1,354,320 research outputs found
DoE Analysis of Approaches for Hydrogel Microbeads' Preparation by Millifluidic Methods
No full textHydrogel microbeads hold great promise for immune-protective cell transplants and in vitro studies. Millifluidic generation of hydrogel microbeads is a highly efficient and reproducible approach enabling a mass production. This paper illustrates the preparation and characterization of highly controlled and reproducible microbeads made by different types of hydrogel using millifluidic approaches. The optimization of the process was made by a design of experiments (DoE) approach. The microbeads' large-scale production can be potentially used for single cells or clusters encapsulation
Optimization of lipospheres production by factorial design and their performances on a dielectrophoretic lab-on-a-chip platform
No full textAim of this study was to investigate the effect of the preparation parameters on the characteristics of
lipospheres that would optimally fit to a lab-on-a-chip platform. Lipospheres were produced by melt
dispersion technique using different lipid mixture heated to 70 ◦C and then emulsified into an external
aqueous phase. The initial part of the work was devoted to the selection of the best lipid composition
by a classical intuitive approach while the optimization and the screening of the experimental parameters
were conducted through a “design of experiments”. Once the best preparation parameters were
selected, they were adopted also for the production of cationic lipospheres (CLS). The second part of the
study describes the analysis of the lipospheres performances when applied to a DEParrayTMChip. The
loading, distribution, movement and separation of neutral and cationic lipospheres were investigated.
The obtained data show that both neutral and cationic lipospheres can be efficiently used in association
with DEParrayTMChip
Design, production and optimization of solid lipid microparticles by flow-focusing technology
No full textEffect of the gelation process on the production of alginate microbeads by microfluidic chip technology
No full textThe present paper reports the production of Ba-alginate microspheres by microfluidic chip technology. The general production strategy is based on the formation of an alginate multiphase flow by a 'Y' junction squeezing mechanism. Special emphasis is given to the relationship existing between the gelation process and the final morphological characteristics of the produced microbeads. A series of different gelation strategies, namely: 'external gelation', 'internal gelation' and 'partial gelation' were compared in terms of size, size distribution and morphology of the produced microbeads. © The Royal Society of Chemistry
Design production and characterization of drug delivery systems by Lab-on-a-Chip technology
No full textIn recent years, advancements in the fields of microfluidic and lab-on-a-chip technologies have provided unique opportunities for the implementation of nanomaterial production processes owing to the miniaturisation of the fluidic environment. It has been demonstrated that microfluidic reactors offer a range of advantages compared to conventional batch reactors, including improved controllability and uniformity of nanomaterial characteristics. In addition, the fast mixing achieved within microchannels, and the predictability of the laminar flow conditions, can be leveraged to investigate the nanomaterial formation dynamics. In this article recent developments in the field of microfluidic production of nanomaterials for drug delivery applications are reviewed. The features that make microfluidic reactors a suitable technological platform are discussed in terms of controllability of nanomaterials production. An overview of the various strategies developed for the production of organic nanoparticles and colloidal assemblies is presented, focusing on those nanomaterials that could have an impact on nanomedicine field such as drug nanoparticles, polymeric micelles, liposomes, polymersomes, polyplexes and hybrid nanoparticles. The effect of microfluidic environment on nanomaterials formation dynamics, as well as the use of microdevices as tools for nanomaterial investigation is also discussed
Application of a new, simple and economic colorimetric method for the determination of non-esterified fatty acids in vegetable oils
No full textThe amount of non-esterified fatty acids in eight different vegetable oil samples has been determined by two different methods: (a) with a standard titration procedure, and (b) with a new colorimetric method which utilizes phenol red solubilized in reverse micelles. The results obtained by the two methods are in good agreement, although the standard deviation in the case of the phenol red method is significantly higher compared with the conventional titration. The main advantage of the new colorimetric method is an economic one: only small amounts of oil samples (less than 0·1 ml) are required and a comparably small amount of organic solvent (less than 5 ml isooctane) is needed
Mithramycin encapsulated in polymeric micelles by microfluidic technology as novel therapeutic protocol for beta-thalassemia
No full textThis report shows that the DNA-binding drug, mithramycin, can be efficiently encapsulated in polymeric micelles (PM-MTH), based on Pluronic® block copolymers, by a new microfluidic approach. The effect of different production parameters has been investigated for their effect on PM-MTH characteristics. The compared analysis of PM-MTH produced by microfluidic and conventional bulk mixing procedures revealed that microfluidics provides a useful platform for the production of PM-MTH with improved controllability, reproducibility, smaller size, and polydispersity. Finally, an investigation of the effects of PM-MTH, produced by microfluidic and conventional bulk mixing procedures, on the erythroid differentiation of both human erythroleukemia and human erythroid precursor cells is reported. It is demonstrated that PM-MTH exhibited a slightly lower toxicity and more pronounced differentiative activity when compared to the free drug. In addition, PM-MTH were able to upregulate preferentially ?-globin messenger ribonucleic acid production and to increase fetal hemoglobin (HbF) accumulation, the percentage of HbF-containing cells, and their HbF content without stimulating ?-globin gene expression, which is responsible for the clinical symptoms of ß-thalassemia. These results represent an important first step toward a potential clinical application, since an increase in HbF could alleviate the symptoms underlying ß-thalassemia and sickle cell anemia. In conclusion, this report suggests that PM-MTH produced by microfluidic approach warrants further evaluation as a potential therapeutic protocol for ß-thalassemia.<br/
Gold hard anodized (GHA) materials with antimicrobial surface properties: mechanical, tribological, and microbiological characterization
No full textInfections acquired in public spaces (i.e., transports, restaurants, and bars, hospitals) present a serious burden for the entire healthsystems. In this respect, appropriate preventative and control measures in order to eliminate or reduce the negative effects ofsurface-transmitted infections appear highly desirable. Alongside recommendations for treatment and hygiene, antimicrobialmaterial surfaces can offer indeed an important contribution to the prevention of infections. The aim of the current paper istherefore to describe the preparation and characterization of a new material obtained by an innovative anodic oxidation, definedas golden hard anodizing GHA. The anodic oxide surface thanks to the nanoporous structure acts as reservoir of silver ions (Ag+)which in turn confer antimicrobial properties to the material surface. Specifically, the manuscript presents a thorough preparationand characterization of a new material obtained by an innovative anodic oxidation treatment applied on commercially availablealuminum alloys including the microscopic analysis and the description of the antimicrobial performances against a number ofmicroorganisms, including among the others, Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli)bacteria. More specifically, the current article describes some of the properties of GHA materials. The tribological properties ofGHA were evaluated through experimental tests performed with a pin-on-disk tribometer. The morphology of the wear surfaceswas studied by means of a scanning electron microscope (SEM) analysis and profilometry investigations. Furthermore, in orderto evaluate the possible anticorrosive properties of GHA, tests in neutral salt spray are in addition described
Production and antiproliferative activity of liposomes containing the antitumour drug chromomycin A(3)
No full textIn the present paper we describe the production and characterization of liposomes as specialized delivery system for chromomycin. Liposomes were prepared by reverse phase evaporation technique followed by extrusion through polycarbonate filters; afterwards the vesicles were characterized in term of dimensions, morphology and encapsulation efficacy. Aim of this work was to produce a drug delivery system able to reduce the toxicity problems related to the future administration of this drug. The analysis of the in vitro antiproliferative activity on cultured human leukemic K562 cells demonstrated that ionic and neutral liposomes containing chromomycin are almost 2 or 10-fold much more effective respectively as compared to the free drug. Based on this results and taking into account the increased solubility of the drug in this specialized system, liposomes could represent a promising delivery system for a future use in experimental therapy of chromomycin
Antitumor activity of (trans)dermally delivered aromatic tetra-amidines
No full textThe present work describes the design and preparation of lecithin microemulsion gels containing the aromatic tetra-benzamidine (TAPP-Br) and the antitumor evaluation of this topical formulation on nude mice xenografted with the highly tumorigenic cell line FH06T 1 -1, in comparison to the antitumor activity of TAPP-Br administered by intraperitoneal injections (0.5 mg/injection).After (trans) dermal treatment with 0.1 ml lecithin gels incorporating TAPP-Br (0.2 mg/ml), a reduction of in vivo tumor cell growth was observed. These results could be of great interest with a view to developing a releasing system useful for experimental chemotherapy of tumor lesions occurring at cutaneous or subcutaneous level. © 1994
- …
