Relation between surface energy and surface tension pdf
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- Surface tension in human pathophysiology and its application as a medical diagnostic tool
E-mail: Dominik. Kramer int. This result should help to resolve the seeming discrepancy between previous work on the surface stress changes of electrodes: Most experimental and theoretical results supported either the view that the variations of surface stress are identical or similar to that of surface tension, i.
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Introduction: Pathological features of disease appear to be quite different. Despite this diversity, the common feature of various disorders underlies physicochemical and biochemical factors such as surface tension. Human biological fluids comprise various proteins and phospholipids which are capable of adsorption at fluid interfaces and play a vital role in the physiological function of human organs.
Surface tension of body fluids correlates directly to the development of pathological states. Methods: In this review, the variety of human diseases mediated by the surface tension changes of biological phenomena and the failure of biological fluids to remain in their native state are discussed.
Results: Dynamic surface tension measurements of human biological fluids depend on various parameters such as sex, age and changes during pregnancy or certain disease. It is expected that studies of surface tension behavior of human biological fluids will provide additional information and might become useful in medical practice.
Theoretical background on surface tension measurement and surface tension values of reference fluids obtained from healthy and sick patients are depicted. Conclusion: It is well accepted that no single biomarker will be effective in clinical diagnosis. The surface tension measurement combined with routine lab tests may be a novel non-invasive method which can not only facilitate the discovery of diagnostic models for various diseases and its severity, but also be a useful tool for monitoring treatment efficacy.
We therefore expect that studies of surface tension behavior of human biological fluids will provide additional useful information in medical practice. Surface tension is a phenomenon that we see in our everyday life. Many biological performances and natural processes involve an understanding of wetting and interfacial tension where most biochemical reactions occur not in solution but at the surface and interface.
Human biological fluids such as serum, urine, gastric juice, amniotic fluid, digestive, urinary and reproductive tracts, endocrine glands, middle ear, cerebrospinal and alveolar lining fluid contain numerous surfactants, proteins, and lipids.
These low and high-molecular weight surfactants are the common materials in various tissues of the body which control surface tension of human interfaces.
The physicochemical processes that take place in these interfaces are of fundamental importance for various tissues and the vital function of body organs. Pathological features of diseases vary in the nature and the magnitude. Despite this diversity, the common feature of various disorders underlies the physicochemical and biochemical factors such as surface tension.
Changes in the surface tension behavior of human biological fluid are characteristic for some diseases. Studying these interfaces and the changes that occur will provide valuable information relating to various diseases and help to monitor the treatment efficacy. In medicine, surface tension measurement is above all used in connection with various pathological states of lung surfactants such as adult respiratory distress syndrome, bronchial asthma, and pneumonia.
In addition to pneumology, there are other studies evaluating the surface tension of plasma, urine and other biological fluids, however beside this work there has been very little work in relating rheology and these forces to pathological disease states.
The impact of surface tension on pharmaceutical formulation and technology has been studied by our group. A reason for this discrepancy could be that the surface rheology is not introduced to medicine and theoretical studies and characteristics of biological fluids are not well established. The molecules of a fluid experience attractive forces exerted on it by all its neighboring molecules. In the bulk phase, molecules are attracted equally in all directions leading to a net force of zero; however molecules at or near the surface experience attractive force which tends to pull them to the interior of the fluid.
The surface free energy of a fluid is measured by its surface tension and the surface free energy of a solid can be revealed by contact angle measurements. Surface tension is dependent on many variables such as temperature, measurement time, materials of the apparatus and the viscosity of the fluid. When a new surface is being formed, surface active chemicals diffuse to the surface and align.
During this process, the surface tension is changing rapidly and continuously. Dynamic surface tension measurements allow us to track these changes. Surface tension, as an intricate property of a fluid, is associated markedly with many variables such as temperature, composition of the solution, presence of impurities in the fluid, measurement time, materials of the apparatus, and viscosity of the liquid.
Human biological fluids contain numerous low-and high-molecular weight surfactants, proteins and lipids that adsorb at fluid interface. The composition of these fluids varies with age, sex, health condition and therapeutic treatment.
The processes which take place at these interfaces could reflect the age and sex of a person. The low content of enzyme, lipoprotein and carbohydrate components in female serum is responsible for the high equilibrium surface tension of biological fluids when compared to that of the male. As the age increases, the surface tension of serum increases while the surface tension of urine decreases.
That is, due to the compositional changes in biological fluids during pregnancy, surface tension of serum decreases. Biological tissues are viscoelastic materials and the cells in a tissue behave very much like molecules in a fluid. This property enables them to change their position and move against each other. The morphology and shape of the organism are driven by the events that occur at the cellular level.
The shape of a cell is the result of a balance of intracellular and extrinsic forces exerted on it. This behaviour is defined through surface tension which tends to minimize the exposed area of the cell aggregate and maximize the cohesive forces. The intracellular forces on the membrane are a result of the cytoskeleton reorganization. Energy at the cellular level is usually measured through physical properties such as cell adhesion, viscosity, and cortical tension.
Intracellular adhesion and repulsion between various cell types cause mobility within cells. Cellular forces are essential for the process of cell coupling, cell morphology and tissue rearrangement. Adhesion contact on neighbouring cells ensures stable organization of tissues. Three kinds of forces, cortical tension, cellular adhesion and cellular viscoelastic properties are mechanically coupled to each other.
Interaction between these mechanical properties governs cell shape and cell arrangement in tissues. These forces regulate cellular behaviours such as tissue development, embryogenesis, protein expression, cell proliferation and differentiation and will help to study the cell behaviour in normal and pathological conditions and invasiveness of malignant tumors. Schematic image of the interaction between cortical tension and cellular adhesion during the formation of cell—cell contacts.
Directions of the forces are depicted with arrows, the red line represents cortical cytoskeleton, black lines are plasma membrane and the purple rods depict adhesion sites, adapted from reference Research has revealed that forces generated by surface tension play a leading role in the position rearrangement of cells and act in minimizing the exposed area of the aggregate.
Cell-cell adhesion is maintained through specific adhesion molecules such as cadherins which are expressed on the cell surface. Due to the different adhesion molecules on various cell types, intensity of adhesion among cells happen to markedly varry.
This hypothesis explains adhesion-driven morphogenic processes in the early embryonic development. Expression of different cadherins changes the cell surface contact and controls the cell shape. Regulation of these adhesion molecules in different cell groups determines cell shape and helps to gain information about cellular aggregates in order to decide on the next migration step. As shown in Fig. Both cell-cell cohesion and cell-matrix interactions are responsible for cell configuration and malignant invasion.
Configuration of two different cell populations with varying adhesion forces, the dark sphere represents cells with high selfadhesion whereas the white sphere represents cells with lower self-adhesion. A no cross-adhesion, B relatively weak crossadhesion, C intermediate cross-adhesion and D preferential cross-adhesion between the cells and E differential adhesion and morphological changes during somatogenesis.
Figures were adapted to reference Surface-modified biomaterials are synthetic materials exhibiting specific physiological behavior. They are currently being employed to create cardiovascular, ophthalmic contact lens and dental orthopedic materials.
Cell adhesion plays a crucial role in medicinal implants. Some factors that influence the cell behavior in contact with foreign material include surface charge, hydrophobicity and surface energy.
Extracellular matrix proteins such as fibronectin, collagen and laminin provide an attachment framework for the cell adhesion in vitro. When such materials are exposed to biological environments, protein adsorption and cell adhesion take place and interfacial properties of the material and cells determine the degree of biocompatibility of the device.
Tumors can arise from cells of all types of tissues. Neoplasms are associated with compositional changes of blood, hormones and immune imbalance. Tumor cell biology and cell thermodynamic function could represent substantial information on cell fate, apoptosis and proliferation.
Bending energy, the amount of energy needed to transform a cell to its lowest energy state; i. Surface tension of tumor cell can be measured from its surface map. The surface of a tumor can be described by Gaussian curvature with corresponds to excess growth and deficiency of growth in cells.
Regions of the tumor with positive Gaussian curvature denote excess cellular growth which is an early indication of the tumour invasion. In regions with low surface tension values, the internal pressure force could overcome it, which could lead to the detachment of carcinoma and possible metastasis and the onset of invasion. Tumor classification to benign or malignant types, grading and staging of tumors can be studied using surface tension measurements. A mathematical model for the growth of a solid tumor was introduced using nonlinear elasticity theory.
This model describes the basic relationship between stress and cell shape. These correlations also help to determine if tumor invasion or metastasis has taken place. The theoretical suggestion may be useful at cellular level in medical profession and can help make objective decisions on the treatment plan.
Morphologies of benign and malignant tumor can be used in diagnosis of tumor stages. The interface of malignant tumor is blurred and irregular where as the surface of benign tumor is smooth and clear.
During tumor transition, interfacial tension between neoplastic and normal cells decrease and cause the two cell populations to mix. These factors change the dynamic surface tension parameter and will help to evaluate cancerous phenotype, cell metastasis and therapeutic efficacy. A decrease in blood glucose level is observed in patients with extended tumors, where interfacial tensiometric parameters correlate negatively with the blood glycemic level.
For a cell to be able to detach from a primary tumour and migrate to a distant location, cancerous cells often undergo some morpho-physiological changes such as pH dysregulation, diminished intercellular adhesion and enhanced motility.
These changes enable subsequent metastasis through local invasion and spreading to other tissues which may induce chemoresistance and immunoresistance in cancerous cells. Most changes in the blood composition were observed for carcinoma of stomach, lung and liver. A decrease in equilibrium surface tension of serum for patients with stomach or lung carcinoma may indicate involvement of the liver and metastatic spreading of the tissue into this organ.
However for mammary gland tumors, no changes were observed in the average surface tension values of serum. In a study E-cadherin was down-regulated in the cancer cells with liver metastasis. This indicates that reduced expression of E-cadherin is closely related to liver metastasis.
Interfacial tension serves as a marker of pathological stage of a tumor disease and changes that occur during carcinogenesis have potential application in diagnosis of certain tumors and monitoring of their treatment plan. For tumors of the female reproductive organ s such as malignant neoplasm of corpus uteri and cervix, dynamic surface tension of the serum is less than normal value.
Malignant cervical tissues contain low triglyceride as compared to the normal tissues. Proteins are down regulated in cervical cancer tissues whereas the total lipid and cholesterol content of the cervical tumor tissue is higher than that of a normal tissue.
Schramm, Laurier L. Saskatchewan Research Council, Saskatchewan, Canada. Last reviewed: June The force acting in the surface of a liquid, tending to minimize the area of the surface. Surface forces, or more generally, interfacial forces, govern such phenomena as the wetting or nonwetting of solids by liquids, the capillary rise of liquids in fine tubes and wicks, and the curvature of free-liquid surfaces Fig.
Surface tension is the tendency of liquid surfaces to shrink into the minimum surface area possible. Surface tension allows insects e. At liquid—air interfaces, surface tension results from the greater attraction of liquid molecules to each other due to cohesion than to the molecules in the air due to adhesion. There are two primary mechanisms in play. One is an inward force on the surface molecules causing the liquid to contract. Because of the relatively high attraction of water molecules to each other through a web of hydrogen bonds , water has a higher surface tension Surface tension is an important factor in the phenomenon of capillarity.
Any surface, in order to decrease its surface energy, contracts. It is shown for the first time that this contraction is formally equivalent to the introdu.
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Surface free energy can be considered as the surface tension of a solid. Surface free energy, or SFE for short, arises from the molecular interactions at the air — solid interface. Surface free energy is important in many application areas.
Any surface, in order to decrease its surface energy, contracts.
Surface tension in human pathophysiology and its application as a medical diagnostic tool
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It is well-known that surface tension and surface energy are distinct quantities for solids. Each can PDF ( KB) relates liquid–vapor surface energy to the difference between solid–vapor and solid–liquid surface energy.
How is surface and interfacial tension measured?
Introduction: Pathological features of disease appear to be quite different. Despite this diversity, the common feature of various disorders underlies physicochemical and biochemical factors such as surface tension. Human biological fluids comprise various proteins and phospholipids which are capable of adsorption at fluid interfaces and play a vital role in the physiological function of human organs. Surface tension of body fluids correlates directly to the development of pathological states. Methods: In this review, the variety of human diseases mediated by the surface tension changes of biological phenomena and the failure of biological fluids to remain in their native state are discussed.
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