Measurement of Radial Elasticity and Original Height of DNA Duplex Using Tapping-Mode Atomic Force Microscopy

Nucleic acid nanostructures for in vivo applications: The influence of morphology on biological fate

The development of programmable biomaterials for use in nanofabrication represents a major advance for the future of biomedicine and diagnostics. Recent advances in structural nanotechnology using nucleic acids have resulted in dramatic progress in our understanding of nucleic acid-based nanostructures (NANs) for use in biological applications. As the NANs become more architecturally and functionally diverse to accommodate introduction into living systems, there is a need to understand how critical design features can be controlled to impart desired performance in vivo. In this review, we survey the range of nucleic acid materials utilized as structural building blocks (DNA, RNA, and xenonucleic acids), the diversity of geometries for nanofabrication, and the strategies to functionalize these complexes. We include an assessment of the available and emerging characterization tools used to evaluate the physical, mechanical, physiochemical, and biological properties of NANs in vitro. Finally, the current understanding of the obstacles encountered along the in vivo journey is contextualized to demonstrate how morphological features of NANs influence their biological fates. We envision that this summary will aid researchers in the designing novel NAN morphologies, guide characterization efforts, and design of experiments and spark interdisciplinary collaborations to fuel advancements in programmable platforms for biological applications.

Insight into Drug Loading Regulated Micellar Rigidity by Nuclear Magnetic Resonance

The rigidity of polymeric micelles plays an important role in their biological behaviors. However, how drug loading affects the rigidity of polymeric micelles remains elusive. Herein, the indomethacin (IMC)-loaded Pluronic F127 micelle is used as a model system to illustrate the impact of drug loading on the rigidity and biological behaviors of polymeric micelles. Against expectations, micelles with moderate drug loading show higher cellular uptake and more severe cytotoxicity as compared to both high and low drug loading counterparts. Extensive one- and two-dimensional nuclear magnetic resonance (NMR) measurements are employed to reveal that the higher drug loading induces stronger interaction between IMC and hydrophilic block to boost the micellar rigidity; consequently, the moderate drug loading imparts micelles with appropriate rigidity for satisfactory cellular uptake and cytotoxicity. In summary, NMR spectroscopy is an important tool to gain insight into drug loading regulated micellar rigidity, which is helpful to understand their biological behaviors.