Condensation Ability Research Articles

Human Topoisomerase IIα Promotes Chromatin Condensation Via a Phase Transition.

Topoisomerase II (topo II) enzymes are essential enzymes known to resolve topological entanglements during DNA processing. Curiously, while yeast expresses a single topo II, humans express two topo II isozymes, topo IIα and topo IIβ, which share a similar catalytic domain but differ in their intrinsically disordered C-terminal domains (CTDs). During mitosis, topo IIα and condensin I constitute the most abundant chromosome scaffolding proteins essential for chromosome condensation. However, how topo IIα enables this function is poorly understood. Here, we discovered a new and functionally distinct role for human topo IIα - it condenses DNA and chromatin at a low topo IIα concentration (100 pM or less) during a polymer-collapse phase transition. The removal of the topo IIα CTDs effectively abolishes its condensation ability, indicating that the condensation is mediated by the CTDs. Although topo IIβ can also perform condensation, it is about 4-fold less effective. During the condensation, topo IIα-DNA condensates form along DNA, working against a DNA tension of up to 1.5 pN, greater than that previously reported for yeast condensin. In addition, this condensation does not require ATP and thus is independent of topo IIα's catalytic activity. We also found that condensation and catalysis can concurrently proceed with minimal mutual interference. Our findings suggest topo IIα may directly participate in chromosome condensation during mitosis.

GFP chromophore derived amphiphiles containing [12]aneN3 and biotin moieties as bio-imaging and targeting nonviral gene vectors

Gene therapy is a promising treatment, that brings the necessary opportunity to cure human genetic and major diseases, but it is hampered by the lack of safe and efficient gene delivery vectors. In this study, four amphiphiles were derived from GFP chromophore benzylimidazolidinone (G) through modifications with oxypropyl (1) or methylene (2) linked di(triazole-[12]aneN3) (M) in the presence or absence of tumor-targeting biotin (B) moiety, GMB-1/2 and GM-1/2. The four compounds showed excellent aggregation-induced emission (AIE) characteristics, strong DNA condensation abilities, and good biocompatibility. Among them, GMB-1, which containing targeting biotin moiety and a flexible propoxy linker, showed the highest transfection efficiency in three cell lines. The luciferase transfection efficiency of GMB-1 was as high as 15.2 times that of Lipofectamine 2000 (Lipo2000) without auxiliary lipid DOPE, and its gene therapy effect of delivering the p53 gene was also significantly better than that of Lipo2000 in HeLa cells due to its obvious targeting property. Fluorescence tracing experiments indicated that GMB-1 was able to quickly carry DNA into cells, to successfully escape from lysosomes, then to release DNA, and at last to smoothly deliver DNA into the nucleus. Moreover, its EGFP transfection efficiency in zebrafish reached 1.7 times that of Lipo2000. The excellent performance of GMB-1 demonstrated that the appreciative incorporation of GFP chromophore, di(triazole-[12]aneN3), and biotin moieties into the nonviral gene vectors provided a promising strategy for their clinical applications.

Temperature/GSH Dual Responsive Fluorinated Mesoporous Silica‐Coated Au NRs for Serum‐Resistant Gene Delivery**

AbstractMesoporous silica nanoparticles (MSN) are emerging as one of the most appealing candidates for gene carriers. Nevertheless, one major obstacle for their clinical application is the lack of efficient controlled release and gene delivery. In this study, a mesoporous silica‐modified gold nanorods (Au NRs) controlled release platform was synthesized. Then a thermosensitive copolymer was grafted to the surface of release platform, to impart the switching response of carrier under the photothermal of Au NRs. Fluorination were modified on the surface of MSN through a disulfide bond to achieve glutathione (GSH) response release and improve serum‐resistant ability. This gene carrier, with notable DNA condensation ability and negligible cytotoxicity, could be easily internalized into cells, enhanced green fluorescent protein expression in the presence of serum under laser irradiation. This work inspired us to solve the problem of traditional controllable sustained release and realize the performance of intracellular switch response to gene sustained release.

Getah virus capsid protein undergoes co-condensation with viral genomic RNA to facilitate virion assembly

Getah virus (GETV) belongs to the Alphavirus genus in the Togaviridae family and is a zoonotic arbovirus causing disease in both humans and animals. The capsid protein (CP) of GETV regulates the viral core assembly, but the mechanism underlying this process is poorly understood. In this study, we demonstrate that CP undergoes liquid-liquid phase separation (LLPS) with the GETV genome RNA (gRNA) in vitro and forms cytoplasmic puncta in cells. Two regions of GETV gRNA (nucleotides 1–4000 and 5000-8000) enhance CP droplet formation in vitro and the lysine-rich Link region of CP is essential for its phase separation. CP(K/R) mutant with all lysines in the Link region replaced by arginines exhibits improved LLPS versus wild type (WT) CP, but CP(K/E) mutant with lysines substituted by glutamic acids virtually loses condensation ability. Consistently, recombinant virus mutant with CP(K/R) possesses significantly higher gRNA binding affinity, virion assembly efficiency and infectivity than the virus with WT-CP. Overall, our findings provide new insights into the understanding of GETV assembly and development of new antiviral drugs against alphaviruses.

Nontoxic, Biodegradable Hyperbranched Poly(β-amino ester)s for Efficient siRNA Delivery and Gene Silencing.

RNA interference (RNAi)-mediated gene silencing is a promising therapeutic approach to treat various diseases, but safe and efficient delivery remains a major challenge to its clinical application. Non-viral gene vectors, such as poly(β-amino esters) (pBAEs), have emerged as a potential candidate due to their biodegradability, low toxicity profile, ease of synthesis, and high gene transfection efficiency for both DNA and siRNA delivery. However, achieving significant gene silencing using pBAEs often requires a large amount of polymer carrier (with polymer/siRNA weight ratio >100) or high siRNA dose (>100 nM), which might potentially exacerbate toxicity concerns during delivery. To overcome these barriers, we designed and optimized a series of hyperbranched pBAEs capable of efficiently condensing siRNA and achieving excellent silencing efficiency at a lower polymer/siRNA weight ratio (w/w) and siRNA dose. Through modulation of monomer combinations and branching density, we identified the top-performing hyperbranched pBAEs, named as h(A2B3)-1, which possess good siRNA condensation ability, low cytotoxicity, and high cellular uptake efficiency. Compared with Lipofectamine 2000, h(A2B3)-1 achieved lower cytotoxicity and higher siRNA silencing efficiency in HeLa cells at a polymer/siRNA weight ratio of 30 and 30 nM siRNA dose. Notably, h(A2B3)-1 enhanced the gene uptake in primary neural cells and effectively silenced the target gene in hard-to-transfect primary cortical neurons and oligodendrocyte progenitor cells, with gene knockdown efficiencies of 34.8 and 53.4% respectively. By incorporating a bioreducible disulfide compartment into the polymer backbone, the cytocompatibility of the h(A2B3)-1 was greatly enhanced while maintaining their good transfection efficiency. Together, the low cytotoxicity and high siRNA transfection efficiency of hyperbranched h(A2B3)-1 in this study demonstrated their great potential as a non-viral gene vector for efficient siRNA delivery and RNAi-mediated gene silencing. This provides valuable insight into the future development of safe and efficient non-viral siRNA delivery systems as well as their translation into clinical applications.

Phase separation of S-RNase promotes self-incompatibility in Petunia hybrida.

Self-incompatibility (SI) is an intraspecific reproductive barrier widely present in angiosperms. The SI system with the broadest occurrence in angiosperms is based on an S-RNase linked to a cluster of multiple S-locus F-box (SLF) genes found in the Solanaceae, Plantaginaceae, Rosaceae, and Rutaceae. Recent studies reveal that non-self S-RNase is degraded by the Skip Cullin F-box (SCF)SLF-mediated ubiquitin-proteasome system in a collaborative manner in Petunia, but how self-RNase functions largely remains mysterious. Here, we show that S-RNases form S-RNase condensates (SRCs) in the self-pollen tube cytoplasm through phase separation and the disruption of SRC formation breaks SI in self-incompatible Petunia hybrida. We further find that the pistil SI factors of a small asparagine-rich protein HT-B and thioredoxin h together with a reduced state of the pollen tube all promote the expansion of SRCs, which then sequester several actin-binding proteins, including the actin polymerization factor PhABRACL, the actin polymerization activity of which is reduced by S-RNase in vitro. Meanwhile, we find that S-RNase variants lacking condensation ability fail to recruit PhABRACL and are unable to induce actin foci formation required for pollen tube growth inhibition. Taken together, our results demonstrate that phase separation of S-RNase promotes SI response in P. hybrida, revealing a new mode of S-RNase action.

Amphiphilic polylactic acid-b-poly(N-(3-aminopropyl) methacrylamide) copolymers: Self-assembly to polymeric micelles for gene delivery

In this study, for the first time diblock copolymers of PLA-b-PAPMA with three different sizes were synthesized in order to fabricate cationic micelles. In this copolymer, p(APMA) block with hydrophilic cationic nature could serve as a nucleic acid condensation platform as well as the shell of micellar structure in the self-assembly process. The p(APMA) block was electrostatically complexed with nucleic acid, and formed a neutral or mildly positive charge micellar surface, thus providing the nanoparticles safety and stability. On the other hand, polylactic acid as a hydrophobic polymer in diblock copolymer structure formed core of micelles which could encapsulate hydrophobic therapeutics. The synthesized copolymers, PLA74-b-PAPMA14, PLA121-b-PAPMA22, PLA121-b-PAPMA103 were evaluated in terms of self-assembly capability, size, polydispersity index, plasmid condensation, transfection efficacy and cytotoxicity against C26 cells. Obtained results demonstrated low CMC values for all copolymers. PLA121-b-PAPMA103 diblock copolymer condensed green fluorescent protein plasmid at C/P 1 and higher, while other diblock copolymers were able to condense plasmid above C/P 70. The self-assembly structures of cationic micelles before and after plasmid condensation showed spherical morphology in SEM analysis while DLS data illustrated appropriate size (161.7 ± 8) and PDI (0.276) for PLA121-b-PAPMA103 diblock copolymer. It could be concluded that the cationic micelles with approximately the molecular weight ratio of hydrophilic block to total polymer mass of 60 % and larger than 50 % provided higher stability, condensation ability and transfection efficiency which could be attributed to the better self-assembly process and better amine groups exposure on the micellar surface.

Self-Assembled Nanoparticle-Forming Derivatives of Dextrin-Conjugated Polyethylenimine Containing Urethane Bonds for Enhanced Delivery of Interleukin-12 Plasmid

Background and Objective: In the present investigation, low molecular weight polyethylenimine (LMW PEI, 1.8 kDa PEI) was conjugated to dextrin via urethane units and tested to transfer plasmid encoding interleukin-12 (IL-12) plasmid. Although high molecular weight PEI (HMW PEI, 25 kDa PEI) has shown substantial transfection efficiency, its wide application has been hampered due to considerable cytotoxicity. Therefore, LMW PEI with low toxic effects was used as the core of our gene transfer construct. Methods: LMW PEI was conjugated to dextrin via urethane units to improve its biophysical characteristics as well as cytotoxic effects. The conjugates were characterized in terms of buffering capacity, plasmid DNA condensation ability, particle size, and zeta potential as well as protection against enzymatic degradation. In Vitro experiments were carried out to evaluate the ability of these LMW PEI conjugates to transfer plasmid encoding human interleukin-12 (hIL- 12) to the cells. The MTT assay was performed to measure the cell-induced toxicity of the conjugates. Results: The results of our study demonstrated that the PEI derivatives with higher amounts of amine content (i.e. higher conjugation degrees) have considerable buffering capacity and plasmid condensation ability. These conjugates could condense plasmid DNA at Carrier to Plasmid ratios (C/P) ≥2 and form polyplexes at the size range of 120-165 nm while their zeta potential was around 5.5-8.5 mV. The results of transfection efficiency demonstrated that the level of IL- 12 production increased by 2-3 folds compared with unmodified LMW PEI while the level of cytotoxicity was not higher than 20%. Conclusion: The strategy used in this study shows a promising way to prepare gene carriers with high transfection efficiency and low toxicity.

Recombinant VAR2CSA malaria protein-targeted exosome-mediated DACT2 gene therapy for effective glioma treatment

A good non-viral vector is the key to the success of gene delivery and therapy; hence, modified exosomes may overcome the physiological barrier in the delivery in vivo. This study aims to design a novel non-viral vector and verify its gene delivery function in vitro and in vivo for dapper homolog 2 (DACT2) genes. In this study, amphipathicity cationic exosomes with receptor targeted function and DACT2 gene loading function were constructed by exosomes, PEG, glycidyl hexadecyl dimethylammonium chloride, and recombinant VAR2CSA malaria protein (RVP) antibody. Characterizations of RVP antibody and PEG modified cationic lipid exosome (RVP-CL) nanocomplexes were evaluated by dynamic light scattering, atomic force microscopy, FTIR, and so on. The DNA condensation ability and stability were assessed by agarose gel electrophoresis. Cellular uptake efficiency and cytotoxicity in glioma cells were investigated. Furthermore, the tumor suppressive effect was evaluated in vitro and in vivo. The results indicated that RVP-CL had a uniform size of 100–200 nm and positive zeta potential. With high uptake efficiency, RVP-CL can rapidly target, recognize, and enter the glioma cell (KNS-42 and U118 mg) and release the gene. Moreover, RVP-CL/DACT2 can effectively inhibit the growth of glioma cells in vitro and in vivo. The modified cationic exosomes may offer a promising strategy for gene delivery in the treatment of RVP-positive gliomas or other tumors.

Overcoming the blood-brain barrier? - prediction of blood-brain permeability of hydrophobically modified polyethylenimine polyplexes for siRNA delivery into the brain with in vitro and in vivo models

The blood-brain barrier (BBB) is a highly selective biological barrier that represents a major bottleneck in the treatment of all types of central nervous system (CNS) disorders. Small interfering RNA (siRNA) offers in principle a promising therapeutic approach, e.g., for brain tumors, by downregulating brain tumor-related genes and inhibiting tumor growth via RNA interference. In an effort to develop efficient siRNA nanocarriers for crossing the BBB, we utilized polyethyleneimine (PEI) polymers hydrophobically modified with either stearic-acid (SA) or dodecylacrylamide (DAA) subunits and evaluated their suitability for delivering siRNA across the BBB in in vitro and in vivo BBB models depending on their structure. Physicochemical characteristics of siRNA-polymer complexes (polyplexes (PXs)), e.g., particle size and surface charge, were measured by dynamic light scattering and laser Doppler anemometry, whereas siRNA condensation ability of polymers and polyplex stability was evaluated by spectrophotometric methods. The composition of the biomolecule corona that absorbs on polyplexes upon encountering physiological fluids was investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and by a liquid chromatography-tandem mass spectrometry (LC-MS-MS) method. Cellular internalization abilities of PXs into brain endothelial cells (hCMEC/D3) was confirmed, and a BBB permeation assay using a human induced pluripotent stem cell (hiPSC)–derived BBB model revealed similar abilities to cross the BBB for all formulations under physiological conditions. However, biodistribution studies of radiolabeled PXs in mice were inconsistent with in vitro results as the detected amount of radiolabeled siRNA in the brain delivered with PEI PXs was higher compared to PEI-SA PXs. Taken together, PEI PXs were shown to be a suitable nanocarrier to deliver small amounts of siRNA across the BBB into the brain but more sophisticated human BBB models that better represent physiological conditions and biodistribution are required to provide highly predictive in vitro data for human CNS drug development in the future.

Evaluation of Poly(N-Ethyl Pyrrolidine Methacrylamide) (EPA) and Derivatives as Polymeric Vehicles for miRNA Delivery to Neural Cells.

MicroRNAs (miRNAs) are endogenous, short RNA oligonucleotides that regulate the expression of hundreds of proteins to control cells' function in physiological and pathological conditions. miRNA therapeutics are highly specific, reducing the toxicity associated with off-target effects, and require low doses to achieve therapeutic effects. Despite their potential, applying miRNA-based therapies is limited by difficulties in delivery due to their poor stability, fast clearance, poor efficiency, and off-target effects. To overcome these challenges, polymeric vehicles have attracted a lot of attention due to their ease of production with low costs, large payload, safety profiles, and minimal induction of the immune response. Poly(N-ethyl pyrrolidine methacrylamide) (EPA) copolymers have shown optimal DNA transfection efficiencies in fibroblasts. The present study aims to evaluate the potential of EPA polymers as miRNA carriers for neural cell lines and primary neuron cultures when they are copolymerized with different compounds. To achieve this aim, we synthesized and characterized different copolymers and evaluated their miRNA condensation ability, size, charge, cytotoxicity, cell binding and internalization ability, and endosomal escape capacity. Finally, we evaluated their miRNA transfection capability and efficacy in Neuro-2a cells and rat primary hippocampal neurons. The results indicate that EPA and its copolymers, incorporating β-cyclodextrins with or without polyethylene glycol acrylate derivatives, can be promising vehicles for miRNA administration to neural cells when all experiments on Neuro-2a cells and primary hippocampal neurons are considered together.

The saponin bomb: a nucleolar-localized β-glucosidase hydrolyzes triterpene saponins in Medicago truncatula.

Plants often protect themselves from their own bioactive defense metabolites by storing them in less active forms. Consequently, plants also need systems allowing correct spatiotemporal reactivation of such metabolites, for instance under pathogen or herbivore attack. Via co-expression analysis with public transcriptomes, we determined that the model legume Medicago truncatula has evolved a two-component system composed of a β-glucosidase, denominated G1, and triterpene saponins, which are physically separated from each other in intact cells. G1 expression is root-specific, stress-inducible, and coregulated with that of the genes encoding the triterpene saponin biosynthetic enzymes. However, the G1 protein is stored in the nucleolus and is released and united with its typically vacuolar-stored substrates only upon tissue damage, partly mediated by the surfactant action of the saponins themselves. Subsequently, enzymatic removal of carbohydrate groups from the saponins creates a pool of metabolites with an increased broad-spectrum antimicrobial activity. The evolution of this defense system benefited from both the intrinsic condensation abilities of the enzyme and the bioactivity properties of its substrates. We dub this two-component system the saponin bomb, in analogy with the mustard oil and cyanide bombs, commonly used to describe the renowned β-glucosidase-dependent defense systems for glucosinolates and cyanogenic glucosides.

Characterization of polypropyleneimine as an alternative transfection reagent.

Polypropyleneimine (PPI) was examined as a transfection reagent comparing with most widely used polymer, polyethyleneimine (PEI). PPI had better responsiveness to the endosomal pH and showed more condensation ability of plasmid DNA than PEI. Although the cytotoxicity of PPI was somewhat higher than PEI, the transfection efficacy of PPI was comparable with PEI or higher than PEI in some cell line. Thus, PPI would be an alternative transfection reagent.

Evaluation of Coronal Micro-Leakage of Fiber Post with Different Luting Cements (In Vitro Study)

Evaluation of Coronal Micro-Leakage of Fiber Post with Different Luting Cements (In Vitro Study)

Interleukin-12 Plasmid DNA Delivery by N-[(2-Hydroxy-3-trimethylammonium)propyl]chitosan-Based Nanoparticles.

Cationic polysaccharides are capable of forming polyplexes with nucleic acids and are considered promising polymeric gene carriers. The objective of this study was to evaluate the transfection efficiency and cytotoxicity of N-[(2-hydroxy-3-trimethylammonium)propyl] chitosan salt (HTCS), a quaternary ammonium derivative of chitosan (CS), which benefits from non-ionizable positive charges. In this work, HTCS with a full quaternization of amino groups and a molar mass of 130,000 g·mol−1 was synthesized to use for delivery of a plasmid encoding the interleukin-12 (IL-12) gene. Thus, a polyplex based on HTCS and the IL-12 plasmid was prepared and then was characterized in terms of particle size, zeta potential, plasmid condensation ability, and protection of the plasmid against enzymatic degradation. We showed that HTCS was able to condense the IL-12 plasmid by the formation of polyplexes in the range of 74.5 ± 0.75 nm. The level of hIL-12 production following the transfection of the cells with HTCS polyplexes at a C/P ratio of 8:1 was around 4.8- and 2.2-fold higher than with CS and polyethylenimine polyplexes, respectively. These findings highlight the role of HTCS in the formation of polyplexes for the efficient delivery of plasmid DNA.

Experimental investigation on the improvement of cooling and dehumidification of a direct-expansion terminal integrated with flat heat pipe

Low energy efficiency and draughts of traditional convection cooling terminals led to the development of radiant cooling terminals; however, they have insufficient cooling capacity and surface condensation or poor dehumidification ability. In this study, we develop a novel direct-expansion terminal by combining a flat heat pipe and an air source heat pump, resulting in a larger cooling capacity, faster cooling speed, and strong adjustability in dehumidification. The cooling capacity of the proposed novel terminal is between 1160 and 2600 W, and the maximum cooling capacity is 2.24 times that of pure radiation. Additionally, the structure optimization enables the proposed terminal to separate the sensible heat and latent heat and adjust dehumidification, demonstrating dynamic and flexible characteristics. Moreover, it meets the demands of part-time and part-space cooling. The indoor humidity ratio experiences a change of between 2.8 and 7.9 g/kg after dehumidification, and the indoor relative humidity can be reduced to a comfortable range in summer within 30 min by adjusting the compressor opening degree. The novel terminal considers the advantages of radiant and convection terminals, and provides opportunity for the future improvement of cooling terminals.

Synthesis of Fast Curing, Water‐Resistant and Photopolymerizable Glass for Recording of Holographic Structures by One‐ and Two‐Photon Lithography

AbstractAdvancements in hybrid sol‐gel technology have provided a new class of holographic materials as photopolymerizable glasses. Recently, a number of photosensitive glass compositions with high dynamic range and high spatial resolution have been reported and their excellent capability for volume holography has been demonstrated. Nevertheless, challenges remain, particularly in relation to the processing time and environmental stability of these materials, that strongly affect the performance and durability of the fabricated holograms. State‐of‐the‐art photopolymerizable glasses possess long curing times (few days) required to achieve thick films, thus limiting the industrial implementation of this technology and its commercial viability. This article presents a novel, fast curing, water‐resistant, photopolymerizable hybrid sol‐gel (PHSG) for holographic applications. Due to introducing an amine‐based modifier that increases the condensation ability of the sol‐gel network, this PHSG overcomes the problem of long curing time and can readily produce thick (up to a few hundred micrometers) layers without cracking and breaking. In addition, this PHSG exhibits excellent water‐resistance, providing stable performance of holographic gratings for up to 400 h of immersion in water. This finding moves photopolymerizable glasses to the next development stage and renders the technology attractive for the mass production of holographic optical elements and their use across a wide number of outdoor applications.

Enhanced fluorescence/magnetic resonance dual imaging and gene therapy of liver cancer using cationized amylose nanoprobe.

Recently, various technologies for targeted gene release in cancer treatment have emerged. However, most of these strategies are facing the challenge of untraceable distribution and poor antitumour treatment effects. In this study, we constructed a gene delivery system that integrated a series of components to assemble multifunctional NPs, providing a promising theranostic nanoplatform for hepatocellular carcinoma (HCC) therapy. Cationized amylose (CA), superparamagnetic iron oxide (SPIO) nanoparticles (NPs), and tetraphenylethylene (TPE) were self-assembled to form nanospheres (CSP/TPE). The prepared NPs was modified with SP94 pepide through amidation reaction, and then survivin small interfering RNA (siRNA) were loaded into the NPs to form CSP/TPE@siRNA-SP94 NPs. Our results showed that the prepared NPs had good size distribution, high RNA condensation and transfection ability. CSP/TPE@siRNA-SP94 NPs exhibited excellent fluorescence and magnetic resonance (MR) imaging properties in vitro and in vivo. The prepared targeted NPs improved Huh-7 cellular uptake in vitro, and the biodistribution of CSP/TPE@siRNA-SP94 in vivo was observed through in/ex vivo fluorescence imaging system and MRI. As survivin siRNA effectively retained in tumour cells, CSP/TPE@siRNA-SP94 NPs considerably inhibited tumour growth in vivo. In addition, H&E staining results showed that all the prepared CSP-based NPs had good biocompatibilities, as few histological changes or tumour metastasis were observed in major organs of the mice in the treatment group. Therefore, we envisage that the prepared CSP/TPE@siRNA-SP94 NPs can represent a promising strategy for HCC diagnosis and treatment.

Per-fluorinated chemical free robust superhydrophobic copper surface using a scalable technique

Robust superhydrophobicity is of immense practical interest in a wide range of applications including self-cleaning, anti-icing, anti-corrosion, atmospheric water harvesting, desalination, condensation, and oil-water separation. However, biohazard associated with the prevalent use of per-fluorinated synthetic chemicals in making these surfaces and the gradual loss of superhydrophobicity have been major roadblocks. Here we develop an environment-friendly and industrially scalable superhydrophobic copper surface using a combination of electrochemical deposition and Lauric acid functionalization. We optimized the synthesis process for ensuring the robustness of these superhydrophobic surfaces. The surface exhibits contact angles as high as 158° with excellent droplet rebounding, self-cleaning, anti-icing, and dropwise condensation abilities. Thermal stability in the range of −15°C to 150°C, mechanical robustness against abrasion, chemical stability under aqueous, acidic, and basic medium, and the excellent plastron layer stability under long-time underwater immersion attest to the high quality of superhydrophobic surfaces for large-scale applications. These coatings when implemented on the curved surface of a copper tube demonstrated appreciable improvement in condensation behavior. Our method provides a sustainable approach for suitable technological interventions in energy and potable water applications requiring robust environment-friendly superhydrophobic surfaces.

DNA Condensation Triggered by the Synergistic Self-Assembly of Tetraphenylethylene-Viologen Aggregates and CT-DNA.

Development of small organic chromophores as DNA condensing agents, which explore supramolecular interactions and absorbance or fluorescence-based tracking of condensation and gene delivery processes, is in the initial stages. Herein, we report the synthesis and electrostatic/groove binding interaction–directed synergistic self-assembly of the aggregates of two viologen-functionalized tetraphenylethylene (TPE-V) molecules with CT-DNA and subsequent concentration-dependent DNA condensation process. TPE-V molecules differ in their chemical structure according to the number of viologen units. Photophysical and morphological studies have revealed the interaction of the aggregates of TPE-V in Tris buffer with CT-DNA, which transforms the fibrous network structure of CT-DNA to partially condensed beads-on-a-string-like arrangement with TPE-V aggregates as beads via electrostatic and groove binding interactions. Upon further increasing the concentration of TPE-V, the “beads-on-a-string”-type assembly of TPE-V/CT-DNA complex changes to completely condensed compact structures with 40–50 nm in diameter through the effective charge neutralization process. Enhancement in the melting temperature of CT-DNA, quenching of the fluorescence emission of ethidium bromide/CT-DNA complex, and the formation of induced CD signal in the presence of TPE-V molecules support the observed morphological changes and thereby verify the DNA condensation abilities of TPE-V molecules. Decrease in the hydrodynamic size, increase in the zeta potential value with the addition of TPE-V molecules to CT-DNA, failure of TPE-V/cucurbit(8)uril complex to condense CT-DNA, and the enhanced DNA condensation ability of TPE-V2 with two viologen units compared to TPE-V1 with a single viologen unit confirm the importance of positively charged viologen units in the DNA condensation process. Initial cytotoxicity analysis on A549 cancer and WI-38 normal cells revealed that these DNA condensing agents are non-toxic in nature and hence could be utilized in further cellular delivery studies.