Synthesis of One-Component Nanostructured Polyion Complexes via Polymerization-Induced Electrostatic Self-Assembly

Nanostructured polyion complexes (PICs) are expected to serve as novel platforms to stabilize and deliver drugs, proteins, and nucleic acids. Yet, traditional self-assembly suffers from lack of scale-up and reproducibility. Particularly for one-component PICs, only spheres are available to date. Here, we report an efficient and scalable strategy to prepare one-component low-dimensional PICs. It involves visible-light-mediated RAFT iterative polymerization of opposite-charge monomers at 25% w/w solids in water at 25 °C. Sphere-film-vesicle transition and charge-/medium-tunable shape selectivity are reported. One-component PIC nanowire, ultrathin film, vesicle, tube, and surface-charged vesicle are easily prepared, and vesicle-polymerization is fulfilled, using this new strategy. This strategy provides a general platform to prepare one-component low-dimensional PICs with tailorable morphologies and high reproducibility on commercially viable scale under eco-friendly conditions

Relative expression of the <i>TubB</i> gene in <i>Phytophthora capsici</i> isolates.

a<p>Isolates were only considered resistant (R) when they were able to grow on PDA plates amended with 30 µg ml⁻¹ zoxamide.</p>b<p>The expression of the <i>PcTubB</i> gene was normalized using the <i>PcWS21</i> gene and then calibrated to the normalized <i>PcTubB</i> mRNA value of the HX-1 isolate in the absence of zoxamide. The mean and standard deviation values indicate the average relative expression between two independent biological experiments. The relative expression was determined in isolates subjected to zoxamide for 6 hours prior to mRNA isolation.</p

Synthesis of Hydrogen-Bonded Pore-Switchable Cylindrical Vesicles via Visible-Light-Mediated RAFT Room-Temperature Aqueous Dispersion Polymerization

Analogous to cellulose, polymers whose monomer units possess both hydrogen donators and acceptors are generally insoluble in ambient water because of hydrogen bonding (HB). Herein we present stimuli-responsive long aqueous cylindrical vesicles (nanotubes) synthesized directly using HB-driven polymerization-induced self-assembly (PISA) under visible-light-mediated RAFT aqueous dispersion polymerization at 25 °C. The PISA undergoes an unprecedented film/silk-to-ribbon-to-vesicle transition and films/silks/ribbons formed at low DPs (∼25–85) of core-forming block in free-flowing aqueous solution. Pore-switchable nanotubes are synthesized by electrostatic repulsive perturbation of the HB association in anisotropic vesicular membranes via inserting minor ionized monomer units into the core-forming block. These nanotubes are synthesized at >35% solids, and tubular membranes are more sensitive than spherical counterparts in response to aqueous surroundings. This facile, robust, and general strategy paves a new avenue toward scale-up production of advanced intelligent nanomaterials

<i>Phytophthora capsici</i> isolates used in this study.

a<p>RZ4-1, RZ3-5, and RZ13-2 are zoxamide-resistant mutants generated from PCAS1 by UV-mutagenesis. XH38-10 and XH38-13 are zoxamide-resistant mutants generated from HX-1 by zoxamide adaption.</p>b<p>Isolates were only considered resistant (R) when they were able to grow on PDA plates amended with 30 µg ml⁻¹ zoxamide.</p

Genetic relationships among 15 isolates of <i>Phytophthora melonis</i>.

<p>The denrogram (UPGMA) shows the relationships among the isolates of <i>P. melonis</i> based on randomly amplified polymorphic DNA (RAPD) analysis with 16 decamer primers. Scale at the bottom depicts the genetic distance.</p

Isolates of <i>Phytophthora melonis</i> used for RAPD analysis and their sensitivities to flumorph, dimethomorph and iprovalicarb.

a<p>One isolate of <i>Phytophthora drechsleri</i> was used as an outgroup control.</p>b<p>EC₅₀ values, the effective concentration for causing 50% inhibition of mycelial growth inhibition of <i>P. melonis</i>.</p>c<p>Number represents a different field in the same district.</p

Segregation of zoxamide-resistance in the sexual progeny of different <i>Phytophthora capsici</i> isolates.

a<p>Sexual progeny were only considered resistant (R) when they were able to grow on PDA plates amended with 30 µg ml⁻¹ zoxamide.</p

Fitness of CAA-resistant and -sensitive isolates of <i>Phytophthora melonis in vitro</i>.

a<p>Isolates in bold font are parents of the resistant isolates listed under them in regular font. Isolates starting with the letter F, D, and I, are flumorph-resistant mutants, dimethomorph-resistant mutants, and iprovalicarb-resistant mutants, respectively.</p>b<p>For each parent and its resistant progeny, means followed by same letters are not significantly different according to Fisher’s least significance difference (α = 0.05).</p>c<p>CFI (compound fitness index)  =  mycelial growth × zoospore production × lesion area on cucumber leaves.</p

Frequency distributions of EC₅₀ values (the effective concentration causing 50% inhibition of mycelial growth of <i>Phytophthora melonis</i>) for flumorph, dimethomorph and iprovalicarb.

<p>In total, 80 isolates of <i>P. melonis</i> were collected from areas never exposed to carboxylic acid amide fungicides.</p

Results of the experiments conducted to induce resistance against flumorph, dimethomorph, and iprovalicarb in <i>Phytophthora melonis</i>.

a<p>SM, spontaneous mutation. UV, UV-mutagenesis.</p>b<p>Survival frequency, number of mutants/total number of zoospores used for mutant generation.</p>c<p>EC₅₀, the effective concentration for causing 50% inhibition of mycelial growth inhibition of <i>P. melonis</i>.</p>d<p>Resistance factor  =  EC₅₀ of resistant isolates at the 10^th transfer/EC₅₀ of its parent.</p