Hydrogel Elastic Energy: A Stressor Triggering an Adaptive Stress-Mediated Cell Response.

The crosstalk between the cells and the extracellular matrix (ECM) is bidirectional and consists of a pushing/pulling stretch exerted by the cells and a mechanical resistance counteracted by the surrounding microenvironment. It is widely recognized that the stiffness of the ECM, its viscoelasticity, and its overall deformation are the most important traits influencing the response of the cells. Here these three parameters are combined into a concept of elastic energy, which in biological terms represents the mechanical feedback that cells perceive when the ECM is deformed.

Elucidating the unexpected cell adhesive properties of agarose substrates. The effect of mechanics, fetal bovine serum and specific peptide sequences.

2D agarose substrates have recently been surprisingly shown to be permissive for cell adhesion, depending on their mechanics and the use of the adhesive proteins of fetal bovine serum (FBS) in the cell culture medium. Here, we elucidate how the cells exhibit two anchoring mechanisms depending on the amount of FBS. Under low FBS conditions, the cells recognize the surface-coupled adhesive sequences of fibronectin via the binding of the heterodimer αβ integrin.

A chemo-enzymatic method for preparation of saturated oligosaccharides from alginate and other uronic acid-containing polysaccharides.

Oligosaccharides from uronic acid-containing polysaccharides can be produced either by chemical or enzymatic degradation. The benefit of using enzymes, called lyases, is their high specificity for various glycosidic linkages. Lyases cleave the polysaccharide chain by an β-elimination reaction, yielding oligosaccharides with an unsaturated sugar (4-deoxy-l-erythro-hex-4-enepyranosyluronate) at the non-reducing end.

Silk Fibroin-Enriched Bioink Promotes Cell Proliferation in 3D-Bioprinted Constructs.

Three-dimensional (3D) bioprinting technology enables the controlled deposition of cells and biomaterials (i.e., bioink) to easily create complex 3D biological microenvironments.

"A lactose-modified chitosan accelerates chondrogenic differentiation in mesenchymal stem cells spheroids".

Spheroids derived from human mesenchymal stem cells (hMSCs) are of limited use for cartilage regeneration, as the viability of the cells progressively decreases during the period required for chondrogenic differentiation (21 days). In this work, spheroids based on hMSCs and a lactose-modified chitosan (CTL) were formed by seeding cells onto an air-dried coating of CTL. The polymer coating can inhibit cell adhesion and it is simultaneously incorporated into spheroid structure.

Ionic Strength Impacts the Physical Properties of Agarose Hydrogels.

Agarose is a natural polysaccharide known for its ability to form thermoreversible hydrogels. While the effects of curing temperature and polysaccharide concentration on mechanical properties have been discussed in the literature, the role of ionic strength has been less studied. In the present manuscript, we investigate the effects of supporting salt concentration and the role of cation (i.

Decurarization After Thoracic Anesthesia using sugammadex compared to neostigmine (DATA trial): a multicenter randomized double-blinded controlled trial.

Background: Thoracic surgery is a high-risk surgery especially for the risk of postoperative pulmonary complications. Postoperative residual paralysis has been shown to be a risk factor for pulmonary complications. Nevertheless, there are few data in the literature concerning the use of neuromuscular blocking agent antagonists in patients undergoing lung surgery.

Alginate-metal cation interactions: Macromolecular approach.

Alginates are a broad family of linear (unbranched) polysaccharides derived from brown seaweeds and some bacteria. Despite having only two monomers, i.e.

Controlled Quenching of Agarose Defines Hydrogels with Tunable Structural, Bulk Mechanical, Surface Nanomechanical, and Cell Response in 2D Cultures.

The scaffolding of agarose hydrogel networks depends critically on the rate of cooling (quenching) after heating. Efforts are made to understand the kinetics and evolution of biopolymer self-assembly upon cooling, but information is lacking on whether quenching might affect the final hydrogel structure and performance. Here, a material strategy for the fine modulation of quenching that involves temperature-curing steps of agarose is reported.

Hydrogels based on methylated-alginates as a platform to investigate the effect of material properties on cell activity. The role of material compliance.

Alginate-based hydrogels with tunable mechanical properties are developed by chemical methylation of the polysaccharide backbone, which was performed either in homogeneous phase (in solution) or in heterogeneous phase (on hydrogels). Nuclear Magnetic Resonance (NMR) and Size Exclusion Chromatography (SEC-MALS) analyses of methylated alginates allow to identify the presence and location of methyl groups on the polysaccharide, and to investigate the influence of methylation on the stiffness of the polymer chains. The methylated polysaccharides are employed for the manufacturing of calcium-reticulated hydrogels for cell growth in 3D.

Solvation and expansion of neutral and charged chains of a carbohydrate polyelectrolyte: Galacturonan in water. A critical revisiting.

Experimental and theoretical data have been revisited to shed light onto the aspects of hydration and chain expansion of pectic acid (galacturonan) upon charging. The prediction of the variation of the number of solvation water molecules between the two limit ionization states from theoretical calculations was confirmed to a very high accuracy by the corresponding number evaluated form dilatometric measurements. The relevance of hydration to the mechanism of bonding of calcium ions by sodium pectate is discussed.

Immediate stress dissipation in dual cross-link hydrogels controls osteogenic commitment of mesenchymal stem cells.

In vitro studies of mesenchymal stem cells (MSCs) differentiation have been predominantly performed with non-physiologically elastic materials. Here we report the effect of different viscoplastic ECM mimics on the osteogenic engagement of MSCs in 2D. We have developed soft hydrogels, composed of a lactose-modified chitosan, using a combination of permanent and temporary cross-links.

Comparative Insights into the Fundamental Steps Underlying Gelation of Plant and Algal Ionic Polysaccharides: Pectate and Alginate.

Pectate and alginate are among the most important biopolymers able to give rise to ionotropic gelation upon the addition of di- or multivalent counterions. The two ionic polysaccharides exhibit several common aspects of the gelation mechanism with calcium ions, the physiologically and commercially most relevant counterion type. The first one pertains to the role that specific Ca/polyion interactions play in the establishment of the ion-mediated chain/chain cross-links.

Taxonomical and functional composition of strawberry microbiome is genotype-dependent.

Introduction: Specific microbial communities are associated to host plants, influencing their phenotype and fitness.Despite the rising interest in plant microbiome, the role of microbial communities associated with perennial fruit plants remains overlooked.

Objectives: This work provides the first comprehensive descriptionof the taxonomical and functional bacterial and fungal microbiota of below- and above-ground organsof three commercially important strawberry genotypes under cultural conditions.

Red and Blue Light Differently Influence Performance and Its Interaction with pv. .

Light composition modulates plant growth and defenses, thus influencing plant-pathogen interactions. We investigated the effects of different light-emitting diode (LED) red (R) (665 nm) and blue (B) (470 nm) light combinations on performance by evaluating biometric parameters, chlorophyll a fluorescence, gas exchange and photosynthesis-related gene expression. Moreover, the influence of light on the infection by pv.

Effect of α-Amylase on the Structure of Chia Seed Mucilage.

Thanks to its nutritional and mechanical properties, chia seed mucilage is becoming increasingly popular in the food industry as a small biomolecule. The mechanical properties of an ingredient are a key element for food appreciation during chewing. Therefore, with this study, we explore for the first time the structural changes that chia seed mucilage undergoes when treated with α-amylase, the most abundant enzyme in human saliva.

Sulfated lactose-modified chitosan. A novel synthetic glycosaminoglycan-like polysaccharide inducing chondrocyte aggregation.

Lactose-modified chitosan (CTL) is sulfated using SO·py or SO·DMF as sulfating agents. The two products are characterized by elemental analysis, FT-IR, H,C-DEPT-HSQC and H,C-HSQC-TOCSY experiments which allow the extent and selectivity of chemical sulfation to be determined. Dynamic Light Scattering shows a pH-dependent association of the sulfated polysaccharides which are described as flexible by the Smidsrød's B parameter and the intrinsic viscosity at infinite ionic strength.

Influence of Temperature and Polymer Concentration on the Nonlinear Response of Highly Acetylated Chitosan-Genipin Hydrogels.

Strain hardening, i.e., the nonlinear elastic response of materials under load, is a physiological response of biological tissues to mechanical stimulation.

On the Molecular Mechanism of the Calcium-Induced Gelation of Pectate. Different Steps in the Binding of Calcium Ions by Pectate.

Pectic acid/sodium pectate is one of the most widespread hydrocolloid used in the food industry. It is able to form strong ionotropic gels by the addition of ions, in particular, calcium ions. The initial steps of binding Ca ions to a sample of sodium pectate with a composition close to 90% of ideal Na-poly(galacturonate) were investigated by means of circular dichroism (CD), microcalorimetry, dilatometry, viscosity, and membrane osmometry, as a function of increasing , being the ratio of the molar concentrations of Ca and pectate repeating units.

Characterization of Thermoresponsive Poly-N-Vinylcaprolactam Polymers for Biological Applications.

Poly-N-Vinylcaprolactam (PNVCL) is a thermoresponsive polymer that exhibits lower critical solution temperature (LCST) between 25 and 50 °C. Due to its alleged biocompatibility, this polymer is becoming popular for biomedical and environmental applications. PNVCL with carboxyl terminations has been widely used for the preparation of thermoresponsive copolymers, micro- and nanogels for drug delivery and oncological therapies.

Does Organic Farming Increase Raspberry Quality, Aroma and Beneficial Bacterial Biodiversity?

Plant-associated microbes can shape plant phenotype, performance, and productivity. Cultivation methods can influence the plant microbiome structure and differences observed in the nutritional quality of differently grown fruits might be due to variations in the microbiome taxonomic and functional composition. Here, the influence of organic and integrated pest management (IPM) cultivation on quality, aroma and microbiome of raspberry ( L.

Strain Hardening in Highly Acetylated Chitosan Gels.

Strain hardening has recently emerged as a near-universal response of biological tissues to mechanical stimulation as well as a powerful regulator of cell fate. Understanding the mechanistic basis for this nonlinear elasticity is crucial for developing bioinspired materials that mimic extracellular matrix mechanics. Here, we show that covalent networks built from highly acetylated chitosans exhibit strain hardening at physiological pH and osmolarity.

Bacterial volatile compound-based tools for crop management and quality.

Bacteria produce a huge diversity of metabolites, many of which mediate ecological relations. Among these, volatile compounds cause broad-range effects at low doses and, therefore, may be exploited for plant defence strategies and agricultural production, but such applications are still in their early development. Here, we review the latest technologies involving the use of bacterial volatile compounds for phytosanitary inspection, biological control, plant growth promotion, and crop quality.

Effect of sodium alginate molecular structure on electrospun membrane cell adhesion.

Alginate-based electrospun nanofibers prepared via electrospinning technique represent a class of materials with promising applications in the biomedical and pharmaceutical industries. However, to date, the effect of alginate molecular mass and block composition on the biological response of such systems remains to some extent unclear. As such, in the present work, three alginates (i.