The Lubricating Activity of Phospholipids on Charged and Neutral Surfaces

2021 ◽  
Author(s):  
Zenon Pawlak ◽  
Krzysztof Gocman ◽  
Tomasz J Kaldonski ◽  
Tadeusz Kaldonski ◽  
Jacek Gospodarczyk
Keyword(s):  
Surface Energy ◽  
Lipid Bilayer ◽  
Membrane Surface ◽  
Interesting Case ◽  
Bovine Articular Cartilage ◽  
Charged Surfaces ◽  
Biological Surfaces ◽  
The Coefficient Of Friction ◽  
Negative Surface ◽  
Bell Shaped Curve

Abstract In this paper, the amphoteric character of cartilage surface is used to study friction between charged (+/+), (-/-) and uncharged (±/±) biological surfaces. The surface of the bovine articular cartilage at varying pH solutions is either charged positively or negatively. When examining the coefficient of friction of the (cartilage/cartilage) pair, depending on the pH, we observe surfaces charged positively, negatively and without charge. The uncharged surface refers to the isoelectric point (IEP) and shows greater friction than the charged surfaces of the cartilage. The measurement of surface energy versus pH of the spherical lipid bilayer will reveal the amphoteric nature of the membrane surface. The friction coefficient of the (cartilage/cartilage) pair and the surface energy of the spherical lipid bilayer versus pH are expressed by a bell-shaped curve. This is an interesting case that confirms the fact that the phospholipid bi-layer is embedded on the surface cartilage. This experimental confirmation of negative surface cartilage is insufficiently highlighted in the literature on natural lubrication.

The role of membrane surface energy on direct contact membrane distillation performance

Desalination ◽  
2013 ◽  
Vol 323 ◽  
pp. 22-30 ◽  
Author(s):  
Ludovic F. Dumée ◽  
Stephen Gray ◽  
Mikel Duke ◽  
Kallista Sears ◽  
Jürg Schütz ◽  
...  
Keyword(s):  
Surface Energy ◽  
Direct Contact ◽  
Membrane Surface ◽  
Membrane Distillation ◽  
Direct Contact Membrane Distillation

Effect of Surface Charge on the Apatite Mineralization Process

2011 ◽  
Vol 493-494 ◽  
pp. 513-518 ◽  
Author(s):  
Vilany Santos Carvalho ◽  
Euler Araujo dos Santos ◽  
Cristiane Xavier Resende
Keyword(s):  
Surface Charge ◽  
Morphological Changes ◽  
Self Assembled Monolayers ◽  
Charged Surfaces ◽  
Glass Slides ◽  
Assembled Monolayers ◽  
Negative Surface ◽  
Sbf Solution ◽  
Initial Attraction ◽  
Effect Of Surface

In this current study it was investigated the influence of positively and negatively charged surfaces on apatite nucleation process from a supersaturate solution containing calcium and phosphorus (SBF solution). Glass slides were coated with polyelectrolytes thin films using a standard method to produce self-assembled monolayers (SAMs). Slides without treatment were used as control. Positive and negative glass slides were soaking in simulated body fluid (1.5 SBF) for 2, 8, 24 and 96 hours. The surfaces were characterized by scanning electron microscopy (SEM). Accordingly, the apatite mineralization was observed on all surfaces, no matter the surface charge. No remarkable morphological changes were verified between the precipitate in both positive and negative surfaces. It suggests that the crystal growth is not influenced by the initial attraction between either a negative surface and Ca2+ ions or a positive one and PO43- ions.

Highly Orientated Calcification in Newly Formed Bones on Negatively Charged Hydroxyapatite Electrets

2005 ◽  
Vol 284-286 ◽  
pp. 897-900 ◽  
Author(s):  
Satoshi Nakamura ◽  
Takayuki Kobayashi ◽  
Kimihiro Yamashita
Keyword(s):  
Electrostatic Force ◽  
Myeloid Cells ◽  
Osteoblastic Cells ◽  
Surface Charges ◽  
Electrical Polarization ◽  
Charged Surfaces ◽  
Negative Surface

Large negative charges induced by electrical polarization on hydroxyapatite (HA) ceramics has been demonstrated to enhance their osteoconductivities. The newly formed bones in the vicinities of the negatively charged surfaces were investigated in the views of crystallography and histology. The newly formed bone layers accompanied by mono-layered osteoblastic cells showed 4 perfect extinction positions in a 360° rotation, parallel and perpendicular to the HA surfaces by the optically polarizing images. The observation revealed that the newly formed bone layers directly bonding to the N-surface were consisted of the well-crystallized and highly orientated HA. Therefore, it was presumed that the enhanced osteobonding by negative surface charges was ascribed to the activation of myeloid cells and the intensified attraction of the HA nuclei by the electrostatic force.

scholarly journals Interaction of botulinum and tetanus toxins with the lipid bilayer surface

1988 ◽  
Vol 251 (2) ◽  
pp. 379-383 ◽  
Author(s):  
C Montecucco ◽  
G Schiavo ◽  
Z Gao ◽  
E Bauerlein ◽  
P Boquet ◽  
...  
Keyword(s):  
Lipid Bilayer ◽  
Clostridium Botulinum ◽  
Membrane Surface ◽  
Light Chains ◽  
Lipid Vesicle ◽  
Clostridium Tetani ◽  
Tetanus Neurotoxin ◽  
Clostridial Neurotoxins ◽  
Zwitterionic Lipids ◽  
Botulinum Neurotoxins

The interaction of botulinum neurotoxins serotypes A, B and E (from Clostridium botulinum) and of tetanus neurotoxin (from Clostridium tetani) with the surface of liposomes made of different lipid compositions was studied by photolabelling with a radioiodinated photoactive phosphatidylethanolamine analogue [125I-dipalmitoyl (3,4-azidosalicylamido)phosphatidylethanolamine]. When the vesicles were made of negatively charged lipids (asolectin), each of these neurotoxic proteins was radioiodinated, thus providing evidence for their attachment to the membrane surface. The presence of gangliosides on liposome membranes enhanced fixation of the neurotoxic proteins to the lipid vesicle surface. Both the heavy and light chains of the clostridial neurotoxins were involved in the attachment to the lipid bilayer surface. Each of the toxins tested here attached poorly to liposomes made of zwitterionic lipids (egg phosphatidylcholine), even when polysialogangliosides were present. The data suggest that the binding of botulinum and tetanus neurotoxins to their target neuronal cells involves negatively charged lipids and polysialogangliosides on the cell membrane.

scholarly journals Membrane Structures of the Hemifusion-Inducing Fusion Peptide Mutant G1S and theFusion-Blocking Mutant G1V of Influenza Virus HemagglutininSuggest a Mechanism for Pore Opening in MembraneFusion

2005 ◽  
Vol 79 (18) ◽  
pp. 12065-12076 ◽  
Author(s):  
Yinling Li ◽  
Xing Han ◽  
Alex L. Lai ◽  
John H. Bushweller ◽  
David S. Cafiso ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Membrane Fusion ◽  
Lipid Bilayer ◽  
Membrane Surface ◽  
Helical Structure ◽  
Fusion Peptide ◽  
Membrane Structures ◽  
Influenza Virus Hemagglutinin ◽  
Target Membrane ◽  
Pore Opening

ABSTRACT Influenza virus hemagglutinin (HA)-mediated membrane fusion is initiated by a conformational change that releases a V-shaped hydrophobic fusion domain, the fusion peptide, into the lipid bilayer of the target membrane. The most N-terminal residue of this domain, a glycine, is highly conserved and is particularly critical for HA function; G1S and G1V mutant HAs cause hemifusion and abolish fusion, respectively. We have determined the atomic resolution structures of the G1S and G1V mutant fusion domains in membrane environments. G1S forms a V with a disrupted “glycine edge” on its N-terminal arm and G1V adopts a slightly tilted linear helical structure in membranes. Abolishment of the kink in G1V results in reduced hydrophobic penetration of the lipid bilayer and an increased propensity to formβ -structures at the membrane surface. These results underline the functional importance of the kink in the fusion peptide and suggest a structural role for the N-terminal glycine ridge in viral membrane fusion.

scholarly journals Sorting of droplets by migration on structured surfaces

2011 ◽  
Vol 2 ◽  
pp. 215-221
Author(s):  
Wilfried Konrad ◽  
Anita Roth-Nebelsick
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Droplet Diameter ◽  
Surface Pattern ◽  
Patterned Surfaces ◽  
Liquid Droplets ◽  
Structured Surfaces ◽  
Biological Surfaces ◽  
Gain Energy ◽  
Droplet Movement

Background: Controlled transport of microdroplets is a topic of interest for various applications. It is well known that liquid droplets move towards areas of minimum contact angle if placed on a flat solid surface exhibiting a gradient of contact angle. This effect can be utilised for droplet manipulation. In this contribution we describe how controlled droplet movement can be achieved by a surface pattern consisting of cones and funnels whose length scales are comparable to the droplet diameter. Results: The surface energy of a droplet attached to a cone in a symmetry-preserving way can be smaller than the surface energy of a freely floating droplet. If the value of the contact angle is fixed and lies within a certain interval, then droplets sitting initially on a cone can gain energy by moving to adjacent cones. Conclusion: Surfaces covered with cone-shaped protrusions or cavities may be devised for constructing “band-conveyors” for droplets. In our approach, it is essentially the surface structure which is varied, not the contact angle. It may be speculated that suitably patterned surfaces are also utilised in biological surfaces where a large variety of ornamentations and surface structuring are often observed.

scholarly journals The amphoteric cartilage surface tested in the pH Range from 2.0 to 9.0

2022 ◽  
Vol 3 (1) ◽  
pp. 01-04
Author(s):  
Zenon Pawlak ◽  
Michal Sojka
Keyword(s):  
Friction Coefficient ◽  
Surface Energy ◽  
Lipid Bilayers ◽  
Lipid Membrane ◽  
Bilayer Lipid Membrane ◽  
Bell Curve ◽  
Bilayer Lipid ◽  
Charged Surfaces ◽  
Pin On Disc ◽  
Novel Concept

Background: Phospholipids adsorbed to negatively-charged proteoglycan matrix form phospholipid (membrane), have negatively charged surface (-PO4-) and are hydrophilic. Strong adsorption and strong cohesion are necessary for phospholipids to provide a good lubricant. The surface energy of spherical lipid bilayers have "bell-curve" shaped has amphoteric character and lowest surface energy at a pH 7.4 ± 1 of the natural joint. Objectives: The amphoteric character of the natural surface of the articular cartilage was determined by measuring the surface energy of the model spherical bilayer lipid membrane. It was found that the friction (f) vs. pH 2.0 to 9.0 of the pair (cartilage/cartilage) has the amphoteric character by exposing "bell-curve" shaped with an isoelectric point (IEP). Methods: The friction coefficient (f) was measured with the sliding pin-on-disc tribotester the friction between two surfaces (cartilage/cartilage) pair. The method of interfacial tension measurements of the spherical lipid bilayer model vs the pH over the range 0.2 to 9.0 was used. Results: The dependence of friction coefficient between two cartilage surfaces on the pH over the range 2.0 to 9.0 is demonstrated by a “bell - curve” in Fig. 2(A). The surface energy of a model spherical bilayer lipid membrane vs. the pH has the character of a “bell - curve” with an (IEP) is shown in Fig. 2(B). Conclusion: The amphoteric effect on friction between the bovine cartilage/cartilage contacts has been found to be highly sensitive to the pH of an aqueous solution. In this paper we demonstrate experimentally that the pH sensitivity of cartilage to friction provides a novel concept in joint lubrication on charged surfaces. The change in friction was consistently related to the change of charge density of an amphoteric surface.

scholarly journals Improving fouling resistance of seawater desalination membranes via surface modification

2013 ◽  
Vol 3 (3) ◽  
pp. 217-223
Author(s):  
Jong-Min Lee ◽  
Hyun-Woong Lee ◽  
Yeo-Jin Kim ◽  
Hyung-Gyu Park ◽  
Sung-Pyo Hong ◽  
...  
Keyword(s):  
Surface Modification ◽  
Surface Energy ◽  
Membrane Surface ◽  
Cross Flow ◽  
Lower Surface ◽  
Fouling Resistance ◽  
Surface Charges ◽  
Cross Flow Filtration ◽  
Modified Membrane ◽  
Surface Modified

A commercial polyamide seawater reverse osmosis membrane (Woongjin Chemical CSM) was surface-modified with fluoro-compounds. The effect of this surface modification on both water and NaCl permeability before and after organic fouling was investigated. The structural and electrical characteristics of the membrane surface were measured using atomic force microscopy and electrokinetic analysis respectively. When modified, the membrane surface showed only slight changes to the surface roughness and surface charges. The modified membrane also showed highly improved fouling resistance during cross-flow filtration of characteristic seawater organic foulants (humic acid and sodium alginate). Contact angle analysis using the Owens-Wendt theory was used to calculate the surface energy of the modified membrane. Lower surface energy of the modified membrane was identified as the key factor in the improved fouling resistance of the membranes.

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