A biomimetic modular polymer with tough and adaptive properties.
Ontology highlight
ABSTRACT:
SUBMITTER: Kushner AM
PROVIDER: S-EPMC2746198 | biostudies-literature | 2009 Jul
REPOSITORIES: biostudies-literature
Publications
A biomimetic modular polymer with tough and adaptive properties.
Kushner Aaron M AM Vossler John D JD Williams Gregory A GA Guan Zhibin Z
Journal of the American Chemical Society 20090701 25
Natural materials employ many elegant strategies to achieve mechanical properties required for survival under varying environmental conditions. Thus these remarkable biopolymers and nanocomposites often not only have a combination of mechanical properties such as high modulus, toughness, and elasticity, but also exhibit adaptive and stimuli-responsive properties. Inspired by skeletal muscle protein titin, we have synthesized a biomimetic modular polymer that not only closely mimics the modular m ...[more]
Similar Datasets
Project description:The development of cost-effective, biocompatible soft wound dressings is highly desirable; however, conventional dressings are only designed for flat wounds, which creates difficulty with promising healing efficiency in complex practical conditions. Herein, we developed a tough, adhesive biomimetic hyaluronic acid methacryloyl hydrogels composed of chemically crosslinked hyaluronic acid methacryloyl (HAMA) network and poly(N-hydroxyethyl acrylamide) (PHEAA) network rich in multiple hydrogen bonding. Due to the multiple chemical crosslinking sites (acrylamide groups) of HAMA; the bulk HEMA/PHEAA hydrogels presented significant enhancements in mechanical properties (∼0.45 MPa) than common hyaluronic acid hydrogels (<0.1 MPa). The abundant hydrogen bonding also endowed the resultant hydrogels with extremely high adhesiveness on many nonporous substrates, including glass and biological tissues (e.g., heart, liver, lung, kidney, stomach, and muscle), with a considerable interfacial toughness of ∼1432 J m-2. Accordingly, since both natural hyaluronic acid derivative polymers and hydrophilic PHEAA networks are highly biocompatible, the hydrogel matrix possesses good blood compatibility (<5% of hemolysis ratio) and satisfies the general dressing requirements (>99% of cell viability). Based on these physicochemical features, we have demonstrated that this adhesive hydrogel, administered in the form of a designed patch, could be applied to wound tissue healing by promoting epithelialization, angiogenesis, and collagen deposition. We believe that our proposed biomimetic hydrogel design holds great potential for wound repair and our developed HAMA/PHEAA hydrogels are extremely promising for the next-generation tissue healings in emergency situations.
| S-EPMC10395096 | biostudies-literature
Project description:The aquatic unicellular organism Paramecium caudatum uses cilia to swim around its environment and to graze on food particles and bacteria. Paramecia use waves of ciliary beating for locomotion, intake of food particles and sensing. There is some evidence that Paramecia pre-sort food particles by discarding larger particles, but intake the particles matching their mouth cavity. Most prior attempts to mimic cilia-based manipulation merely mimicked the overall action rather than the beating of cilia. The majority of massive-parallel actuators are controlled by a central computer; however, a distributed control would be far more true-to-life. We propose and test a distributed parallel cilia platform where each actuating unit is autonomous, yet exchanging information with its closest neighboring units. The units are arranged in a hexagonal array. Each unit is a tileable circuit board, with a microprocessor, color-based object sensor and servo-actuated biomimetic cilia actuator. Localized synchronous communication between cilia allowed for the emergence of coordinated action, moving different colored objects together. The coordinated beating action was capable of moving objects up to 4 cm/s at its highest beating frequency; however, objects were moved at a speed proportional to the beat frequency. Using the local communication, we were able to detect the shape of objects and rotating an object using edge detection was performed; however, lateral manipulation using shape information was unsuccessful.
| S-EPMC6352704 | biostudies-literature
Project description:The ribosome is an ancient machine, performing the same function across organisms. Although functionally unitary, recent experiments suggest specialized roles for some ribosomal proteins. Our central thesis is that ribosomal proteins function in a modular fashion to decode genetic information in a context dependent manner. We show through large data analyses that although many ribosomal proteins are essential with consistent effect on growth in different conditions in yeast and similar expression across cell and tissue types in mice and humans, some ribosomal proteins are used in an environment specific manner. The latter set of variable ribosomal proteins further function in a coordinated manner forming modules, which are adapted to different environmental cues in different organisms. We show that these environment specific modules of ribosomal proteins in yeast have differential genetic interactions with other pathways and their 5'UTRs show differential signatures of selection in yeast strains, presumably to facilitate adaptation. Similarly, we show that in higher metazoans such as mice and humans, different modules of ribosomal proteins are expressed in different cell types and tissues. A clear example is nervous tissue that uses a ribosomal protein module distinct from the rest of the tissues in both mice and humans. Our results suggest a novel stratification of ribosomal proteins that could have played a role in adaptation, presumably to optimize translation for adaptation to diverse ecological niches and tissue microenvironments.
| S-EPMC5094737 | biostudies-literature
Project description:Polymer nanocomposite fibers are important one-dimensional nanomaterials that hold promising potential in a broad range of technological applications. It is, however, challenging to organize advanced polymer nanocomposite fibers with sufficient mechanical properties and flexibility. Here, we demonstrate that strong, tough and flexible polymer nanocomposite fibers can be approached by electrospinning of a supramolecular ensemble of dissimilar and complementary components including flexible multiwalled carbon nanotubes (CNT), and stiff cellulose nanocrystals (CNC) in an aqueous poly(vinyl alcohol) (PVA) system. CNT and CNC are bridged by a water-soluble aggregation-induced-emission (AIE) molecule that forms π-π stacking with CNT via its conjugated chains, and electrostatic attraction with CNC through its positive charges leading to a soluble CNT-AIE-CNC ensemble, which further assembles with PVA through hydrogen bonds. A high level of ordering of the nanoscale building blocks combined with hydrogen bonding leads to a more efficient stress transfer path between the reinforcing unit and the polymer. The nanocomposite fiber mat is capable of selective detection of nitroaromatic explosives.
| S-EPMC9078929 | biostudies-literature
Project description:Inspired by the ability of the sea cucumber to (reversibly) increase the stiffness of its dermis upon exposure to a stimulus, we herein report a stimuli-responsive nanocomposite that can reversibly increase its stiffness upon exposure to warm water. Nanocomposites composed of cellulose nanocrystals (CNCs) that are grafted with a lower critical solution temperature (LCST) polymer embedded within a poly(vinyl acetate) (PVAc) matrix show a dramatic increase in modulus, for example, from 1 to 350 MPa upon exposure to warm water, the hypothesis being that grafting the polymers from the CNCs disrupts the interactions between the nanofibers and minimizes the mechanical reinforcement of the film. However, exposure to water above the LCST leads to the collapse of the polymer chains and subsequent stiffening of the nanocomposite as a result of the enhanced CNC interactions. Backing up this hypothesis are energy conserving dissipative particle dynamics (EDPD) simulations which show that the attractive interactions between CNCs are switched on upon the temperature-induced collapse of the grafted polymer chains, resulting in the formation of a percolating reinforcing network.
| S-EPMC5571458 | biostudies-literature
Project description:Subunit vaccines can have excellent safety profiles, but their ability to give rise to robust immune responses is often compromised. For glycan-based vaccines, insufficient understanding of B and T cell epitope combinations that yield optimal immune activation hinders optimization. To determine which antigen features promote desired IgG responses, we synthesized epitope-functionalized polymers using ring-opening metathesis polymerization (ROMP) and assessed the effect of B and T cell epitope loading. The most robust responses were induced by polymers with a high valency of B and T cell epitopes. Additionally, IgG responses were greater for polymers with T cell epitopes that are readily liberated upon endosomal processing. Combining these criteria, we used ROMP to generate a nontoxic, polymeric antigen that elicited stronger antibody responses than a comparable protein conjugate. These findings highlight principles for designing synthetic antigens that elicit strong IgG responses against inherently weak immune targets such as glycans.
| S-EPMC7382022 | biostudies-literature
Project description:Epicuticular wax, the first protective film for numerous ground plant species, is crucial for modulating the evolution in plants. Since the waxy film is inherently thermoresponsive, many efforts focus on engineering materials for water/oil proofing, delivery, and collection, as well as microactuators by mimicking such film nature. Nonetheless, relatively fewer works address the mechanism of how the underlying substrates direct the reconstruction of waxy films while their temperature approaches the melting point. Here, we presented a strategy in which distinct frameworks of molten wax films could be examined among various substrates. Both "waxphobic" and "waxphilic" traits were first unveiled and could be achieved by the hydrophilic (water contact angle (WCA) = 42~82°) and hydrophobic (WCA = 109°) substrates, respectively. A theoretical model, based on experimental results, fluidic dynamics, and balance of surface energy, was developed to elucidate the above findings. Moreover, we demonstrated the above biomimetic epicuticular surface (BeSurface) can be applied for rewritable paper, erasable coding, and rehealable electronics without manual repairing. Remarkably, the healing time can be reduced down to 30 s, and the cycled folding test can be continued up to 500 times. All the new findings present the potentials of the BeSurface to improve the study of rehealable materials.
| S-EPMC8467712 | biostudies-literature
Project description:Microarray analysis was used to evaluate expression differences from a single donor human bone marrow stromal cells (hBMSCs) as a function of varied polymer-based tissue engineering scaffolds. The results revealed that gene expression patterns of hBMSCs grouped according to scaffold. A library of scaffolds prepared from polycaprolactone (PCL) or poly D,L-lactic acid (PDLLA) was sythesized and cultured with hBMSCs for 14 days with RNA extracted from cells on Day 1 and Day 14. Gene expression analysis was performed using BRB ArrayTools. GF = gas foam, SC = spun coat, BNF = big nanofiber, SNF = small nanofiber, FFF = free-form fabricated, TCPS = tissue culture polystyrene, TCPS+OS = tissue culture polystyrene with osteogenic supplements. The 72 arrays data was used previously in the publication: Kumar et al. The determination of stem cell fate by 3D scaffold structures through the control of cell shape, Biomaterials (2011) 32, 9188-9196. A companion data set of 24 arrays was submitted separately to GEO as GSE50744 and will be referenced to Baker et al. Ontology Analysis of Global Gene Expression Differences of Human Bone Marrow Stromal Cells Cultured on 3D Scaffolds or 2D Films
2013-11-01 | E-GEOD-50743 | biostudies-arrayexpress
Project description:Despite the promise of high flexibility and conformability of hydrogel ionic conductors, existing polymeric conductive hydrogels have long suffered from compromises in mechanical, electrical, and cryoadaptive properties due to monotonous functional improvement strategies, leading to lingering challenges. Here, we propose an all-in-one strategy for the preparation of poly(acrylic acid)/cellulose (PAA/Cel) hydrogel ionic conductors in a facile yet effective manner combining acrylic acid and salt-dissolved cellulose, in which abundant zinc ions simultaneously form strong coordination interactions with the two polymers, while free solute salts contribute to ionic conductivity and bind water molecules to prevent freezing. Therefore, the developed PAA/Cel hydrogel simultaneously achieved excellent mechanical, conductive, and cryogenically adaptive properties, with performances of 42.5 MPa for compressive strength, 1.6 MPa for tensile strength, 896.9% for stretchability, 9.2 MJ m-3 for toughness, 59.5 kJ m-2 for fracture energy, and 13.9 and 6.2 mS cm-1 for ionic conductivity at 25 and -70 °C, respectively. Enabled by these features, the resultant hydrogel ionic conductor is further demonstrated to be assembled as a self-powered electronic skin (e-skin) with high signal-to-noise ratio for use in monitoring movement and physiological signals regardless of cold temperatures, with hinting that could go beyond high-performance hydrogel ionic conductors.
| S-EPMC10786319 | biostudies-literature
Project description:There is a growing need for sensing materials that can provide multiple sensing capabilities for wearable devices, implantable sensors, and diagnostics tools. As complex human physiology requires materials that can simultaneously detect and respond to slow and fast pressure fluctuations. Mimicking the slow adaptive (SA) and fast adaptive (FA) mechanoreceptors in skin can lead to the development of dual sensing electrospun polymer nanocomposites for biomedical applications. These dual sensing nanocomposites can provide simultaneous sensing of both slow and fast pressure fluctuations, making them ideal for applications such as monitoring vital signs, detecting a wider range of movements and pressures. Here we develop a novel dual sensing PVDF-HFP-based nanocomposite that combines the advantages of capacitive and piezoelectric properties through controling electrospinning environment and processing parameters, polymer solution composition, and addition of nucleating agents such as Carbon Black (CB) to enhance the crystalline development of β-phase, fibre thickness, and morphology. The developed PVDF-HFP/CB nanocomposite presents and response to both slow and fast pressure fluctuations with high capacitance (5.37 nF) and output voltage (1.51 V) allowing for accurate and reliable measurements.
| S-EPMC10913024 | biostudies-literature