scholarly journals Hierarchically electrospraying a PLGA@chitosan sphere-in-sphere composite microsphere for multi-drug-controlled release

2020 ◽  
Vol 7 (4) ◽  
pp. 381-390
Author(s):  
Zhu Liu ◽  
Weilong Ye ◽  
Jingchuan Zheng ◽  
Qindong Wang ◽  
Guowu Ma ◽  
...  
Keyword(s):  
Controlled Release ◽  
Drug Loading ◽  
Uv Spectrophotometry ◽  
Composite Microsphere ◽  
Ionization Time ◽  
Composite Microspheres ◽  
Flight Mass Spectrometry ◽  
Sequential Administration ◽  
Cellular Behaviors

Abstract Sequential administration and controlled release of different drugs are of vital importance for regulating cellular behaviors and tissue regeneration, which usually demands appropriate carriers like microspheres (MS) to control drugs releases. Electrospray has been proven an effective technique to prepare MS with uniform particle size and high drug-loading rate. In this study, we applied electrospray to simply and hierarchically fabricate sphere-in-sphere composite microspheres, with smaller poly(lactic-co-glycolic acid) MS (∼8–10 μm in diameter) embedded in a larger chitosan MS (∼250–300 μm in diameter). The scanning electron microscopy images revealed highly uniform MS that can be accurately controlled by adjusting the nozzle diameter or voltage. Two kinds of model drugs, bovine serum albumin and chlorhexidine acetate, were encapsulated in the microspheres. The fluorescence-labeled rhodamine-fluoresceine isothiocyanate (Rho-FITC) and ultraviolet (UV) spectrophotometry results suggested that loaded drugs got excellent distribution in microspheres, as well as sustained, slow release in vitro. In addition, far-UV circular dichroism and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) results indicated original secondary structure and molecular weight of drugs after electrospraying. Generally speaking, our research proposed a modified hierarchically electrospraying technique to prepare sphere-in-sphere composite MS with two different drugs loaded, which could be applied in sequential, multi-modality therapy.

scholarly journals PREPARATION, CHARACTERISATION AND EVALUATION OF ROPINIROLE HYDROCHLORIDE LOADED CONTROLLED RELEASE MICROSPHERES USING SOLVENT EVAPORATION TECHNIQUE

2018 ◽  
Vol 10 (6) ◽  
pp. 57
Author(s):  
Koyel Kar ◽  
R. N. Pal ◽  
N. N. Bala
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Release Kinetics ◽  
Drug Loading ◽  
Solvent Evaporation ◽  
In Vitro Drug Release ◽  
Aqueous Solvent ◽  
Evaporation Technique ◽  
Ropinirole Hydrochloride

Objective: The major objective of the research work was to design, characterise and evaluate controlled release microspheres of ropinirole hydrochloride by using non-aqueous solvent evaporation technique to facilitate the delivery of the drug at a predetermined rate for a specific period of time.Methods: Ropinirole hydrochloride microspheres were prepared by using different low-density polymers such as eudragit RL 100, eudragit RS 100 and ethylcellulose either alone or in combination with the help of non-aqueous solvent evaporation technique. All the formulated microparticles were subjected to various evaluation parameters such as particle size analysis, micrometric properties, drug entrapment efficiency, percentage drug loading, percentage yield and in vitro drug release study. The compatibility of the drug and polymers was confirmed by physical compatibility study, fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and x-ray diffraction study (XRD). The formation of the most optimized batch of the microsphere (F12) was confirmed by scanning electron microscopy (SEM), DSC, FTIR, and XRD. In vitro drug release study and in vitro drug release kinetics study of the formulated microspheres were also carried out.Results: Drug-polymer compatibility studies performed with the help of FTIR and DSC indicated that there were no interactions. Results revealed that non-aqueous solvent evaporation technique was a suitable technique for the preparation of microspheres as most of the formulations were discrete, free-flowing and spherical in shape with a good yield of 55.67% to 80.09%, percentage drug loading of 35.52% to 94.50% and percentage drug entrapment efficiency of 36.24% to 95.07%. Different drug-polymer ratios, as well as the combination of polymers, played a significant role in the variation of over-all characteristics of formulations. Based on the data of various evaluation parameters such as particle size analysis, percentage drug loading, percentage drug entrapment, percentage yield, rheological studies and in vitro drug release characteristics, formulation F12 was found to fulfil the criteria of ideal controlled release drug delivery system. F12 showed controlled release till the 14th hour (97.99%) and its in vitro release kinetics was best explained by zero-order kinetics and followed Korsemeyer-Pappas model (Non-Fickian mechanism). SEM of F12 revealed the formation of spherical structures. The FTIR study of F12 confirmed the stable nature of ropinirole in the drug-loaded microspheres. DSC and XRD patterns showed that ropinirole hydrochloride was dispersed at the molecular level in the polymer matrix.Conclusion: The controlled release microparticles were successfully prepared and from this study, it was concluded that the developed microspheres of ropinirole hydrochloride can be used for controlled drug release to improve the bioavailability and patient compliance and to maintain a constant drug level in the blood target tissue by releasing the drug in zero order pattern.

O-glycans on human high endothelial CD34 putatively participating in L-selectin recognition

Blood ◽  
2002 ◽  
Vol 99 (7) ◽  
pp. 2609-2611 ◽  
Author(s):  
Tero Satomaa ◽  
Ossi Renkonen ◽  
Jari Helin ◽  
Juha Kirveskari ◽  
Antti Mäkitie ◽  
...  
Keyword(s):  
Laser Desorption ◽  
Sialyl Lewis X ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Flight Mass Spectrometry ◽  
Sialyl Lewis ◽  
Candidate Structure ◽  
Selectin Ligands ◽  
Matrix Assisted Laser

Leukocyte traffic into lymph nodes and sites of inflammation is guided by L-selectin. Experiments performed in vitro and with gene-deleted mice suggest that CD34 recognizes L-selectin if decorated by 6-sulfo sialyl Lewis x (sLex) saccharides and the MECA-79 epitope. However, very little is known about glycosylation of human L-selectin ligands. We report here on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) profiles of N- and O-linked oligosaccharide fractions from human tonsillar endothelial CD34. All detected O-glycans were sialylated; some were also monosulfated or monosulfated and monofucosylated. If a given CD34-glycan may carry all requirements for L-selectin recognition, that is, both 6-sulfo-sLex and MECA-79 epitopes, only one O-glycan fraction, O-9, SA2Hex3HexNAc3- Fuc1(SO3)1, meets the criteria. A candidate structure is SAα2-3Galβ1-4(Fucα1-3)(6-sulfo)GlcNAcβ1-3Galβ1-3(SAα2-3Galβ1-4GlcNAcβ1-6)GalNAc. However, if sulfo sLex glycans are supplemented with separate sulfated, nonfucosylated O-glycans, saccharides in O-6, O-8, or O-9, putatively carrying MECA-79 epitopes, could form multiglycan binding epitopes for L-selectin.

scholarly journals Oviduct Fluid Extracellular Vesicles Change the Phospholipid Composition of Bovine Embryos Developed In Vitro

2020 ◽  
Vol 21 (15) ◽  
pp. 5326 ◽  
Author(s):  
Charles Banliat ◽  
Daniel Le Bourhis ◽  
Ophélie Bernardi ◽  
Daniel Tomas ◽  
Valérie Labas ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Intact Cell ◽  
Phospholipid Composition ◽  
Cell Number ◽  
Phospholipid Content ◽  
Ionization Time ◽  
Flight Mass Spectrometry ◽  
Before And After ◽  
Oviduct Fluid

Oviduct fluid extracellular vesicles (oEVs) have been proposed as bringing key molecules to the early developing embryo. In order to evaluate the changes induced by oEVs on embryo phospholipids, fresh bovine blastocysts developed in vitro in the presence or absence of oEVs were analyzed by intact cell MALDI-TOF (Matrix assisted laser desorption ionization—Time of flight) mass spectrometry (ICM-MS). The development rates, cryotolerance, and total cell number of blastocysts were also evaluated. The exposure to oEVs did not affect blastocyst yield or cryotolerance but modified the phospholipid content of blastocysts with specific changes before and after blastocoel expansion. The annotation of differential peaks due to oEV exposure evidenced a shift of embryo phospholipids toward more abundant phosphatidylcholines (PC), phosphatidylethanolamines (PE), and sphingomyelins (SM) with long-chain fatty acids. The lipidomic profiling of oEVs showed that 100% and 33% of the overabundant masses in blastocysts and expanded blastocysts, respectively, were also present in oEVs. In conclusion, this study provides the first analysis of the embryo lipidome regulated by oEVs. Exposure to oEVs induced significant changes in the phospholipid composition of resulting embryos, probably mediated by the incorporation of oEV-phospholipids into embryo membranes and by the modulation of the embryonic lipid metabolism by oEV molecular cargos.

scholarly journals Identification of a Protein That Inactivates the Competence-Stimulating Peptide of Streptococcus pneumoniae

2002 ◽  
Vol 184 (2) ◽  
pp. 610-613 ◽  
Author(s):  
Mathieu Bergé ◽  
Hanno Langen ◽  
Jean-Pierre Claverys ◽  
Bernard Martin
Keyword(s):  
Streptococcus Pneumoniae ◽  
Laser Desorption ◽  
Physiological Property ◽  
Laser Desorption Ionization ◽  
Treatment Results ◽  
Ionization Time ◽  
Flight Mass Spectrometry ◽  
Licl Treatment

ABSTRACT Competence for genetic transformation of Streptococcus pneumoniae is a transient physiological property inducible by a competence-stimulating peptide (CSP). A 68-kDa CSP-inactivating protein was previously obtained following lithium chloride (LiCl) extraction. By the same protocol, a CSP-inactivating protein was purified and identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry as an endopeptidase, PepO. Analysis of a pepO mutant provided no support for the hypothesis that PepO participates in competence regulation. To reconcile in vitro and in vivo data, we suggest that LiCl treatment results in the release of intracellular molecules, including PepO.

Preparation and Characterization of Cyclophosphamide-Loaded Chitosan Microspheres

2012 ◽  
Vol 621 ◽  
pp. 130-133
Author(s):  
Yi Lin Ding ◽  
Su Su Ding ◽  
Guo Fang Ding
Keyword(s):  
Drug Release ◽  
Anticancer Agent ◽  
Loading Rate ◽  
Drug Loading ◽  
Average Diameter ◽  
Uv Spectrophotometry ◽  
Chitosan Microspheres ◽  
Dialysis Bag

Chitosan microspheres were prepared by using a cross linking agent combined with an emulsion technique. Cyclophosphamide was loaded as an anticancer agent. Obtained microspheres were spherical and regular, with a smooth surface morphology, having an average diameter of 15.7±9.0μm. After preparation, the drug-loading rate and entrapment rate of cyclophosphamide was investigated by UV spectrophotometry. Drug release was tested in vitro in a dynamic dialysis system with a dialysis bag. The chitosan microspheres prepared were proved to have good drug release profiles.

scholarly journals In Vitro Susceptibility of Fusarium to Isavuconazole

2019 ◽  
Vol 64 (2) ◽  
Author(s):  
A. Broutin ◽  
J. Bigot ◽  
Y. Senghor ◽  
A. Moreno-Sabater ◽  
J. Guitard ◽  
...  
Keyword(s):  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
In Vitro Susceptibility ◽  
Ionization Time ◽  
Valuable Alternative ◽  
Flight Mass Spectrometry ◽  
Microdilution Method ◽  
Species Complexes ◽  
Broth Microdilution Method

ABSTRACT To evaluate the in vitro susceptibility of Fusarium to isavuconazole, 75 clinical isolates were identified using matrix-assisted laser desorption ionization–time of flight mass spectrometry and then tested with a broth microdilution method (EUCAST) and the gradient concentration strip (GCS) technique. The activity of isavuconazole overall was shown to be limited, with an MIC50 of >16 μg/ml, without significant differences between the species complexes. The categorical agreement between GCS and EUCAST was 97.4% to 100%, making the GCS as a valuable alternative.

scholarly journals Locating Methyl-Etherified and Methyl-Esterified Uronic Acids in the Plant Cell Wall Pectic Polysaccharide Rhamnogalacturonan II

2020 ◽  
Vol 25 (4) ◽  
pp. 329-344
Author(s):  
Malcolm A. O’Neill ◽  
Ian Black ◽  
Breeanna Urbanowicz ◽  
Vivek Bharadwaj ◽  
Mike Crowley ◽  
...  
Keyword(s):  
Plant Species ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Pectic Polysaccharide ◽  
Ionization Time ◽  
Methyl Esterification ◽  
Flight Mass Spectrometry ◽  
Borate Ester ◽  
Rhamnogalacturonan Ii

Rhamnogalacturonan II (RG-II) is a structurally complex pectic polysaccharide that exists as a borate ester cross-linked dimer in the cell walls of all vascular plants. The glycosyl sequence of RG-II is largely conserved, but there is evidence that galacturonic acid (GalA) methyl etherification and glucuronic acid (GlcA) methyl esterification vary in the A sidechain across plant species. Methyl esterification of the galacturonan backbone has also been reported but not confirmed. Here we describe a new procedure, utilizing aq. sodium borodeuteride (NaBD4)-reduced RG-II, to identify the methyl esterification status of backbone GalAs. Our data suggest that up to two different GalAs are esterified in the RG-II backbone. We also adapted a procedure based on methanolysis and NaBD4 reduction to identify 3-, 4-, and 3,4- O-methyl GalA in RG-II. These data, together with matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry (MALDI-TOF) MS analysis of sidechain A generated from selected RG-IIs and their NaBD4-reduced counterparts, suggest that methyl etherification of the β-linked GalA and methyl esterification of the GlcA are widespread. Nevertheless, the extent of these modifications varies between plant species. Our analysis of the sidechain B glycoforms in RG-II from different dicots and nonpoalean monocots suggests that this sidechain has a minimum structure of an O-acetylated hexasaccharide (Ara-[MeFuc]-Gal-AceA-Rha-Api-). To complement these studies, we provide further evidence showing that dimer formation and stability in vitro is cation and borate dependent. Taken together, our data further refine the primary sequence and sequence variation of RG-II and provide additional insight into dimer stability and factors controlling dimer self-assembly.

Controlled Release of Doxycycline by Magnetized Microporous MIL53(Fe); Focus on Magnetization and Drug Loading

2018 ◽  
Vol 16 (1) ◽  
pp. 42-50 ◽  
Author(s):  
Shakiba Naeimi ◽  
Hossein Faghihian
Keyword(s):  
Drug Delivery ◽  
Controlled Release ◽  
Drug Loading ◽  
In Vitro Release ◽  
Time Intervals ◽  
Drug Content ◽  
Releasing Process ◽  
Phosphate Buffered Saline ◽  
Vitro Release

Background: In this research, MIL-53(Fe) was magnetized and the performance of the magnetized material as a drug delivery system for doxycycline was studied. Objectives: The experiments were designed to load the magnetic delivery compounds with different amount of the drug. Methods: The in vitro release rate of doxycycline from magnetic MIL-53(Fe) with different drug content into saline buffered fluid (SBF, pH=7.4) and phosphate buffered saline (PBS, pH=3) was then studied. Results: The results showed that the releasing process of the drug in PBS media achieved the equilibration within 48h with 98% of releasing efficiency, while the releasing process in SBF media (pH=7.4) was slower and the equilibrium was established within 264 h with the releasing efficiency of 95%. The amount of the released doxycycline from the samples with different drug content was measured at various time intervals. Conclusion: It was concluded that in PBS media after 75 h, 85, 95 and 98% of loaded doxycycline released, respectively, from the sample containing 22, 32 and 35% of the drug. In SBF media, the release was slower and after 350 h, 82, 91 and 95% of loaded doxycycline released from the samples, respectively, containing 22, 32 and 35 % of the drug. The results of this study indicated that by use of drugreleasing profile and selecting appropriate carrier dose, the released amount of the drug into the patient body can be controlled.

The preparation, drug loading and in vitro NIR photothermal-controlled release behavior of raspberry-like hollow polypyrrole microspheres

2015 ◽  
Vol 3 (47) ◽  
pp. 9186-9193 ◽  
Author(s):  
Jie Wang ◽  
Fuxing Lin ◽  
Jinxing Chen ◽  
Mozhen Wang ◽  
Xuewu Ge
Keyword(s):  
Controlled Release ◽  
Cancer Therapy ◽  
Drug Loading ◽  
Release Behavior ◽  
Templating Method ◽  
Therapy Effect

Raspberry-like hollow polypyrrole microspheres (H-PPy), which are prepared through a templating method, exhibit promising synergistic cancer therapy effect.

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