New cell delivery system CellSaic with adipose-derived stromal cells promotes functional angiogenesis in critical limb ischemia model mice.

Current therapies for patients with critical limb ischemia have not reduced amputation risk owing to poor cell engraftment. The recombinant peptide Cellnest increases the engraftment rate of administered cells by forming a complex with the cells (CellSaic). We hypothesized that CellSaic containing adipose-derived stromal cells (ADSCs) could improve lower limb blood flow better than ADSCs alone, resulting in better transplanted cell engraftment. ADSCs were extracted from 8-week-old C57BL/6N mice. Thirty-two critical limb ischemia model mice were established by ligating femoral arteries. They were divided into CellSaic (n = 11), ADSC (n = 10), saline (n = 9), and Cellnest (n = 9) groups. Blood flow rate (affected side blood flow / healthy side blood flow × 100%) was evaluated using a laser Doppler blood flow meter every week. Mice were euthanized on day 28 for histological evaluation. Compared with the ADSC group (54.5 ± 17.2%), treated side blood flow rate of the CellSaic group (78.0 ± 24.9%) showed significant improvement on day 28 after administration (p < 0.05). CD31 staining showed significantly higher number of capillary vessels in the CellSaic group (53.0 ± 8.9 cells/mm3) than in the ADSC group (43.0 ± 6.8 cells/mm3) (p < 0.05). Fluorescent staining showed significantly higher number of arterioles containing both CD31 and αSMA double-positive cells in the CellSaic group than in the ADSC group (p < 0.05). CellSaic containing ADSCs exhibited superiority to ADSC transplantation alone in promoting functional angiogenesis, suggesting its potential in improving clinical outcomes of angiogenic therapy for ischemic limbs.