3D-Printed Photocurable Resin with Synergistic Hydrogen Bonding Based on Deep Eutectic Solvent

Vat polymerization, one of the 3D printing technologies, has been widely applied owing to its advantageous properties, such as high accuracy and surface quality. However, the applicability of this technology is limited to end-use product manufacturing, requiring advancements due to a gradual increase in the performance requirements and functional demands of the products. In this study, deep eutectic solvent-based photocurable resins (PCRs) with synergistic hydrogen bonding are synthesized using a facile and ecofriendly procedure to tune monomer proportions. The as-prepared PCRs, with ultralow viscosity and ultrahigh curing rate, are compatible with commercial liquid-crystal display printers. The 3D-printed parts with high optical transparency, stiffness, and thermal resistance exhibit humidity-dependent electrical conductivity and mechanical properties. In addition, the 3D-printed objects demonstrate self-healing features due to the synergistic effect of high-density hydrogen bonding in the microphase-separated polymer matrix. Moreover, different categories of structural assembly, from 2D to 3D and small to large, are demonstrated, and their solubility ensued in recycling and remolding. The synthesized PCRs are suitable for fabricating sacrificial molds, enabling the on-demand fabrication of precise multifunctional structures with various materials, which are otherwise incompatible with UV-based 3D printing, facilitating 3D printing by overcoming its material-selection limitations

Generation of Silk Fibroin Nanoparticles via Solution-Enhanced Dispersion by Supercritical CO₂

A solution-enhanced dispersion by supercritical CO₂ (SEDS) was employed to prepare silk fibroin (SF) nanoparticles. The results of 2⁴ full factorial experiment indicated that SF nanoparticles with particle size (PS) from 52.5 to 102.3 nm and particle size distribution (PSD) from 0.32 to 0.66 can be fabricated successfully. Moreover, reducing precipitation pressure or increasing concentration of SF solution, flow rate of SF solution, or precipitation temperature can increase PS and PSD of SF nanoparticles. The nanoparticle formation mechanism was elucidated through the formation and growth of SF nuclei in the gaseous miscible phase evolved from initial droplets generated by liquid–liquid phase split. Mass transfer between supercritical CO₂ and SF solution superimposed on supersaturation was the most important process parameter affecting nanoparticle formation. Furthermore, Fourier transform infrared spectroscopy and X-ray powder diffraction analysis revealed that SF nanoparticles exhibited predominant random coil and α-helix structure with minor β-sheet conformation

Overcoming Multidrug Resistance through the Synergistic Effects of Hierarchical pH-Sensitive, ROS-Generating Nanoreactors

Recently, multidrug resistance (MDR) has become a major clinical chemotherapeutic burden that robustly diminishes the intracellular drug levels through various mechanisms. To overcome the doxorubicin (Dox) resistance in tumor cells, we designed a hierarchical nanohybrid system possessing copper-substituted mesoporous silica nanoparticles (Cu-MSNs). Further, Dox was conjugated to copper metal in the Cu-MSNs framework through a pH-sensitive coordination link, which is acutely sensitive to the tumor acidic environment (pH 5.0–6.0). In the end, the nanocarrier was coated with D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS), a P-gp inhibitor-entrenched compact liposome net for obstructing the drug efflux pump. Copper ions in the framework synergize the antitumor activity of Dox by enhancing the intracellular reactive oxygen species (ROS) levels through a Fenton-like reaction-mediated conversion of hydrogen peroxide. Furthermore, intracellularly generated ROS triggered the apoptosis by reducing the cellular as well as mitochondrial membrane integrity in MDR cells, which was confirmed by the mitochondrial membrane potential (MMP) measurement. The advancement of the design and critical improvement of cytotoxic properties through free radical attack demonstrate that the proposed hierarchical design can devastate the MDR for efficient cancer treatment

Hydrophobic Hydrogels: Toward Construction of Floating (Bio)microdevices

Hydrogels, formed through cross-linking of hydrophilic polymer chains, represent a class of materials that are capable of holding large volumes of water. Here we report a novel class of hydrophobic hydrogels that can free-float on the surface of different aqueous media by coating conventional hydrogels with a layer of hydrophobic microparticles. We further demonstrate that these floating hydrogel-based devices can be used for sensing applications on liquid surfaces such as the construction of floating pH meters. Moreover, we demonstrate that the floating hydrogels present high mobility with excellent self-assembling property on the surface of water. Importantly, the floating systems reserved the intrinsic biocompatibility of the core hydrogels, enabling microengineering of floating tissue constructs. It is expected that these floating hydrophobic hydrogel-based devices will likely find widespread applications including but not limited to sensing, tissue engineering, and biomedicine