This article was originally published here
Interfaces ACS Appl Mater. 2022 Apr 29. doi: 10.1021/acsami.2c03265. Online ahead of print.
Nested DNA nanostructures perform programmable nanoscale movements such as sliding, contraction, and expansion. However, the use of nanoscale nested motions to regulate larger scale matrix functions and the development of their applications have not yet been reported. Here, we describe the assembly of a DNA-based daisy chain rotaxane nanostructure (DNA-DCR) composed of two hollow DNA nanostructures as macrocycles, two interlocking axes, and two shaped DNA structures. of triangular prism as caps, in which three mechanical states─fixed extended state (FES), slip state (SS) and fixed contracted state (FCS)─are characterized by the use of reaction of foot-mediated strand displacement (SDR). DNA-DCRs are further used as nanocomposites and introduced into the hydrogel matrix to produce nested hydrogels, which exhibit tunable stiffness by elongating the nested axes to regulate hydrogel swelling with d chain reaction treatment. hybridization (HCR). Then, DCR hydrogels are used as dynamic biointerfaces for human mesenchymal stem cell (hMSC) adhesion studies. First, hMSCs showed lower cell density on bare DCR hydrogel treated with HCR-initiated swelling for decreased stiffness. Second, cell adhesion ligand (RGD)-modified DNA-DCRs are constructed for hydrogel functionalization. ground floor(RGD) the hydrogel confers RGD mobility by changing the mechanical states of the DNA-DCR. HMSCs showed increased cell density on DCRSS(RGD) hydrogel than on DCRFCS (RGD) hydro gel. Therefore, our DNA-DCR nanocomposite hydrogel exhibits dual programming performance, including swelling adjustment and providing slip for incorporated ligands, both of which can be used as dynamic scaffolds to regulate stem cell adhesion. Programmable dual-scale regulation of DNA nanostructures embedded in the hydrogel matrix was achieved, demonstrating a novel DNA-based materials pathway.