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A new class of polymer spherical nucleic acid (SNA) conjugates comprised of poly(lactic-co-glycolic acid) (PLGA) nanoparticle (NP) cores is reported. The nucleic acid shell that defines the PLGA-SNA exhibits a half-life of more than 2 h in fetal bovine serum. Importantly, the PLGA-SNAs can be utilized to encapsulate a hydrophobic model drug, coumarin 6, which can then be released in a polymer composition-dependent tunable manner, while the dissociation rate of the nucleic acid shell remains relatively constant, regardless of core composition. Like prototypical gold NP conjugate SNAs, PLGA-SNAs freely enter Raw-Blue cells and can be used to activate toll-like receptor 9 in a sequence- and dose-dependent manner. Taken together, the data show that this novel nanoconstruct provides a means for controlling the release kinetics of encapsulated cargos in the context of the SNA platform, which may be useful for developing combination therapeutics.

Plants are naturally abundant and display high sensitivity to ecological factors to thrive in diverse environmental conditions. As sessile organisms, they have evolved complex, internal, and interplant signaling pathways with distinct structures to promptly adjust to the constantly changing environment. In the past five years, the unique ways in which they exchange information with and function in the environment have inspired an emerging field of plant nanobionics, which describes the interface between living plants and nanotechnology to impart the former with novel and useful functions. The structural merits of plant organs and organelles have also inspired the creation of plant‐derived structures through biointerfacing with nanoparticles containing electronic and optical properties. Here, the emerging applications and vision of plant nanobionics are highlighted together with related plant‐inspired materials in potentially replacing the myriad devices in the everyday lives stamped out of plastic, containing circuit boards and consuming power from the electrical grid. Applications in environmental sensing, communication devices, and energy harvesting and conversion are comprehensively discussed.

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Nanosensors have proven to be powerful tools to monitor single cells, achieving spatiotemporal precision even at molecular level. However, there has not been way of extending this approach to statistically relevant numbers of living cells. Herein, we design and fabricate nanosensor array in microfluidics that addresses this limitation, creating a Nanosensor Chemical Cytometry (NCC). nIR fluorescent carbon nanotube array is integrated along microfluidic channel through which flowing cells is guided. We can utilize the flowing cell itself as highly informative Gaussian lenses projecting nIR profiles and extract rich information. This unique biophotonic waveguide allows for quantified cross-correlation of biomolecular information with various physical properties and creates label-free chemical cytometer for cellular heterogeneity measurement. As an example, the NCC can profile the immune heterogeneities of human monocyte populations at attomolar sensitivity in completely non-destructive and real-time manner with rate of ~600 cells/hr, highest range demonstrated to date for state-of-the-art chemical cytometry.

As the male gametophyte of flowering plants, pollen grains are ideal targets for the introduction of transgenes for plant genetic engineering and crop improvement. However, the difficulty of delivering exogenous DNA into pollen grains, because of chemically inert cell walls, has hindered their widespread application in plant biotechnology. Herein, we report a new class of nanocarriers, composed of imidazolium (IM)-functionalized single-walled carbon nanotubes (SWNTs), which can efficiently traverse past pollen barriers and deliver genes without external physical aid. IM-SWNTs display high biocompatibility with pollen grains, compared to existing SWNT nanocarriers previously used for cargo delivery into living plant cells. Using IM-SWNTs as nanotransporters, we investigate the compatibility of various pollen-specific promoters with oil palm pollen transcription machinery. We show that nanoparticle transport past the pollen plasma membrane is mainly controlled by its zeta potential, and we describe this entry mechanism with the lipid exchange envelope penetration model. We further estimate the pollen membrane effective dielectric constant with this model. These findings provide insights for the rational design and refinement of nanocarriers for plant biotechnology applications.

Colloidal dispersions of nanomaterials are often polydisperse in size, significantly complicating their characterization. This is particularly true for materials early in their historical development due to synthetic control, dispersion efficiency, and instability during storage. Because a wide range of system properties and technological applications depend on particle dimensions, it remains an important problem in nanotechnology to identify a method for the routine characterization of polydispersity in nanoparticle samples, especially changes over time. Commonly employed methods such as dynamic light scattering or analytical ultracentrifugation (AUC) accurately estimate only the first moment of the distribution or are not routine. In this work, the use of single‐particle tracking (SPT) to probe size distributions of common nanoparticle dispersions, including polystyrene nanoparticles, single‐walled carbon nanotubes, graphene oxide, chitosan‐tripolyphosphate, acrylate, hexagonal boron nitride, and poly(lactic‐co‐glycolic acid), is proposed and explored. The analysis of particle tracks is conducted using a newly developed Bayesian algorithm that is called Maximum A posteriori Nanoparticle Tracking Analysis. By combining SPT and AUC techniques, it is shown that it is possible to independently estimate the mean aspect ratio of anisotropic particles, an important characterization property. It is concluded that SPT provides a facile, rapid analytical method for routine nanomaterials characterization.

Macrophages are a critical part of the human immune response, and their collective heterogeneity is implicated in disease progression and prevention. A nondestructive, label-free tool does not currently exist for profiling the dynamic, antigenic responses of single macrophages in a collection to correlate with specific molecular expression and correlated biophysical properties at the cellular level, despite the potential for diagnosis and therapeutics. Herein, we develop a nanosensor chemical cytometry (NCC) that can profile the heterogeneity of inducible nitric oxide synthase (iNOS) responses from macrophage populations. By integrating a near-infrared (nIR) fluorescent nanosensor array and collagen layer with microfluidics, the cellular lensing effect of the macrophage was utilized to characterize both nitric oxide (NO) efflux and refractive index (RI) changes at a single-cell level. Using a parallel, multichannel approach, distinct iNOS heterogeneities of macrophages can be monitored at an attomolar (10 −18 mol) sensitivity in a nondestructive and real-time manner with a throughput of exceeding the 200 cells/frame. We demonstrate that estimated mean NO efflux rates of macrophage populations are elevated from 342 (σ = 199) to 464 (σ = 206) attomol/cell•hr with a 3% larger increase in the heterogeneity, and estimated RI of macrophage decrease from 1.366 (σ = 0.015) to 1.359 (σ = 0.009) with trimodal subpopulations under lipopolysaccharide (LPS) activation. These measured values are also in good agreement with Griess assay results and previously reported measurements. This work provides an efficient strategy for single-cell analysis of macrophage populations for cellular manufacturing and biopharmaceutical engineering.