of ADRCS obtained, cells' viability, viable ADRCS per gram of fat processed, ADRCS for active dose and total volume for cell therapy were statistically analyzed in correlation with patients' BMI, sport activity, sex, age and smoking habits and amount of processed fat.