Liquid crystalline behaviour of self-assembled LAPONITE®/PLL–PEG nanocomposites

Xu, Peicheng; Lan, Yang; Xing, Zhongyang; Eiser, Erika

doi:10.1039/c7sm01613a

Cited by 11 publications

(8 citation statements)

References 33 publications

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“…Normally, the nanodiscs quickly recover their isotropic arrangement when shear force desists. [ 58 ] However, the strong interactions between LAP and the hydrogel constituents and its dense nature prevent this reorientation. Eventually, the UV‐curing preserves this arranged microstructure leading to the anisotropic hydrogel sheet with anisotropic responsiveness.…”

Section: Resultsmentioning

confidence: 99%

Development of Thermoinks for 4D Direct Printing of Temperature‐Induced Self‐Rolling Hydrogel Actuators

Podstawczyk

Nizioł

Szymczyk‐Ziółkowska

et al. 2021

Adv Funct Materials

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4D printing has emerged as an important technique for fabricating 3D objects from programmable materials capable of time‐dependent reshaping. In the present investigation, novel 4D thermoinks composed of laponite (LAP), an interpenetrating network of poly(N‐isopropylacrylamide) (PNIPAAm), and alginate (ALG) are developed for direct printing of shape‐morphing structures. This approach consists of the design and fabrication of 3D honeycomb‐patterned hydrogel discs self‐rolling into tubular constructs under the stimulus of temperature. The shape morphing behavior of hydrogels is due to shear‐induced anisotropy generated via 3D printing. The compositionally tunable hydrogel discs can be programmed to exhibit different actuation behaviors at different temperatures. Upon immersion in 12 °C water, singly crosslinked sheets roll up into a tubular construct. When transferred to 42 °C water, the tubes first rapidly unfold and then slightly curve up in the opposite direction. Through a dual photocrosslinking of PNIPAAm, it is possible to inverse temperature‐dependent shape morphing and induce self‐folding at higher and unrolling at lower temperatures. The extensive self‐assembling motion is essential to developing thermal actuators with broad applications in, e.g., soft robotics and active implantology, whereas controllable self‐rolling of planar hydrogels is of the highest interest to biomedical engineering as it allows for effective fabrication of hollow tubes.

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Section: Resultsmentioning

confidence: 99%

Development of Thermoinks for 4D Direct Printing of Temperature‐Induced Self‐Rolling Hydrogel Actuators

Podstawczyk

Nizioł

Szymczyk‐Ziółkowska

et al. 2021

Adv Funct Materials

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“…A very high nanofiller-content nanocomposite was obtained. The authors also followed a formation of a liquid crystalline texture as the suspension was being dried [ 74 ]. It is this very morphology that the current paper attempts to form using laponite and newly synthesized flame-retardant elastomeric polybenzoxazine.…”

Section: Resultsmentioning

confidence: 99%

Nacre-Mimetic Green Flame Retardant: Ultra-High Nanofiller Content, Thin Nanocomposite as an Effective Flame Retardant

et al. 2020

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A nacre-mimetic brick-and-mortar structure was used to develop a new flame-retardant technology. A second biomimetic approach was utilized to develop a non-flammable elastomeric benzoxazine for use as a polymer matrix that effectively adheres to the hydrophilic laponite nanofiller. A combination of laponite and benzoxazine is used to apply an ultra-high nanofiller content, thin nanocomposite coating on a polyurethane foam. The technology used is made environmentally friendly by eliminating the need to add any undesirable flame retardants, such as phosphorus additives or halogenated compounds. The very-thin coating on the polyurethane foam (PUF) is obtained through a single dip-coating. The structure of the polymer has been confirmed by proton nuclear magnetic resonance spectroscopy (1H NMR) and Fourier transform infrared spectroscopy (FTIR). The flammability of the polymer and nanocomposite was evaluated by heat release capacity using microscale combustion calorimetry (MCC). A material with heat release capacity (HRC) lower than 100 J/Kg is considered non-ignitable. The nanocomposite developed exhibits HRC of 22 J/Kg, which is well within the classification of a non-ignitable material. The cone calorimeter test was also used to investigate the flame retardancy of the nanocomposite’s thin film on polyurethane foam. This test confirms that the second peak of the heat release rate (HRR) decreased 62% or completely disappeared for the coated PUF with different loadings. Compression tests show an increase in the modulus of the PUF by 88% for the 4 wt% coating concentration. Upon repeated modulus tests, the rigidity decreases, approaching the modulus of the uncoated PUF. However, the effect of this repeated mechanical loading does not significantly affect the flame retarding performance.

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“…62 The negatively charged edge may directly interact with the positively charged surface and form selfassembled gels. 63 The viscosity of the gels is strongly thixotropic, and the gels can rapidly reform after removing the applied stress ( Figure 1C and D). Therefore, the current method of using SN to fabricate injectable hydrogels offers considerable advantages compared with conventional chemical engineering approaches.…”

Section: Discussionmentioning

confidence: 99%

<p>Nano-Silicate-Reinforced and SDF-1α-Loaded Gelatin-Methacryloyl Hydrogel for Bone Tissue Engineering</p>

Shi

Mulatibieke

et al. 2020

IJN

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Autologous bone grafts are the gold standard for treating bone defects. However, limited bone supply and morbidity at the donor site restrict its extensive use. Therefore, developing bone graft materials as an alternative to autologous grafts has gained considerable attention. Injectable hydrogels endowed with osteogenic potential have the ability to fill irregular bone defects using minimally invasive procedures and have thus been attracting researchers' attention. However, from a clinical perspective, most fabrication methods employed for the current injectable osteogenic hydrogels are difficult and inconvenient. In the current study, we fabricated an injectable osteogenic hydrogel using a simple and convenient strategy. Materials and Methods: Gelatin-methacryloyl (GelMA) pre-polymer was synthetized. Nano silicate (SN) and stromal cell-derived factor-1 alpha (SDF-1α) were introduced into the pre-polymer to achieve injectability, controlled release property, excellent osteogenic ability, and efficient stem cell homing. Results: The GelMA-SN-SDF-1α demonstrated excellent injectability via a 17-G needle at room temperature. The loaded SDF-1α exhibited a long-term controlled release pattern and efficiently stimulated MSC migration and homing. The GelMA-SN-SDF-1α hydrogel amplified cell spreading, migration, osteogenic-related biomarker expression, and matrix mineralization. The GelMA-SN-SDF-1α hydrogel filled critical-sized calvaria defects in rats and demonstrated excellent bone regeneration ability, as assessed using micro-CT scanning and histomorphometric staining. Conclusion: The GelMA-SN-SDF-1α hydrogel provides a simple and convenient strategy for the fabrication of injectable osteogenic graft materials.

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Liquid crystalline behaviour of self-assembled LAPONITE®/PLL–PEG nanocomposites

Cited by 11 publications

References 33 publications

Development of Thermoinks for 4D Direct Printing of Temperature‐Induced Self‐Rolling Hydrogel Actuators

Development of Thermoinks for 4D Direct Printing of Temperature‐Induced Self‐Rolling Hydrogel Actuators

Nacre-Mimetic Green Flame Retardant: Ultra-High Nanofiller Content, Thin Nanocomposite as an Effective Flame Retardant

<p>Nano-Silicate-Reinforced and SDF-1α-Loaded Gelatin-Methacryloyl Hydrogel for Bone Tissue Engineering</p>

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