Nucleic Acid Nanostructure Assisted Immune Modulation

Morphology Dictated Immune Activation with Framework Nucleic Acids

Framework nucleic acids (FNAs) of various morphologies, designed using the precise and programmable Watson-Crick base pairing, serve as carriers for biomolecule delivery in biology and biomedicine. However, the impact of their shape, size, concentration, and the spatial presentation of cytosine-phosphate-guanine oligodeoxynucleotides (CpG ODNs) on immune activation remains incompletely understood. In this study, representative FNAs with varying morphologies are synthesized to explore their immunological responses. Low concentrations (50 nM) of all FNAs elicited no immunostimulation, while high concentrations of elongated DNA nanostrings and tetrahedrons triggered strong activation due to their larger size and increased cellular uptake, indicating that the innate immune responses of FNAs depend on both dose and morphology. Notably, CpG ODNs' immune response can be programmed by FNAs through regulating the spatial distance, with optimal spacing of 7-8 nm eliciting the highest immunostimulation. These findings demonstrate FNAs' potential as a designable tool to study nucleic acid morphology's impact on biological responses and provide a strategy for future CpG-mediated immune activation carrier design.

Locoregional Lymphatic Delivery Systems Using Nanoparticles and Hydrogels for Anticancer Immunotherapy

The lymphatic system has gained significant interest as a target tissue to control cancer progress, which highlights its central role in adaptive immune response. Numerous mechanistic studies have revealed the benefits of nano-sized materials in the transport of various cargos to lymph nodes, overcoming barriers associated with lymphatic physiology. The potential of sustained drug delivery systems in improving the therapeutic index of various immune modulating agents is also being actively discussed. Herein, we aim to discuss design rationales and principles of locoregional lymphatic drug delivery systems for invigorating adaptive immune response for efficient antitumor immunotherapy and provide examples of various advanced nanoparticle- and hydrogel-based formulations.

A molecular beacon-like Ag nanocluster fluorescence probe for nucleic acid detection

We have developed a type of low-cost, label-free silver nanocluster molecular beacon-like fluorescence sensor with a DNA template. To detect target DNA with this probe, we use a hairpin DNA sequence based on a "turn-on" strategy. The transformation of hairpin DNA would visibly influence the formation of Ag nanoclusters, such that the stronger fluorescence will be measured with the solution containing target nucleic acids than that without targets nucleic acids. There is a good liner relationship between the fluorescence and the target DNA concentrations, ranging from 1 to 750 nmol L-1. Importantly, the detection sensing platform allows down to 1 nmol L-1, which is much lower than other studies.

Functional Immunostimulating DNA Materials: The Rising Stars for Cancer Immunotherapy

Cancer immunotherapy has risen as a promising method in clinical practice for cancer treatment and DNA-based immune intervention materials, along with DNA nanotechnology, have obtained increasing importance in this field. In this review, various immunostimulating DNA materials are introduced and the mechanisms via which they exerted an immune effect are explained. Then, representative examples in which DNA is used as the leading component for anticancer applications through immune stimulation are provided and their efficacy is evaluated. Finally, the challenges for those materials in clinical applications are discussed and suggestions for possible further research directions are also put forward.