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Ultrasonics Sonochemistry Nov 2014Ultrasonic standing waves (USW) separation is an established technology for micro scale applications due to the excellent control to manipulate particles acoustically... (Review)
Review
Ultrasonic standing waves (USW) separation is an established technology for micro scale applications due to the excellent control to manipulate particles acoustically achieved when combining high frequency ultrasound with laminar flow in microchannels, allowing the development of numerous applications. Larger scale systems (pilot to industrial) are emerging; however, scaling up such processes are technologically very challenging. This paper reviews the physical principles that govern acoustic particle/droplet separation and the mathematical modeling techniques developed to understand, predict, and design acoustic separation processes. A further focus in this review is on acoustic streaming, which represents one of the major challenges in scaling up USW separation processes. The manuscript concludes by providing a brief overview of the state of the art of the technology applied in large scale systems with potential applications in the dairy and oil industries.
Topics: Emulsions; Models, Theoretical; Sonication; Suspensions; Transducers
PubMed: 24629579
DOI: 10.1016/j.ultsonch.2014.02.016 -
Stem Cell Research Sep 2012Human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs), collectively termed human pluripotent stem cells (hPSCs), are typically derived and...
Human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs), collectively termed human pluripotent stem cells (hPSCs), are typically derived and maintained in adherent and semi-defined culture conditions. Recently a number of groups, including Chen et al., 2012, have demonstrated that hESCs can now be expanded efficiently and maintain pluripotency over long-term passaging as aggregates in a serum-free defined suspension culture system, permitting the preparation of scalable cGMP derived hPSC cultures for cell banking, high throughput research programs and clinical applications. In this short commentary we describe the utility and potential future uses of suspension culture systems for hPSCs.
Topics: Cell Culture Techniques; Cells, Cultured; Humans; Pluripotent Stem Cells; Suspensions; Time Factors
PubMed: 22771716
DOI: 10.1016/j.scr.2012.06.001 -
Molecules (Basel, Switzerland) Aug 2022A novel stability-indicating, reversed-phase, high-performance liquid chromatography (RP-HPLC) method was developed and validated for the determination of favipiravir in...
A novel stability-indicating, reversed-phase, high-performance liquid chromatography (RP-HPLC) method was developed and validated for the determination of favipiravir in an oral suspension. The effective separation of favipiravir and its degradation products was achieved on a Zorbax Eclipse Plus C18 column (5 μm particle size, 150 mm length × 4.6 mm diameter). The mobile phase was prepared by mixing 5 mM of phosphate buffer (pH 3.5) and methanol in a 75:25 ratio delivered at a 1.0 mL/min flow rate. The eluents were monitored using a photodiode array detector at a wavelength of 322 nm. The stability-indicating nature of this method was evaluated by performing force degradation studies under various stress conditions, such as acidic, alkali, oxidative, thermal, and photolytic degradation. Significant degradation was observed during the alkali stress degradation condition. The degradation products generated during various stress conditions were well separated from the favipiravir peak. In addition, the major degradation product formed under alkali stress conditions was identified using UPLC-ESI-TQ-MS/MS and NMR. Method validation was performed according to the ICH Q2 (R1) guideline requirements. The developed method is simple, accurate, robust, and reliable for routine quality control analysis of favipiravir oral suspensions.
Topics: Alkalies; Amides; Chromatography, High Pressure Liquid; Pyrazines; Suspensions; Tandem Mass Spectrometry
PubMed: 36080375
DOI: 10.3390/molecules27175606 -
Scientific Reports Mar 2020Paclitaxel is the top-selling chemotherapeutic drug used for the treatment of lung, ovarian and breast cancer as well as Kaposi's sarcoma. Cell suspension culture (CSC)...
Paclitaxel is the top-selling chemotherapeutic drug used for the treatment of lung, ovarian and breast cancer as well as Kaposi's sarcoma. Cell suspension culture (CSC) of Corylus avellana has been addressed as a promising alternative for producing paclitaxel. In this study, endophytic fungus strain YEF was isolated from Taxus baccata and identified as Coniothyrium palmarum. The effects of the elicitors derived from this fungus including cell extract, culture filtrate and cell wall (CW) and also chitin, alone or in combination with Methyl-β-Cyclodextrin (MBCD), on paclitaxel biosynthesis in C. avellana CSC were assayed for the first time. CW of C. palmarum was the most efficient fungal elicitor for paclitaxel biosynthesis in C. avellana CSC. The results revealed that MBCD affected paclitaxel biosynthesis differently depending on fungal elicitor type and vice versa. MBCD, either alone or in combination with fungal elicitors, induced a high secretion of paclitaxel, suggesting the decrement of toxicity and retro-inhibition processes of paclitaxel for cells. The joint effects of C. palmarum CW (2.5% (v/v) on 17 day) and 50 mM MBCD synergistically enhanced paclitaxel biosynthesis (402.4 µg l; 5.8-fold), 78.6% of which (316.5 µg l) were secreted into culture medium, a level 146% higher than that in control.
Topics: Ascomycota; Cell Culture Techniques; Cell Wall; Cells, Cultured; Corylus; Culture Media; Paclitaxel; Suspensions; Taxus; beta-Cyclodextrins
PubMed: 32214149
DOI: 10.1038/s41598-020-62196-4 -
Breast Cancer Research : BCR Aug 2023Intratumor heterogeneity is a well-established hallmark of cancer that impedes cancer research, diagnosis, and treatment. Previously, we phenotypically sorted human...
BACKGROUND
Intratumor heterogeneity is a well-established hallmark of cancer that impedes cancer research, diagnosis, and treatment. Previously, we phenotypically sorted human breast cancer cells based on migratory potential. When injected into mice, highly migratory cells were weakly metastatic and weakly migratory cells were highly metastatic. The purpose of this study was to determine whether these weakly and highly migratory cells interact with each other in vitro or in vivo.
METHODS
To assess the relationship between heterogeneity in cancer cell migration and metastatic fitness, MDA-MB-231 and SUM159PT triple negative breast cancer cells were phenotypically sorted into highly migratory and weakly migratory subpopulations and assayed separately and in a 1:1 mixture in vitro and in vivo for metastatic behaviors. Unpaired, two-tailed Student's t-tests, Mann-Whitney tests, ordinary, one-way ANOVAs, and Kruskal-Wallis H tests were performed as appropriate with p < 0.05 as the cutoff for statistical significance.
RESULTS
When highly and weakly migratory cells are co-seeded in mixed spheroids, the weakly migratory cells migrated farther than weakly migratory only spheroids. In mixed spheroids, leader-follower behavior occurred with highly migratory cells leading the weakly migratory cells in migration strands. When cell suspensions of highly migratory, weakly migratory, or a 1:1 mixture of both subpopulations were injected orthotopically into mice, both the mixed cell suspensions and weakly migratory cells showed significant distal metastasis, but the highly migratory cells did not metastasize significantly to any location. Notably, significantly more distal metastasis was observed in mice injected with the 1:1 mixture compared to either subpopulation alone.
CONCLUSIONS
This study suggests that weakly migratory cells interact with highly migratory cells in a commensal fashion resulting in increased migration and metastasis. Together, these findings indicate that cancer cell subpopulation migration ability does not correlate with metastatic potential and that cooperation between highly migratory and weakly migratory subpopulations can enhance overall metastatic fitness.
Topics: Humans; Animals; Mice; Triple Negative Breast Neoplasms; Suspensions; Symbiosis; Cell Movement; Biological Assay
PubMed: 37649089
DOI: 10.1186/s13058-023-01696-3 -
European Journal of Pharmaceutics and... Aug 2023The aim of this work was the evaluation and introduction of the Bertin Precellys® Evolution homogenizer with Cryolys® as a valuable and versatile tool for the...
The aim of this work was the evaluation and introduction of the Bertin Precellys® Evolution homogenizer with Cryolys® as a valuable and versatile tool for the improvement of workflows in the preformulation phase of drug development. The presented pilot experiments indicate that the instrument can be applied for (1) screening of appropriate vehicles for the generation of micro- and nano suspensions, (2) small-scale manufacturing of suspension formulations for preclinical animal studies, (3) drug amorphization and identification of appropriate excipients for amorphous systems, and (4) preparation of homogenous powder blends. The instrument allows the rapid, parallel, and compound-sparing screening of formulation approaches and small-scale formulation manufacturing, in particular for low solubility compounds. For the characterization of generated formulations, miniaturized methods are introduced such as a screening tool for suspension sedimentation and redispersion and a non-sink dissolution model in biorelevant media in microtiter plates. This work summarizes exploratory, proof-of-concept studies and opens up new opportunities for more extended studies with this instrument in various application areas.
Topics: Animals; Chemistry, Pharmaceutical; Solubility; Excipients; Suspensions; Particle Size
PubMed: 37245695
DOI: 10.1016/j.ejpb.2023.05.002 -
Drug Design, Development and Therapy 2019Electronic tongue (ET) is a well-established technology that is used to detect the taste of a food or a medicinal product and to differentiate between different products...
BACKGROUND
Electronic tongue (ET) is a well-established technology that is used to detect the taste of a food or a medicinal product and to differentiate between different products based on their tastes. In addition, it can be used to monitor environmental parameters and biochemical and biological processes.
PURPOSE
This study aims to assess any correlation between the results of pharmacopeial quality control (ie, assay, impurities, and dissolution, etc) and ET analysis for reconstituted cefdinir (CR) suspension over 10 days (ie, shelf-life).
METHODS
The reconstituted CR suspension was tested for several quality attributes such as dissolution behavior, pH, assay, related substances, and microbial contamination. An HPLC analytical method was verified and then used for chemical analysis. The taste of CR reconstituted suspension was followed over 10 days and was then compared with the quality control results. Moreover, Pearson's correlation test was used to find a correlation between chemical analysis results and ET results.
RESULTS
Pearson's test of correlation showed a significant correlation (-value <0.05) between the conventional chemical analysis results (% of CR, % of preservative, % of released CR, % of total impurities and % of total undefined impurities in the reconstituted suspension) with the change of their taste (ie, % pattern discrimination index). ET was able to correlate the results of stability of CR suspension with the change in the taste of the suspension during the shelf life of the reconstituted suspension.
CONCLUSION
The obtained results may suggest the use of ET as a new tool for a rapid assessment of the general quality of a suspension. Moreover, such results would suggest the use of ET to identify fake or substandard products, especially those have been stored under inappropriate storage conditions.
Topics: Cefdinir; Drug Stability; Electronic Nose; Quality Control; Substandard Drugs; Suspensions; Taste; Time Factors
PubMed: 31571827
DOI: 10.2147/DDDT.S214228 -
Carbohydrate Polymers Sep 2022This research aimed to investigate the effect of starch gelatinization and swelling degree on the lubrication properties of starch aqueous suspensions. Three types of...
This research aimed to investigate the effect of starch gelatinization and swelling degree on the lubrication properties of starch aqueous suspensions. Three types of maize starch with different amylose content of 70% (HAS), 25% (NS), and <1% (WS) were used to vary the swelling capacities. The granule suspension of NS showed the highest swelling factor (SF) of 26.5, and gave the best lubrication capacity by decreasing friction by 78%. WS was only able to decrease friction by 50% due to a lower swelling capacity. The leached-out amylose increased friction of highly swollen granules (SF = 26.5) but decreased friction of stiff granules (SF = 2.5). Adding unstimulated human saliva to starch suspensions with native and limited swollen granules reduced friction and masked differences in friction coefficients among starch types. Both the salivary layer on the contact surfaces and the salivary proteins in the bulk phase played a role in determining lubrication properties.
Topics: Amylose; Friction; Humans; Lubrication; Starch; Suspensions
PubMed: 35698326
DOI: 10.1016/j.carbpol.2022.119523 -
Nature Communications May 2022The transfer of chirality across length-scales is an intriguing and universal natural phenomenon. However, connecting the properties of individual building blocks to the...
The transfer of chirality across length-scales is an intriguing and universal natural phenomenon. However, connecting the properties of individual building blocks to the emergent features of their resulting large-scale structure remains a challenge. In this work, we investigate the origins of mesophase chirality in cellulose nanocrystal suspensions, whose self-assembly into chiral photonic films has attracted significant interest. By correlating the ensemble behaviour in suspensions and films with a quantitative morphological analysis of the individual nanoparticles, we reveal an inverse relationship between the cholesteric pitch and the abundance of laterally-bound composite particles. These 'bundles' thus act as colloidal chiral dopants, analogous to those used in molecular liquid crystals, providing the missing link in the hierarchical transfer of chirality from the molecular to the colloidal scale.
Topics: Cellulose; Liquid Crystals; Nanoparticles; Optics and Photonics; Suspensions
PubMed: 35550506
DOI: 10.1038/s41467-022-30226-6 -
Proceedings of the National Academy of... Jan 2022We present a numerical method specifically designed for simulating three-dimensional fluid-structure interaction (FSI) problems based on the reference map technique...
We present a numerical method specifically designed for simulating three-dimensional fluid-structure interaction (FSI) problems based on the reference map technique (RMT). The RMT is a fully Eulerian FSI numerical method that allows fluids and large-deformation elastic solids to be represented on a single fixed computational grid. This eliminates the need for meshing complex geometries typical in other FSI approaches and greatly simplifies the coupling between fluid and solids. We develop a three-dimensional implementation of the RMT, parallelized using the distributed memory paradigm, to simulate incompressible FSI with neo-Hookean solids. As part of our method, we develop a field extrapolation scheme that works efficiently in parallel. Through representative examples, we demonstrate the method's suitability in investigating many-body and active systems, as well as its accuracy and convergence. The examples include settling of a mixture of heavy and buoyant soft ellipsoids, lid-driven cavity flow containing a soft sphere, and swimmers actuated via active stress.
Topics: Computer Simulation; Humans; Locomotion; Mechanics; Models, Cardiovascular; Suspensions
PubMed: 34969855
DOI: 10.1073/pnas.2105338118