Swelling Studies of Porous and Nonporous Semi-IPN Hydrogels for Sensor and Actuator Applications

Franke, Daniela; Gerlach, Gerald

doi:10.3390/mi11040425

Cited by 12 publications

(5 citation statements)

References 29 publications

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“…The surface part of the hydrogel thus shrinks and forms a hydrophobic barrier for the transport of solvent molecules from the inner part of the hydrogel, causing a very slow release of water and thus the longer characteristic time represented in the second step. Two-step behavior of deswelling curve was previously found for semi-interpenetrating hydrogels based on PNIPAAm [ 52 ].…”

Section: Resultsmentioning

confidence: 89%

External Stimuli-Responsive Characteristics of Poly(N,N′-diethylacrylamide) Hydrogels: Effect of Double Network Structure

Šťastná

Ivaniuzhenkov²,

Hanyková³

2022

Gels

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Swelling experiments and NMR spectroscopy were combined to study effect of various stimuli on the behavior of hydrogels with a single- and double-network (DN) structure composed of poly(N,N′-diethylacrylamide) and polyacrylamide (PAAm). The sensitivity to stimuli in the DN hydrogel was found to be significantly affected by the introduction of the second component and the formation of the double network. The interpenetrating structure in the DN hydrogel causes the units of the component, which is insensitive to the given stimulus in the form of the single network (SN) hydrogel, to be partially formed as globular structures in DN hydrogel. Due to the hydrophilic PAAm groups, temperature- and salt-induced changes in the deswelling of the DN hydrogel are less intensive and gradual compared to those of the SN hydrogel. The swelling ratio of the DN hydrogel shows a significant decrease in the dependence on the acetone content in acetone–water mixtures. A certain portion of the solvent molecules bound in the globular structures was established from the measurements of the 1H NMR spin–spin relaxation times T2 for the studied DN hydrogel. The time-dependent deswelling and reswelling kinetics showed a two-step profile, corresponding to the solvent molecules being released and absorbed during two processes with different characteristic times.

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Section: Resultsmentioning

confidence: 89%

External Stimuli-Responsive Characteristics of Poly(N,N′-diethylacrylamide) Hydrogels: Effect of Double Network Structure

Šťastná

Ivaniuzhenkov²,

Hanyková³

2022

Gels

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“…Significant differences among HSAMA 4 hydrogels reflect that swelling behavior was affected by the polymer concentration, which is in good agreement with the literature. [90,[93][94][95] Higher concentrations of HSAMA 4 would generate higher crosslinking densities and denser networks with lower swelling ratios.…”

Section: Swelling Behavior Of Hsama Hydrogelsmentioning

confidence: 99%

Human Albumin‐Based Hydrogels for Their Potential Xeno‐Free Microneedle Applications

Rong

Mehwish

Niu

et al. 2023

Macromolecular Bioscience

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Nowadays, hydrogels-based microneedles (MNs) have attracted a great interest owing to their outstanding qualities for biomedical applications. For the fabrication of hydrogels-based microneedles as tissue engineering scaffolds and drug delivery carriers, various biomaterials have been tested. They are required to feature tunable physiochemical properties, biodegradability, biocompatibility, nonimmunogenicity, high drug loading capacity, and sustained drug release. Among biomaterials, human proteins are the most ideal biomaterials for fabrication of hydrogels-based MNs; however, they are mechanically weak and poorly processible. To the best of the knowledge, there are no reports of xeno-free human protein-based MNs so far. Here, human albumin-based hydrogels and microneedles for tissue engineering and drug delivery by using relatively new processible human serum albumin methacryloyl (HSAMA) are engineered. The resultant HSAMA hydrogels display tunable mechanical properties, biodegradability, and good biocompatibility. Moreover, the xeno-free HSAMA microneedles display a sustained drug release profile and significant mechanical strength to penetrate the model skin. In vitro, they also show good biocompatibility and anticancer efficacy. Sustainable processible human albumin-based biomaterials may be employed as a xeno-free platform in vivo for tissue engineering and drug delivery in clinical trials in the future.

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“…The volume changes caused by the swelling of hydrogels are of interest for a number of applications, such as sensors, actuators, soft-bodied robots, or drug delivery vehicles [ 1 , 2 , 3 ]. In sensors, for example, the change in volume is converted into an electrical output signal by suitable transducers [ 4 ].…”

Section: Introductionmentioning

confidence: 99%

Nearly Reversible Expansion and Shrinkage of Casein Microparticles Triggered by Extreme pH Changes

2023

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Solvent flows in the fL/s range across the total surface of a casein microparticle cause its expansion and shrinkage. Microparticles prepared from the milk protein casein have a porous and flexible inner structure with water-filled channels and cavities. Solvent uptake occurs in two phases and results in disintegration if de-swelling is not triggered by acidification. So far, nothing is known about the reversibility of the swelling/de-swelling steps. We performed pH jump experiments between pH 11 and pH 1 on a single micro-particle and analyzed the swelling-induced size changes with system dynamics modeling. Both the swelling steps and the subsequent de-swelling process proceed reversibly and at an unchanged rate over a sequence of at least three pH exchange cycles. We observed that the duration of the first swelling step increased during the sequence, while the second step became shorter. Both of the time intervals are negatively correlated, while a statistical evaluation of only one swelling cycle for an ensemble of microparticles with different stabilities did not reveal any significant correlation between the two parameters. Our results indicate that the pH-induced swelling/shrinkage of casein microparticles is, to a large extent, reversible and only slightly influenced by the acid-induced decomposition of colloidal calcium phosphate.

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Swelling Studies of Porous and Nonporous Semi-IPN Hydrogels for Sensor and Actuator Applications

Cited by 12 publications

References 29 publications

External Stimuli-Responsive Characteristics of Poly(N,N′-diethylacrylamide) Hydrogels: Effect of Double Network Structure

External Stimuli-Responsive Characteristics of Poly(N,N′-diethylacrylamide) Hydrogels: Effect of Double Network Structure

Human Albumin‐Based Hydrogels for Their Potential Xeno‐Free Microneedle Applications

Nearly Reversible Expansion and Shrinkage of Casein Microparticles Triggered by Extreme pH Changes

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