Spontaneous Adhesion Research Articles

Engineering multicomponent tissue by spontaneous adhesion of myogenic and adipogenic microtissues cultured with customized scaffolds

The integration of intramuscular fat—or marbling—into cultured meat will be critical for meat texture, mouthfeel, flavor, and thus consumer appeal. However, culturing muscle tissue with marbling is challenging since myocytes and adipocytes have different media and scaffold requirements for optimal growth and differentiation. Here, we present an approach to engineer multicomponent tissue using myogenic and adipogenic microtissues. The key innovation in our approach is the engineering of myogenic and adipogenic microtissues using scaffolds with customized physical properties; we use these microtissues as building blocks that spontaneously adhere to produce multicomponent tissue, or marbled cultured meat. Myocytes are grown and differentiated on gelatin nanofiber scaffolds with aligned topology that mimic the aligned structure of skeletal muscle and promotes the formation of myotubes in both primary rabbit skeletal muscle and murine C2C12 cells. Pre-adipocytes are cultured and differentiated on edible gelatin microbead scaffolds, which are customized to have a physiologically-relevant stiffness, and promote lipid accumulation in both primary rabbit and murine 3T3-L1 pre-adipocytes. After harvesting and stacking the individual myogenic and adipogenic microtissues, we find that the resultant multicomponent tissues adhere into intact structures within 6–12 h in culture. The resultant multicomponent 3D tissue constructs show behavior of a solid material with a Young’s modulus of ∼ 2 ± 0.4 kPa and an ultimate tensile strength of ∼ 23 ± 7 kPa without the use of additional crosslinkers. Using this approach, we generate marbled cultured meat with ∼ mm to ∼ cm thickness, which has a protein content of ∼ 4 ± 2 g/100 g that is comparable to a conventionally produced Wagyu steak with a protein content of ∼ 9 ± 4 g/100 g. We show the translatability of this layer-by-layer assembly approach for microtissues across primary rabbit cells, murine cell lines, as well as for gelatin and plant-based scaffolds, which demonstrates a strategy to generate edible marbled meats derived from different species and scaffold materials.

Myeloid Src-family kinases are critical for neutrophil-mediated autoinflammation in gout and motheaten models.

Autoinflammatory diseases include a number of monogenic systemic inflammatory diseases, as well as acquired autoinflammatory diseases such as gout. Here, we show that the myeloid Src-family kinases Hck, Fgr, and Lyn are critical for experimental models of gout, as well as for genetically determined systemic inflammation in the Ptpn6me-v/me-v (motheaten viable) mouse model. The Hck-/-Fgr-/-Lyn-/- mutation abrogated various monosodium urate (MSU) crystal-induced pro-inflammatory responses of neutrophils, and protected mice from the development of gouty arthritis. The Src-family inhibitor dasatinib abrogated MSU crystal-induced responses of human neutrophils and reduced experimental gouty arthritis in mice. The Hck-/-Fgr-/-Lyn-/- mutation also abrogated spontaneous inflammation and prolonged the survival of the Ptpn6me-v/me-v mice. Spontaneous adhesion and superoxide release of Ptpn6me-v/me-v neutrophils were also abolished by the Hck-/-Fgr-/-Lyn-/- mutation. Excessive activation of tyrosine phosphorylation pathways in myeloid cells may characterize a subset of autoinflammatory diseases.

Effect of a liquid bridge on the dynamic behavior of diamond wires during slicing

Diamond wire sawing with narrower kerf losses and thinner as-cut wafers is a critical technology to further reduce wafering costs in the semiconductor industry. Nevertheless, as the scale of the wire web decreases, the effect of the liquid bridge formed by the capillary condensation of the cutting fluid between the diamond wires becomes significant. Moreover, the transverse wire vibration reduces the wire web gap at certain moments, which makes it easier for the wires to adhere to each other after wetting, thus hindering the slicing process. Therefore, a dynamical model for a double-wire system with liquid bridge action was developed in this study based on the transverse vibration theory of a diamond wire under support excitations to reveal the action mechanism of the liquid bridge between diamond wires. The dynamic adhesion process between the diamond wires moving with the supports is discussed. The effects of the guide wheel manufacturing error and the sawing parameters on the critical gap for spontaneous adhesion between the diamond wires are analyzed. The results show that the static double-wire system does not generate spontaneous adhesion when the surface gap of the wires is between the critical gap for spontaneous adhesion and the maximum adhesion gap. The support excitation causes the transverse wire displacement, which increases the critical gap for spontaneous adhesion to increase the risk of wires adhesion. The critical gap for spontaneous adhesion increases with increases in the guide wheel manufacturing error and the wire span as well as the wire speed and decreases with increases in the wire groove diameter and the wire tension. When the manufacturing error is doubled, the critical gap for spontaneous adhesion will increase more than twice this error increment. Strict control of the guide wheel manufacturing error is the most effective way of reducing the risk of wires adhesion during processing. Increases in the guide wheel diameter and decreases in the wire span and the wire speed within a reasonable range, or enhancing the mechanical properties of the wire to improve its breaking force, also help to reduce the critical gap for spontaneous adhesion.

The effect of surface tension on the adhesion performance of nanoscale fibrillary structures——a theoretical prediction

The last decade witnesses the thorough investigation of bio-inspired nanoscale fibrillary structures with strong adhesion to stiff substrates. In the present study, we explore the effect of surface tension on the adhesion behavior of a rigid nanoscale fiber and an elastic substrate. With the existence of surface tension, we reconsider the optimal shape of the fiber, critical condition for spontaneous adhesion, saturation of adhesion strength and flaw-tolerant capability. The results indicate that the critical fiber radius for spontaneous adhesion and threshold value for crack size can be significantly enhanced due to surface tension. Meanwhile, the adhesion strength can approach the maximum value faster with fiber radius decreasing ascribed to surface tension, compared with the situation with the absence of surface tension. These conclusions present an inspiration for the optimization of adhesion strength of fibrillary surfaces.

Tannin-Based Spontaneous Adhesion Superhydrophilic Coatings for Efficient Oil-in-Water Emulsion Separation and Dye Removal

Tannin-Based Spontaneous Adhesion Superhydrophilic Coatings for Efficient Oil-in-Water Emulsion Separation and Dye Removal

Current Approach to Treatment for Central Serous Chorioretinopathy. Review

Central serous chorioretinopathy (CSC) is a disease of complex origin and unknown etiology. Traditionally, two clinical forms of CSC are verified in accordance with the activity and duration of the pathological process: classic acute form and chronic CSC. Nowadays, there is no unified concept accepted for the management of patients with this disease, particular difficulties exist in cases of chronic CSC. This literature review highlights current trends and approaches to the treatment of CSC patients — from focal laser photocoagulation to physical methods oh therapy. The therapeutic approach as a whole depends on the form of the CHS. In most cases of the acute form of CSF, spontaneous regression, spontaneous adhesion of RPE detachment and retinal neuroepithelium are noted within several months from the onset of the disease. Therapy for the chronic form of this disease is still a difficult task and a controversial issue. Direct laser coagulation of the retina at the oozing point is recognized as the most effective method of therapy for acute typical form of CSF. In the chronic form of CSC, photodynamic therapy, transpupillary thermotherapy and subthreshold micropulse laser exposure are used. The goal of drug therapy for CSF is to activate the processes of resorption of serous fluid from the subretinal or subpigmented space, reduce the activity of pathological processes in the choroid, and improve trophism and metabolism. The currently used methods of treating chronic CSH have a number of disadvantages and variable efficacy. The existence of treatment-resistant cases is the subject of further research and clinical research. The development of new physical and physiopharmacological methods of treatment for CSF is perspective.

Adhesion of Norovirus to Surfaces: Contribution of Thermodynamic and Molecular Properties Using Virus-Like Particles.

The aim of the study was to assess human norovirus and feline calicivirus (FCV) surface free energy, hydrophobicity, and ability to interact with fresh foods and food-contact surfaces. Virus-like particles (VLPs) of human norovirus (GI.1 and GII.4) and FCV were produced, purified, and analyzed for their surface free energy, hydrophobicity, and the total interfacial free energy of interaction [Formula: see text] with lettuce, strawberry, polyethylene, and stainless steel. GII.4 VLPs were further tested for adhesion at different pH, ionic strengths, and temperature. All the VLPs and the test materials showed low surface energies, as well as hydrophobic characters except for GI.1. Nearly all [Formula: see text] values were propitious for spontaneous adhesion. GII.4 VLPs adsorbed almost indifferently to stainless steel, polyethylene, and lettuce. Isoelectric point and high temperature generally promoted adhesion while ionic strength effect was surface-dependant. According to this study, all the materials assessed are of low-energy and hydrophobic nature except GI.1 VLPs. Interfacial free energies of interaction were favorable for spontaneous adhesion ([Formula: see text] < 0) of all VLPs to the test materials, except for GI.1 VLPs to both stainless steel and straweberry. It is also found that norovirus adhesion is more sensitive to physicochemical conditions than to surface character itself.

Genèse et facticité

By opening the investigation to scattered and inchoative states, Marc Richirʼs phenomenology reverses the relation between legitimation and receptivity. He calls into question the idea of a spontaneous adhesion of the experience to itself and reformulates the Husserlian problematic of Ur-doxa without abandoning the ambition of legitimation. Legitimation is no longer ensured by the donation of a sense but by a gesture of reinstitution.

Reactive Oxidative Species-Modulated Ca2+ Release Regulates β2 Integrin Activation on CD4+ CD28null T Cells of Acute Coronary Syndrome Patients.

The number and activity of T cell subsets in the atherosclerotic plaques are critical for the prognosis of patients with acute coronary syndrome. β2 Integrin activation is pivotal for T cell recruitment and correlates with future cardiac events. Despite this knowledge, differential regulation of adhesiveness in T cell subsets has not been explored yet. In this study, we show that in human T cells, SDF-1α-mediated β2 integrin activation is driven by a, so far, not-described reactive oxidative species (ROS)-regulated calcium influx. Furthermore, we show that CD4+CD28null T cells represent a highly reactive subset showing 25-fold stronger β2 integrin activation upon SDF-1α stimulation compared with CD28+ T cells. Interestingly, ROS-dependent Ca release was much more prevalent in the pathogenetically pivotal CD28null subset compared with the CD28+ T cells, whereas the established mediators of the classical pathways for β2 integrin activation (PKC, PI3K, and PLC) were similarly activated in both T cell subsets. Thus, interference with the calcium flux attenuates spontaneous adhesion of CD28null T cells from acute coronary syndrome patients, and calcium ionophores abolished the observed differences in the adhesion properties between CD28+ and CD28null T cells. Likewise, the adhesion of these T cell subsets was indistinguishable in the presence of exogenous ROS/H2O2 Together, these data provide a molecular explanation of the role of ROS in pathogenesis of plaque destabilization.

Natural Adhesion Blepharoplasty Technique.

Nonincisional blepharoplasty is widely practiced to make natural double eyelids. However, this method has the disadvantage of the double fold loosening compared to incisional blepharoplasty. Many researchers have proposed a method of nonincisional blepharoplasty with lower risk of loosening. The authors innovated the method to induce spontaneous adhesion in a nonincisional blepharoplasty with induction of partial linear adhesions, and, therefore, lowering the risk of suture loosening. While performing this procedure, the orbicularis oculi muscle and the levator palpebrae muscle were partially incised through eight tiny incisions to induce adhesion, and the double eyelid was made with the nonincisional continuous suture technique. This study included 99 patients who underwent natural adhesion blepharoplasty technique between January and December 2018. After 1 year of follow-up, no double eyelid loosening was observed. Natural adhesion blepharoplasty is simple technique to create natural-looking results and a durable double fold with satisfactory aesthetic results.

Polydopamine-based surface modification of hemoglobin particles for stability enhancement of oxygen carriers

Templated assembly techniques have been extensively used to develop various types of hemoglobin (Hb) loaded particles with improved performance. However, several instability issues must still be solved, including Hb exposure, enhanced Hb auto-oxidation, and the relatively weak binding of Hb to cross-linkers. Herein, to meet the stability requirements for novel hemoglobin-based oxygen carriers (HBOCs), hemoglobin-polydopamine particles (Hb-PDA) were fabricated using a mild process that combines the co-precipitation of Hb and an inorganic template with the spontaneous adhesion of PDA. The Hb-PDA showed uniform size distribution, chemical integrity of both Hb and PDA, high biocompatibility, and robust oxygen delivery. Our results demonstrated that the use of polydopamine as a biocompatible coating material reduced Hb leakage from the particles under both static and flow conditions, thus mitigating the toxicity associated with free Hb and strengthening the stability of Hb particles. In addition, Hb-PDA reduced HUVEC (Human Umbilical Vein Cells) oxidative injury and scavenged 85% of the available hydroxyl radicals, exhibiting its potential to act as an antioxidant for encapsulated Hb. Hb-PDA therefore shows significant promise as a cell-like structurally and functionally stable HBOCs.

Interaction forces between colloidal starch and quartz and hematite particles in mineral flotation

In this study, we present theoretical and experimental data on the interaction forces between starch and particles of hematite and quartz as well as their implications for flotation and aggregation. The individual Hamaker constant for starch acting through vacuum, A11, was calculated, and its value, 6.27 × 10−20J, demonstrates the highly hydrophilic character of gelatinized starch. The Hamaker constants for quartz/water/starch and for hematite/water/starch, A132, were also calculated, and these values were 6.07 × 10−21J and 17.90 × 10−20J, respectively. It was confirmed that starch strongly adsorbs onto hematite, whereas on quartz, starch may adsorb onto only silicon surface sites. In fact, AFM images of quartz surfaces showed non-adsorbed areas or areas with a thin layer of starch that certainly do not interfere in subsequent adsorption by the collector (etheramine). The interaction energies between gelatinized starch and the hematite and quartz surfaces were estimated based on DLVO theory at pH 10.5 and a constant ionic strength (10−3 mol.L−1 NaCl). The repulsion electrostatic energy was higher for the quartz-starch system than for the interactions between hematite and starch. The calculated total energy of interaction between quartz and starch revealed that there is no possibility of aggregation for the individual colloids of starch and quartz particles. On the other hand, spontaneous adhesion between the colloids and hematite particles was confirmed by DLVO theory.

A JKR solution for a ball-in-socket contact geometry as a bi-stable adhesive system

In the present note, we start by observing that in the classical JKR theory of adhesion, using the usual Hertzian approximations, the pull-off load grows unbounded when the clearance goes to zero in a conformal "ball in socket" geometry. To consider the case of the conforming geometry, we use a recent rigorous general extension of the original JKR energetic derivation proposed by the first author which necessitates only of adhesionless solutions, and an approximate adhesionless solution given in the literature. We find that depending on a single governing parameter of the problem, theta=DeltaR/(2 pi w R E*) where E* is the plane strain elastic modulus of the material couple, w the surface energy, DeltaR the clearance and R the radius of the sphere, the system shows the classical bistable behaviour for a single sinusoid or a dimpled surface: pull off is approximately that of the JKR theory for theta>0.82 only if the system is not "pushed" strongly enough and otherwise a "strong adhesion" regime is found. Below this value theta<0.82, a strong spontaneous adhesion regime is found similar to "full contact". From the strong regime, pull-off will require a separate investigation depending on the actual system at hand.

Spontaneous Adhesion of DOPA and Tryptophan Functionalized PEG to Polystyrene Nanobeads: An EPR Study

Wet adhesion is achieved by mussels so naturally. Their adhesion mechanism has inspired scientists to obtain wet adhesives for a long time. The amino acid 3,4-dihydroxyphenylalanine (DOPA) produced by mussels adheres to different types of surfaces and also contributes to cohesive interactions. Here, we showed the spontaneous adhesion of DOPA functionalized four armed poly (ethylene glycol) (PEG) polymer to spin labeled polystyrene (SL-PS) nanosurfaces by electron paramagnetic resonance (EPR) spectroscopy. In addition to DOPA, adhesion property of another amino acid of tryptophan (Trp) was studied. Trp attached four armed PEG polymers did not adhere to the surface of SL-PS in the force free condition. However, two armed DOPA and two armed Trp functionalized PEG adhere to the PS.

Macroscopic Adhesion of Thermoreversible ABC Triblock Copolymer-Based Hydrogels Via Boronic Acid-Sugar Complexation.

Two complementary thermoreversible ABC triblock copolymers containing either phenylboronic acids with low pKa values or galactosyl groups in the hydrophilic B blocks are synthesized by sequential reversible addition-fragmentation chain transfer polymerization and subsequent modification of the functional groups. Both ABC triblock copolymers undergo reversible sol-to-gel transitions upon temperature change and form physically cross-linked hydrogels under physiological conditions. Furthermore, the spontaneous adhesion of these thermoreversible hydrogels via the formation of boronic esters between the phenylboronic acid and galactosyl groups under physiological conditions is realized for the first time.

The Spontaneous Adhesion of BMMC onto Self-Assembled Peptide Nanoscaffold without Activation Inhibits Its IgE-Mediated Degranulation.

Mast cells play a distinct role in the innate immune response. Engineered microenvironments for the express purpose of influencing mast cell activity will provide a novel means of designing biomaterials, as well as a means to systematically investigate mast cell biology in a 3D setting. Here, the effect of nanoscaffolds composed of self-assembling peptides, namely (RADA)4 , on bone-marrow-derived murine mast cell (BMMC) activity is reported. Unlike most studies that stimulate mast cells to induce adhesion, this results show that BMMCs spontaneously adhere to the artificial nanoscaffold without initiating their activation. It is observed that the classical immunoglobulin (IgE) antigen-mediated degranulation of adhered BMMC is inhibited by the nanoscaffold, while non-IgE (A23187)-induced degranulation is unaffected. The inhibition of IgE-antigen-mediated degranulation is likely a result of inhibited molecular diffusion within the matrix; antigen diffusion, IgE-FcεRI complex shuttling, and/or formation of multiple IgE-FcεRI clusters may be physically hindered in the presence of the polyvalent nanofiber network. Moreover, the IgE/antigen-induced inflammatory cytokine tumor necrosis factor α release from adherent BMMCs is significantly reduced likely due to interaction with the nanofiber matrix. This work is considered the first step in quantifying mast cell activity in artificial matrices composed of self-assembling peptides.

Determination of force-free wet adhesion of mussel-inspired polymers to spin labeled surface

Hydration repulsive forces oppose the adhesive interactions, especially in the force-free conditions. Here, we studied spontaneous wet adhesion of 3,4-dihydroxyphenylalanine (DOPA) functionalized poly(ethylene glycol) (PEG) polymers inspired by marine mussels. Using electron paramagnetic resonance (EPR) spectroscopy, we can monitor spontaneous adhesion of DOPA containing polymer to suspended spin labeled hydrophobic polystyrene nanobeads at molecular level. The surface coverage up to 82% is obtained from EPR measurements. However, in the force-free condition, EPR measurements do not show any detectable DOPA based adhesion to hydrophilic silica nanobead.

Lipid for biodiesel production from attached growth Chlorella vulgaris biomass cultivating in fluidized bed bioreactor packed with polyurethane foam material

The potential to grow attached microalgae Chlorella vulgaris in fluidized bed bioreactor was materialized in this study, targeting to ease the harvesting process prior to biodiesel production. The proposed thermodynamic mechanism and physical property assessment of various support materials verified polyurethane to be suitable material favouring the spontaneous adhesion by microalgae cells. The 1-L bioreactor packed with only 2.4% (v/v) of 1.00-mL polyurethane foam cubes could achieve the highest attached growth microalgae biomass and lipid weights of 812±122 and 376±37mg, respectively, in comparison with other cube sizes. The maturity of attached growth microalgae biomass for harvesting could also be determined from the growth trend of suspended microalgae biomass. Analysis of FAME composition revealed that the harvested microalgae biomass was dominated by C16-C18 (>60%) and mixture of saturated and mono-unsaturated fatty acids (>65%), satiating the biodiesel standard with adequate cold flow property and oxidative stability.

Self-Assembly of Thermoreversible Hydrogels via Molecular Recognition toward a Spatially Organized Coculture System.

In this study, we present the spontaneous adhesion of two thermoreversible physically cross-linked hydrogels via molecular recognition under a physiological condition. We successfully prepared two types of hydrogels generated using two kinds of well-defined ABA type triblock copolymers: CAT-ABA and PBA-ABA, which contain catechol and phenylboronic acid groups as functional side chains, respectively. Both types of ABA triblock copolymers were able to undergo sol-to-gel transition with the increase in temperature resulting from the formation of physical cross-links at a physiological temperature, which enables easy cell encapsulation in the hydrogel. It was determined that the cell encapsulating hydrogels exhibited spontaneous macroscopic adhesion through the formation of boronic esters between phenylboronic acid and catechol at the hydrogel interface. This novel system likely represents a promising method to construct a precisely organized, three-dimensional coculture system to enable the reconstruction of complicated tissues such as the liver in vitro.

Severity assessment of atopic dermatitis in children

The article is devoted to the analysis of methods to assess the degree of atopic dermatitis (AD) severity, of their clinical manifestations and laboratory diagnosis. Treatment and prognosis of atopic dermatitis depends on the assessment of disease severity. The severity of the disease is the main factor for a doctor in the therapy of a child with AD. There are many scientific studies devoted to the objective classification of diseases and the development of the most effective methods of severity assessment. It is not always possible to quickly determine objectively measurable parameters ofpathologic skin process. Because of that assessment methods of skin diseases are often approximate and subjective. The new pathogenetic data of atopic dermatitis and the main types of defects are described. Dermatology indexes of atopic dermatitis severity were considered. The new biochemical methods to assess the degree of atopic dermatitis severity in children by measuring indicators of spontaneous adhesion of neutrophils were analyzed. Immunological method, in which serum of children with atopic dermatitis is determined by the level of total IgE and IgE antibodies to allergens, with using ImmunoCAP 100 and level IgG- and IgE-antibodies against tissue antigens by ELISA, were analyzed. The indicators of oxidative status were examined. The concentration of circulating biological peroxides (PPI) and nukliozida 8-OHdG (8-hydroxy-2’-deoxyguanosine) differed significantly in mild, moderate and severe AD. Bacteriological methods, based on an integrated assessment of microbiological parameters, characterizing the nonspecific resistance of skin and mucous membranes in the assessment of severity and prognosis of atopic dermatitis in children, were performed.