Porcine MSCs were used as a target to generate aptamers by combinatorial chemistry out of a huge random library with in vitro technology called systematic evolution of exponential enrichment (SELEX). After cloning and sequencing, the binding affinity was detected using a cell sorting assay with streptavidin-coated magnetic microbeads. We also used 12-well plates immobilized with aptamers to fish out MSCs from the cell solution, and a FITC-labeled aptamer to sort MSCs from bone marrow using high-speed FACS. The cells showed high potency to differentiate into osteogenic, as well as into adipogenic lineages with typical morphological characteristics. Surface marker staining showed that the attached cells were CD29⁺, CD44⁺, CD45^-, CD90⁺, SLA class I⁺, SLA DQ^- and SLA DR^-.

Compared to existing methods, this study established a novel, rapid, and efficient method for direct isolation of aMSCs from porcine bone marrow by using an aptamer as a probe to fish out the aMSCs. This new application of aptamers can facilitate aMSCs isolation and enrichment greatly, thereby enhancing the rate of aMSC-derived cells after in vitro differentiation for various applications in the emerging field of tissue engineering and regenerative medicine.