scholarly journals Rheological examination of erythrocyte aggregation in the presence of lipid-based fine particles

2005 ◽  
Vol 11 (2) ◽  
pp. 49-54
Author(s):  
Ivana Pajic-Lijakovic ◽  
Branko Bugarski ◽  
Milenko Plavsic
Keyword(s):  
Lipid Emulsion ◽  
Fine Particles ◽  
Drug Carriers ◽  
Erythrocyte Aggregation ◽  
Rheological Parameters ◽  
Aggregate Formation ◽  
Structural Ordering ◽  
Liposome Dispersion ◽  
Structural Parts

The development of lipid-based fine particles as potential drug carriers requires a detailed investigation of the possible effects of these carriers on the rheological properties of blood. In this study, we investigated the influence of dynamic conditions on aggregate formation and stability in dispersions of lipid-based fine particles in whole blood under in vitro conditions. The rheological parameters of two concentrations of liposome dispersion and two concentrations of lipid emulsion in blood were examined. A micro-rheological model of aggregating dispersions is proposed in which the apparent viscosity is estimated as the sum of the hydrodynamic and structural parts which are correlated with system structural ordering in the flow. The dynamics of structural ordering of the aggregating system an considered by examining the evolution of the state of the system in phase space depending on the shear rate. The addition of lipid-based particles induced aggregate formation in the blood, which was more pronounced at higher concentrations of lipid-based fine particles. Furthermore, larger and more stable aggregates are formed in liposome dispersions as compared to lipid emulsions in blood.

A Simple and Rapid Method to Determine GPIIb/IIIa-Receptor Inhibitor Activity in Whole Blood

1999 ◽  
Vol 19 (03) ◽  
pp. 134-138
Author(s):  
Gitta Kühnel ◽  
A. C. Matzdorff
Keyword(s):  
Flow Cytometry ◽  
Platelet Count ◽  
Blood Sample ◽  
Platelet Activation ◽  
Whole Blood ◽  
Receptor Occupancy ◽  
Aggregate Formation ◽  
Inhibitor Activity ◽  
Receptor Inhibitor

SummaryWe studied the effect of GPIIb/IIIa-inhibitors on platelet activation with flow cytometry in vitro. Citrated whole blood was incubated with increasing concentrations of three different GPIIb/IIIa-inhibitors (c7E3, DMP728, XJ757), then thrombin or ADP were added and after 1 min the sample was fixed. Samples without c7E3 but with 0.1 U/ml thrombin had a decrease in platelet count. Samples with increasing concentrations of c7E3 had a lesser or no decrease in platelet count. The two other inhibitors (DMP 725, XJ757) gave similar results. GPIIb/IIIa-inhibitors prevent aggregate formation and more single platelets remain in the blood sample. The agonist-induced decrease in platelet count correlates closely with the concentration of the GPIIb/IIIa inhibitor and receptor occupancy. This correlation may be used as a simple measure for inhibitor activity in whole blood.

In Vitro Elucidation of the Folding Intermediates and Aggregate Formation of Hemoglobin Induced by Acetonitrile: A Multispectroscopic Approach

2016 ◽  
Vol 23 (10) ◽  
pp. 884-891 ◽  
Author(s):  
Mohammad Furkan ◽  
Asim Rizvi ◽  
Mohammad Afsar ◽  
Mohammad Rehan Ajmal ◽  
Rizwan H. Khan ◽  
...  
Keyword(s):  
Aggregate Formation ◽  
Folding Intermediates

Polysorbate 20 Vesicles as Multi-drug Carriers: in Vitro Preliminary Evaluations

2013 ◽  
Vol 10 (3) ◽  
pp. 212-218 ◽  
Author(s):  
Carlotta Marianecci ◽  
Federica Rinaldi ◽  
Luisa Di Marzio ◽  
Alessia Ciogli ◽  
Sara Esposito ◽  
...  
Keyword(s):  
Drug Carriers ◽  
Polysorbate 20

Stereocomplexation Assisted Assembly of Poly(γ-glutamic Acid)-graft-polylactide Nano-micelles and Their Efficacy as Anticancer Drug Carrier

2018 ◽  
Vol 18 (2) ◽  
pp. 302-311
Author(s):  
Shulin Dai ◽  
Yucheng Feng ◽  
Shuyi Li ◽  
Yuxiao Chen ◽  
Meiqing Liu ◽  
...  
Keyword(s):  
Glutamic Acid ◽  
Drug Carrier ◽  
Drug Loading ◽  
Drug Carriers ◽  
Cancer Drug ◽  
Drug Release Profile ◽  
Sustained Drug Release ◽  
Anti Cancer ◽  
Physical Interactions

Background: Micelles as drug carriers are characterized by their inherent instability due to the weak physical interactions that facilitate the self-assembly of amphiphilic block copolymers. As one of the strong physical interactions, the stereocomplexation between the equal molar of enantiomeric polylactides, i.e., the poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA), may be harnessed to obtain micelles with enhanced stability and drug loading capacity and consequent sustained release. </P><P> Aims/Methods: In this paper, stereocomplexed micelles gama-PGA-g-PLA micelles) were fabricated from the stereocomplexation between poly(gama-glutamic acid)-graft-PLLA gama-PGA-g-PLA) and poly(gamaglutamic acid)-graft-PDLA gama-PGA-g-PLA). These stereocomplexed micelles exhibited a lower CMC than the corresponding enantiomeric micelles. Result: Furthermore, they showed higher drug loading content and drug loading efficiency in addition to more sustained drug release profile in vitro. In vivo imaging confirmed that the DiR-encapsulated stereocomplexed gama-PGA-g-PLA micelles can deliver anti-cancer drug to tumors with enhanced tissue penetration. Overall, gama-PGA-g-PLA micelles exhibited greater anti-cancer effects as compared with the free drug and the stereocomplexation may be a promising strategy for fabrication of anti-cancer drug carriers with significantly enhanced efficacy.

scholarly journals Semi-Crystalline Copolymer Hydrogels as Smart Drug Carriers: In Vitro Thermo-Responsive Naproxen Release Study

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 158
Author(s):  
Snežana Ilić-Stojanović ◽  
Ljubiša Nikolić ◽  
Vesna Nikolić ◽  
Slobodan Petrović ◽  
Violeta Oro ◽  
...  
Keyword(s):  
Drug Carrier ◽  
Drug Carriers ◽  
Xrd Analysis ◽  
Hplc Method ◽  
Potential Candidate ◽  
Swelling Kinetic ◽  
Model Drug ◽  
Xrd Techniques ◽  
Responsive Hydrogels

In this study, poly(N-isopropylacrylamide-co-2-hydroxypropyl methacrylate) hydrogels were synthesized using free radical initiated copolymerization method. Four hydrogels with different cross-linker concentrations were prepared. Semi-crystalline, cross-linked copolymer networks were confirmed by FTIR, SEM and XRD analysis. Variation of swelling behaviour was monitored gravimetrically and thermo-responsiveness has been noticed. An application of synthesized thermo-responsive hydrogels as carriers for the modulated release of anti-inflammatory model drug was investigated. Moreover, naproxen loading into these hydrogels was also determined using FTIR, SEM and XRD techniques and release was analyzed using HPLC method at simulated physiological conditions. Swelling kinetic and mechanism of water transport, as well as diffusion of naproxen through the hydrogels were analyzed. Thus, the aim of this work was to study various compositions of obtained hydrogels and their possibility of application as a thermo-responsive carrier for prolonged naproxen release in order to evaluate as a potential candidate for drug carrier in future pharmaceutical applications.

scholarly journals Silver Nanocolloids Loaded with Betulinic Acid with Enhanced Antitumor Potential: Physicochemical Characterization and In Vitro Evaluation

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 152
Author(s):  
Iulia Pinzaru ◽  
Cristian Sarau ◽  
Dorina Coricovac ◽  
Iasmina Marcovici ◽  
Crinela Utescu ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Betulinic Acid ◽  
Water Solubility ◽  
Physicochemical Characterization ◽  
A549 Cells ◽  
Drug Carriers ◽  
Biological Evaluation ◽  
Correlation Spectroscopy ◽  
Hydrodynamic Diameter

Betulinic acid (BA), a natural compound with various health benefits including selective antitumor activity, has a limited applicability in vivo due to its poor water solubility and bioavailability. Thus, this study focused on obtaining a BA nano-sized formulation with improved solubility and enhanced antitumor activity using silver nanocolloids (SilCo and PEG_SilCo) as drug carriers. The synthesis was performed using a chemical method and the physicochemical characterization was achieved applying UV-Vis absorption, transmission electron microscopy (TEM), Raman and photon correlation spectroscopy (PCS). The biological evaluation was conducted on two in vitro experimental models—hepatocellular carcinoma (HepG2) and lung cancer (A549) cell lines. The physicochemical characterization showed the following results: an average hydrodynamic diameter of 32 nm for SilCo_BA and 71 nm for PEG_SilCo_BA, a spherical shape, and a loading capacity of 54.1% for SilCo_BA and 61.9% for PEG_SilCo_BA, respectively. The in vitro assessment revealed a cell type- and time-dependent cytotoxic effect characterized by a decrease in cell viability as follows: (i) SilCo_BA (66.44%) < PEG_SilCo_BA (72.05%) < BA_DMSO (75.30%) in HepG2 cells, and (ii) SilCo_BA (75.28%) < PEG_SilCo_BA (86.80%) < BA_DMSO (87.99%) in A549 cells. The novel silver nanocolloids loaded with BA induced an augmented anticancer effect as compared to BA alone.

scholarly journals Triglyceride-rich lipoproteins prevent septic death in rats.

1995 ◽  
Vol 182 (1) ◽  
pp. 267-272 ◽  
Author(s):  
T E Read ◽  
C Grunfeld ◽  
Z L Kumwenda ◽  
M C Calhoun ◽  
J P Kane ◽  
...  
Keyword(s):  
Lipid Emulsion ◽  
Tumor Necrosis ◽  
Lethal Dose ◽  
Cecal Ligation ◽  
Serum Levels ◽  
Cecal Ligation And Puncture ◽  
Gram Negative ◽  
Necrosis Factor ◽  
Serum Tumor Necrosis

Triglyceride-rich lipoproteins bind and inactive bacterial endotoxin in vitro and prevent death when given before a lethal dose of endotoxin in animals. However, lipoproteins have not yet been demonstrated to improve survival in polymicrobial gram-negative sepsis. We therefore tested the ability of triglyceride-rich lipoproteins to prevent death after cecal ligation and puncture (CLP) in rats. Animals were given bolus infusions of either chylomicrons (1 g triglyceride/kg per 4 h) or an equal volume of saline for 28 h after CLP. Chylomicron infusions significantly improved survival (measured at 96 h) compared with saline controls (80 vs 27%, P &lt; or = 0.03). Chylomicron infusions also reduced serum levels of endotoxin, measured 90 min (26 +/- 3 vs 136 +/- 51 pg/ml, mean +/- SEM, P &lt; or = 0.03) and 6 h (121 +/- 54 vs 1,026 +/- 459 pg/ml, P &lt; or = 0.05) after CLP. The reduction in serum endotoxin correlated with a reduction in serum tumor necrosis factor, measured 6 h after CLP (0 +/- 0 vs 58 +/- 24 pg/ml, P &lt; or = 0.03), suggesting that chylomicrons improve survival in this model by limiting macrophage exposure to endotoxin and thereby reducing secretion of inflammatory cytokines. Infusions of a synthetic triglyceride-rich lipid emulsion (Intralipid; KabiVitrum, Inc., Alameda, CA) (1 g triglyceride/kg) also significantly improved survival compared with saline controls (71 vs 27%, P &lt; or = 0.03). These data demonstrate that triglyceride-rich lipoproteins can protect animals from lethal polymicrobial gram-negative sepsis.

In vitro and in vivo antitumor effects of doxorubicin loaded with bacterial magnetosomes (DBMs) on H22 cells: The magnetic bio-nanoparticles as drug carriers

2007 ◽  
Vol 258 (1) ◽  
pp. 109-117 ◽  
Author(s):  
Jian-Bo Sun ◽  
Jin-Hong Duan ◽  
Shun-Ling Dai ◽  
Jun Ren ◽  
Yan-Dong Zhang ◽  
...  
Keyword(s):  
Drug Carriers ◽  
Antitumor Effects

scholarly journals Behaviour of Human Erythrocyte Aggregation in Presence of Autologous Lipoproteins

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
C. Saldanha ◽  
J. Loureiro ◽  
C. Moreira ◽  
J. Martins e Silva
Keyword(s):  
Particle Number ◽  
Plasma Osmolality ◽  
Erythrocyte Aggregation ◽  
Lipoprotein Subfractions ◽  
Autologous Plasma ◽  
Aggregation Index ◽  
Number Range ◽  
Human Blood Samples ◽  
Range Of Values

The aim of this work was to evaluatein vitrothe effect of autologous plasma lipoprotein subfractions on erythrocyte tendency to aggregate. Aliquots of human blood samples were enriched or not (control) with their own HDL-C, LDL-C, or VLDL-C fractions obtained from the same batch by density gradient ultracentrifugation. Plasma osmolality and erythrocyte aggregation index (EAI) were determined. Blood aliquots enriched with LDL-C and HDL-C showed significant higher EAI than untreated aliquots, whereas enrichment with VLDL-C does not induce significant EAI changes. For the same range of lipoprotein concentrations expressed as percentage of osmolality variation, the EAI variation was positive and higher in presence of HDL-C than upon enrichment with LDL-C (P<0.01). Particle size, up to LDL diameter values, seems to reinforce erythrocyte tendency to aggregate at the same plasma osmolality (particle number) range of values.

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