Double Rolling Circle Amplification Generates Physically Cross-Linked DNA Network for Stem Cell Fishing
Chi Yao, Han Tang, Weijian Wu, Jianpu Tang, Weiwei Guo, Dan Luo, Dayong Yang
Abstract
Stem cells have been widely studied in cell biology and utilized in cell-based therapies, and fishing stem cells from marrow is highly challenging due to the ultralow content. Herein, a physically cross-linked DNA network-based cell fishing strategy is reported, achieving efficient capture, 3D envelop, and enzyme-triggered release of bone marrow mesenchymal stem cells (BMSCs). DNA network is constructed via a double rolling circle amplification method and through the intertwining and self-assembly of two strands of ultralong DNA chains. DNA-chain-1 containing aptamer sequences ensures specific anchor with BMSCs from marrow. Hybridization between DNA-chain-1 and DNA-chain-2 enables the cross-link of cell-anchored DNA chains to form a 3D network, thus realizing cell envelop and separation. DNA network creates a favorable microenvironment for 3D cell culture, and remarkably the physically cross-linked DNA network shows no damage to cells. DNA network is digested by nuclease, realizing the deconstruction from DNA network to fragments, and achieving enzyme-triggered cell release; after release, the activity of cells is well maintained. The strategy provides a powerful and effective method for fishing stem cells from tens of thousands of nontarget cells.