Halloysite nanotube-based self-healing fluorescence hydrogels in fabricating 3D cube containing UV-sensitive QR code information

Developments in anticorrosive organic coatings modulated by nano/microcontainers with porous matrices

The durability and functionality of many metallic structures are seriously threatened by corrosion, which makes the development of anticorrosive coatings imperative. This state-of-the-art survey explores the recent developments in the field of anticorrosive organic coatings modulated by innovations involving nano/microcontainers with porous matrices. The integration of these cutting-edge delivery systems seeks to improve the protective properties of coatings by enabling controlled release, extended durability, targeted application of corrosion inhibitors, and can be co-constructed to achieve defect filling by polymeric materials. The major highlight of this review is an in-depth analysis of the functionalities provided by porous nano/microcontainers in the active protection and self-healing of anticorrosive coatings, including their performance evaluation. In one case, after 20 days of immersion in 0.1 M NaCl, a scratched coating containing mesoporous silica nanoparticles loaded with an inhibitor benzotriazole and shelled with polydopamine (MSNs-BTA@PDA) exhibited coating restoration indicated by a sustained corrosion resistance rise over an extended period monitored by impedance values at 0.01 Hz frequency, rising from 8.3 × 104 to 7.0 × 105 Ω cm2, a trend assigned to active protection by the release of inhibitors and self-healing capabilities. Additionally, some functions related to anti-fouling and heat preservation by nano/microcontainers are highlighted. Based on the literature survey, some desirable properties, current challenges, and prospects of anticorrosive coatings doped with nano/microcontainers have been summarized. The knowledge gained from this survey will shape future research directions and applications in a variety of industrial areas, in addition to advancing smart corrosion prevention technology.

Dopamine-Modified Chitosan Patterning Hydrogel with Dynamic Information Storage Ability

The storage of dynamic information in hydrogels has aroused considerable interest regarding the multiple responsiveness of soft matter. Herein, we propose an electrical writing methodology to prepare dopamine (DA)-modified chitosan hydrogels with a dynamic information storage ability. A pH-responsive chitosan hydrogel medium was patterned by cathodic writing to in situ generate OH- in the writing area, at which dopamine underwent an auto-oxidation reaction in the locally alkaline environment to generate a dark color. The patterned information on the hydrogel can be encoded simply by electrical signals. The speed of information retrieval is positively correlated with the charge transfer during the electrical writing process, and the hiding of information is negatively correlated with the environmental stimulus (i.e., dopamine concentration, pH value, etc.). To showcase the versatility of this medium for information storage and the precision of the pattern, a quick response (QR) code is electronically written on dopamine-modified chitosan hydrogel and can be recognized programmably by a standard mobile phone. The results show that electrical regulation is a novel means to program the information storage process of hydrogels, which inspires future research on structural and functional information storage using stimulus-responsive hydrogels.

Halloysite nanotubes as nano-support matrix for programming the photo/H2O dual triggered reversible gel actuator

Gel actuators are a kind of soft intelligent material that can convert external stimuli into deformations to generate mechanical responses. The development of gel actuators with advanced structures to integrate multiple responsiveness, programmability, and fast deformation ability is urgently needed. Here, we explored a poly(7-(2-methacryloyloxyethoxy)-4-methylcoumarin-co-acrylic acid-co-glycol) ternary gel network as an actuator with reprogrammable photo/H2O dual responsibilities. In such a design, [2 + 2] photodimerization and photocleavage reactions of coumarin moieties can be realized under 365 and 254 nm light irradiation, respectively, affording reversible photodriven behaviour of the gels. The abundant carboxylic acid in the backbone has the capacity to form additional crosslinks to assist and accelerate the photodriven behaviour. The incorporation and orientation of halloysite nanotubes (HNTs) in gel matrices support an axial direction force and result in a more controllable and programmable actuating behaviour. The synergistic response enables fast grasping-releasing of 5-times the weight of the object in water within 10 min by fabricating HNT-incorporated gels as a four-arm gripper.

Enzymatically crosslinked magnetic starch-grafted poly(tannic acid) hydrogel for "smart" cancer treatment: An in vitro chemo/hyperthermia therapy study

A novel strategy was designed and developed based of horseradish peroxidase (HRP)-mediated crosslinking of tyramine-functionalized starch (Tyr-St), tannic acid (TA) and phenolated-magnetic nanoparticles (Fe3O4-PhOH NPs), and simultaneous loading of doxorubicin hydrochloride (Dox) to afford a pH-responsive magnetic hydrogel-based drug delivery system (DDS) for synergistic in vitro chemo/hyperthermia therapy of human breast cancer (MCF-7) cells. The developed St-g-PTA/Fe3O4 magnetic hydrogel showed porous micro-structure with saturation magnetization (δs) value of 19.2 emu g-1 for Fe3O4 NPs content of ∼7.4 wt%. The pore sizes of the St-g-PTA/Fe3O4 hydrogel was calculated to be 2400 ± 200 nm-2. In vitro drug release experiments exhibited the developed DDS has pH-dependent drug release behavior, while at physiological pH (7.4) released only 30 % of the loaded drug after 100 h. Human serum albumin (HSA) adsorption capacities of the synthesized St/Fe3O4 and St-g-PTA/Fe3O4 magnetic hydrogels were obtained as 86 ± 2.2 and 77 ± 1.9 μgmg-1, respectively. The well-known MTT-assay approved the cytocompatibility of the developed St-g-PTA/Fe3O4 hydrogel, while the Dox-loaded system exhibited higher anti-cancer activity than those of the free Dox as verified by MTT-assay, and optical as well as florescent microscopies imaging. The synergistic chemo/hyperthermia therapy effect was also verified for the developed St-g-PTA/Fe3O4-Dox via hot water approach.

Exploring maleimide-anchored halloysites as nanophotoinitiators for surface-initiated photografting strategies

Maleimide-functionalized HNTs (HNTs-I) were prepared and explored as a nanophotoinitiator. Vinyl monomers can be grafted onto the nanotubes following a spatially controllable, metal-free and non-contact photoinitiated approach. The obtained HNTs-I were further used in a 3D printing system to fabricate hydrogels with designed configurations.

Fabrication of a magnetic alginate-silk fibroin hydrogel, containing halloysite nanotubes as a novel nanocomposite for biological and hyperthermia applications

In this study, the main focus was on designing and synthesizing a novel magnetic nanobiocomposite and its application in hyperthermia cancer treatment. Regarding this aim, sodium alginate (SA) hydrogel with CaCl₂ cross-linker formed and modified by silk fibroin (SF) natural polymer and halloysite nanotubes (HNTs), followed by in situ Fe₃O₄ magnetic nanoparticles preparation. No important differences were detected in red blood cells (RBCs) hemolysis, confirming the high blood compatibility of the treated erythrocytes with this nanobiocomposite. Moreover, the synthesized SA hydrogel/SF/HNTs/Fe₃O₄ nanobiocomposite does not demonstrate toxicity toward HEK293T normal cell line after 48 and 72 h. The anticancer property of SA hydrogel/SF/HNTs/Fe₃O₄ nanobiocomposites against breast cancer cell lines was corroborated. The magnetic saturation of the mentioned magnetic nanobiocomposite was 15.96 emu g⁻¹. The specific absorption rate (SAR) was measured to be 22.3 W g⁻¹ by applying an alternating magnetic field (AMF). This novel nanobiocomposite could perform efficiently in the magnetic fluid hyperthermia process, according to the obtained results.