Effect Of Plasma Components Research Articles

Platelet adhesion on commercially pure titanium plates in vitro I: effects of plasma components and involvement of the von Willebrand factor and fibronectin

BackgroundPlatelet-rich plasma (PRP) is widely used in regenerative dentistry. Furthermore, it is often applied in the pretreatment of titanium implants to improve their surface bioaffinity and initial stability. However, effects of PRP application on implant surface at cellular and molecular levels remain poorly understood. Therefore, we examined platelet adhesion on commercially pure titanium (cp-Ti) plates, with a particular focus on fibrinogen (FGN), von Willebrand factor (vWF), and fibronectin (FN), in the presence or absence of plasma components.MethodsCitrated blood samples were obtained from six healthy male volunteers, and pure-PRP (P-PRP) and pure platelet suspensions in phosphate-buffered saline (PBS) were prepared. Platelet adhesion on cp-Ti plate surface was evaluated by phalloidin staining and tetrazolium dye assay. Distribution of FGN, vWF, FN, albumin, CD62P, and CD63 was examined by immunocytochemical analysis.ResultsPlatelets in PBS suspensions rapidly and time-dependently adhered to cp-Ti plate surface, but this adhesion was substantially disturbed by the presence of plasma components. FGN was most preferably adsorbed regardless of the presence or absence of plasma components, while vWF and FN showed greater accumulation on platelet adhesion area.ConclusionsAlthough FGN is rapidly and abundantly adsorbed on cp-Ti plate surface, vWF and FN function as major platelet adhesion molecules in citrated blood samples. After pretreatment with P-PRP, however, platelets adhered to cp-Ti much less efficiently. Therefore, P-PRP pretreatment might not directly contribute to surface functionalization, initial stabilization, and osseointegration of machined or similar types of implants.

The effect of plasma components on hemoglobin release test in red blood cells (RBC)

ABSTRACTElectrophoresis release test (ERT) was established by our lab to observe the re-released hemoglobin (Hb) from red blood cells (RBCs) and whole blood. In this study, ERT was performed to study the effects of different plasma components including plasma, serum, albumin, globulin, fibrinogen, glucose, amino acid, vitamin, insulin, hormone, and inorganic ions on re-released Hb from RBC and whole blood samples during ERT. The results showed that plasma, serum, albumin, globulin, compound amino acid, essential amino acid, vitamin C, insulin, hormone, NaCl, KCl, CaCl2, and NaHCO3− decreased re-released RBC Hb; while glucose, vitamin B1, vitamin B2, and vitamin B12 elevated re-released RBC Hb. The differing effects of various plasma components on re-released Hb of RBC may play a significant role in blood conservation.

Effect of plasma components on the stability and permeability of microcapsule

Immobilization of hepatocytes in microcapsules has been a potentially alternative methodology for bioartificial livers (BALs). Moreover, the stability and permeability are the key parameters of these microcapsules. However, these alginate-based microcapsules are unstable if the surrounding medium disrupts the ionic interactions between alginate and the polycation. As hundreds of components are included in human plasma, the stability and permeability in plasma of microcapsules need to be sufficiently investigated. In the present study, the stability of three kinds of alginate-based microcapsules was evaluated when they were immersed in plasma. Our results showed that stability of alginate-α-poly (L-lysine)-alginate (α-APA) microcapsules was well maintained, better than those of alginate-ε-poly (L-lysine)-alginate (ε-APA) and alginate-chitosan-alginate (ACA) microcapsules. Also, factors affecting the stability of microcapsules in plasma were analyzed and it showed that heparin was the key factor that affected the stability of α-APA microcapsules, whereas heparin and low molecular electrolytes such as HCO3(-) and H2 PO4(-)/HPO4(2-) were the factors to ε-APA and ACA microcapsules. In addition, the permeability evaluation showed no decrease in permeability of microcapsules after incubation in plasma. Our study might provide a foundation for the selection and modification of materials for microcapsule-based BAL devices.

Dextran-protamine polycation: An efficient nonviral and haemocompatible gene delivery system

Despite the remarkable progress in the field of gene therapy with viral vectors, nonviral vectors have attracted great interests due to their unique properties. Imparting desired characteristics to nonviral gene delivery systems requires the development of cationic polymers. The purpose of this work was to design a cationic derivative (Dex-P) of dextran using protamine in order to assert target specific cellular binding. Our objective was to elucidate the potential use of Dex-P as a haemocompatible, nontoxic and efficient nonviral candidate for gene therapy. Nanoplexes were prepared with calf thymus DNA and Dex-P. Derivatization was confirmed by FTIR, gel permeation chromatography and TNBS assay. Dynamic light scattering and TEM studies determined the size and morphology of the nanoplex. The buffering behaviour was assessed by acid base titration. Complexation stability was evaluated using agarose gel electrophoresis and EtBr displacement assay. The protection of ctDNA from nuclear digestion and the effect of plasma components towards stability of the nanoplexes were also analyzed. Various haemocompatible studies were performed to check haemolysis, aggregation, clotting time, and complement activation. Transfection and cytotoxicity experiments were performed in vitro. The nanosize, spherical shape and stability of nanoplexes were affirmed. Various experiments conducted confirmed Dex-P to be nontoxic and haemocompatible. Transfection experiments revealed the capability of Dex-P to facilitate high gene expression and cellular uptake in HepG2 cells. With the improved physicochemical, biological and transfection properties, Dex-P seems to be a promising gene delivery system.

Alteration in the temperature-dependent content release property of thermosensitive liposomes in plasma.

The effect of plasma components on the temperature-dependent content release property of thermosensitive liposomes has been described. Temperature-sensitive liposomes containing mitomycin C (MMC) were prepared from dipalmitoylphosphatidylcholine (DPPC liposomes) and a 7 : 3 mixture of DPPC and dipalmitoylophosphatidylglycerol (DPPC/DPPG liposomes). We defined in this study the difference in the content release between 38 degrees C and 44 degrees C as an index of the temperature-dependent content release efficiency (Delta% release). In the absence of rat plasma, the Delta% release of the DPPC liposomes and the DPPC/DPPG liposomes was 83% and 71%, respectively. However, when the release study was conducted with rat plasma, the Delta% release increased to about 96% for both liposomes. In addition, while the DPPC liposomes were destabilized by rat plasma below the gel-to-liquid crystalline phase transition temperature (T(m)), MMC leakage from the DPPC/DPPG liposomes below T(m) was suppressed by rat plasma. Moreover, the plasma protein binding onto lipid bilayer was concomitant with the gel-to-liquid crystalline phase transition and then enhanced the temperature-dependent release from the DPPC/DPPG liposomes. The possible mechanism of interaction between liposomes and plasma proteins, especially serum albumin, was discussed based on differential scanning calorimetry and protein binding experiments.

Factors influencing interaction of human plasma low-density lipoproteins with discoidal complexes of apolipoprotein A-I and phosphatidylcholine

The effect of plasma components on the particle size distribution and chemical composition of human plasma low-density lipoproteins (LDL) during interaction with discoidal complexes of human apolipoprotein A-I and phosphatidylcholine (PC) was investigated. Incubation (37°C, 1 h and 6 h) of LDL with discoidal complexes in the presence of the plasma ultracentrifugal d > 1.20 g/ml fraction (activity of lecithin-cholesterol acyltransferase inhibited) produces an increase in LDL apparent particle diameter two-to six-fold greater than that observed in the absence of the plasma d > 1.20 g/ml fraction. In incubation mixtures of LDL and discoidal complexes, both in the presence and absence of the plasma d > 1.20 g/ml fraction, the extent of LDL apparent particle diameter increase is: (1) approximately three-fold greater at 6 h than at 1 h, and (2) markedly greater for LDL with initially small (22.4–24.0 nm) major components than for LDL with initially large (26.2–26.8 nm) major components. The facilitation factor in the plasma d > 1.20 g/ ml fraction is not plasma phospholipid transfer protein. Purified human serum albumin produces an apparent particle diameter increase comparable to the plasma d > 1.20 g/ml fraction. The discoidal complex-induced increase in LDL apparent particle diameter value by albumin is associated with an increase in phospholipid uptake by LDL and a decreased loss of LDL unesterified cholesterol. In preliminary experiments, high-density lipoproteins (HDL) reverse the apparent particle diameter increase originally induced by discoidal complexes. The presence of HDL (HDL phospholipid/LDL phospholipid molar ratio of 10:1) in the incubation (6 h) mixture of LDL and discoidal complexes also attenuates LDL apparent particle diameter increase. In vivo, the plasma LDL /HDL ratio may be a controlling factor in determining the extent to which phospholipid uptake and the associated change in LDL particle size distribution occurs.

Effect of plasma components on the feeding response of the mosquito Aedes aegypti L. to adenine nucleotides

ABSTRACT. The gorging response of Aedes aegypti to the ATP dissolved in platelet‐poor plasma is greater than that of ATP dissolved in 0.15 m NaCl. The plasma components NaHCO3 and albumin account for the full effect of the potentiation. Phosphate or tris buffers do not duplicate the bicarbonate effect. In 0.15 m NaCl with bicarbonate but lacking albumin the concentrations inducing 50% feeding are 58 μM ATP, 140 μM ADP, 460 μM AMP and 1500 μM cAMP. Non‐adenine nucleotides such as ITP and GTP and phytic acid, and 2,3‐diphosphoglyceric acid had no activity.

Effects of plasma components on platelet adhesion to microcapsules.

Adhesion of rabbit platelets to microcapsules having different numbers of carboxyl groups was examined. The platelets adhered more easily to microcapsules having higher negative charges than to those having lower ones. It was strongly suggested that this trend was caused by plasma components adsorbed on the microcapsules ; the difference in surface negative charge caused a difference in adsorption of plasma components, which would in turn result in the difference in platelet adhesion. Among various plasma components, the major proteins, albumin, γ-globulin and fibrinogen, were all found to inhibit platelet adhesion to the microcapsules, while fresh rabbit serum facilitated it, irrespective of surface negative charge. On the other hand, heat-inactivated rabbit serum was found to inhibit platelet adhesion almost completely. These findings led us to conclude that certain complement adsorbed on the microcapsule surface facilitate platelet adhesion, and the difference in platelet adhesion, which is dependent on the surface negative charge of the microcapsules in the presence of plasma, can be explained in terms of competitive adsorption of the complement and fibrinogen.