Phenylboronic Acid-Dopamine Dynamic Covalent Bond Involved Dual-Responsive Polymeric Complex: Construction and Anticancer Investigation

Hyperbranched Thiol-Capped Polyurethane: A Toughening Curing Agent for High-Performance Epoxy Adhesives

Thermosetting epoxy resins are widely used in the fields of adhesives, coatings, electronic encapsulation, and aerospace. However, their inherent brittleness, due to their high cross-link density, has limited their application in advanced, high-precision fields. To address this, we designed and synthesized a series of thiol-terminated branched polyurethanes with varying molecular weights to act as curing agents for epoxy resins. This approach addresses issues like compatibility, dispersion, and optimal mixing ratio associated with adding separate toughening agents. By adjusting the molecular weight and cross-linking density of the curing agent, we optimized the curing rate, chain mobility, toughness, and adhesion of the resin. The cured epoxy adhesive demonstrated a lap shear strength of 27 MPa, a tensile strength of 47 MPa, and a fracture toughness of 4.1 MPa m1/2, while also exhibiting broad substrate compatibility and excellent solvent resistance. Compared with conventional epoxy curing agents and commercially available polysulfide curing agents, the polyurethane-cured epoxy adhesive displays superior mechanical properties.

Solute Stabilization Effects of Nanoparticles Containing Boronic Acids in the Absence of Binding Pairs

Boronic acids are widely used in materials science because of their ability to reversibly bind with diol and catechol moieties through dynamic covalent interactions in a pH- and oxidative-dependent manner. Considerably fewer studies focus on property modulation of boronic acid-based materials in the absence of a biding pair. Herein, we discuss the effects of the boronic acid-containing polymer block length on solute release kinetics from nanoparticles in a stimuli-responsive manner for on-demand delivery. In this study, ABC-type linear amphiphiles of poly(d,l-lactide) and poly(2-methacryloyloxyethyl phosphorylcholine) containing a middle block functionalized with 3-aminophenylboronic acid were synthesized by a combination of ring-opening and controlled free radical polymerizations. Nile red-loaded nanoparticles were self-assembled using a multi-inlet vortex mixer in a well-controlled manner. Release was evaluated at pH above and below the pKa of the boronic acid and in the presence of hydrogen peroxide. Our results show that release kinetics from nanoparticles incorporating a boronic acid-functionalized interlayer were slower than those without it, and the rate could be modulated according to pH and oxidative conditions. These effects can be attributed to several factors, including the hydrophobicity of the boronic acid block as well as hydrogen bonding interactions existing between locally confined boronic acids. While boronic acids are generally utilized as boronic/boronate esters, their stabilizing effects in the absence of appropriate binding pairs are relevant and should be considered in the design of boronic acid-based technologies.

Construction of biodegradable core cross-linked nanoparticles from near infrared dyes encoded in polyprodrug amphiphiles and investigation of their synergistic anticancer activity

Amphiphilic polyprodrugs with reduction-responsive camptothecin prodrug and photothermal converted IR780 dyes was performed via core cross-linking protocol. The nanoparticles could be served as a nanocarrier and presented severe cytotoxicity to HeLa cells.

A bio-bar-code photothermal probe triggered multi-signal readout sensing system for nontoxic detection of mycotoxins

Herein, a photothermal triggered multi-signal readout (MSR) system was innovatively established with great convenience for low-cost and sensitive point-of-care testing (POCT). In this sensing system, an intelligent multi-signal readout interface (MSRI) with multidimensional response-ability to thermal stimulus was developed and utilized as a sensing element. A bio-bar-code photothermal probe peptides@H₂N-HCNTs acted as a target associated photothermal agent anchored on MSRI via competitive reaction. The multi-signal assay of target was realized under the driven of 808 nm laser, photo-to-thermal conversion effect of photothermal probe caused dramatically thermal energy increase on MSRI. As a result, the competitive recognition events were translated into several detectable signals on MSRI, including a local temperature elevation, a visual color change from blue to green as well as weight loss on MSRI, all of these signals were proportional to the target concentration. This assay has been successfully applied in field work for detecting zearalenone (ZEN), a common mycotoxin in grain food, with linear ranger from 10^-7 ng/mL to 10^-1 ng/mL and detection limits of 1.06 × 10^-7 ng/mL. Combination of the different signal principles was expected to result in more reliable and precise results. Accordingly, this creatively designed MSR-system not only provided a platform for sensitive monitor of mycotoxin but also offered new method for reliable and affordable personal assays in daily life and low-resource setting.