A Multiple Shape Memory Hydrogel Induced by Reversible Physical Interactions at Ambient Condition.
Ontology highlight
ABSTRACT:
SUBMITTER: Xiao H
PROVIDER: S-EPMC6432359 | biostudies-literature | 2017 Apr
REPOSITORIES: biostudies-literature
Publications
A Multiple Shape Memory Hydrogel Induced by Reversible Physical Interactions at Ambient Condition.
Xiao He H Ma Chunxin C Le Xiaoxia X Wang Li L Lu Wei W Theato Patrick P Hu Tuoping T Zhang Jiawei J Chen Tao T
Polymers 20170412 4
A novel multiple shape memory hydrogel is fabricated based on two reversible physical interactions. The multiple shape memory property is endowed by a simple treatment of soaking in NaOH or NaCl solutions to form chitosan microcrystal or chain-entanglement crosslinks as temporary junctions. ...[more]
Similar Datasets
Project description:The proper microenvironment is critical for the storage and transportation of embryonic stem cells (ESCs). To mimic a dynamic 3D microenvironment as it exists in vivo and consider “off-the-shelf” availability reaching the destination, we proposed an alternative approach that allows for facile storage and transportation of stem cells in the form of ESCs-dynamic hydrogel construct (CDHC) under ambient conditions. To form CDHC, mouse embryonic stem cells (mESCs) were in-situ encapsulated within a polysaccharide-based dynamic and self-biodegradable hydrogel. After storing CDHC in a sterile and hermetic environment for 3 days and then transferring to a sealed vessel with fresh medium for another 3 days, the large and compact colonies retained a 90% survival rate and pluripotency. Furthermore, after transporting and arriving at the destination, the encapsulated stem cell could be automatically released from the self-biodegradable hydrogel. After continuous cultivation of 15 generations of retrieved cells, automatically released from the CDHC, the mESCs underwent 3D encapsulation, storage, transportation, release, and continuous long-term subculture; resumed colony forming capacity and pluripotency were revealed by stem cell markers both in protein and mRNA levels. We believe that the dynamic and self-biodegradable hydrogel provides a simple, cost-effective, and valuable tool for storing and transporting “ready-to-use” CDHC under ambient conditions, facilitating “off-the-shelf” availability and widespread applications. Graphical Abstract
| S-EPMC10219609 | biostudies-literature
Project description:Water-blown polyurethane (PU) foams are of enormous technological interest as they are widely applied in various fields, i.e., consumer goods, medicine, automotive or aerospace industries. The discovery of the one-way shape-memory effect in PU foams provided a fresh impetus for extensive investigations on porous polymeric actuators over the past decades. High expansion ratios during the shape-recovery are of special interest when big volume changes are required, for example to fill an aneurysm during micro-invasive surgery or save space during transportation. However, the need to program the foams before each operation cycle could be a drawback impeding the entry of shape-memory polymeric (SMP) foams to our daily life. Here, we showed that a reversible shape-memory effect (rSME) is achievable for polyurethane water-blown semicrystalline foams. We selected commercially available crystallizable poly(ε-caprolactone)-diols of different molecular weight for foams synthesis, followed by investigations of morphology, thermal, thermomechanical and shape-memory properties of obtained compositions. Densities of synthesized foams varied from 110 to 180 kg∙m-3, while peak melting temperatures were composition-dependent and changed from 36 to 47 °C, while the melting temperature interval was around 15 K. All semicrystalline foams exhibited excellent one-way SME with shape-fixity ratios slightly above 100% and shape-recovery ratios from the second cycle of 99%. The composition with broad distribution of molecular weights of poly(ε-caprolactone)-diols exhibited an rSME of about 12% upon cyclic heating and cooling from Tlow = 10 °C and Thigh = 47 °C. We anticipate that our experimental study opens a field of systematic investigation of rSMEs in porous polymeric materials on macro and micro scale and extend the application of water-blown polyurethane foams to, e.g., protective covers with zero thermal expansion or even cushions adjustable to a certain body shape.
| S-EPMC6431911 | biostudies-literature
Project description:Fluorescent materials have attracted widespread attention for information encryption owing to their stimuli-responsive color-shifting. However, the 2D encoding of fluorescent images poses a risk of information leakage. Herein, inspired by the mimic octopus capable of camouflage by changing colors and shapes, we develop a thermadapt shape-memory fluorescent film (TSFF) for integrating 2D/3D encoding in one system. The TSFF is based on anthracene group with reversible photo-cross-linking and poly (ethylene-co-vinyl acetate) network with thermadapt shape-memory properties. The reversible photo-cross-linking of anthracene is accompanied by repeatable fluorescence-shifting and enables rewritable 2D encoding. Meanwhile, the thermadapt shape-memory properties not only enables the reconfiguration of the permanent shape for creating and erasing 3D patterns, i.e., rewritable 3D information, but also facilitates recoverable shape programming for 3D encoding. This rewritable 2D/3D encoding strategy can enhance information security because only designated inspectors can decode the information by providing sequential heating for shape recovery and UV exposure. Overall, TSFF capable of rewritable 2D/3D encoding will inspire the design of smart materials for high-security information carriers.
| S-EPMC10628284 | biostudies-literature
Project description:Development of reversible wet or underwater adhesives remains a grand challenge. Because weakened intermolecular interactions by water molecules or/and low effective contact area cause poor interface to the wet surfaces, which significantly decreases adhesive strength. Herein, a new photocured, bio-based shape memory polymer (SMP) that shows both chemical and structural wet adhesion to various types of surfaces is developed. The SMP is polymerized from three monomers mainly from bio-sources to form linear polymer chains dangled with hydrophobic side chains. The hydrogen acceptor and donor groups in the chains form hydrogen bonding with the surfaces, which is protected by the hydrophobic chains in the interface. The SMP shows tunable phase transition temperature (Tg) of 17-38 °C. In a rubbery state above Tg, the adhesive forms conformable contact with the targeted surfaces. Below Tg, a transition to a glassy state locks the conformed shapes to largely increase the effective contact area. As a result, the adhesive exhibits long-term underwater adhesion of > 15 days with the best adhesion strength of ~ 0.9 MPa. Its applications in leak repair, underwater on-skin sensors were demonstrated. This new, general strategy would pave avenues to designing bio-based, long-lasting, and reversible adhesives from renewable feedstocks for widespread applications.
| S-EPMC10361415 | biostudies-literature
Project description:Small-scale shape memory ceramics exhibit superior shape memory or superelasticity properties, while their integration into a matrix material and the subsequent attainment of their reversible tetragonal-monoclinic phase transformations remains a challenge. Here, cerium-doped zirconia (CZ) reinforced aluminum (Al) matrix composite is fabricated, and both macroscopic and microscopic mechanical tests reveal more than doubled compressive strength and energy absorbance of the composites as compared with pure Al. Full austenitization in the CZ single-crystal clusters is achieved when they are constrained by the Al matrix, and reversible martensitic transformation triggered by thermal or stress stimuli is observed in the composite micro-pillars without causing fracture in the composite. These results are interpreted by the strong geometric confinement offered by the Al matrix, the robust CZ/Al interface and the local three-dimensional particle network/force-chain configuration that effectively transfer mechanical loads, and the decent flowability of the matrix that accommodates the volume change during phase transformation.
| S-EPMC10625574 | biostudies-literature
Project description:The success of stem cell therapies is highly dependent on the ability to control their programmed differentiation. So far, it is commonly believed that the differentiation behavior of stem cells is supposed to be identical when they are cultured on the same homogeneous platform. However, in this report, we show that this is not always true. By utilizing a double-ion-triggered shape memory effect, the pre-seeded hMSCs were controllably located in different growth positions. Here, we demonstrate for the first time that the differentiation behavior of hMSCs is highly sensitive to their growth position on a hydrogel scaffold. This work will not only enrich the mechanisms for controlling the differentiation of stem cells, but also offer a one-of-a-kind platform to achieve a heterogeneously differentiated stem cell-seeded hydrogel scaffold for complex biological applications.
| S-EPMC5376171 | biostudies-literature
Project description:Smart hydrogels with responsive behaviors have attracted tremendous attention. However, it is still a challenge to synthesize stretchable hydrogels capable of changing their original properties in response to multiple external stimuli. Here, integration of actuation function, shape memory, and self-healing capability in a highly stretchable hydrogel under triple external triggers is achieved by rationally engineering multiple functional moieties. The hydrogel exhibits high stretchability (average relative strain (mm/mm) is >15) and excellent fatigue resistance during 100 loading cycles of 100% strain. Incorporating a moisture-insensitive polymer film with the hydrogel, hydroactuated functionality is demonstrated. Moreover, shape memory and self-healing abilities of the hydrogel are realized by the formation of ionic crosslinking or dynamic borate ester in conditions of multivalent cations and pH, respectively. Deformable plastic flowers are displayed in this work as a proof-of-concept, and it is believed that this smart hydrogel could be used in plenty of frontier fields, such as designing electronic devices, soft robotics, and actuators.
| S-EPMC6096994 | biostudies-literature
Project description:A series of polyimide (PI) films with a high-temperature-induced shape memory effect and tunable properties were prepared via the facile random copolymerization of 4,4'-oxydianiline (ODA) with 4,4'-(hexafluoroisopropyl)diphthalic anhydride (6FDA) and 4,4'-oxydiphthalic anhydride (ODPA). The trigger temperature can be controlled from 294 to 326 °C by adjusting the ratio of monomers. The effects of monomer rigidity on the chain mobility, physical properties, and shape memory performance of as-prepared copolyimide were systematically investigated. The introduction of ODPA could enhance the mobility of PI macromolecular chains, which made chain entanglement more likely to occur and increased the physical crosslinking density, thereby improving the PI's shape recovery up to 97%. Meanwhile, the existence of 6FDA enabled PI films to set quickly at low temperatures with a shape fixation of 98%. The shape memory cycling characteristics of the polyimide films are also studied, and the relationship between the PI chemical structure and the film properties are further discussed.
| S-EPMC8512334 | biostudies-literature
Project description:Direct injection of cell-laden hydrogels shows high potentials in tissue regeneration for translational therapy. The traditional cell-laden hydrogels are often used as bulk space fillers to tissue defects after injection, likely limiting their structural controllability. On the other hand, patterned cell-laden hydrogel constructs often necessitate invasive surgical procedures. To overcome these problems, herein, we report a unique strategy for encapsulating living human cells in a pore-forming gelatin methacryloyl (GelMA)-based bioink to ultimately produce injectable hierarchically macro-micro-nanoporous cell-laden GelMA hydrogel constructs through three-dimensional (3D) extrusion bioprinting. The hydrogel constructs can be fabricated into various shapes and sizes that are defect-specific. Due to the hierarchically macro-micro-nanoporous structures, the cell-laden hydrogel constructs can readily recover to their original shapes, and sustain high cell viability, proliferation, spreading, and differentiation after compression and injection. Besides, in vivo studies further reveal that the hydrogel constructs can integrate well with the surrounding host tissues. These findings suggest that our unique 3D-bioprinted pore-forming GelMA hydrogel constructs are promising candidates for applications in minimally invasive tissue regeneration and cell therapy.
| S-EPMC7941201 | biostudies-literature
Project description:In the context of three-dimensional (3D) cell culture and tissue engineering, 3D printing is a powerful tool for customizing in vitro 3D cell culture models that are critical for understanding the cell-matrix and cell-cell interactions. Cellulose nanofibril (CNF) hydrogels are emerging in constructing scaffolds able to imitate tissue in a microenvironment. A direct modification of the methacryloyl (MA) group onto CNF is an appealing approach to synthesize photocross-linkable building blocks in formulating CNF-based bioinks for light-assisted 3D printing; however, it faces the challenge of the low efficiency of heterogenous surface modification. Here, a multistep approach yields CNF methacrylate (CNF-MA) with a decent degree of substitution while maintaining a highly dispersible CNF hydrogel, and CNF-MA is further formulated and copolymerized with monomeric acrylamide (AA) to form a super transparent hydrogel with tuneable mechanical strength (compression modulus, approximately 5-15 kPa). The resulting photocurable hydrogel shows good printability in direct ink writing and good cytocompatibility with HeLa and human dermal fibroblast cell lines. Moreover, the hydrogel reswells in water and expands to all directions to restore its original dimension after being air-dried, with further enhanced mechanical properties, for example, Young's modulus of a 1.1% CNF-MA/1% PAA hydrogel after reswelling in water increases to 10.3 kPa from 5.5 kPa.
| S-EPMC10428165 | biostudies-literature