Extreme Extensibility in Physically Cross-Linked Nanocomposite Hydrogels Leveraging Dynamic Polymer–Nanoparticle Interactions

Grosskopf, Abigail K.; Mann, Jay D.; Baillet, Julie; Hernandez, Hector Lopez; Autzen, Anton A. A.; Yu, Anthony C.; Appel, Eric A.

doi:10.1021/acs.macromol.2c00649

Cited by 7 publications

(2 citation statements)

References 70 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It should also be noted that the extremely high elongation at break of the a-PNIPAM hydrogel may support its practical application as a 3D printing and injectable biomaterial [ 47 ].…”

Section: Resultsmentioning

confidence: 99%

Electrospinning of Aqueous Solutions of Atactic Poly(N-isopropylacrylamide) with Physical Gelation

Chuang

Chang

Tsai

et al. 2022

Gels

View full text Add to dashboard Cite

The phase diagram of a given polymer solution is used to determine the solution’s electrospinnability. We constructed a phase diagram of an aqueous solution of atactic poly(N-isopropylacrylamide) (a-PNIPAM) based on turbidity measurements and the rheological properties derived from linear viscoelasticity. Several important transition temperatures were obtained and discussed, including the onset temperature for concentration fluctuations T1, gel temperature Tgel, and binodal temperature Tb. On heating from 15 °C, the one-phase a-PNIPAM solution underwent pronounced concentration fluctuations at temperatures above T1. At higher temperatures, the thermal concentration fluctuations subsequently triggered the physical gelation process to develop a macroscopic-scale gel network at Tgel before the phase separation at Tb. Thus, the temperature sequence for the transition is: T1 < Tgel < Tb~31 °C for a given a-PNIPAM aqueous solution. Based on the phase diagram, a low-temperature electrospinning process was designed to successfully obtain uniform a-PNIPAM nanofibers by controlling the solution temperature below T1. In addition, the electrospinning of an a-PNIPAM hydrogel at Tgel < T < Tb was found to be feasible considering that the elastic modulus of the gel was shown to be very low (ca. 10–20 Pa); however, at the jet end, jet whipping was not seen, though the spitting out of the internal structures was observed with high-speed video. In this case, not only dried nanofibers but also some by-products were produced. At T > Tb, electrospinning became problematic for the phase-separated gel because the enhanced gel elasticity dramatically resisted the stretching forces induced by the electric field.

show abstract

“…It should also be noted that the extremely high elongation at break of the a-PNIPAM hydrogel may support its practical application as a 3D printing and injectable biomaterial [ 47 ].…”

Section: Resultsmentioning

confidence: 99%

Electrospinning of Aqueous Solutions of Atactic Poly(N-isopropylacrylamide) with Physical Gelation

Chuang

Chang

Tsai

et al. 2022

Gels

View full text Add to dashboard Cite

show abstract

“…Extensional rheological characterization of PHMs: Extensibility of PHMs was determined via a modified filament stretching extensional rheology protocol 59 (FiSER, Anton Paar MCR 302 rheometer) using a 25 mm parallel plate geometry. Briefly, 500 𝜇l of PHM scaffold was added to the rheometer stage and the gap height was lowered to 1 mm.…”

Section: Preparation Of Crosslinkable Phmsmentioning

confidence: 99%

Packed hydrogel microfibers as a granular medium

Grewal,

Helein,

Sumey

et al. 2023

Preprint

View full text Add to dashboard Cite

Particle-based (granular) hydrogels are an attractive class of biomaterials due to their unique properties and array of applications in the biomedical space - serving as platforms for extrusion printing and injecting as well as permissive materials for 3D cell culture. Physical properties of particle-based hydrogels are governed in part by contact forces between particles, which are limited to interactions with neighboring particles. Secondary annealing mechanisms are often used to increase mechanical properties and serve to link particles across the granular material volume. Here, we present a novel particle-based hydrogel where each "particle" is a discrete electrospun hydrogel microfiber that has been segmented to a length of 93 +/- 51 um, with a diameter of 1.6 +/- 0.3 um. The fibers are flexible and have aspect ratios that are greater than one order of magnitude larger than most traditional hydrogel microparticles. This enables long-range entanglements of discrete fibers following packing into a bulk material, yielding unique properties. Without crosslinking, these packed hydrogel microfiber materials are mechanically robust, they can stretch without breaking when strained, and they exhibit stress relaxation under constant strain. As a cell culture scaffold, shear-induced alignment of the individual fibers within 3D printed filaments confers contact guidance cues to cells and promotes anisotropic cellular morphologies. Packed hydrogel microfibers can also be used as 3D cell culture environments, with cells able to spread due to the permissive nature of the scaffold. Overall, this work introduces a particle-based material system comprised of individual hydrogel microfibers that allows unique properties to be engineered into biomaterials that might be used in extrusion processes and cell cultures and, ultimately, in tissue engineering and regenerative medicine applications.

show abstract

Strong and Tough Nanostructured Hydrogels and Organogels Prepared by Polymerization‐Induced Self‐Assembly

Zeng

et al. 2023

Small Methods

View full text Add to dashboard Cite

In nature, the hierarchical structure of biological tissues endows them with outstanding mechanics and elaborated functions. However, it remains a great challenge to construct biomimetic hydrogels with well-defined nanostructures and good mechanical properties. Herein, polymerization-induced self-assembly (PISA) is for the first time exploited as a general strategy for nanostructured hydrogels and organogels with tailored nanodomains and outstanding mechanical properties. As a proof-of-concept, PISA of BAB triblock copolymer is used to fabricate hydrogels with precisely regulated spherical nanodomains. These nanostructured hydrogels are strong, tough, stretchable, and recoverable, with mechanical properties correlating to their nanostructure. The outstanding mechanical properties are ascribed to the unique network architecture, where the entanglements of the hydrophilic chains act as slip links that transmit the tension to the micellar crosslinkers, while the micellar crosslinkers dissipate the energy via reversible deformation and irreversible detachment of the constituting polymers. The general feasibility of the PISA strategy toward nanostructured gels is confirmed by the successful fabrication of nanostructured hydrogels, alcogels, poly(ethylene glycol) gels, and ionogels with various PISA formulations. This work has provided a general platform for the design and fabrication of biomimetic hydrogels and organogels with tailorable nanostructures and mechanics and will inspire the design of functional nanostructured gels.

show abstract

Extreme Extensibility in Physically Cross-Linked Nanocomposite Hydrogels Leveraging Dynamic Polymer–Nanoparticle Interactions

Cited by 7 publications

References 70 publications

Electrospinning of Aqueous Solutions of Atactic Poly(N-isopropylacrylamide) with Physical Gelation

Electrospinning of Aqueous Solutions of Atactic Poly(N-isopropylacrylamide) with Physical Gelation

Packed hydrogel microfibers as a granular medium

Strong and Tough Nanostructured Hydrogels and Organogels Prepared by Polymerization‐Induced Self‐Assembly

Contact Info

Product

Resources

About