Self-Crosslinking AuNPs Composite Hydrogel Bolus for Radiophotothermal Therapy.

Radiophotothermal therapy is a promising treatment for superficial tumors. Traditional radiotherapy requires tissue boluses on the patient's skin to increase therapeutic effectiveness due to the dose-buildup effect of high-energy radiation. However, combining radiotherapy with photothermal therapy leads to uncertainties as the low-penetration near-infrared light dose is reduced after penetrating the bolus. To enhance precision and effectiveness, this study introduces a novel bolus made of AuNPs@poly(AM-THMA-DMAEMA) composite hydrogel. This hydrogel is prepared through a one-pot method involving the reduction of trihydrate chloroauric acid (HAuCl4·3H2O) and copolymerization of acrylamide (AM) and N-[Tris(hydroxymethyl)methyl]acrylamide (THMA) in a redox system with dimethylaminoethyl methacrylate (DMAEMA) and potassium persulfate (KPS). The gold nanoparticles (AuNPs) improve the mechanical strength (tensile strength of 320.84 kPa, elongation at break of 830%) and antibacterial properties (>99% against Staphylococcus aureus). The local surface plasmon resonance (LSPR) effect of AuNPs enables the hydrogel to absorb near-infrared light for precise monitoring of the infrared radiation dose. The hydrogel's biocompatibility is enhanced by the absence of additional crosslinking agents, and its excellent surface adhesion strength is due to numerous hydrogen bonds and electrostatic interactions. This study offers new possibilities for nanoparticle composite hydrogels as tissue boluses, achieving high precision and efficiency in radiophotothermal therapy.

Synergistic Bonding of Poly(N-isopropylacrylamide)-Based Hybrid Microgels and Gold Nanoparticles Used for Temperature-Responsive Controllable Catalysis of p-Nitrophenol Reduction.

Stimuli-responsive hybrid nanoparticles used for controllable catalysis have been attracting increasing attention. This study aims to prepare hybrid microgels with excellent temperature-sensitive colorimetric and catalytic properties through combining the surface plasmon resonance properties of gold nanoparticles (AuNPs) with the temperature-sensitive properties of poly(N-isopropylacrylamide) (PNIPAM)-based microgels. Microgels with hydroxy groups (MG-OH) were prepared by soap-free emulsion polymerization, using N-isopropylacrylamide as the main monomer, hydroxyethyl methylacrylate as the functional monomer, N,N'-methylene bisacrylamide as the crosslinker, and 2,2'-azobis(2-methylpropionamidine) dihydrochloride as an initiator to ensure the microgels are positively charged. Furthermore, chemical modification on the surface of MG-OH was carried out by 3-mercaptopropyltriethoxysilane to obtain thiolated microgels (MG-SH). Two kinds of hybrid nanoparticles, AuNPs@MG-OH and AuNPs@MG-SH, were self-assembled, through electrostatic interaction between positive MG-OH and negative citrate-stabilized AuNPs as well as through synergistic bonding of electrostatic interaction and Au-S bonding between positive MG-SH and negative AuNPs. The morphology, stability, temperature-sensitive colorimetric properties, and catalytic properties of hybrid microgels were systematically investigated. Results showed that although both AuNPs@MG-OH and AuNPs@MG-SH exhibit good temperature-sensitive colorimetric properties and controllable catalytic properties for the reduction reaction of p-nitrophenol, AuNPs@MG-SH with synergistic bonding has better stability and higher catalytic performance than AuNPs@MG-OH. This work has good competitiveness against known PNIPAM-based materials and may provide an effective method for preparing smart catalysts by self-assembly with stimuli-responsive polymers, which has a great potential application for catalyzing a variety of reactions.

PDMS-Infused Poly(High Internal Phase Emulsion) Templates for the Construction of Slippery Liquid-Infused Porous Surfaces with Self-cleaning and Self-repairing Properties.

Advanced liquid-repelling materials that resist both water-based and oil-based contaminants have significant applications in many fields. Herein, a novel protocol for the fabrication of a robust poly(high internal phase emulsion) (polyHIPE)-based slippery liquid-infused porous surface (SLIPS) system with combined self-repairing and self-cleaning properties is developed. Specifically, polystyrene-based polyHIPE (PS-HIPE) membranes with an interconnected porous structure were prepared from polymerization of the continuous oil phase in the water-in-oil HIPE templates. These polyHIPE membranes were used, for the first time, as porous substrates for loading low surface tension silicone oils as lubricating liquids for the fabrication of polyHIPE-based SLIPS membranes. These polyHIPE-based SLIPS membranes could easily repel both water- and oil-based contaminants (e.g., ink, milk, and coffee) with very low sliding angles (3.0 ? 1.3?) and could even repel solid contaminants (e.g., dust) upon washing with water. Meanwhile, such membranes exhibit excellent self-repairing properties so that physical scratching damage, such as cutting a trench, does not affect the liquid-repelling performance. The liquid-repelling ability could be recovered completely within 10 s. More significantly, such a SLIPS membrane shows excellent durability so that the water sliding angle of the SLIPS could be maintained at less than 5.0? for about 80 cycles owing to the regenerated poly(dimethylsiloxane) layer on the surface. This work represents a robust methodology to enrich the development of hydrophobic and oleophobic slippery surfaces, which is promising for many areas, such as biomedical, self-cleaning, antifouling, and self-repairing materials.

Synthesis and Self-Assembly of Block Copolymers Containing Temperature Sensitive and Degradable Chain Segments.

In this work, polylactide-b-poly(N-isopropylacrylamide) were synthesized by the combination of controlled ring-opening polymerization and reversible addition fragmentation chain transfer polymerization. These block copolymers with molecular weight range from 7,900 to 12,000 g/mol and narrow polydispersity (≤1.19) can self-assemble into micelles (polylactide core, poly(N-isopropylacrylamide) shell) in water at certain temperature range, which have been evidenced by laser particle size analyzer proton nuclear magnetic resonance and transmission electron microscopy. Such micelles exhibit obvious thermo-responsive properties: (1) Poly(N-isopropylacrylamide) blocks collapse on the polylactide core as system temperature increase, leading to reduce of micelle size. (2) Micelles with short poly(N-isopropylacrylamide) blocks tend to aggregate together when temperature increased, which is resulted from the reduction of the system hydrophilicity and the decreased repulsive force between micelles.

[Preparation and drug release of curcumin-loaded poly (α-isobutyl cyanoacrylate) microspheres].

Curcumin-loaded poly (α-isobutyl cyanoacrylate) microspheres (Cur-HP-ß-CD-PiBCA) were prepared by one-step emulsification with α-isobutyl cyanoacrylate as materials, poloxamer 188 as emulsifier, and curcumin complex with hydroxypropyl-ß-cyclodextrin (Cur-HP-ß-CD) as drug prepared by kneading method. Effects of emulsifier and drug concentration on microspheres size and distribution, drug loading and encapsulation efficiency were investigated in detail. And the curcumin release of drug-loaded microspheres was also studied. Results showed that as the emulsifier concentration increased from 0.01% to 0.07%, particle size of the drug-loaded microspheres decreased while particle size distribution, drug loading and entrapment efficiency increased. The optimized concentration of surfactant was 0.05%. With increasing the concentration of drug from 0.03% to 0.07%, drug loading of Cur-HP-ß-CD-PiBCA increased, but encapsulation efficiency decreased. Additionally, the results of drug release experiments revealed that the higher drug loading of Cur-HP-ß-CD-PiBCA was, the lower cumulative release percentage was. Drug-loading of cumulative inclusions in HP-ß-CD by PiBCA can improve its wettability, and increase the degree of dissolution and bioavailability.

Bio-Based Waterborne Polyurethane Coatings with High Transparency, Antismudge and Anticorrosive Properties.

Green and environment-friendly preparation are of the utmost relevance to the development of transparent antismudge coatings. To prepare a waterborne polyurethane (WPU) coating with antismudge property, it is challenging to balance the stability of dispersion and the antismudge property of coating. Herein, we prepare a transparent bio-based WPU coating grafted with a minor proportion of poly(dimethylsiloxane) (WPU-g-PDMS) using renewable castor oil, monocarbinol-terminated PDMS, hexamethylene diisocyanate trimer, and 2,2-bis(hydroxymethyl)propionic acid as raw materials. Effects of the dosage of monocarbinol-terminated PDMS, the curing temperature, and the curing time on the antismudge performance were studied. Results showed that rigorous stirring (3000 rpm) is necessary to obtain a stable WPU-g-PDMS dispersion with a storage time longer than 6 months. A high curing temperature (>160 °C) and a period of curing time (>1 h) are indispensable to obtain the excellent antismudge property because they would facilitate the grafted low-surface-tension PDMS chains to migrate from the interior to the coating surface. The facts that simulated contaminated liquids such as water, HCl solution, NaOH solution, artificial blood, and tissue fluid could slide off easily and cleanly, and marker ink lined on the coating surface could shrink, indicated that the WPU-g-PDMS coating has good antismudge properties, which could be self-compensated shortly after deterioration. Due to the high cross-linking degree caused by multifunctional polyol and isocyanate, the WPU-g-PDMS coating has high hardness and good anticorrosive performance. The antismudge functionalization and waterborne technology of bio-based polyurethane coatings proposed in this work could be a promising contribution to the green and sustainable development of functional coatings. This kind of WPU-g-PDMS coating is expected to protect and decorate electronic screens, vehicles, and buildings, especially endoscopes.

Preparation and Self-Assembling of PLA-b-PNIPAM-b-PS Triblock Copolymer Thin Films.

Polylactide-b-poly(N-isopropylacrylamide)-b-polystyrene (PLA-b-PNIPAM-b-PS) triblock copolymers (tri-BCPs) with various chemical compositions (block ratio) were prepared from the combination of ring-opening polymerization and reversible addition-fragmentation chain transfer polymerization. Subsequently, the self-assembling behaviors of these tri-BCP films obtained from spin-coating were investigated by annealing them under different solvent atmosphere. We found that these films could self-assemble into various morphologies due to the microphase separation of incompatible copolymer blocks. Atomic force microscopy confirmed the perpendicular cylindrical morphology self-assembled from PLA4.5k-b-PNIPAM5.2k-b-PS22.4k tri-BCP film under mixed solvent atmosphere of toluene/acetone (7:3, v/v). Self-assembled PLA cylinders are evenly distributed among the PS matrix and perpendicular to the film surface, with PNIPAM component taking place at the PLA/PS interphase. Furthermore, by etching the degradable PLA component, porous PS film decorated with PNIPAM "brushes" hoisting channels were generated. This work provides a facile method and detailed protocol for fabricating stimuli-responsive porous films which are promising for thermoresponsive "smart" separation technologies.

[Preparation and properties of poly (acrylic ester) hydrogel as basic materials for intraocular lens].

Poly (acrylic ester) hydrogel materials were widely used in intraocular lens and contact lens because of their excellent optical performance and biocompatibility. In this paper, the bulk copolymerization behavior of hydrophilic hydroxyethyl methacrylat with hydrophobic methyl metharylate was studied; and the optical performance, calcium deposits, equilibrium water content of polymers and its hydrogels obtained by different ratios of monomers were systematically investigated. The experimental results showed that the average light transmittance and the equilibrium water content of the obtained hydrogels increased with the increasing of the hydrophilic monomer content from 0 to 100%; however, the hardness decreased. The highest light transmittance reached 97% and the hardness of Shore A fell from 92 to 25, the equilibrium water content of hydrogel increased from 16% to 64%. The absorbent capacity of copolymers reduced with the adding of cross-linking monomer. When m(hydrophilic monomer): m(hydrophobic monomer) = 90 : 10, the combination property of the polymer and its hydrogel obtained is optimum.