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The combination of ionizable lipids bearing alkyl chains and fluorinated alkyl chains improves the cellular uptake and mRNA expression of lipid nanoparticles.

The mutant form of the guanosine triphosphatase (GTPase) KRAS is a key driver in human tumors but remains a challenging therapeutic target, making KRAS MUT cancers a highly unmet clinical need. Here, we report a class of bottlebrush polyethylene glycol (PEG)–conjugated antisense oligonucleotides (ASOs) for potent in vivo KRAS depletion. Owing to their highly branched architecture, these molecular nanoconstructs suppress nearly all side effects associated with DNA–protein interactions and substantially enhance the pharmacological properties of the ASO, such as plasma pharmacokinetics and tumor uptake. Systemic delivery to mice bearing human non–small-cell lung carcinoma xenografts results in a significant reduction in both KRAS levels and tumor growth, and the antitumor performance well exceeds that of current popular ASO paradigms, such as chemically modified oligonucleotides and PEGylation using linear or slightly branched PEG. Importantly, these conjugates relax the requirement on the ASO chemistry, allowing unmodified, natural phosphodiester ASOs to achieve efficacy comparable to that of chemically modified ones. Both the bottlebrush polymer and its ASO conjugates appear to be safe and well tolerated in mice. Together, these data indicate that the molecular brush–ASO conjugate is a promising therapeutic platform for the treatment of KRAS -driven human cancers and warrant further preclinical and clinical development.

Despite potency against a variety of cancers in preclinical systems, melittin (MEL), a major peptide in bee venom, exhibits non-specific toxicity, severe hemolytic activity, and poor pharmacological properties. Therefore, its advancement in the clinical translation system has been limited to early-stage trials. Herein, we report a biohybrid involving a bottlebrush-architectured poly(ethylene glycol) (PEG) and MEL. Termed pacMEL, the conjugate consists of a high-density PEG arrangement, which provides MEL with steric inhibition against protein access, while the high molecular weight of pacMEL substantially enhances plasma pharmacokinetics with a ~ 10-fold increase in the area under the curve (AUC(∞)) compared to free MEL. The pacMEL also significantly reduces hepatic damage and unwanted innate immune response, and all but eliminated hemolytic activities of MEL. Importantly, pacMEL passively accumulates at subcutaneously inoculated tumor sites and exhibits stronger tumor-suppressive activity than molecular MEL. Collectively, pacMEL makes MEL a safer and a more appealing drug candidate.

The combination of metasurface and holographic technology is the most cutting-edge development, but most of the proposed designs are static and do not allow active changes through external stimulation after fabrication, which takes only a limited part of the advantage provided by metasurface. Here, we propose and demonstrate a switchable hybrid active metasurface hologram in the terahertz (THz) regime composed of dynamic pixels (VO

Interstitial fluid (ISF) provides important information of clinical value and physiological significance beyond blood tests for obtaining more precise health information and disease theranostics. Generally, current strategies are limited to simple extraction with time-consuming follow-up procedures. Facing challenges in efficient and real-time monitoring of target analytes in transdermal ISF, we develop metal-organic framework (MOF)-functionalized microneedle (MN) patches to achieve efficient antibiotics sampling, coupling direct analysis in real time mass spectrometry (DART-MS). The MOF MN microtrapper is constructed in a double-layered structure with a hard core and a better tissue penetration was accomplished. The MOF-based microtrapper manifests good in-vitro and in-vivo antibiotics tracking capability with a semi-quantitative method established. Moreover, the hydrogen-bond driven interaction is clarified by using molecular dynamics simulations (MDS) and related computational analysis. Good penetration safety is confirmed by histological analysis with promising clinical transnationality. We anticipate MOF MN-based microdevices provide a versatile minimally invasive strategy for transdermal ISF extraction and an extendable platform for a range of target molecules monitoring, including drugs, metabolites, biomarkers, et c, with promising clinical transnationality.

Soft lithography provides a convenient and effective method for the fabrication of microdevices with uniform size and shape. However, formation of an embossed, connective film as opposed to discrete features has been an enduring shortcoming associated with soft lithography. Removing this residual layer requires additional postprocessing steps that are often incompatible with organic materials. This limits adaptation and widespread realization of soft lithography for broader applications particularly in drug discovery and drug delivery fields. A novel and versatile approach is demonstrated that enables fabrication of discrete, multilayered, fillable, and harvestable microparticles directly from any thermoplastic polymer, even at very high molecular weights. The approach, isolated microparticle replication via surface-segregating polymer blend mold, utilizes a random copolymer additive, designed with a highly fluorinated segment that, when blended with the mold's matrix, spontaneously orients to the surface conferring an extremely low surface energy and nonwetting properties to the template. The extremely nonwetting properties of the mold are further utilized to load soluble biologics directly into the built-in microwells in a rapid and efficient manner using an innovative screen-printing approach. It is believed that this approach holds promise for fabrication of large-array, 3D, complex microstructures, and is a significant step toward clinical translation of microfabrication technologies.

The modulation of the terahertz (THz) wave is fundamental for its applications in next-generation communications, biological imaging, sensing, and so forth. Searching for higher efficient modulation is still in progress, although plenty of materials have been explored for tuning THz wave. In this work, optical-transparent self-assembled MXene films are used to modulate the THz reflection at the SiO2/MXene/air interface based on the impedance matching mechanism. By adjusting the number of stacked MXene layers/concentrations of MXene dispersions, the sheet conductivity of the MXene films will be changed so that the impedance at the SiO2/MXene/air interface can be tuned and lead to a giant modulation of THz reflection. Particularly, we demonstrate that the MXene films have highly efficient THz modulation from antireflection to reflection-enhancing with a relative reflection of 27% and 406%, respectively. This work provides a new pathway for developing the MXene films with the combination of optical-transparency and high smart THz reflection characteristics, and the films can be applied for THz antireflection or reflection-enhancing.

Oligonucleotide-based materials such as spherical nucleic acid (SNA) have been reported to exhibit improved penetration through the epidermis and the dermis of the skin upon topical application. Herein, we report a self-assembled, skin-depigmenting SNA structure, which is based upon a bifunctional oligonucleotide amphiphile containing an antisense oligonucleotide and a tyrosinase inhibitor prodrug. The two components work synergistically to increase oligonucleotide cellular uptake, enhance drug solubility, and promote skin penetration. The particles were shown to reduce melanin content in B16F10 melanoma cells and exhibited a potent antimelanogenic effect in an ultraviolet B-induced hyperpigmentation mouse model.

DNA biotechnology offers intriguing opportunities for amplification-based sensitive detection. However, spatiotemporally-controlled manipulation of signal amplification for in situ imaging of the tumor microenvironment remains an outstanding challenge. Here, we demonstrate a DNA-based strategy that can spatial-selectively amplify the acidic signal in the extracellular milieu of the tumor to achieve specific imaging with improved sensitivity. The strategy, termed mild acidosis-targeted amplification (MAT-amp), leverages the specific acidic microenvironment to engineer tumor cells with artificial DNA receptors through a pH (low) insertion peptide, which permits controlled recruitment of fluorescent amplifiers via a hybridization chain reaction. The acidosis-responsive amplification cascade enables significant fluorescence enhancement in tumors with a reduced background signal in normal tissues, leading to improved signal-to-background ratio. These results highlight the utility of MAT-amp for in situ imaging of the microenvironment characterized by pH disequilibrium.

The implementation of Terahertz (THz) modulation is critical for applications in high-speed wireless communications, security screening and so on. Therefore, it is particularly significant to obtain THz wave modulation devices with stable and flexible performance, easy manipulation of the modulation method, and multi-functionality. Here, we propose a flexible all-dielectric metamaterial by embedding zirconia (ZrO2) microspheres into a vanadium dioxide/polydimethylsiloxane (VO2/PDMS) composite, which can achieve thermal and mechanical tuning of THz wave transmission. When the temperature of the ZrO2/VO2/PDMS metamaterial increases, VO2 changes from the insulating phase to the metallic phase, and the 1st (at 0.304 THz) and 2nd (at 0.414 THz) order magnetic resonances exhibit the tunability of 20 GHz and 15 GHz, respectively. When stretched, the 1st and 2nd order magnetic resonances show the tunability of 12 GHz and 10 GHz, respectively. In the meantime, there are accompanying changes in transmittance at the resonances. The ZrO2/VO2/PDMS all-dielectric metamaterial presented in this work provides an alternative strategy for developing actively tunable, flexible, and versatile THz devices. In addition, it has the merits of simple preparation and low cost, promising large-area and rapid preparation of meta-arrays.

Background: Cancer nanovaccine has become a promising approach for cancer immunotherapy. The major challenge of cancer vaccines is limited efficacy caused by lack of desirable tumor specific antigens (TSA). Chemotherapeutics can trigger immunogenic cell death (ICD) and release TSAs, which initiate tumor-specific immune responses. However, ICD-triggered immune responses are usually not potent enough to eliminate the tumor cells. Herein, we developed liposomal spherical nucleic acids (SNA) that can simultaneously deliver and release doxorubicin (DOX) and CpG oligonucleotides upon biological stimuli in tumors to augment antitumor immune responses. Results: SNA nanoparticle increased DOX accumulation at the tumor tissue to induce tumor cells apoptosis and autophagy to activate both ICD-triggered and autophagy-mediated Th1-type immune responses. Meanwhile, CpG, which was co-delivered with DOX, functioned synergistically to potentiate the antitumor immune responses. These nanoparticles effectively inhibited tumor growth and extended animal survival of a mouse lymphoma model. Conclusions: This work provided a simple strategy of delivering chemotherapeutics and adjuvants to tumors to improve immunotherapeutic efficacy of nanovaccines.

Chemotherapeutics that can trigger immunogenic cell death (ICD) and release tumor-specific antigens are effective on treating a variety of cancers. The codelivery of chemotherapeutics with adjuvants is a promising strategy to achieve synergistic therapeutic effect. However, low drug loading and complicated preparation of current delivery systems lead to carrier-associated toxicity and immunogenicity. Herein, we developed a facile approach to construct liposomal spherical nucleic acids (SNA) by the self-assembly of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE)-doxorubicin conjugate and DOPE-matrix metalloproteinases-9 (MMP-9) responsive peptide-CpG conjugate (DOPE-MMP-CpG). Liposomal SNAs efficiently co-delivered DOX and CpG into tumors and released the two drugs upon biological stimuli of MMP-9 enzyme in tumor microenvironment (TME) and high concentration of endogenous glutathione in tumor cells. We demonstrated that liposomal SNA enhanced activation of dendritic cells (DCs), promoted expansion of CD8+ and CD4+ T cells in both tumors and spleen, inhibited tumor growth, and extended animal survival. This work provided a simple strategy of delivering chemotherapeutics and adjuvants to tumors with synergistic therapeutic effect and reduced side effect. Graphical Abstract

Checkpoint inhibitors, such as antibodies blocking the PD-1/PD-L1 pathway, are among the most promising immunotherapies to treat metastatic cancers, but their response rate remains low. In addition, the usage of monoclonal antibodies as checkpoint inhibitors is associated with a series of drawbacks. Herein, an all synthetic nanoparticle with PD-L1 blockade capability is developed for cancer photothermal-immunotherapy. The polymeric nanoparticle integrates photothermal treatment, antitumor vaccination, and PD-1/PD-L1 blockade in a single system to augment the antitumor efficacy. In a CT26 bilateral tumor model, intravenously injected nanoparticles accumulate in tumor sites and mediate strong photothermal effects, eradicate the NIR treated primary tumors and elicit strong antitumor immunity by inducing immunogenic cell death (ICD). Growth of the untreated distant tumors is also suppressed due to the synergies of systemic antitumor immune activation and PD-L1 blockade. Our strategy offers a simple but promising approach for the treatment of metastatic cancer.

The combination of metasurface and holographic technology is the most cutting-edge development, but most of the proposed designs are static and do not allow active changes through external stimulation after fabrication, which takes only a limited part of the advantage provided by metasurface. Here, we propose and demonstrate a switchable hybrid active metasurface hologram in the terahertz (THz) regime composed of dynamic pixels (VO2-CSRR) and static pixels (Au-CSRR) based on an intelligent algorithm, which can display some/all information in different temperature ranges. In particular, such performance shows excellent potential in the field of optical communication security, making it a promising candidate. To prove this possibility, we propose a scheme for optical information encryption/decryption and transmission, which takes metasurfaces as carriers of encrypted information and state/polarization/positions as the secret key components. Only when the two matches correctly can we get the hidden real information. The security of our proposed scheme has reached an unprecedented level, providing a new road for communication security.

Nanovaccines have emerged as promising alternatives or complements to conventional cancer treatments. Despite the progresses, specific co-delivery of antigen and adjuvant to their corresponding intracellular destinations for maximizing the activation of antitumor immune responses remains a challenge. Herein, a lipid-coated iron oxide nanoparticle is delivered as nanovaccine (IONP-C/O@LP) that can co-deliver peptide antigen and adjuvant (CpG DNA) into cytosol and lysosomes of dendritic cells (DCs) through both membrane fusion and endosome-mediated endocytosis. Such two-pronged cellular uptake pattern enables IONP-C/O@LP to synergistically activate immature DCs. Iron oxide nanoparticle also exhibits adjuvant effects by generating intracellular reactive oxygen species, which further promotes DC maturation. IONP-C/O@LP accumulated in the DCs of draining lymph nodes effectively increases the antigen-specific T cells in both tumor and spleen, inhibits tumor growth, and improves animal survival. Moreover, it is demonstrated that this nanovaccine is a general platform of delivering clinically relevant peptide antigens derived from human papilloma virus 16 to trigger antigen-specific immune responses in vivo.

We investigate particle injectability as an essential parameter for design of microparticle-based drug delivery systems., Inefficient injection of microparticles through conventional hypodermic needles can impose serious challenges on clinical translation of biopharmaceutical drugs and microparticle-based drug formulations. This study aims to determine the important factors affecting microparticle injectability and establish a predictive framework using computational fluid dynamics, design of experiments, and machine learning. A numerical multiphysics model was developed to examine microparticle flow and needle blockage in a syringe-needle system. Using experimental data, a simple empirical mathematical model was introduced. Results from injection experiments were subsequently incorporated into an artificial neural network to establish a predictive framework for injectability. Last, simulations and experimental results contributed to the design of a syringe that maximizes injectability in vitro and in vivo. The custom injection system enabled a sixfold increase in injectability of large microparticles compared to a commercial syringe. This study highlights the importance of the proposed framework for optimal injection of microparticle-based drugs by parenteral routes.

Herein, we report the DNA-mediated self-assembly of bivalent bottlebrush polymers, a process akin to the step-growth polymerization of small molecule monomers. In these "condensation reactions", the polymer serves as a steric guide to limit DNA hybridization in a fixed direction, while the DNA serves as a functional group equivalent, connecting complementary brushes to form well-defined, one-dimensional nanostructures. The polymerization was studied using spectroscopy, microscopy, and scattering techniques and was modeled numerically. The model made predictions of the degree of polymerization and size distribution of the assembled products, and suggested the potential for branching at hybridization junctions, all of which were confirmed experimentally. This study serves as a theoretical basis for the polymer-assembly approach which has the potential to open up new possibilities for suprapolymers with controlled architecture, macromonomer sequence, and end-group functionalities.

Significance Spherical nucleic acids (SNAs) made thus far are inherently polydisperse due to variations in surface nucleic acid density, particle size, or both. In this article, we describe the synthesis and characterization of two types of molecular SNAs with precise numbers of surface DNA strands using T 8 polyoctahedral silsesquioxane and buckminsterfullerene C 60 scaffolds. The surface DNA densities for these molecular structures fall inside the range of typical SNAs, which allows them to exhibit SNA-related properties, including enhanced cellular uptake and the ability to function as a gene regulation agent. With a route to molecularly pure SNAs opened, it becomes possible to use them to unveil the molecular details of SNA interactions with complementary ligands and living systems.

Herein, we design and synthesize site-specifically PEGylated oligonucleotide hairpins and demonstrate that their ability to undergo hybridization chain reaction is nearly unaffected by the PEGylation. The resulting DNA-backboned bottlebrush polymers with PEG side chains exhibit increased resistance against nucleolytic degradation, enhanced thermal stabilities, and elevated blood retention times in vivo, which collectively pave the way for more therapeutically focused DNA nanostructure designs.

PEGylation of an oligonucleotide using a brush polymer can improve its biopharmaceutical characteristics, including enzymatic stability and biodistribution. Herein, we quantitatively explore the nuclease accessibility of the nucleic acid as a function of “depth” towards the backbone of the brush polymer. It is found that protein accessibility decreases as the nucleotide is located closer to the backbone. Thus, by moving the conjugation point from the terminus of the nucleic acid strand to an internal position, much smaller brushes can be used to achieve the same level of steric shielding. This finding also makes it possible to assess antisense gene regulation efficiency of these brush-DNA conjugates as a function of their nuclease stability.

Activation of the stimulator of interferon gene (STING) pathway within the tumor microenvironment has been shown to generate a strong antitumor response. Although local administration of STING agonists has promise for cancer immunotherapy, the dosing regimen needed to achieve efficacy requires frequent intratumoral injections over months. Frequent dosing for cancer treatment is associated with poor patient adherence, with as high as 48% of patients failing to comply. Multiple intratumoral injections also disrupt the tumor microenvironment and vascular networks and therefore increase the risk of metastasis. Here, we developed microfabricated polylactic-co-glycolic acid (PLGA) particles that remain at the site of injection and release encapsulated STING agonist as a programmable sequence of pulses at predetermined time points that mimic multiple injections over days to weeks. A single intratumoral injection of STING agonist-loaded microparticles triggered potent local and systemic antitumor immune responses, inhibited tumor growth, and prolonged survival as effectively as multiple soluble doses, but with reduced metastasis in several mouse tumor models. STING agonist-loaded microparticles improved the response to immune checkpoint blockade therapy and substantially decreased the tumor recurrence rate from 100 to 25% in mouse models of melanoma when administered during surgical resection. In addition, we demonstrated the therapeutic efficacy of STING microparticles on an orthotopic pancreatic cancer model in mice that does not allow multiple intratumoral injections. These findings could directly benefit current STING agonist therapy by decreasing the number of injections, reducing risk of metastasis, and expanding its applicability to hard-to-reach cancers.

Development of safe and effective delivery vectors remains a critical challenge for oligonucleotides-based biopharmaceuticals. In this work, we incorporate antisense oligonucleotides into micellar nanoparticles via co-assembly of two block copolymers, DNA-b-poly(ɛ-caprolactone) and poly(ethylene glycol)-b-poly(ɛ-caprolactone), and the hydrophobic homopolymer, poly(ɛ-caprolactone). By fine-tuning the spacing of particle surface moieties through adding a diluent homopolymer to the micellar core, we conduct a systematic investigation of structure-property correlations among hybridization kinetics, nuclease resistance, cellular uptake, and antisense efficacy. It is found that, when an intermediate density is achieved, nuclease access of the DNA is greatly hindered, but formation of double-stranded DNA is nearly unaffected. Remarkably, micelles showing the highest selectivity (good nuclease resistance while still maintaining hybridization kinetics) also exhibit the highest antisense gene silencing efficacies. ...

PEGylation, the attachment of poly(ethylene glycol) (PEG), has been adopted to improve the pharmacokinetic properties of oligonucleotide therapeutics for nearly 30 years. Prior efforts mainly focused on the investigation of linear or slightly branched PEG having different molecular weights, terminal functional groups, and possible oligonucleotide sites for functionalization. Recent studies on highly branched PEG (including brush, star, and micellar structures) indicate superior properties in several areas including cellular uptake, gene regulation efficacy, reduction of side effects, and biodistribution. This review focuses on comparing the effects of PEG architecture on the physiochemical and biological properties of the PEGylated oligonucleotide.

Bottlebrush-structured PEG substantially enhances the pharmacokinetics of conjugated siRNA and RNAi activity in vivo., Nonhepatic delivery of small interfering RNAs (siRNAs) remains a challenge for development of RNA interference–based therapeutics. We report a noncationic vector wherein linear poly(ethylene glycol) (PEG), a polymer generally considered as inert and safe biologically but ineffective as a vector, is transformed into a bottlebrush architecture. This topology provides covalently embedded siRNA with augmented nuclease stability and cellular uptake. Consisting almost entirely of PEG and siRNA, the conjugates exhibit a ~25-fold increase in blood elimination half-life and a ~19-fold increase in the area under the curve compared with unmodified siRNA. The improved pharmacokinetics results in greater tumor uptake and diminished liver capture. Despite the structural simplicity these conjugates efficiently knock down target genes in vivo without apparent toxic and immunogenic reactions. Given the benign biological nature of PEG and its widespread precedence in biopharmaceuticals, we anticipate the brush polymer–based technology to have a significant impact on siRNA therapeutics.

Micronutrient deficiencies affect up to 2 billion people and are the leading cause of cognitive and physical disorders in the developing world. Food fortification is effective in treating micronutrient deficiencies; however, its global implementation has been limited by technical challenges in maintaining micronutrient stability during cooking and storage. We hypothesized that polymer-based encapsulation could address this and facilitate micronutrient absorption. We identified poly(butylmethacrylate-co-(2-dimethylaminoethyl)methacrylate-co-methylmethacrylate) (1:2:1) (BMC) as a material with proven safety, offering stability in boiling water, rapid dissolution in gastric acid, and the ability to encapsulate distinct micronutrients. We encapsulated 11 micronutrients (iron; iodine; zinc; and vitamins A, B2, niacin, biotin, folic acid, B12, C, and D) and co-encapsulated up to 4 micronutrients. Encapsulation improved micronutrient stability against heat, light, moisture, and oxidation. Rodent studies confirmed rapid micronutrient release in the stomach and intestinal absorption. Bioavailability of iron from microparticles, compared to free iron, was lower in an initial human study. An organotypic human intestinal model revealed that increased iron loading and decreased polymer content would improve absorption. Using process development approaches capable of kilogram-scale synthesis, we increased iron loading more than 30-fold. Scaled batches tested in a follow-up human study exhibited up to 89% relative iron bioavailability compared to free iron. Collectively, these studies describe a broad approach for clinical translation of a heat-stable ingestible micronutrient delivery platform with the potential to improve micronutrient deficiency in the developing world. These approaches could potentially be applied toward clinical translation of other materials, such as natural polymers, for encapsulation and oral delivery of micronutrients.

Nucleic acids are generally regarded as the payload in gene therapy, often requiring a carrier for intracellular delivery. With the recent discovery that spherical nucleic acids enter cells rapidly, we demonstrate that nucleic acids also have the potential to act as a delivery vehicle. Herein, we report an amphiphilic DNA-paclitaxel conjugate, which forms stable micellar nanoparticles in solution. The nucleic acid component acts as both a therapeutic payload for intracellular gene regulation and the delivery vehicle for the drug component. A bioreductively activated, self-immolative disulfide linker is used to tether the drug, allowing free drug to be released upon cell uptake. We found that the DNA-paclitaxel nanostructures enter cells ∼100 times faster than free DNA, exhibit increased stability against nuclease, and show nearly identical cytotoxicity as free drug. These nanostructures allow one to access a gene target and a drug target using only the payloads themselves, bypassing the need for a cocarrier system.

Negatively charged nucleic acids are often complexed with polycationic transfection agents before delivery. Herein, we demonstrate that a noncationic, biocompatible polymer, polyethylene glycol, can be used as a transfection vector by forming a brush polymer-DNA conjugate. The brush architecture provides embedded DNA strands with enhanced nuclease stability and improved cell uptake. Because of the biologically benign nature of the polymer component, no cytotoxicity was observed. This approach has the potential to address several long-lasting challenges in oligonucleotide therapeutics.

The emergence of antimicrobial resistance poses a major challenge to healthcare. Probiotics offer a potential alternative treatment method but are often incompatible with antibiotics themselves, diminishing their overall therapeutic utility. This work uses biofilm-inspired encapsulation of probiotics to confer temporary antibiotic protection and to enable the coadministration of probiotics and antibiotics. Probiotics are encapsulated within alginate, a crucial component of pseudomonas biofilms, based on a simple two-step alginate cross-linking procedure. Following exposure to the antibiotic tobramycin, the growth and metabolic activity of encapsulated probiotics are unaffected by tobramycin, and they show a four-log survival advantage over free probiotics. This results from tobramycin sequestration on the periphery of alginate beads which prevents its diffusion into the core but yet allows probiotic byproducts to diffuse outward. It is demonstrated that this approach using tobramycin combined with encapsulated probiotic has the ability to completely eradicate methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa in coculture, the two most widely implicated bacteria in chronic wounds.

Nanopore-based sensors for nucleic acid sequencing and single-molecule detection typically employ pore-forming membrane proteins with hydrophobic external surfaces, suitable for insertion into a lipid bilayer. In contrast, hydrophilic pore-containing molecules, such as DNA origami, have been shown to require chemical modification to favor insertion into a lipid environment. In this work, we describe a strategy for inserting polar proteins with an inner pore into lipid membranes, focusing here on a circular 12-subunit assembly of the thermophage G20c portal protein. X-ray crystallography, electron microscopy, molecular dynamics, and thermal/chaotrope denaturation experiments all find the G20c portal protein to have a highly stable structure, favorable for nanopore sensing applications. Porphyrin conjugation to a cysteine mutant in the protein facilitates the protein’s insertion into lipid bilayers, allowing us to probe ion transport through the pore. Finally, we probed the portal interior size and shape using a series of cyclodextrins of varying sizes, revealing asymmetric transport that possibly originates from the portal’s DNA-ratchet function.

Difficult biopharmaceutical characteristics of oligonucleotides, such as poor enzymatic stability, rapid clearance by reticuloendothelial organs, immunostimulation, and coagulopathies, limit their application as therapeutics. Many of these side effects are initiated via sequence-specific or nonsequence-specific interactions with proteins. Herein, we report a novel form of brush-polymer/DNA conjugate that provides the DNA with nanoscale steric selectivity: Hybridization kinetics with complementary DNA remains nearly unaffected, but interactions with proteins are significantly retarded. The relative lengths of the brush side chain and the DNA strand are found to play a critical role in the degree of selectivity. Being able to evade protein adhesion also improves in vivo biodistribution, thus making these molecular nanostructures promising materials for oligonucleotide-based therapies.