Hydrophilic/Hydrophobic Heterogeneity Anti-Biofouling Hydrogels with Well-Regulated Rehydration

Abstract

Hydrogels, as a representative of soft and biocompatible materials, have been widely used in biosensors, biomedical devices, soft robotics, and the marine industry. However, the ir-recoverability of hydrogels after dehydration, which causes the loss of original mechanical, optical, and wetting properties, has severely restricted their practical applications. At present, this critical challenge of maintaining hydrogels’ accurate character has attracted less attention. To address this, here we report a hydrogel based on synergistic effects to achieve both well-regulated rehydration and deswelling properties. The hydrogel after dehydration can quickly restore its original state both on the macro- and microscale. In addition, the hydrogel has excellent mechanical stability after several dehydration–rehydration cycles. All of these properties offer a possibility of water condition endurance and increase the service life. The robust property is attributed to the hydrophilic–hydrophobic and ionic interactions induced by the synergy of hydrophilic/oleophilic heteronetworks. Moreover, zwitterionic segments as hydrophilic network play a vital role in fabricating anti-biofouling hydrogels. The durable and reusable hydrogel may have promising applications for biomedical materials, flexible devices, and the marine industry.

Nickel-Catcher-Doped Zwitterionic Hydrogel Coating on Nickel–Titanium Alloy Toward Capture and Detection of Nickel Ions

“…To verify the introduction of Ni-catchers, we compared the pristine NiTi, H-NiTi, and CS-NiTi from surface morphology, WCAs, XPS spectra, transmittance, optical images, and biocompatibility. As shown in Figure 2A , the introduction of Ni-catchers resulted in the porous morphology of CS-NiTi, compared with the flat morphology of H-NiTi, probably because of the phase separation ( Su et al, 2020 ). Furthermore, the WCAs decreased from 83.5 ± 3.7° (NiTi) to 59.0 ± 3.4° (CS-NiTi), indicating the hydrophilicity of CS-NiTi ( Figure 2B ).…”

“…The CS-NiTi was fabricated according to previous literature, with some modifications ( Su et al, 2020 ). Firstly, pristine NiTi alloy was immersed in bis-HEMAP (5% ethanol solution) for 24 h and washed with deionized water for three times.…”

“…Herein, we present a Ni-catcher-doped zwitterionic hydrogel coating on the surface of NiTi alloy, showing robust anti-bacteria and long-term Ni 2+ ion capture ( Figure 1 ). In brief, zwitterionic hydrogel was firstly prepared on the surface of NiTi alloy (H-NiTi) by the copolymerization of 2-hydroxyethyl methacrylate (HEMA), 3-dimethyl(methacryloyloxyethyl)ammonium propane-sulfonate (DMAPS), and methyl methacrylate (MMA; Su et al, 2020 ). Then, the CS 2 as a Ni-catcher was grafted into zwitterionic hydrogel by immersing H-NiTi in the mixture of CS 2 and triethylamine (TEA) to obtain CS-NiTi ( Figure 1A and Supplementary Figure 1 ).…”

The effects of surface topography modification on hydrogel properties

“…The swelling or deswelling behaviors occurring in these processes would depend on the swelling ratio of the hydrogel and can also cause feature deformation. 70 As is introduced above, hydrogel-induced swelling behavior can even be employed as a specific patterning method. The swelling behavior utilized in these methods will be controllable and precisely designed.…”

Tailoring Materials with Specific Wettability in Biomedical Engineering

“…With the increasing attention to healthcare, the practical values of wettability materials in biomedical‐related fields are receiving remarkable interests and researches. [ 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ] Previous literatures have revealed that surface wettability, especially the superwettability like superhydrophobicity and superhydrophilicity, have great influence on the biomolecular behaviors such as adhesion and proliferation. [ 32 , 33 , 34 ] To be specific, the superhydrophobic surfaces are capable of effectively resisting bacterial adhesion, protein adsorption, cell adhesion, and blood coagulation; while the superhydrophilic ones have the ability of antibacterial and facilitating cell attachment.…”