Effect of bile components on the surface properties of bifidobacteria

2002 ◽  
Vol 69 (2) ◽  
pp. 293-302 ◽  
Author(s):  
GUILLERMO KOCIUBINSKI ◽  
ANDREA GÓMEZ ZAVAGLIA ◽  
PABLO F. PÉREZ ◽  
EDGARDO A. DISALVO ◽  
GRACIELA L. DE ANTONI
Keyword(s):  
Zeta Potential ◽  
Surface Properties ◽  
Highly Hydrophobic ◽  
Negative Zeta Potential

The action of bile on bifidobacteria was studied by measuring changes in zeta potential, hydrophobicity and adherence to enterocyte-like cells in vitro. Highly hydrophobic strains shocked with bile displayed more negative zeta potential values and a decrease in adherence. When a non-hydrophobic non-adherent strain (CIDCA 5324) was shocked with bile, an increase in hydrophobicity was observed. However, no changes of zeta potential or adherence properties were apparent. The action of the bile components was different from the action of whole bile. Cholate and deoxycholate produced a decrease in the negativity of zeta potential values of all strains studied whereas taurocholate displayed a shift in zeta potential of hydrophobic strains to more negative values, thus explaining the decrease in the autoaggregation by charge repulsion. However, the decrease in zeta potential caused by cholate and deoxycholate did not increase autoaggregation in a hydrophobic non-adherent strain (CIDCA 531). This suggests that other forces are contributing to autoaggregation.

scholarly journals In Vitro and Ex Vivo Evaluation of Nepafenac-Based Cyclodextrin Microparticles for Treatment of Eye Inflammation

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 709 ◽  
Author(s):  
Blanca Lorenzo-Veiga ◽  
Patricia Diaz-Rodriguez ◽  
Carmen Alvarez-Lorenzo ◽  
Thorsteinn Loftsson ◽  
Hakon Hrafn Sigurdsson
Keyword(s):  
Zeta Potential ◽  
Physicochemical Properties ◽  
Inflammatory Mediators ◽  
Ex Vivo ◽  
Posterior Segment ◽  
Inflammatory Activity ◽  
Commercial Formulation ◽  
Anti Inflammatory ◽  
Negative Zeta Potential

The aim of this study was to design and evaluate novel cyclodextrin (CD)-based aggregate formulations to efficiently deliver nepafenac topically to the eye structure, to treat inflammation and increase nepafenac levels in the posterior segment, thus attenuating the response of inflammatory mediators. The physicochemical properties of nine aggregate formulations containing nepafenac/γ-CD/hydroxypropyl-β (HPβ)-CD complexes as well as their rheological properties, mucoadhesion, ocular irritancy, corneal and scleral permeability, and anti-inflammatory activity were investigated in detail. The results were compared with a commercially available nepafenac suspension, Nevanac® 3 mg/mL. All formulations showed microparticles, neutral pH, and negative zeta potential (–6 to –27 mV). They were non-irritating and nontoxic and showed high permeation through bovine sclera. Formulations containing carboxymethyl cellulose (CMC) showed greater anti-inflammatory activity, even higher than the commercial formulation, Nevanac® 0.3%. The optimized formulations represent an opportunity for topical instillation of drugs to the posterior segment of the eye.

Sodium pentosan polysulphate as a polyanionic inhibitor of calcium oxalate crystallization in vitro and in vivo

1985 ◽  
Vol 68 (3) ◽  
pp. 369-371 ◽  
Author(s):  
R. W. Norman ◽  
D. S. Scurr ◽  
W. G. Robertson ◽  
M. Peacock
Keyword(s):  
Zeta Potential ◽  
Calcium Oxalate ◽  
Human Subjects ◽  
Stone Disease ◽  
Active Inhibitor ◽  
Novel Approach ◽  
Pentosan Polysulphate ◽  
Negative Zeta Potential

1. Studies in vitro showed that sodium pentosan polysulphate (SPP) is an active inhibitor of calcium oxalate crystal growth and agglomeration and that it acts by increasing the negative zeta potential on the surface of calcium oxalate crystals. 2. Oral administration to human subjects resulted in an increase in the negative zeta potential, which is consistent with an increase in the polyanionic inhibitory activity of urine. SPP may offer a novel approach to the medical management of recurrent calcium oxalate stone disease.

Tantalum-containing mesoporous bioactive glass powder for hemostasis

2020 ◽  
pp. 088532822096515
Author(s):  
Malvika Nagrath ◽  
Reid Gallant ◽  
Alireza Rahimnejad Yazdi ◽  
Andrew Mendonca ◽  
Saidur Rahman ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Blood Coagulation ◽  
Intrinsic Pathway ◽  
Extrinsic Pathway ◽  
Bioactive Glasses ◽  
In Vitro Methods ◽  
Hemostatic Agents ◽  
Negative Zeta Potential ◽  
Mesoporous Bioactive Glass

This study evaluates the hemostatic properties of tantalum-containing mesoporous bioactive glasses (Ta-MBGs) through a suite of in-vitro methods: hemolysis percentage, zeta potential, blood coagulation assays (Activated Partial Thromboplastin Time – APTT and Prothrombin Time - PT) and cytotoxicity tests. Five compositions of Ta-MBG, with x mol% Ta2O5 added to the glass series (80- x)SiO2-15CaO-5P2O5- xTa2O5 where x=0 (0Ta), x=0.5 (0.5Ta), x=1 (1Ta), x=5 (5Ta), and x=10 (10Ta) mol%, were synthesised. The hemostatic potential of all the Ta-MBGs was confirmed by their negative zeta potential (–23 to –31 mV), which enhances the intrinsic pathway of blood coagulation. The hemolysis percentages of all Ta-MBGs except 10Ta showed statistically significant reductions compared to the same experiments carried out both in the absence of a sample (‘no treatment’ group) and in the presence of 10Ta. These observations validate the consideration of Ta-MBGs as hemostatic agents as they do not cause significant lysis of red blood cells. Cytotoxicity analysis revealed that Ta-MBGs had no effect on bovine fibroblast viability. Furthermore, a reduction in both APTT (a test to evaluate the intrinsic pathway of coagulation) and PT (a test to evaluate the extrinsic pathway) signified enhancement of hemostasis: 5Ta caused a significant reduction in APTT compared to ‘no treatment’, 1Ta and 10Ta and a significant reduction in PT compared to 0Ta. Therefore, we conclude that 5mol% of Ta optimised the hemostatic properties of these mesoporous bioactive glasses.

Formulation and Evaluation of Nanosuspension of Simvastatin

2015 ◽  
Vol 8 (2) ◽  
pp. 2858-2873
Author(s):  
Rupali L. Shid ◽  
Shashikant N. Dhole ◽  
Nilesh Kulkarni ◽  
Santosh L Shid
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Factorial Design ◽  
Dissolution Rate ◽  
In Vitro Dissolution ◽  
Total Drug ◽  
23 Factorial Design ◽  
Rate Of Dissolution

Poor water solubility and slow dissolution rate are issues for the majority of upcoming and existing biologically active compounds. Simvastatin is poorly water-soluble drug and its bioavailability is very low from its crystalline form. The purpose of this study wasto increase the solubility and dissolution rate of simvastatin by the  preparation of nanosuspension by emulsification solvent diffusion method at laboratory scale. Prepared nanosus-pension was evaluated for its particle size and in vitro dissolution study and characterized by zeta potential,differential scanning calorimetry (DSC) and X-Ray diffractometry (XRD), motic digital microscopy, entrapment efficiency, total drug content, saturated solubility study and in vivo study. A 23 factorial design was employed to study the effect of independent variables, amount of SLS (X1), amount of PVPK-30 (X2) and poloxamer-188 (X3) and dependent variables are total drug content and polydispersity Index. The obtained results showed that particle size (nm) and rate of dissolution has been improved when nanosuspension prepared with the higherconcentration of PVPK-30 with the higher concentration of PVP K-30 and Poloxamer-188 and lower concentration of SLS. The particle size and zeta potential of optimized formulation was found to be 258.3 nm and 23.43. The rate of dissolution of the optimized nanosuspension was enhanced (90% in 60min), relative to plain simvastatin  (21% in 60 min), mainly due to the formation of nanosized particles. These results indicate the suitability of 23 factorial  design for preparation of simvastatin loaded nano-suspension significantly improved in vitro dissolution rate and thus possibly enhance fast onset of therapeutic drug effect. In vivo study shows increase in bioavailability in nanosuspension formulation than the plain simvastatin drug.

Optimization and Characterization of Aqueous Micellar Formulations for Ocular Delivery of an Antifungal Drug, Posaconazole

2020 ◽  
Vol 26 (14) ◽  
pp. 1543-1555 ◽  
Author(s):  
Meltem E. Durgun ◽  
Emine Kahraman ◽  
Sevgi Güngör ◽  
Yıldız Özsoy
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Size Distribution ◽  
Encapsulation Efficiency ◽  
Fungal Infections ◽  
In Vitro Release ◽  
Pluronic F127 ◽  
Glycol Succinate ◽  
Vitro Release

Background: Topical therapy is preferred for the management of ocular fungal infections due to its superiorities which include overcoming potential systemic side effects risk of drugs, and targeting of drugs to the site of disease. However, the optimization of effective ocular formulations has always been a major challenge due to restrictions of ocular barriers and physiological conditions. Posaconazole, an antifungal and highly lipophilic agent with broad-spectrum, has been used topically as off-label in the treatment of ocular fungal infections due to its highly lipophilic character. Micellar carriers have the potential to improve the solubility of lipophilic drugs and, overcome ocular barriers. Objective: In the current study, it was aimed optimization of posaconazole loaded micellar formulations to improve aqueous solubility of posaconazole and to characterize the formulations and to investigate the physical stability of these formulations at room temperature (25°C, 60% RH), and accelerated stability (40°C, 75% RH) conditions. Method: Micelles were prepared using a thin-film hydration method. Pre-formulation studies were firstly performed to optimize polymer/surfactant type and to determine their concentration in the formulations. Then, particle size, size distribution, and zeta potential of the micellar formulations were measured by ZetaSizer Nano-ZS. The drug encapsulation efficiency of the micelles was quantified by HPLC. The morphology of the micelles was depicted by AFM. The stability of optimized micelles was evaluated in terms of particle size, size distribution, zeta potential, drug amount and pH for 180 days. In vitro release studies were performed using Franz diffusion cells. Results: Pre-formulation studies indicated that single D-ɑ-tocopheryl polyethylene glycol succinate (TPGS), a combination of it and Pluronic F127/Pluronic F68 are capable of formation of posaconazole loaded micelles at specific concentrations. Optimized micelles with high encapsulation efficiency were less than 20 nm, approximately neutral, stable, and in aspherical shape. Additionally, in vitro release data showed that the release of posaconazole from the micelles was higher than that of suspension. Conclusion: The results revealed that the optimized micellar formulation of posaconazole offers a potential approach for topical ocular administration.

Moxifloxacin Hydrochloride-Loaded Eudragit® RL 100 and Kollidon® SR Based Nanoparticles: Formulation, In vitro Characterization and Cytotoxicity.

2020 ◽  
Vol 23 ◽  
Author(s):  
Gülsel Yurtdaş Kırımlıoğlu ◽  
Sinan Özer ◽  
Gülay Büyükköroğlu ◽  
Yasemin Yazan
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Spray Drying ◽  
Prolonged Release ◽  
Ocular Delivery ◽  
Corneal Permeability ◽  
Release Pattern ◽  
In Vitro Characterization ◽  
Ocular Bioavailability

Background: Considering the low ocular bioavailability of conventional formulations used for ocular bacterial infection treatment, there’s a need for designing efficient novel drug delivery systems that may enhance of precorneal retention time and corneal permeability. Aim and Objective: The current research focuses on developing nanosized and non-toxic Eudragit® RL 100 and Kollidon® SR nanoparticles loaded with moxifloxacin hydrochloride (MOX) for its prolonged release to be promising for effective ocular delivery. Methods: In this study, MOX was incorporation was carried out by spray drying method aiming ocular delivery. In vitro characteristics were evaluated in detail with different methods. Results: MOX was successfully incorporated into Eudragit® RL 100 and Kollidon® SR polymeric nanoparticles by spray-drying process. Particle size, zeta potential, entrapment efficiency, particle morphology, thermal, FTIR, XRD and NMR analyses and MOX quantification using HPLC method were carried out to evaluate the nanoparticles prepared. MOX loaded nanoparticles demonstrated nanosized and spherical shape while in vitro release studies demonstrated modified release pattern which followed Korsmeyer-Peppas kinetic model. Following successful incorporation of MOX into the nanoparticles, the formulation (MOX: Eudragit® RL 100, 1:5) (ERL-MOX 2) was selected for further studies by the reason of its better characteristics like cationic zeta potential, smaller particle size, narrow size distribution and more uniform prolonged release pattern. Moreover, ERL-MOX 2 formulation remained stable for 3 months and demonstrated higher cell viability values for MOX. Conclusion: In vitro characterization analyses showed that non-toxic, nano-sized and cationic ERLMOX 2 formulation has the potential of enhancing ocular bioavailability.

In Vitro Estimation of Photo-Protective Potential of Pomegranate Seed Oil and Development of a Nanoformulation

2019 ◽  
Vol 15 (1) ◽  
pp. 87-102 ◽  
Author(s):  
Surbhi Dhawan ◽  
Sanju Nanda
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Seed Oil ◽  
Topical Delivery ◽  
Inflammatory Activity ◽  
Pomegranate Seed Oil ◽  
Protective Potential ◽  
Release Studies ◽  
Pomegranate Seed

Background: Since ancient times, people have been using natural resources for photoprotection purposes. One such highly recognised natural agent is pomegranate seed oil, considered as wonder oil owing to the presence of several beneficial phytoconstituents. </P><P> Objective: The study aimed to establish the photoprotective potential of pomegranate seed oil through various in vitro and biochemical studies along with the formation of nanoemulsion, an efficient topical delivery system for the oil. </P><P> Method: Photo-protective potential of the oil was estimated by determining in vitro antioxidant and anti-inflammatory activity, total phenolic content, anti elastase, antihyaluronidase and anticollagenase activities of the oil. Ultrasonication method was used to formulate nanoemulsions. The optimisation was done following the central composite design. The characterisation was done by particle size analysis, zeta potential, polydispersity index, pH, viscosity, stability testing and transmission electron microscopy. The optimised nanoemulsion was loaded into a gel base for topical application and further release studies were carried out. </P><P> Results: The IC50 values of anti-elastase, anti-collagenase and anti-hyaluronidase were found to be 309 mg/ml, 4 mg/ml and 95 mg/ml respectively. The results of anti-oxidant and anti-inflammatory activity were also significant, which thereby established the photo-protective potential of the oil. The optimum batch 2 had particle size 83.90 nm, 0.237 PDI and -5.37 mV zeta potential. The morphology was confirmed by TEM. Batch 2 was incorporated into a gel base and release studies showed 74.12 % release within 7 hours. </P><P> Conclusion: Pomegranate seed oil possesses a potential photo-protective ability. Nanoemulsions proved to be a promising carrier for the topical delivery of the oil.

Development and In Vitro Characterization of Paclitaxel Loaded Solid Lipid Nanoparticles

2019 ◽  
Vol 9 (1) ◽  
pp. 76-85 ◽  
Author(s):  
R. Nithya ◽  
K. Siram ◽  
R. Hariprasad ◽  
H. Rahman
Keyword(s):  
Zeta Potential ◽  
Solid Lipid Nanoparticles ◽  
In Vitro Release ◽  
Lipid Nanoparticles ◽  
Release Profile ◽  
Mcf7 Cells ◽  
Solid Lipid ◽  
Cancerous Cells ◽  
Vitro Release

Background: Paclitaxel (PTX) is a potent anticancer drug which is highly effective against several cancers. Solid lipid nanoparticles (SLNs) loaded with anticancer drugs can enhance its toxicity against tumor cells at low concentrations. Objective: To develop and characterize SLNs of PTX (PSLN) to enhance its toxicity against cancerous cells. Method: The solubility of PTX was screened in various lipids. Solid lipid nanoparticles of PTX (PSLN) were developed by hot homogenization method using Cutina HR and Gelucire 44/14 as lipid carriers and Solutol HS 15 as a surfactant. PSLNs were characterized for size, morphology, zeta potential, entrapment efficiency, physical state of the drug and in vitro release profile in 7.4 pH phosphate buffer saline (PBS). The ability of PTX to enhance toxicity towards cancerous cells was tested by performing cytoxicity assay in MCF7 cell line. Results: Solubility studies of PTX in lipids indicated better solubility when Cutina HR and Gelucire 44/14 were used. PSLNs were found to possess a neutral zeta potential with a size range of 155.4 ± 10.7 nm to 641.9 ± 4.2 nm. In vitro release studies showed a sustained release profile for PSLN over a period of 48 hours. SLNs loaded with PTX were found to be more toxic in killing MCF7 cells at a lower concentration than the free PTX.

scholarly journals Dye Separation and Antibacterial Activities of Polyaniline Thin Film-Coated Poly(phenyl sulfone) Membranes

Membranes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 25
Author(s):  
Javed Alam ◽  
Arun Kumar Shukla ◽  
Mohammad Azam Ansari ◽  
Fekri Abdulraqeb Ahmed Ali ◽  
Mansour Alhoshan
Keyword(s):  
Zeta Potential ◽  
Surface Properties ◽  
Antibacterial Activities ◽  
Pani Film ◽  
Force Microscopy ◽  
Water Permeation ◽  
Membrane Pores ◽  
Membrane Performance ◽  
Phenyl Sulfone ◽  
The Impact

We fabricated a nanofiltration membrane consisting of a polyaniline (PANI) film on a polyphenylsulfone (PPSU) substrate membrane. The PANI film acted as a potent separation enhancer and antimicrobial coating. The membrane was analyzed via scanning electron microscopy and atomic force microscopy to examine its morphology, topography, contact angle, and zeta potential. We aimed to investigate the impact of the PANI film on the surface properties of the membrane. Membrane performance was then evaluated in terms of water permeation and rejection of methylene blue (MB), an organic dye. Coating the PPSU membrane with a PANI film imparted significant advantages, including finely tuned nanometer-scale membrane pores and tailored surface properties, including increased hydrophilicity and zeta potential. The PANI film also significantly enhanced separation of the MB dye. The PANI-coated membrane rejected over 90% of MB with little compromise in membrane permeability. The PANI film also enhanced the antimicrobial activity of the membrane. The bacteriostasis (BR) values of PANI-coated PPSU membranes after six and sixteen hours of incubation with Escherichia coli were 63.5% and 95.2%, respectively. The BR values of PANI-coated PPSU membranes after six and sixteen hours of incubation with Staphylococcus aureus were 70.6% and 88.0%, respectively.

scholarly journals Production and Characterization of Chitosan–Polyanion Nanoparticles by Polyelectrolyte Complexation Assisted by High-Intensity Sonication for the Modified Release of Methotrexate

2020 ◽  
Vol 13 (1) ◽  
pp. 11 ◽  
Author(s):  
Yhors Ciro ◽  
John Rojas ◽  
Maria Alhajj ◽  
Gustavo Carabali ◽  
Constain Salamanca
Keyword(s):  
Zeta Potential ◽  
Maleic Acid ◽  
High Intensity ◽  
Physical Stability ◽  
Release Mechanism ◽  
Diffusion Controlled ◽  
Polyelectrolyte Complexation ◽  
Anticancer Treatment ◽  
Particle Parameters

A promising strategy to improve the effectivity of anticancer treatment and decrease its side effects is to modulate drug release by using nanoparticulates (NPs) as carriers. In this study, methotrexate-loaded chitosan–polyanion nanoparticles were produced by polyelectrolyte complexation assisted by high-intensity sonication, using several anionic polymers, such as the sodium and potassium salts of poly(maleic acid-alt-ethylene) and poly(maleic acid-alt-octadecene), here named PAM-2 and PAM-18, respectively. Such NPs were analyzed and characterized according to particle size, polydispersity index, zeta potential and encapsulation efficiency. Likewise, their physical stability was tested at 4 °C and 40 °C in order to evaluate any change in the previously mentioned particle parameters. The in vitro methotrexate release was assessed at a pH of 7.4, which simulated physiological conditions, and the data were fitted to the heuristic models of order one, Higuchi, Peppas–Sahlin and Korsmeyer–Peppas. The results revealed that most of the MTX-chitosan–polyanion NPs have positive zeta potential values, sizes <280 nm and monodisperse populations, except for the NPs formed with PAM-18 polyanions. Further, the NPs showed adequate physical stability, preventing NP–NP aggregation. Likewise, these carriers modified the MTX release by an anomalous mechanism, where the NPs formed with PAM-2 polymer led to a release mechanism controlled by diffusion and relaxation, whereas the NPs formed with PAM-18 led to a mainly diffusion-controlled release mechanism.

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