Synthesis of graft polyrotaxane by simultaneous capping of backbone and grafting from rings of pseudo-polyrotaxane

Modification of conducting arylidene copolymers by formation of inclusion complexes: synthesis, characterization, and applications as highly corrosion inhibitors for mild steel

Modifying the metal surface is one solution to the industry's growing corrosion problem. Thus, via threading approach and insertion of copolymers (CoP5-7) containing polyarylidenes through the internal cavity beta-cyclodextrin β-CD, novel pseudopolyrotaxanes copolymers (PC5-7) are developed, resulting in mild steel corrosion inhibition. Inhibitors of corrosion based on β-CD molecules adsorb strongly to metal surfaces because of their many polar groups, adsorption centers, many linkages of side chains, and benzene rings. The corrosion inhibition efficiencies IE % statistics have been revised via the Tafel polarization method and Spectroscopy based on the electrochemical impedance (EIS), with PC7 achieving the highest 99.93% in 1.0 M H₂SO₄; they are mixed-type inhibitors. The chemical composition of the resulting PCs is determined with Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) is utilized to examine the morphological structure of the produced polymers, and X-ray diffraction is employed to identify crystallinity. Encapsulating CoP5-7 with β-CD changes the morphological structures and increases the generated PCs' crystallinity. The thermal stability of PCs is studied, indicating the presence of these CoPs within the β-CD cavities enhances their thermal stability. This research will be a stepping stone for developing high-efficiency anti-corrosion coatings and various industrial applications.

Supramolecular Self-Assembly of Methylated Rotaxanes for Solid Polymer Electrolyte Application

Li⁺-conducting solid polymer electrolytes (SPEs) obtained from supramolecular self-assembly of trimethylated cyclodextrin (TMCD), poly(ethylene oxide) (PEO), and lithium salt are investigated for application in lithium-metal batteries (LMBs) and lithium-ion batteries (LIBs). The considered electrolytes comprise nanochannels for fast lithium-ion transport formed by CD threaded on PEO chains. It is demonstrated that tailored modification of CD beneficially influences the structure and transport properties of solid polymer electrolytes, thereby enabling their application in LMBs. Molecular dynamics (MD) simulation and experimental data reveal that modification of CDs shifts the steady state between lithium ions inside and outside the channels, in this way improving the achievable ionic conductivity. Notably, the designed SPEs facilitated galvanostatic cycling in LMBs at fast charging and discharging rates for more than 200 cycles and high Coulombic efficiency.

Histone Deacetylase Inhibitor (HDACi) Conjugated Polycaprolactone for Combination Cancer Therapy

The short chain fatty acid, 4-phenylbutyric acid (PBA), is used for the treatment of urea cycle disorders and sickle cell disease as an endoplasmic reticulum stress inhibitor. PBA is also known as a histone deacetylase inhibitor (HDACi). We report here the effect of combination therapy on HeLa cancer cells using PBA as the HDACi together with the anticancer drug, doxorubicin (DOX). We synthesized γ-4-phenylbutyrate-ε-caprolactone monomer which was polymerized to form poly(γ-4-phenylbutyrate-ε-caprolactone) (PPBCL) homopolymer using NdCl3·3TEP/TIBA (TEP = triethyl phosphate, TIBA = triisobutylaluminum) catalytic system. DOX-loaded nanoparticles were prepared from the PPBCL homopolymer using poly(ethylene glycol) as a surfactant. An encapsulation efficiency as high as 88% was obtained for these nanoparticles. The DOX-loaded nanoparticles showed a cumulative release of >95% of DOX at pH 5 and 37 °C within 12 h, and PBA release was monitored by 1H NMR spectroscopy. The efficiency of the combination therapy can notably be seen in the cytotoxicity study carried out on HeLa cells, where only ∼20% of cell viability was observed after treatment with the DOX-loaded nanoparticles. This drastic cytotoxic effect on HeLa cells is the result of the dual action of DOX and PBA on the DNA strands and the HDAC enzymes, respectively. Overall, this study shows the potential of combination treatment with HDACi and DOX anticancer drug as compared to the treatment with an anticancer drug alone.

Multivalent polyrotaxane vectors as adaptive cargo complexes for gene therapy

The philosophy to design and construct polyrotaxane carriers, as efficient gene delivery systems.