DNA-Based Daisy Chain Rotaxane Nanocomposite Hydrogels as Dual-Programmable Dynamic Scaffolds for Stem Cell Adhesion

Abstract

Interlocked DNA nanostructures perform programmable movements in nanoscales such as sliding, contraction, and expansion. However, utilizing nanoscaled interlocked movements to regulate the functions of larger length scaled matrix and developing their applications has not yet been reported. Herein we describe the assembly of DNA-based daisy chain rotaxane nanostructure (DNA-DCR) composed of two hollow DNA nanostructures as macrocycles, two interlocked axles and two triangular prism-shaped DNA structures as stoppers, in which three mechanical statesfixed extended state (FES), sliding state (SS), and fixed contracted state (FCS)are characterized by using toehold-mediated strand displacement reaction (SDR). The DNA-DCRs are further used as nanocomposites and introduced into hydrogel matrix to produce interlocked hydrogels, which shows modulable stiffness by elongating the interlocked axles to regulate the hydrogel swelling with hybridization chain reaction (HCR) treatment. Then the DCR-hydrogels are employed as dynamic biointerfaces for human mesenchymal stem cells (hMSCs) adhesion studies. First, hMSCs showed lower cell density on bare DCR-hydrogel treated with HCR-initiated swelling for stiffness decreasing. Second, the cell adhesion ligand (RGD) modified DNA-DCRs are constructed for hydrogel functionalization. DCR (RGD) hydrogel endows the mobility of RGDs by switching the mechanical states of DNA-DCR. HMSCs showed increased cell density on DCR SS(RGD) hydrogel than on DCR FCS(RGD) hydrogel. Therefore, our DNA-DCR nanocomposite hydrogel exhibit dual-programmable performances including swelling adjustment and offering sliding for incorporated ligands, which can be both utilized as dynamic scaffolds for regulating the stem cell adhesion. The dual-programmable cross-scale regulation from interlocked DNA nanostructures to hydrogel matrix was achieved, demonstrating a new pathway of DNA-based materials.

Daisy chain architectures: from discrete molecular entities to polymer materials

“…Recently, the groups of Yang and Qian described the first polymer material made of DNA-based daisy chain rotaxanes (DNA-DCR). 99 After confirming the nanoscale motion of the DNA-DCR by fluorescence experiments, a polyacrylamide hydrogel with DNA-DCR as cross-links was synthesized. However, although the swelling degree of the hydrogel and its stiffness could be controlled by the addition of hairpin DNA strands which can initiate hybridization chain reaction (HCR) on the axles of the DNA-DCR, the changes observed at the macroscopic level were not related to a motion of the mechanical bond but to an elongation of the axles by HCR.…”

Investigation of the Impact of Hydrogen Bonding Degree in Long Single-Stranded DNA (ssDNA) Generated with Dual Rolling Circle Amplification (RCA) on the Preparation and Performance of DNA Hydrogels

“…In fact, the integration of various nanomaterials, including gold/silver nanoparticles (Au/Ag NPs), carbon materials, magnetic nanoparticles, and clays, into DNA hydrogels [36,37] has become a commonly used approach to regulating the properties of DNA hydrogels [38]. This is attributed to the fact that nanomaterials offer a broader spectrum of opportunities and potential for the utilization of DNA hydrogels, as they enhance mechanical properties, improve stability, regulate morphology and structure, and provide responsiveness.…”